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POWER TECHNOLOGIES THE OFFICIAL PUBLICATION OF THE SOUTH AFRICAN INSTITUTE OF ELECTRICAL ENGINEERS | JANUARY 2020 wattnow | January 2020 |1


ACTOM HIGH VOLTAGE EQUIPMENT COMPLETES R22-MILLION GENERATION TRANSMISSION INTERFACE CONTRACT FOR ESKOM’S KUSILE POWER STATION.

ACTOM High Voltage Equipment was awarded a R22-million contract for the generation transmission interface for all six generation units at Eskom’s new Kusile power station currently under construction near Emalahleni in Mpumalanga. The contract, involving the supply and erection of 400 kV transmission lines from each of the six generation units to the nearby transmission substation that will link the new power station

to the national electricity grid, was awarded to the division in mid-2015. The contract also included supplying and erecting galvanised steel crossbeams, which are to be installed between each of the generation units to support the transmission lines strung across to the transmission substation. The contract follows the award to ACTOM High Voltage Equipment

in mid-2012 of the generation transmission interface contract for Medupi, Eskom’s other new coalfired power station, near Lephalale, Limpopo Province. ACTOM High Voltage Equipment has successfully completed erection of the transmission lines and associated equipment linking Kusile’s Generation Units to the transmission substation. It was completed as scheduled.

HIGH VOLTAGE EQUIPMENT A division of ACTOM (Pty) Ltd

ACTOM (Pty) Ltd: 2 Magnet Road, Knights, 1413 | PO Box 13024, Knights, 1413 Tel: +27 (0) 11 820 5369 | www.actom.co.za 2 | wattnow | January 2020


CONTENTS 18 26 50

A NOVEL DUAL INPUT HIGH-STEP UP DC-DC CONVERTER - experimental results are obtained in three different modes

THE SPEED OF THE ENERGY TRANSITION - should it be a gradual or rapid change?

POTENTIAL OF WIND TURBINE MANUFACTURING IN SA - it is possible to design with less expensive technologies

18 56

8 14 62 SAIEE

@saiee

LIGHTNING & SURGE PROTECTION FOR ELECTROMOBILITY

26

INDUSTRY AFFAIRS

50

NEWS LOOKING BACK... JANUARY

62 wattnow | January 2020 | 3


Dear Valued Reader We are at the end of the first month of 2020 - where has it gone? To all our readers, welcome to 2020. Our very first issue of 2020, focusses on Power Technologies. Our first feature article, on page 18, “A Novel Dual Input High-Step up DC-DC Converter with One Bi-directional Port for Renewables” discusses how a new dual-input high step DC-DC converter is developed. The structure of the proposed converter consists of one unidirectional and one bidirectional port. The second feature article, asks the questions: Will the global energy transition from fossil fuels to sustainable energy be gradual or rapid? A paper from the World Energy Forum discussing the speed of the global Energy Transition. Find it on page 26. The China-based monopoly of high-energy permanent magnet materials, used in modern wind generators, impact the economic viability and local content value of most wind turbines installed in South Africa, especially in large installations. I share with you a paper on “Potentials of locally manufactured wind generators in SA” - find it on page 50.

SAIEE 2019 OFFICE BEARERS President George Debbo Deputy President Sy Gourrah Senior Vice President Sunil Maharaj Junior Vice President Prince Moyo Immediate Past President Hendri Geldenhuys Honorary Treasurer Viv Crone Honorary Vice President Marius van Rensburg Chief Executive Officer Sicelo Xulu ISSN: 1991-0452

South African Institute of Electrical Engineers. All material is strictly copyright and all rights are reserved. Reproduction without permission is forbidden. The views expressed in this publication are not necessarily those of the SAIEE. E&OE

4 | wattnow | January 2020

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2 019 SA I E E P R E S I DEN T

DRONES Benefit or Curse? GEORGE DEBBO 2019 SAIEE PRESIDENT During the past few weeks two incidents occurred which got me thinking about the use of Drones and whether such technology has added value to our lives or created a curse.

6 | wattnow | January 2020

The first incident involved the killing of Iranian General Qasem Soleimani on 3rd January 2020 when the United States military used a drone strike that attacked the General’s car convoy near the Baghdad International Airport. Although the General was the prime target the drone attack killed 10 individuals including Soleimani. The use of drones or Unmanned Aerial Vehicles (UAVs) has been around for many years within the military. They are predominantly used in situations were manned flight is too risky or difficult. A drone strike uses one or more of these UAVs in an unmanned manner in order to attack a predetermined target. The attack usually involves the firing of a missile or the release of a bomb at the target. The drone can be equipped with different weapons systems including guided bombs, cluster bombs, incendiary devices, air-to-air missiles, air-to-service missiles, anti-tank guided missiles or any type of precision guided ammunition. Since the early 2000’s most of the drone strikes have been carried out by the USA Military in countries such as Afghanistan,

Pakistan, Syria, Iraq, Somalia and Yemen using air-to-service missiles. However, other countries are also known to have manufactured operational UAVs; these included Israel, China, Iran, Italy, India, Pakistan, Russia, Turkey and Poland. One area of research and development work at present is to design anti-UAV systems that can be used to counter the threat of drone strikes. However, developing such system is proving difficult and the reason for this is because of the legislation and regulation that is currently being applied in order to protect against consumer drones. An article recently appeared on the Defenceone.Com website stated that if you bought and deployed all of the emerging counter drone technologies available today within the USA, you would be in violation of up to two dozen different US Laws dealing with everything from privacy to communication channels to aircraft interdiction. The second incident occurred much closer to home. We have recently relocated to the coast and shortly after New Year one of our new neighbour’s test drove a


new recreational drone that he must have received, I assume, as a Christmas gift. This was even though the rules for the Estate in which we live prohibit the use of drones. He flew the drone from his front porch out over the sea for some way and then turned it around and brought it back for a perfect landing at his feet. He repeated this manoeuvre a few times and as I watched, thinking about the Soleimani incident which had used a drone, I began thinking about the positive benefits that drones have made to our lives. Besides recreational value drones are also significantly contributing to other parts of our lives. For example, drones are currently being used extensively in the agricultural environment to detect areas where crops have been affected by weeds to target the use of herbicides rather than “blanket bombing� crops with herbicides as was done in the past.

Drones are also being used in populated areas in order to deliver parcels, to assist in the maintenance of buildings and other civil infrastructure and in the filming of sports events like marathon. For example, in conjunction with using 5G mobile technology for communications, drones were used during the 2018 Winter Olympics in PyeongChang South Korea in order to provide live television images of the skiers as they raced down the slopes. A recordbreaking formation of 1200 drones were also used during the opening ceremony in order to create a constellation of LED lights in the night sky above PyeongChang Medal Plaza. Drones can also be used to provide safety at large events by monitoring and controlling crowds, and they can provide valuable support to police, security and fire services.

They can also be of valuable assistance during sea search and rescue operations, as the sea can be viewed above if someone is lost at sea drones can search for them very quickly and efficiently. So, as can be seen from the few examples that are described above, drones do provide valuable support to our daily activity in many areas and therefore can definitely be considered a benefit to the human race even if on occasion they used to carry out operations, military or otherwise, that not everyone would agree with.

G Debbo | SAIEE President 2019 Pr. Eng | FSAIEE wattnow | January 2020 | 7


‘ENGINEERS OF CHANGE’ HONOURED AT SAIEE 2019 ANNUAL AWARDS Excellence in engineering was in the spotlight as the South African Institute of Electrical Engineers (SAIEE) “celebrated visionaries, the engineers of change” at the 108th SAIEE Annual Awards Dinner held at the Sandton Convention Centre in Johannesburg last week. The black-tie event, which coincided with the organisation’s inaugural national conference, honoured the best in the industry for their contributions to the sector. Guest speaker, Saray Khumalo, the first black African women to reach the summit of Mount Everest, received a standing ovation as she shared her journey of courage and perseverance. Surprise act, Arias Anonymous, delighted guests as the duo transformed from chef and manager to a singing sensation, serenading the crowd with classic arias. Jacaranda FM’s Scenic Drive with Rian presenter, Philicity Reeken, brough her signature energy as the MC and was joined by SAIEE’s President and CEO, George Debbo and Sicelo Xulu, during the awards ceremony. The recipients in six award categories, including the winners of the SAIEE National Students Project Competition, was announced.

[from left] Monde Soni, Casbah Zwane (Actom) and George Debbo (SAIEE).

[from left] Francesco Pagin (Fluke), George Debbo (SAIEE), TC Madikane.

Load Research Chapter. He wrote a paper for CIGRE SA on “Bulk Energy Integration Studies” – a relatively new subject internationally and more particularly in developing countries. His methodology for bulk energy storage modelling and simulation is considered the first to be developed in South Africa. He currently also serves as an SAIEE Council Member on the institute’s education and technology & knowledge leadership committees.

KwaZulu-Natal). In 2006, he was crowned the SAIEE Engineer of the Year Award. Madikane’s contribution and involvement in the SAIEE never ceased throughout the year and he was eventually appointed as the SAIEE President in 2016.

SAIEE WOMEN IN ENGINEERING AWARD BERTHA DLAMINI

SAIEE ENGINEERING EXCELLENCE AWARD TC MADIKANE Sponsored by Fluke, the award honours an individual who excels in electrical engineering and demonstrates aboveaverage participation in the SAIEE and its activities.

SAIEE ENGINEER OF THE YEAR MONDE SONI Sponsored by Actom, the award recognises an engineer who energetically works towards promoting electrical science for the benefit of the Southern African community. Soni, a senior planning engineer at Eskom, facilitated the establishment of the SAIEE 8 | wattnow | January 2020

Madikane is a highly respected engineer with more than 24 years’ experience in the industry. He heads up his own engineering company, Igoda Projects, that is celebrating its 20th anniversary this year. Madikane has a long history with the SAIEE, joining the institute as the Student Chapter Chairperson while he was studying at the then University of Natal (now University of

[from left] Sicelo Xulu (SAIEE), Bertha Dlamini and George Debbo (SAIEE). A new category of the awards, it seeks to recognise an individual for her contribution to promoting and inspiring women in engineering.


Dlamini needs no introduction in the industry as a passionate advocate for the accelerated participation of African women and youth in Africa’s power and energy sector. Using her vast network, she mobilises global stakeholders to work together to break down the barriers for women and young people in the industry. She is currently the President of African Women in Energy and Power (AWEaP). She has also been a strategic advisor to the Association for Municipal Electricity Utilities (AMEU) where she played a critical role in advancing gender mainstreaming in South Africa’s energy sector.

1959 at the then Johannesburg Electricity Department (now City Power) and left after 43 years as the utility’s director. He is recognised as a pioneer in the early implementation of a pre-payment metering philosophy. After he retired, he joined the SAIEE’s administrative staff and introduced much-needed financial management and governance processes and procedures that the institute still uses today.

KEITH PLOWDEN YOUNG ACHIEVER MICHELLE GOVENDER

and is currently working on an initiative to connect aspiring founding engineers who are keen to start their businesses with South African engineers and CEOs.

SAIEE CENTRE OF THE YEAR SAIEE CENTRAL GAUTENG CENTRE This award, which was introduced as a new category in 2018, seeks to honour the best among SAIEE’s centres, recognising their contributions to the institute and the engineering profession. See photo above.

SAIEE NATIONAL STUDENTS PROJECT COMPETITION DESWILL WILLEMSE & KAI GOODALL

SAIEE PRESIDENT’S AWARD STANLEY BRIDGENS

[from left] Sicelo Xulu (SAIEE), Stanley Bridgens and George Debbo (SAIEE). This prestigious award recognises the significant contributions of an engineer to the sector and is selected by the SAIEE President. Bridgens has made a massive contribution to the electricity supply industry over the course of his long career. He’s a Fellow and Past President of the SAIEE, serving as a member of the institute for over 54 years. He started as an apprentice electrician in

[from left] Michelle Govender, George Debbo (SAIEE) and Adolf Erasmus (SGB-SMIT POWER MATLA).

[from left] Kai Goodall, George Debbo (SAIEE) and Deswill Willemse.

Sponsored by SGB-SMIT POWER MATLA, the award recognising the most outstanding young achiever in electrical or electronic engineering of the year.

Final year electrical, electronic and computer engineering students from academic universities and universities of technology compete to complete an intensive design project as part of the competition every year.

Govendor is a force to be reckoned with as an Engineering Council of South Africa (ECSA) registered engineer and cybersecurity specialist for the World BankCIGRE African Utilities Initiative. She also serves an advisor for the Electricity Power Research Institute (EPRI) and as a member of the SABS SC 27 Technical Committee. Govender is passionate about connecting the youth with the engineering industry

Engineering students, Deswill Willemse from the Cape Peninsula University of Technology (CPUT) and Kay Goodall from the University of Cape Town (UCT) beat out 15 other students with their final year projects. The pair was flown up to Johannesburg to accept their prizes in person. wattnow | January 2020 | 9


Point and Shoot Laser Distance Meter COMTEST is pleased to announce Fluke’s new 417D, an accurate, durable, point and shoot laser distance meter, designed for indoor and outdoor, dusty and wet conditions. The easy, one-button operation means users can minimize time taken by measuring, while the Fluke brand assures the quality and reliability of measurements taken. And, with simple function buttons, three different measurement tasks can be completed quickly and easily. The extra bright laser is clearly visible, so the target point can always be seen, even if the target object is in a hard-to-reach spot, or at a long distance. The 417D has a large 2-line illumi¬nated LCD screen and three-buttons for easy-to-use one-handed measurements.

417D’S FEATURES AND BENEFITS: • Measures up to 40 m (accuracy of 2 mm) • 1 button instant distance measurement • Quick calculation of area (square meters) • Continuous measurement capable • Battery life 3 000 measurements and improved by ‘auto shut-off ’ • 1-meter drop tested • IP54 dust and water resistant • 3-year warranty Contact COMTEST for more information on Fluke’s 417D laser distance meter, or for upcoming seminars, demos or to locate the nearest dealer, on 010 595 1821 or sales@comtest.co.za

Dust extraction specialist announces attendance at UK’s premier event Dustcontrol UK is set to exhibit its range of high-performance extraction equipment at the eagerly anticipated Southern Manufacturing & Electronics 2020 Exhibition. Taking place from 11 - 13 February at the Farnborough International Exhibition and Conference Centre, Hampshire, the Dustcontrol team will be showcasing the firm’s extensive range of both fixed and mobile cyclone-based dust extractors and air cleaners at Stand A1028. The DC11-Module for example, which comes in several models, is an optimised stand-alone unit for source extraction and industrial cleaning. It has been designed to service up to six normal extraction points or several cleaning outlets at a time and is modularly built, meaning it can be 10 | wattnow | January 2020

tailor-made to suit any manufacturing and production environment. As with all of Dustcontrol UK’s equipment, the DC11-Module can be fitted with HEPA 13 filters, meaning exhaust air can be safely returned to the work environment. James Miller, Managing Director of Dustcontrol UK, said: “The Southern Manufacturing & Electronics Exhibition promises to be another exciting event for those in the industry. The exhibition will provide us with an excellent opportunity to show the manufacturing and electronics industry how we can help businesses stay healthy through the use of efficient dust extraction.” For further information on Dustcontrol UK, visit www.dustcontroluk.co.uk


Ice-cream factory switches from coal boilers to HPCMS station

An ice-cream factory has replaced its old coal-fired boilers with more efficient and ‘green’ natural gas fired boilers. When looking for an efficient solution to switch from its old and inefficient coal fired boilers, an ice-cream factory looked for a trusted product from a reputable supplier. Egoli Gas supplied the factory with an HPCMS (High Pressure Customer Metering Solution) which was acquired from Energas Technologies, a leading supplier of high-end and specialised equipment to the oil and gas industries in Africa. The factory will benefit from the more efficient and environmentallyfriendly natural gas fired boilers. Energas is a specialist supplier of complete skid-mounted HPCMS for natural gas. According to Laetitia Jansen van Vuuren, Technologies Product Engineer at Energas Technologies, natural gas is a very

reliable, safe and cost-effective solution for industrial users, compared with other conventional sources of energy such as electricity, diesel, coal or LPG. “Natural gas can be supplied via a pipeline network or by means of compressed natural gas cylinders to users not in the vicinity of a pipeline,” explains Jansen van Vuuren. She adds that these skid-mounted units supplied by Energas offer an array of benefits: the single source reduces client man-hours spent; the pre-packaged factory-built skids cost less than individual equipment and piping construction and installation on site; these units reduce field construction time and overall project schedule; a complete factory test is conducted before shipment, which reduces risk; the units are easy to install in remote areas; and customers have peace of mind as a result of single source accountability.

The skid-mounted stations from Energas Technologies are designed, shop-fabricated and assembled, fully-tested and packaged before transported to the site. The skid includes filtration, pressure reduction, over-pressure protection and metering. The station will reduce the pressure from 35 bar (inlet line pressure) down to 1 bar (outlet pressure to the user) within one stage of pressure reduction. “The station has a single run and has a flow capacity of 200 Sm3/h. A second run can be added for redundancy if required. The station includes the skid frame, piping, insulation joints, pressure regulator valve, slam-shut valve, pressure relief valves, gauges and isolation valves. The station is designed according to ASME B31.3,” concludes Jansen van Vuuren.

wattnow | January 2020 | 11


World Energy Council publishes new research outlining necessary steps for progress in energy storage The World Energy Council has published its latest Insights Brief with the launch of Innovation Insights Brief: “Five Steps to Energy Storage”. Developed in collaboration with the California Independent System Operator (CAISO), the Brief outlines the steps necessary to enabling progress in the deployment of energy storage. The Brief contains exclusive information on the current state-of-play of energy storage and showcases 10 case studies focused on a the latest technologies being deployed across varied geographies, providing actionable insight based on lessons learned and concrete examples of new developments in the energy storage space.

The Council’s research shows that, whilst there is plenty of visionary thinking, recent progress has focused on short-duration and battery-based energy storage for efficiency gains and ancillary services. There is limited progress in developing daily, weekly and even seasonal cost-effective solutions which are indispensable for a global reliance on intermittent renewable energy sources. In response, the Brief includes an actionable five-step approach to enabling energy storage and truly capturing its potential as a flexibility tool. Working with its global network, the Council will convene interactive workshops to further test and accelerate the adoption of this approach.

Steve Berberich, CEO, CAISO said: “The Energy Storage Brief is an enormously powerful outline of the value of storage and the regulatory and market opportunities that need to exist for it to truly flourish.” Dr Angela Wilkinson, Secretary General of the Council said: “Energy storage is a gamechanger and this innovation brief highlights the reality that we need new and different storage pathways to enable better lives and a healthy planet. It is time to look beyond battery technology innovation and enable new policies on storage and its roles as an energy resource, an enabler of whole systems reliability and accelerator the global energy transition.”

Economical magnetic-inductive flowmeters INSTROTECH now offers Kobold’s MIK, a compact, magnetic-inductive flowmeter, combining a large measuring range, from at 0.01 l/min and currently to 700 l/min, and six different measuring tube sizes, from G ½ male to G 2 ¾ male; perfect for users with smaller to mediumsized measuring ranges. MIK measures the flow rates of electrically conductive liquids with a high degree of precision and is not influenced by the medium or its material characteristics (density, viscosity, or temperature). Particular advantages include uninterrupted flow of the medium, no moving parts, and installation in any position desired. MIK has various material combinations for different media in the chemical industry. Flow housings are available in PPS with stainless steel electrodes and PVDF with Hastelloy electrodes. For extremely aggressive liquids, a combination of PVDF 12 | wattnow | January 2020

and Tantalum is used. A variety of seals are available in NBR, FPM, or the highly chemically resistant FFKM. Installation is quick and easy thanks to practical materialspecific connection possibilities, such as PVC glue-in, stainless steel weld-on or PVC hose connections. Characteristics include: • Range from liquids, acids and caustic solutions: 0.01-0.5 ... 36-700 l/min • Accuracy: +2.0% of full scale • Pressure max: 10 bar; Temp max: 80 °C • Advantages: no moving parts in the measuring tube; low pressure loss; any mounting position; short reaction time (a replacement for calorimetric flow switch) MIK applications include the monitoring of additives or cooling agents, totalizing, or batching, the devices which use the magnetic-inductive principle of

measurement, are an optimum and costeffective solution. Matching electronics are offered for various tasks, from designs with only switching or analogue output to those with counting and dosing electronics.


Quick Repair Puts Arcelormittal Turbine Generator Back To Work

ACTOM Turbo Machines technicians (from left) Louis Claasen, Jacques Zandberg and Dehan Meyer prepare to work on the 19 t rotor of the 40 MW turbine generator, as a rigger guides it into position. A 40 MW turbine generator from ArcelorMittal’s Vanderbijlpark works was repaired on a fast track schedule by ACTOM Turbo Machines. The emergency repairs were required after the generator broke down in October 2018, with damage including failed bearings on the generator train. ACTOM Turbo Machines, a division of ACTOM (Pty) Ltd, undertook to complete the work and have the generator back in operation by midDecember 2018. Demonstrating its high level of expertise as a mechanical repairer, ACTOM Turbo Machines first diagnosed all the elements that would require attention during the repair. All four bearings – as well as the rotor sealing elements – were found to

be damaged. Other damage, which was unrelated to the October failure, was also discovered. “The damage involved a crack on the highpressure (HP) gland section of the main steam casing, while a second unforeseen irregularity was a malfunction in the starting or auxiliary oil pump,” Danie Bloem, ACTOM Turbo Machines’ project manager on the contract, says.

were replaced with new ones manufactured at our Sasolburg works.” He notes that the process of repairing the crack in the main steam casing took the team five days, working around the clock. “A high level of welding expertise was required here, as the casing is made of a special material,” he adds.

Other irregularities were an incorrect bolt clearance on one of the HP palms, probably due to faulty installation.

The repair of the starting oil pump was also performed in only two days. This required the manufacture of a new shaft, and also the reconditioning of the mechanical seals.

“In addition to repairing the damaged bearings, we also had to recondition a spare set of bearings that ArcelorMittal had in reserve,” Bloem says. “The sealing segments

Once the generator resumed operation, vibration testing confirmed that its performance had improved significantly, Bloem points out. wattnow | January 2020 | 13


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Pragma invites engineering students to apply for its acclaimed 3-week Student Training Programme Leading enterprise asset management engineering company Pragma, will again host its awardwinning Student Training Programme (STP) in June and July 2020 at its head office in Cape Town. Students are invited to apply for one of the ten sought after spots on this programme between 1 March and 31 March 2020.

14 | wattnow | January 2020

Says Stéphan Pieterse, Chief People Officer at Pragma: “The three-week programme is specifically aimed at B.Eng. or B.Sc.Eng. (Industrial, Mechanical, Electrical, Electrical and Computer or Mechatronic) students in their third or fourth year of studies. The content of the programme ensures that students are introduced to the concepts of enterprise asset management as well as Pragma’s service offering. Furthermore, participants also have the opportunity to be part of various coaching and mentoring sessions with Pragma’s senior management team in order to provide them with valuable life and career lessons.” According to Darius Booyens, Associate Consultant at Pragma, the theme will be Data Science | Future-proof your career. Booyens explains: “Data Science is a regular topic within Pragma. It goes hand in hand with connected tech - another big drive within Pragma. I personally believe that data science will go from being a wanted

skill to a necessary skill in the near future, especially considering the incredibly fast expansion and use of technology in the physical asset management space. The era of connected devices and big data is upon us and if we (the proverbial employer and employee) aren’t ready, we’ll be left behind. The ability to do complex problem solving is the top skill needed in jobs going into 2020 and beyond. To future proof your career is extremely important if we look at the pace at which new jobs are created and traditional ones come to an end. Data science and machine learning will help us become better at our jobs so that we can be more efficient to keep up with market demands.” Nina Booysen, Project Engineer at Pragma, adds that the student training programme typically runs from the start of the last week in June to the end of the second week in July, i.e. fifteen working days. “The programme will run from the 22 June until 10 July 2020. This year we celebrate a decade


of Pragma’s Student Training Programme (STP), which also coincides with Pragma’s 30th birthday! We’ll aim to reunite our Pragma STP Alumni at this momentous occasion. 2020 ought to be a big year for the Pragma STP, and will prove to demonstrate the impact that the programme has had on the lives of the Alumni.” Pieterse explains that Pragma has a very thorough and intensive student selection process. “We look at practical skills and knowledge, soft skills (presentation skills), and personality tests. By looking at all of these criteria, we’re able to filter through hundreds of applications and identify talented individuals from a myriad of universities. Many of these individuals end up working for Pragma and become great assets and team mates at the company. Both Darius and Nina participated in the programme. We only consider university students for

the STP. Pragma has other opportunities available for non-university students. Please refer to our website.” Pieterse concludes: “It’s been an amazing privilege and honour to have been part of the design and execution of this programme since the very first one presented back in 2011. Over the last nine years, I’ve seen a tremendous amount of growth in the individuals we worked with and I know that many of them are making a lasting impact at the companies they work for. We’ve also experienced that impact at Pragma. It’s time for me to hand over the reins and who better to take over than two STP alumni’s! I wish Darius Booyens and Nina (nee Van Rooyen) Booysen all the very best. I know they will take the programme to even greater heights!” Launched in 2011, the programme has been an enormous success and has won various industry accolades. It excelled at the 2015 Skills Development Summit,

winning in all three categories the programme was nominated in, including Best Graduate Training Programme, Best Training Programme Large Company and Best Innovative Training Programme. Further to this, it won first place at the 2019 Skills Development Summit as Best Graduate Training Programme and was a finalist in the Best Training Programme Large Company and Best Innovative Training Programme categories. The Student Training Programme was also a finalist in the Best Graduate Development Programme at the 2019 Future of HR Summit. With limited space available, interested students are urged to apply as soon as the application window is open at https://www. pragmaworld.net/culture-careers/studenttraining-programme/ by 1 March 2020. For further info, visit www.pragmaworld.net.

wattnow | January 2020 | 15


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CIGRE COLLOQUIUM FEEDBACK INDIA - NOVEMBER 2019

Sharon Msuhabe, Nishal Mahatho & Khayakazi Dioka representing the Southern African National Committee of Cigre.

Dr Ralf Pietsch (at the podium) and Dr Jens Seifert (seated) during the D1 Tutorial session.

Entrance into the HVDC Multi-terminal station.

A joint A2, B2 and D1 CIGRE Colloquium & Tutorials event was held in New Delhi, India from the 18th - 22nd November 2019. Southern Africa was represented by Ms Khayakazi Dioka (A2 – Transformers & Reactors), Ms Sharon Mushabe (B2 – Overhead Lines) and Mr Nishal Mahatho (D1 – Materials & Emerging Test Techniques). This article focuses on the Study Committee D1 related issues.

The week comprised of D1 working groups held by various conveners, the D1 Study Committee chaired by the international chair – Dr Ralf Pietsch and the main D1 Colloquium and tutorial session.

African countries. This is in an effort to create more collaboration with the other African countries as well as to spread the word of the Cigre technical work and to support these utilities. • Feedback was presented by all the international convenors on the progress in their working groups. Nishal Mahatho, D1 SA rep, is also the convenor for a WG D1.61 entitled “Optical Corona Detection and Measurement. This group deals with the use of corona cameras for the location of electrical faults on powerlines and substations, and how their use or interpretation may be standardised, as there are currently no calibration standards or usage guidelines available. Nishal presented the progress made by the group – all of the round robin tests carried out by the international members have been completed, and the results are being collated and analysed, together with the limited experience from utilities. It is expected that this technical brochure will be completed by the first half of 2020.

BY | NISHAL MAHATHO SENIOR SPECIALIST ESKOM & CIGRE D1 SA REPRESENTATIVE 16 | wattnow | January 2020

At the D1 SC meeting, there were a number of matters discussed: • A large focus was on the upcoming Paris 2020 session. The idea of this year’s Paris session is to promote more technical discussions. It was noted that there is an increase in the number of submissions, and this can be attributed to the inclusion of Distribution topics into Cigre. • Dr Ralf Pietsch, on behalf of D1, has compiled a 30-page contribution to the Cigre Green book (The CIGRE Green Book provides the entire know-how about switches in a high voltage system). • The matter regarding the use of Webinars was raised, and it was felt that more use should be made of these as a platform to share information, or to present some on-going work. The UK is using webinars successfully, in what they call “lunch-time-webinars”. • The South African National Committee was briefly discussed, and the initiative that is underway with the World Bank to fund tutorials, attendance at conferences, etc. for some of the other

The theme paper for the D1 technical session of the Colloquium, was presented by Dr BP Muni from India. Dr Muni spoke about the very large developments in India – the grid is growing at a rapid rate and as at


A presentation to the Cigre delegation by the station manager on a model prior to entering the HVDC station. October 2019, they were at 364 GW. There are many renewables projects currently on the horizon.. India has some of the largest HVDC developments in the world, but there is still much understanding required in this area and this creates much room for collaboration and research. There were three preferential subjects (PS) for the D1 Colloquium, viz. PS1 – Testing, Monitoring and Diagnostics, PS2 – Functional Properties and Degradation of Insulation Materials and PS3 – Insulation Systems of Advanced Components. There were 17 papers in the two day D1 session with 12 submissions being international and 5 from India. The theme for the technical session 1 was the Long Term Performance Insulation systems (AC & DC); technical session 2 focussed on Test Techniques for UHV (including HVDC), and session 3 contained papers relating to Advanced Diagnostic Techniques. There were two D1 tutorials: • Materials, Technologies, Testing and Diagnosis for Polymeric Overhead Line by Dr Jens Seifert. This tutorial was based on the work done as part of WG D1.27 and the TB 611. It covered aspects relating to polymer insulators, hydrophobicity, fingerprinting of materials and the different types of testing methods currently in use, and the new ones proposed. • High Voltage On-Site Testing with Partial Discharge (PD) Measurements by Dr Ralf Pietsch. This tutorial was based on the work done in WG D1.33 and the TB 502. It covered aspects of

The iconic Taj Mahal in Agra.

high voltage sources and accessories for on-site applications, on-site pd measurements, pre-conditions for insite testing and finally examples of test and measuring techniques for apparatus and systems. Overall the SC meeting, WG sessions, Colloquium and Tutorials were a great success with high attendance, both locally and internationally. The Saturday following the Colloquium included a technical visit to a 6000 MW, 800 kV HVDC Converter Station in Agra, with a visit to the iconic and breath-taking Taj Mahal included! With the focus on the upcoming Cigre Paris Session in August 2020, the preferential subjects for D1 are:

PS1: TESTING, MONITORING AND DIAGNOSTICS • Experience and insight from monitoring systems. • Reliability of test equipment and systems for testing, monitoring and diagnostics. • Data handling, analytics and advanced condition assessment.

PS2: FUNCTIONAL PROPERTIES AND DEGRADATION OF INSULATION MATERIALS • New stresses, e.g. power electronics, load cycling, higher temperatures and compact applications, • Materials with lower environmental footprint during production, operation, and disposal • Characterization methods for validating functional properties.

PS3 : INSULATION SYSTEMS OF ADVANCED COMPONENTS • Materials under high stresses e.g. field stress, flux, electric current and frequency. • Experience and requirements for new test procedures and standards. • Development of new materials, e.g. 3D printing, lamination, casting and additive or subtractive manufacturing. As D1 SA we will need to provide some input into these preferential subjects, and begin with the compilation of presentations for the D1 session. D1 will only accept formal representation for discussion of PS, and will not entertain spontaneous contributions at this year’s session. There are also three new working groups that have been proposed: • D1.72: Test of material resistance against surface arcing under DC (D1 has proposed N Mahatho as a member). • B1/D1.75: Interaction between cable and accessory materials in HVAC and HVDC (chemical interactions). • D1/B1.75: Surface charges for HVDC cables. D1 SA will need to consider our involvement in these groups, and put forward names of contributing members in the coming weeks. I also encourage anybody who is interested in joining any D1 working groups to please contact the author using the following email address: MahathN@eskom.co.za or 011 629 5341.

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In this paper, a new dual-input high step DC-DC converter is developed. The structure of the proposed converter consists of one unidirectional and one bidirectional port. The bidirectional port is connected to a battery for energy balancing purpose. That is, the battery stores extra produced energy and releases stored energy in situations where there is a lack of energy.

A Novel Dual Input High-Step up DC-DC Converter with One Bi-directional Port for Renewables

On the other hand, the bidirectional port

variability of the resources is critical [4,

for renewable energy applications where the output voltage is low. The proposed structure is superior over the previously proposed ones in terms of the number of components, energy interaction, simple configuration, and flexibility. The experimental results obtained in three different modes (i.e., without battery, with battery charging, and with battery discharging) are presented to verify the theoretical analysis and the performance of the proposed converter.

photovoltaic (PV) panels are unable to supply load at night. Moreover, the rate of energy produced varies according to insolation and temperature. Most renewable energy output voltage is very low and variable. To deal with the problems mentioned above, most renewable energy resources need high step-up converters to run alongside them [11].

BY | M A BAGHERPOURA, is employed as the primary power source. 9]. Due to the characteristics of renewable P FARHADIB The high step-up output voltage gain of energy sources, they need to be used in N B HASSANLOUEIC the proposed converter makes it suitable parallel with other resources. For example,

In recent years, due to the expanding use of renewable energy sources like PV, FC, wind, etc., designing new converters with appropriate control methods to reflect the 18 | wattnow | January 2020

By increasing the efficiency of renewable energy sources, multi-input converters are introduced [2, 3, 6, 7, 12]. In [12], a dual input DC-DC converter is presented. One key benefit of this converter is individual control of the source to provide the desired voltage at the output and MPP (Maximum


Power Point) for inputs. An improved structure of a dual input DC-DC converter is introduced in [2]. Compared to [12] the proposed converter in [2] has better output voltage gain and resolves some of the drawbacks of the converters in [12]. The converters introduced in [3, 6, 7] are mostly modular with a high number of power sources and switches. In these circuit structures, each module uses an individual power switch for control. The power source’s energy is transferred to load by a single inductor of the energy source. As mentioned earlier, most renewable energy sources generate a low-value voltage. High gain DC-DC converters are offered in two primary groups, converters with coupled inductors and low numbers of circuit elements and circuits without coupled inductors with a high number of

circuit elements. [8, 10] offer two high gain DC-DC converters, with and without using a coupled inductor. [8] presents a coupled inductor based high gain DC-DC converter. In this structure output, voltage gain can be changed by varying the transformer ratio. The proposed converter in [10] is a high gain DC-DC converter. In this circuit voltage gain is increased without using a coupled inductor, but the high number of power switches and circuit components can be viewed as drawbacks. The recently proposed high gain multiinput DC-DC converter and PDFCM [1, 5] are suitable for use in renewable energy sources. The high step-up capability makes this structure flexible for use across ample voltage ranges. Also, by having a multi-input circuit, the efficiency of the converter is increased by making it reliable

to use off-grid. In this paper, a high stepup multi-input DC-DC converter is proposed. In addition to the benefits that were mentioned for high gain and multiinput converters, the proposed converter consists of two ports, a unidirectional and a bidirectional. Having a bidirectional port provides an opportunity to use a battery in the converter structure to save extra produced power and to supply load when the generated energy is too low.

OPERATIONAL PRINCIPLES Fig. 1 shows the circuit structure of the proposed converter. It consists of four power switches (S1, S2, S3, and S4), two diodes (D1 and D2), two capacitors (C1 and C2), magnetizing and leakage inductors (Lm and Lk), and load (RLoad).

wattnow | January 2020 | 19


F EAT UR E

energy is too low to be individually supplied by the energy source.

DC - DC Converter continues from page 19

2. Operational Principles

The converter is operated in three operation modes: 1. Without Battery, 2. Battery Charging, 3. Battery Discharging. Each mode operation is divided into submodes as described below.

Journal of Power Technologies 99 (4) (2019) 264–271

WITHOUT BATTERY (MODE-I) Operation sub-modes of the converter in mode one are depicted in Fig. 2. The equivalent waveform of the proposed converter in this mode is also shown in Fig. 3.

First Sub-Mode [t0 – t1]: This mode starts by turning on switches S1, S4 or S2, S3. Due to the difference in leakage and magnetizing inductors’ current value, diode D2 conducts. Leakage and magnetizing inductors’ current difference charge capacitor C2 on the secondary side of the coupled inductor. Magnetizing inductor’s current decreases due to the negative voltage on it, but the leakage inductor’s stored energy increases.

Figure 1: Circuit structure of the proposed converter.

Figure 1: Circuit structure of the proposed converter

Fig. 1 shows the circuit structure of the prop converter. It consists of four power switches (S1 S3 , and S4 ), two diodes (D1 and D2 ), two capac Second Sub-Mode [t1 – t2]: This sub(C1 and C2 ), magnetizing and leakage inductors mode starts when leakage and magnetizing inductors’ stored energy become equal with and Lk ), and load (RLoad ). The converter is operat each other and diode D2 is turned off. This sub-mode lasts until the power switches three operation modes: turn off.

1. Without Battery, 2. Battery Charging, 3. Battery Discharging.

Third Sub-Mode [t2 – t3]: This sub-mode starts when the power switches turn off. In this sub-mode, the switches’ parallel capacitors start to be charged by turning the power switches off. The capacitors continue charging until the switches’ parallel capacitors voltage reaches capacitor C1’s. In this mode, the inductors’ stored energy decreases and this mode finishes when diode D1 and D2 conduct.

Each mode operation is divided into sub-modes a scribed below. Figure 2: Sub-modes of the proposed converter in mode-I:

20 | wattnow | January 2020

Figure 2: Sub-modes of the proposed converter in mode-I: (a) [t0 -t1 ], (b) [t1 -t2 ], (c) [t2 -t3 ], (d) [t3 -t4 ]

(a) [t0-t1], (b) [t1-t2], (c) [t2-t3], (d) [t3-t4]


I bat illus mo F ing sub and duc Fourth Sub-Mode [t3 – t4]: In this subfere Journal of Power Technologies 99 (4) (2019) 264–271 mode, each of the leakage and magnetizing the Journal of Power Technologies 99 (4) (2019) 264–271 dec inductors face different parallel voltages. 2.2. Battery charging (Mode II) lea The difference between the inductors’ 2.2.In Battery charging (Mode II) energy is st this mode extra produced S current is transferred to the secondary side Figure 3: The proposed converter’s equivalent in mode-I In this Sub-modes mode extrawaveforms produced energyinissam st battery. of the converter this of the coupled inductor to charge capacitor battery. Sub-modes of theforms converter this illustrated in Fig. 4. Wave of theinconv sta C2. Capacitor C1 charges with leakage illustrated in Fig. 4. Wave forms of the conve mode is depicted in Fig. 5. ene inductors’ current and this sub-mode lasts mode is Sub-Mode depicted Fig. 5. In mode one, consideration is not in given to sub-mode 0 1 First [t – t ]: This mode sta turn 0 1 until the power switches turn on. Sub-Mode t 1 ]:S22to This mode sta one and sub-mode three in calculations their ingFirst on switches S11[t , 0S44– due or , S3. Justturn sa ing on switches S1 , one, S4 or , S3. Just sa small and unimportant size. InofDT interval, D due isSequal to sub-mode mode to difference 2 T Fig. 3 shows some of the waveforms of sub-mode of period mode one, to difference duty cycle and T stands for the of thedue switching, and magnetizing inductors current value, dio off the proposed converter in mode one. and magnetizing inductors current inductors value, this dio giving: ducts. Leakage and magnetizing The waveforms include power switches ducts. magnetizing inductors ferenceLeakage charges and capacitor C22 on the second bat turning on and off times, input current, ference charges capacitor C2 on the second the coupled inductor. Magnetizing inducto with VLm = Vin (2) magnetizing inductor current and diodes the coupleddue inductor. Magnetizing inducto decreases to the negative voltage on hig current. To calculate the output voltage’s due to the negative onF leakage inductors’ stored energyvoltage increases. where VLm and Vdecreases in are magnetizing inductor’s voltage gain of the proposed converter, the leakage inductors’ stored energy increases. Second Sub-Mode [t – t ]: This sub-m 1 2 the 1 2 and input voltage, respectively. Figure 3: The proposed converter’s equivalent waveforms in mode-I following condition is assumed: Second Sub-Mode [t 1sub-mode – t 2 ]: This sub-m same as the respective of mode swi And,ininmode-I (1-D)T interval: Figure operates 3: The proposed converter’s equivalent waveforms 1. The proposed converter in same theleakage respective of mode starts as when andsub-mode magnetizing induc the continuous conduction mode (CCM); starts leakage andwith magnetizing induct energywhen become equal each other and ing 2. Due to the small size In of mode the leakage V = V − V (3) one, consideration is not given to sub-mode Lm in C1 energy become equal with each and turns off. This sub-mode lasts untilother the pow tha In mode one, is not given to sub-mode inductor, it is notone considered in consideration and sub-mode three in calculations due to their turns off. This sub-mode lasts until the powe turn off. ene one three to their calculations. smalland andsub-mode unimportant size.inIncalculations DT interval, due D is equal to turn off. Sub-Mode [t 22 – t 33 ]: By turning Third D1 N1 small and unimportant size. interval, D isswitching, equal to duty cycle and T stands for In theDT period of the Sub-Mode [t – t ]: By turning 2 3 3 offVThird and turning switch S on, this sub-mode VC2 (4) F 3 Lm = − N2 the duty cycle and T stands for the period of the switching, Eq. (1) is a general assumption in proposed giving: off turning switch S3 source on, thisenergy sub-mode thisand sub-mode power tran in t converter calculations.giving: this sub-mode the power energyinduc tran battery andfollowing leakage and source magnetizing ind Using (2), (3) and (4), the relationship can battery and leakage and magnetizing induct with lower slope (assuming the power sourc of t Lm = Vin in VLm be obtained:(2) with lower (assuming the power source higher thanslope the battery voltage). VO = VC1 + VC2 VLm = Vin (2) of t higher than the battery voltage). (1) 3 4 Fourth Sub-Mode [t and V are magnetizing inductor’s voltage where VLm – t ]: To start this itor Lm in 3 4 Figure 3: The proposed converter’s equivalent waveforms in mode-I in Vin VC1 = Sub-Mode [t 3 – toff. start theFourth power switches turns In(5) this this sub where VO, VC1, and VC2 are output 4 ]: To where sub Lm and Vrespectively. in are magnetizing inductor’s voltage and inputVvoltage, voltage, 1−D the powerparallel switches turns off.start In to this subandAnd, input respectively. first capacitor’s voltage and second switches’ capacitors charge T in voltage, (1-D)T interval: switches’ parallel capacitors start to charge the power switches off. The capacitors cont capacitor’s voltage, respectively. two And, in (1-D)T interval: N2 the switches off.parallel The capacitors conti ing power until the switches’ capacitors’ vo in dut N1 DV V = (6) Lm = Vin in − VC1 C1 VLm (3) C2 ing the vol thatuntil of capacitor In thiscapacitors’ mode induct ind In mode one, consideration is not given 1 −switches’ D C11’s.parallel VLm = Vin − VC1 (3) that of capacitor C ’s. In this mode induct energy decreases and this mode finishes w 1 In F to sub-mode one and sub-mode three At the end, by using (1), (5) and (6) output voltage energy decreases and this mode finishes w D1 and D2 conduct. ren in calculations due to their small and N11 In1the end,2by using (1), (5) and (6) output gain is: D and D conduct. 1 2 C2 Lm 4 5 V (4) V = − Fifth Sub-Mode [t – t ]: As in the prev and C2 Lm 4 5 unimportant size. In DT interval, D is equal N voltage gain is: N122V V = − (4) Fifth Sub-Mode [t – t ]: As in the prev in this sub-mode, each of the leakage and m Lm C2 4 5 I to duty cycle, and T stands for the period of N2 in this sub-mode, each of the leakage and m inductors face different parallel voltages. The mo V /V = (1 + (N /N )D)/(1 − D) (7) O in 2 1 the switching, giving: Using (2), (3) and (4), the following relationship can /Vinface = (1 different + (N /N1)D)/(1 − D) Using (2), (3) and relationship (4), the following 2 inductors parallel voltages. The of theVOinductors’ current transfers to the seco Using (2), (3) and (4), the following can be obtained: VLm = Vin (7) relationship can be obtained: of the inductors’ current transfers to the seco of the coupled inductor to charge capacitor be obtained: (2) — 267 —C of the to charge capacitor itor C11coupled chargesinductor with leakage inductors’ curre in Vin where VLm and Vin are magnetizing C1 = VC1 (5) itor C charges with leakage inductors’ curre sub-mode lasts until the power switches turn 1 Vin inductor’s voltage and input voltage, VC1 = 1 − D (5) sub-mode lasts untilofthe switches turn The waveforms thepower proposed convert 1−D respectively. The the5.proposed two arewaveforms depicted inof Fig. D11 and D22converte are the N22 N wattnow 21forthe in two depicted Fig. 5. |DJanuary and2020 D2 |are 1converter N1 DVin dutyare cycle of theinproposed ch N1 N VC2 = (6) 2 C2 DV duty cyclewithout of the battery proposed for ch 1 − Din N1 inductors andconverter with battery, re

Journal of Power Te

Figure 3: The proposed converter’s equivalent waveforms in

In mode one, consideration is not given to subone and sub-mode three in calculations due to small and unimportant size. In DT interval, D is eq duty cycle and T stands for the period of the swit giving:


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DC - DC Converter continues from page 21

Journal of Power Technologies 99 (4) (2019) 264–271 Journal of Power Technologies 99 (4) (2019) 264–271

BATTERY CHARGING (MODE II) In this mode, extra produced energy is stored in the battery. Sub-modes of the converter in this mode is illustrated in Fig. 4. Waveforms of the converter in this mode are depicted in Fig. 5. First Sub-Mode [t0 – t1]: This mode starts by turning on switches S1, S4 or S2, S3. Just same as first sub-mode of Mode one, due to difference in leakage and magnetizing inductors current value, diode D2 conducts. Leakage and magnetizing inductors current difference charges capacitor C2 on the secondary side of the coupled inductor. Second Sub-Mode [t1 – t2]: This sub-mode is the same as the respective sub-mode of mode one, and it starts when leakage and magnetizing inductors’ stored energy become equal with each other and diode D2 turns off. This sub-mode lasts until the power switches turn off. Third Sub-Mode [t2 – t3]: By turning switch S4 off and turning switch S3 on, this submode starts. In this sub-mode, the power source energy transfers to the battery and leakage and magnetizing inductors charge with lower slope (assuming the power source voltage is higher than the battery voltage).

Figure 4: Sub-modes of the proposed converter in mode-II: (a) [t -t ], (b) [t -t ], (c) [t -t ],

Figure 4: Sub-modes of the proposed converter in mode-II: (a) [t0 -t1 ], (b)0 [t11 -t2 ], (c) [t1 2 -t23 ], (d) [t32-t4 ]3 , (e) [t4 -t5 ] Figure 4: Sub-modes of the proposed converter (d) [t -tin ]mode-II: , (e) [t (a) -t ][t0 -t1 ], (b) [t1 -t2 ], (c) [t2 -t3 ], (d) [t3 -t4 ] , (e) [t4 -t5 ] 3

4

4

5

N1 VLm = N−1 VC2to secondary side of the coupled VLm = − inductor VC2 N2 N2 . Capacitor C charges charge capacitor C Using (8), (9) in: 2 and (10) results 1 Using (8), (9) and (10) results in: with leakage inductors’ current and this Vin − D2 VBattery sub-mode last until Vthe VBattery =power in − D2switches C1 V VC1 = 1 − D 1 − D2 turn on. 1 − D 1 − D2

N2  converter in The waveforms ofNthe proposed VC2 = N12 N1  Vin (D1 + D2 ) − D2 VBa + Dand 1 − D1 − in DV 2 V Batte in (D 2 ) −DD 2Fig. modeVC2 two=are depicted 5.1 D 1 2 1 − D 1 − D2 are the equivalent cycle of the Finally, byduty using (1), (11)proposed and (12) outp Finally, by usingthe (1),inductors (11) and (12) output Fourth Sub-Mode [t3 – t4]: By starting converter for charging gain in mode two is calculatedwithout as: gain in mode two is calculated as: this sub-mode, the power switches turn battery and with battery, respectively. In Fig.   off. In this sub-mode, the switches’ parallel 5, Iin stands for input I  stands for   N Figure 5: The proposed converter’s equivalent waveforms in modeNcurrent, Figure 5: The proposed converter’s 2 (D1 + DLm Vin 1 N+2 N1 Figure converter’s equivalent waveforms in mode2 ) − V Battery D2N2 N II 5: capacitors start to charge by turning theThe proposed (D ) − V 1 + V + D currentVOflowing through 1 the2 magnetizing Battery D2 N1 + =in equivalent waveforms in mode- II N1 II V = − D2 1 − D O 1 power switches off. The capacitors continue inductor, and ID1 and ID21stand − Dcurrent − D1 for 2 For interval DSub-Mode charging until the switches’ parallel 1 +D2 , we have: Fifth [t4 – t5]: As in the previous flowing diodes. 2.3.through Battery discharging (Mode-III) For interval D1 +D 2 , we have: 2.3. Battery discharging (Mode-III) capacitors’ voltage reach that of capacitor mode, in this sub-mode, each of the In this mode, the power source is assume VLm = (D1 + D2 )Vin − D2 VBattery (8) In this mode, the power source is assumed t C1’s. In this mode, inductors’ stored energy Vleakage inductors face output voltage’s in this (8) To calculate able to the provide the load’s gain required energy a Lm = (Dand 1 + Dmagnetizing 2 )Vin − D2 V Battery able to provide the load’s required energy and decreases and this mode finishes when And fordifferent interval 1-(D1+D2), we have: tery is responsible for supplying the rest of t parallel voltages. The difference mode, assumptions of Mode-I are valid. And for interval 1-(D1+D2), we have: tery is responsible for supplying the rest of the energy. For instance, the supply shortage m diode D1 and D2 conduct. of the inductors’ current transfers to the energy. For instance, the supply shortage may PV during night time or very high and/or ve VLm = Vin − VC1 (9) PV during night time or very high and/or very VLm = Vin − VC1 (9)

22 | wattnow | January 2020

— 268 — — 268 —


1 − D 1 − D2 of the inductors’ current transfers to the secondary side of the coupled inductor to charge capacitor C2 . CapacN2 chnologies 99 (4) (2019) 264–271   N1 C1 charges with leakage Vitor VC2 = (12) inductors’ current and this in (D1 + D2 ) − D2 V Battery 1 − D1 − D2 sub-mode lasts until the power switches turn on. Fig.and 7 shows waveforms Finally, by using (1), (11) (12) output voltages of the converter in mode three. as: D1 and D2 are inductors’ charging duty cycle gain in mode two is calculated without battery and with battery discharging respec  N  tively. The proposed converter’s equivalent waveforms in modeN2 2 (D1 + D2 ) − VBattery D2 N1 Vin 1 + N1 +1 For D1 +D2 interval, we(13) have: VO = 1 − D 1 − D2 current decrease due to negative voltage For D1+D2 interval, we have: For interval D1+D2, we have: terval D1 +D2 , we have: VLm = (D D2+VBattery (14) 2.3. Battery discharging 2) V on it; however, leakage (Mode-III) inductors stored VLm = (D1 + D2)Vin − D2VBattery V1Lm+=D (D + inD2+) V D2VBattery (14) 1 in In this mode, the power In source is assumed to be unaddition, for 1- D VLm = (D1 + D2 )Vin − D2 VBattery (8)(8) energy increase. 1 -D2 interval we have: able to provide the load’s required energy and the batAlso, for 1- D1-D2 interval we have: or interval 1-(D1+D2), we have: tery is responsible for supplying the rest of the required Second Sub-Mode [t1 – t2]: This sub- VLm = Vin − VC1 And for interval 1-(D1+D2), we have: (15) energy. For instance, the supply shortage may include mode starts when leakage and magnetizing V = V V (15) [t -t ], (d) [t -t ] , (e) [t -t ] Lm in C1 1 ], (b) [t1 -t2 ], (c) 2 3 3 4 4 5 PV during night time or very high and/or very low wind VLm = Vin − VC1 (9) inductors’ stored energy become equal with 1 ], (b) [t1 -t2 ], (c) [t2 -t3 ], (d) [t3 -t4 ] , (e) [t4 -t5 ] N1 (16) VC2 each other and diode D2 is turned off as in VLm = − N2 — 268 — N1 mode one and mode two. This sub-mode in mode-II: (a) [t -tV],Lm (b) [t=-t − ], (c) [t -t (10) V],C2(d) [t -t ] , (e) [t -t ] The following relationship can be gained by using N2 N1 lasts until the power switches turn off. The following relationship can be gained by −], (c) [tV-tC2], (d) [t -t ] , (e) [t -t ] (10) er in mode-II: (a) [t V -t Lm ], (b)= [t -t (14), and(2019) (16): 264–271 Journal of Power Technologies(15) 99 (4) N2 in: (8), (9) and (10) results using (14), (15) and (16):

hnologies 99 (4) (2019) 264–271

0

1

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3

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prop shou Inpu simil rents are a Ex Char and Expe conv simil put c simil diode resp Fig (Batt dere conv

N1 VLm =in: − VC2 (10) (8), (9)Using and (10) results N2results in: (8), and (10) Third Sub-Mode [t2 – t3]: By turning off −D Vin(9) 2 V Battery N 1 velocities turbines, etc. Waveforms the proUsing and (10) in: VC1 (8), = (9) (11) VLm results = for − wind (10) VC2 Journal of Power Technologies 99 (4) (2019) 264–271 — 269 switch S1 andofturning on switch S2 this subVin 1 − D12 V−Battery D2N2 Vin + D2 VBattery posed converter are depicted in Fig. 6. VUsing = (11) − D V V C1 (8), (9) and (10) VC1 = (17) in results 2 Battery in: modeforstarts. In thisetc. sub-mode, power (11) velocities 1 V−C1D=1 −1 D wind turbines, Waveformsthe of the pro2 −D 1 − D1 −VinD+2D2 VBattery −D 1 2 mode starts by turnFirst Sub-Mode [t 0 – t 1 ]: This Journal of Power Technologies 99 (4) (2019) 264–271 posed converter depicted in Fig.and 6. leakage and Vin − D2 VBattery source andare battery charge VC1 = (17) N2  ingVon 1 − D 1 − D2 C1 =switches S , S or S (11) JustSub-Mode same as[t 0first sub– t 1 ]: This mode starts by turn4 2 , S3 .First N1 1 − D 1 − D2 1 N magnetizing inductors with a higher slope. (D ) 2 − D V + D V (12) N2 2 Battery   1  2 velocities for wind offirst the subpro- N2 ing on switches S1 ,turbines, S4 or S2 ,etc. S3in . Waveforms Just same as  inmode N1 1 − DN1 ofin (D mode  N2  1 V−C2D − D2 Vand =2 V (12) two, due to difference Vin + D2 VBattery 1 + D2 )one Battery mode converter areand depicted Fig.due 6. to difference in N1 1 −VD −2 D12 + D2 ) − D2 V Battery (12) posed mode of mode one modeintwo, VC1 + = D ) + D V  (17) in1N(D (D V V = N1   C2 in 1 2 2 Battery 1 − D − D 1 − D1 − D2 leakage and magnetizing inductors value, diode VC2 = Vin (D1 +1 D2 ) 2+ D2 VBattery (18) (18) N1 Firstcurrent Sub-Mode [t 0 – tinductors starts bydiode turn1 ]: This mode and magnetizing current value, 1 − D − D (Dand D2 Vvoltages V(11) (12) leakage VC2 (1), = by using y, by using (11) and output in (12) 1+D 2 ) − output Battery 1 2 1 − D − D Fourth Sub-Mode [t – t ]: This subFinally, (1), (12) voltages 1 2 1 −D D1 −conducts. D2 4 inductors’ ing on switches S1 , S4 or S2 ,magnetizing S3 .3 Just same as first subD conducts. Leakage and curLeakage and magnetizing inductors’ cur2 2 gain is in mode is calculated as:output voltages mode calculated as: (12) N y, by two using (1),bytwo (11) and Output voltage gain of the proposed converter starts when the two, power turn Finally, using andoutput (12) voltages outputmode of mode one and capacitor mode to difference in  proposed  inin rentmode difference charges Cdue the secondary 2 atswitches Finally, by using (1),(1), (11)(11) and charges (12) Output voltage gain ofN12 the converter rent difference capacitor C at the secondary )+D 2 Vin (Dusing V = C2 1 + D2(1), 2 V Battery Mode-III can be calculated (17) and (18)(18) as leakage and magnetizing inductors current value, diode mode two is calculated as: sideoff. of theSwitches’ coupled inductor. Magnetizing inductors curgain in mode two is calculated as: 1 − D − D     parallel capacitors start to voltages gain in mode two is calculated as: The output voltage gain of the proposed 2 odeN2 N2 Mode-III can befollows: calculated1 using (1), (17) and (18) as D conducts. Leakage and magnetizing inductors’ curof the coupled inductor. Magnetizing inductors cur(D )     − V Vin 1 +side + D D + 1 2 rent decrease due to negative voltage on it; however, 1 2 Battery 2 N1 N2 N1 VNO2 =(D + D ) − V Output voltage gain of thecan proposed converter in charge bycharges turning the power switches off. converter in Mode-III be calculated Vmode+ N1negative difference capacitor C2 atfollows: the secondary  (13) rent in 1 + N1 1 rent 2N  decrease leakage inductors energy increase. 1 −Battery D1 − DD2 2due N1 to voltage on it;stored however,  2 2   beN calculated using  as Mode-III can (1), (17) Nand (18) (D ) − V 1 + V + D in 1 2 Battery N2 N2D2 N1 + 1(13) side of the capacitors coupled inductor. Magnetizing inductors curN1 Second Sub-Mode [t – t ]: This sub-mode starts 2 1 2 The continue charging until using (1), (17) and (18) as follows: (D Vin 1 +2.3. D2D)1 − D2 + 1 energy VOBattery = 1+ (13) Vin 1 + N1 (D1 + D2 ) + VBattery D2 N12 + 1 Battery −V D 1 discharging − N1 2inductors leakage increase. follows: rent decrease due to negative voltage on it; however, 1 (Mode-III) − D1 − D2 N1stored (13) when leakage and magnetizing inductors’ stored enVO =  1 − D 1 − D2  N   (19) switches’ parallel capacitors’ voltage inductors stored increase. In this mode, is assumed to un-t 2leakage − D2source 1 − the DSecond ergy become equal with energy each other and diode D2 is 1 power Sub-Mode [tbe ]: the This sub-mode starts N2 2  1 – (8) discharging 2.3. Battery discharging (Mode-III)    tery (Mode-III) (D ) + V 1 + + D + 1 V D 1 2N2 in Battery 2 able to provide the load’s required energy and the bat- turned Second Sub-Mode [tone t 2 ]: mode This starts N2 N1 1 – and off as in mode two.this This subreach that ofstored capacitor C ’s. sub-mode In mode, BATTERY DISCHARGING (MODE-III) (D1 + D2 ) + VBatteryN1 Vin 1 + N1 D2 N1 + 1(19) 1 when leakage and magnetizing inductors’ enV = In this mode, the power source is assumed to be un3. Experimental Results tery is responsible for supplying the rest of the required O when leakage and magnetizing inductors’ stored entery (Mode-III) (19) lasts until the power switches turn off. (8) discharging mode, thethis power source is assumed to assumed be un- mode the inductors’ stored decreases and VO = 1 − D1 − D In mode, source 1 −2 D1 − D2 able to For provide thethe load’s required energyis andinclude theeach bat- ergy energy. instance, thepower supply shortage may ergy become equal with other andequal diode D2 energy isother become each and off diode D2 Sis1 Third Sub-Mode [twith By turning switch 2 – t 3 ]: In order to verify performance of the proposed conprovide the load’s required energy and the batmode, the power source is assumed to be untery is responsible supplying the rest very of the required PV night time very highthe and/or low wind turned (9) offmode ason inswitch mode and mode two. this finishes when diode DThis andsubD verter, an experimental circuit is investigated. The pertoduring be unable tofororprovide load’s required andmode turning Sone sub-mode starts. 2 this turned off as one and two. This sub1 In this 2 For instance, the shortage may include 3. Experimental Results esponsible supplying thesupply restin of mode the required provide energy. thefor load’s required energy and the batmode lasts until the power switches turn off. sub-mode, the power source and battery charge and 3. Experimental Results formance of the converter in experimental research is energy the lasts battery responsible for conduct. PV during and night time or very until highisand/or very low wind (9) mode the power switches turn off. For instance, the supply shortage may include Third Sub-Mode [t – t ]: By turning off switch S — 268 — 2 3 esponsible for supplying the rest of the required leakage and magnetizing inductors with higher slope. 1 In order verifymodes, performance of the condivided intotothree reflecting theproposed performance supplying the rest of the necessary energy. By verifying the circuit performance ofThethe turning on switch sub-mode starts. In this Third Sub-Mode [tinclude t 3 ]: and By turning off switch Fourth Sub-Mode [tS32 this – t 4S ]: starts ng night time or very highshortage and/or very low wind verter, an experimental is investigated. per2 – 1This sub-mode For instance, the supply may principles. The switching frequency of the proposed In order to verify performance of the proposed con— 268 — sub-mode, the power source and battery charge and when the power switches turn off. Switches’ parallel caformance of the converter in experimental research is Fifth Sub-Mode [t – t ]: As in previous proposed converter, an innovative circuit converter in this research is about 30 kHz and the voltand turning on switch S this sub-mode starts. In this ng night time or very high and/or very low 2wind leakage and magnetizing inductors 4 5 an experimental circuit is battery investigated. The perwithverter, higherswitches slope. pacitors start to charge by turning the power divided three and modes, reflecting performance ages of into the input are 20the V and 15 the V reFor instance, the supply shortage may modes, in this sub-mode, each of the is investigated. The performance of sub-mode, the power source off. and charge Fourth Sub-Mode [t 3 – tand sub-mode starts 4 ]: Thisuntil Thebattery capacitors continue charging the switches’ The in switching frequency theexperimenproposed formance of theprinciples. converter experimental research is spectively. Load is about 100 V for all ofof the the power switches turn off. that Switches’ parallelCface caparallel capacitors’ voltage reach of capacitor include PV duringand the magnetizing night time or inductors verywhen leakage and magnetizing inductors converter inresearch exploratory isits converter in this is about 30 research kHz and theonvolt1 ’s. leakage with higher slope. tal tests and we tested the proposed converter divided into three modes, reflecting the performance pacitors start to by turning powerdecreases switches In this mode thecharge inductors’ storedthe energy of the input and are 20 V and 15 the V the recapability tointo provide allbattery three modes. Fig 8 shows high and very low wind velocities [t for parallel voltages. The differenceTheages divided three modes, reflecting Fourth Sub-Mode – t 4 off. ]: different This sub-mode starts 3 wind continue principles. switching frequency the proposed andThe this capacitors mode finishes whencharging diode D1until andthe D2 switches’ conduct. spectively. Load is about 100 V for of the experimenperformance of the converter inof theall first mode (Without parallel capacitors’ voltage reach that of capacitor ’s. turbines, when etc. Waveforms the proposed ofSwitches’ the inductors’ transfers toC1the performance principles. The switching the powerofswitches turn off. parallel As in previous modes, in this Fifth Sub-Mode [t 4 – t current tal tests and we the30 proposed converter onvoltits 5 ]:caBattery). From uptested to down wave forms are output converter in research is about kHz and the voltIn mode the inductors’ storedand energy decreases thisthis sub-mode, each ofswitches the the leakage magnetizing incapability provide all three Fig showsin age, inputtocurrent, diode D2 ’smodes. current and8 diode Dthe converterpacitors are depicted Fig. 6. secondary side of coupled inductor to frequency of the proposed converter startinto charge by turning the power of the input and battery are 20in the V and 15 (Without V re-1 ’s and this face modedifferent finishesparallel when diode D1 ages and D2difference conduct. ductors voltages. The performance of the converter current. According to equation (7),first out mode voltage of the off. The capacitors continue charging until the charge capacitor C C1modes, charges this research about 30forms kHz, the t 52]:. Capacitor As in in Sub-Mode [tswitches’ 4 –transfers of Fifth the inductors’ current to previous thespectively. secondary side LoadBattery). is about 100 Vindown for of the experimenFrom up is to wave areand output proposed converter thisall mode considering D = volt1/3 this sub-mode, each of the leakage and magnetizing inof the coupled inductor to charge capacitor C . Capacparallel[tcapacitors’ voltage reach that of capacitor C ’s. age, input current, diode D ’s current and diode D 2 First Sub-Mode – t ]: This mode starts with leakage inductors’ current and this voltages of the input and battery are 20 V1 ’s 2 should be 140 V which the experimental results verify. 1 tal tests and we tested the proposed converter on its 0 1 ductors face different parallelinductors’ voltages. current The difference itor C1 charges with leakage and this current. According to12 equation (7), out voltage of the Input isrespectively. about A in its peak and waveform is In on this mode Sthe stored energy decreases by turning switches , S4 inductors’ or S2, S3. Just sub-mode last until theto the power switches and current 15all V,three The load is about capability to provide modes. Fig 8 shows of the inductors’ current secondary 1 sub-mode lasts until the transfers power switches turn on. side proposed converter in this in mode =the 1/3 similar to expected results Fig. considering 3. Diode D1 ,D2s’ curof Fig. the coupled inductor to charge capacitor C2 .inCapacand sub-mode this modeoffinishes when diode D and D2 conduct. 7 1shows waveforms of the converter mode ofshould same as first Mode one and turn on. 100 V allVof thethe experimental befor 140 which the experimental results verify. performance the are converter in first modetests, (Without rents similar to presumed waveforms in Fig.and 3 and itor C1 charges leakage inductors’ current andcycle this three. D1 and with D2 are inductors’ charging duty Input current is about 12 A in its peak and waveform are about 5 A and 10 A at their peak respectively. – t ]: As in previous modes, in Fifth Sub-Mode [t 4 5and Mode two, due to difference in leakage we tested the proposed converter on its is Battery). From up to down wave forms are output voltsub-mode lasts until switches turn on.respecwithout battery and the withpower battery discharging similar to expected results Fig. 3. Diode D1 , (Battery 2s’ curExperimental results for inthe second mode thisinductors sub-mode, eachvalue, of thediode leakage magnetizing Fig. 7 shows waveforms ofinthe of converter in mode magnetizing current Fig.and 7 shows waveforms the converter capability toDto provide all9.waveforms three Fig age, input current, diode current and diode ’s tively. rents are similar presumed in Fig. 3=1and 2 ’s Charging) is depicted in Fig. In this modes. mode D1D 1/3 three. D D2 are inductors’ charging duty cycle 1 and For D +D interval, we have: ductors face different parallel voltages. The difference are about 5 A and 10 A at their peak respectively. 1 2 and D2to = 1/3, results in 95ofV according tothe (13). D2 conducts. Leakage and magnetizing in mode three. D1 and D2 current. are inductors’ 8 shows thewhich performance the converter According equation (7), out voltage of without battery and with battery discharging respecExperimental results for the second mode (Battery Experimental results in Fig. 9 verify performance of the inductors’ current charges transfers to the secondary side inductors’of the current difference charging battery (14) and in theinfirst mode (Without proposed converter this mode considering Dare=DFrom 1/3 tively. Charging) depicted In Battery). this mode + D2 VBattery VLm duty = (D1 +cycle D2 ) Vinwithout 1 = 1/3 converter inisthis mode.inInFig. Fig. 9. 9 wave forms ordered inductor capacitor Cdischarging, CapacD1 +D have: 2 .we 2 interval, D 1/3, which results 95As Vresults according to (13). should be 140 and V the experimental verify. capacitorofC2the at coupled the secondary sidetoofcharge the For with battery respectively. upwhich to2 to=down waveforms are output voltage, similar the first mode (Fig.in8). was expected, inIn addition, for 1- D1 -D2 interval we have: Experimental results Fig. 9 and verifydiode performance of are the itor C charges with leakage inductors’ current and this put current, diode Dits current D1 current 2 in 1 Input current is about 12 A in peak and waveform is coupled inductor. Magnetizing inductors input current, diode D ’s current and diode VLm = (D1 + D2 ) Vin + D2 VBattery (14) 25.9 wave converter this mode.inInFig. Fig. forms areDordered similar to in waveforms Input’s, diode 2 ’s and sub-mode lasts until the power switches turn Von. Lm = Vin − VC1 similar to(15) expected results in Fig. 3. Diode ,42s’ cursimilar to the first mode (Fig. 8). As 1 expected, diode D ’s currents at their peaks are|was 8D A, A 2020 and 6| inA, 1 In addition, for 1- D1 -D2 interval we have: wattnow January 23 Fig. 7 shows waveforms of the converter in mode put diode D2waveforms current and diode D1 current are respectively. rents are similar tocurrent, presumed in Fig. 3 and N1 similar to waveforms in Fig. 5.results Input’s, D2 ’smode and Fig. 10 experimental fordiode the third three. D1 and D2 are inductors’ charging duty cycle (16) VLm =V −in − VC2 V Lm = C1 are about(15) 5 A and 10 Ashows at their peak respectively.

EXPERIMENTAL RESULTS


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Journal of Power Technologies 99 (4)

DC - DC Converter continues from page 23

Journal of Power Technologies 99 (4) (2019) 264–271

D1’s current. According to equation (7), out voltage of the proposed converter in this mode considering D = 1/3 should be 140 V which the experimental results verify. Input current is about 12 A in its peak and waveform is similar to expected outcomes in Fig. 3. Diode D1, 2s’ currents are identical to presumed waveforms in Fig. 3 and are about 5 A and 10 A at their peak respectively. Experimental results for the second mode (Battery Charging) is depicted in Fig. 9. In this mode, D1 = 1/3 and D2 = 1/3, which results in 95 V according to (13). Experimental results in Fig. 9 verify the performance of the converter in this mode. In Fig. 9 waveforms are ordered similar to the first mode (Fig. 8). As was expected, input current, diode D2 current and diode D1 current are identical to waveforms in Fig. 5. Input’s, diode D2’s and diode D1’s currents at their peaks are 8 A, 4 A and 6 A, respectively.

Figure 6: Sub-modes of the proposed converter mode-III: Figure 6: Sub-modes of the6:proposed converter mode-III: (a) [t0 -t1 ], (b)in[t -t2 ], (c) [t2 -t3in ], (d) [t3 -t4 ] , (e)(a) [t4 -t5[t] 0 -t1 Figure Sub-modes of theinproposed converter 1mode-III: (a) [t0-t1], (b) [t1-t2], (c) [t2-t3], (d) [t3-t4] , (e) [t4-t5]

Figure 8: Experimental results for proposed converter in Fig. 10 shows experimental results for the third mode (Battery Discharging). In this mode, waveforms are ordered similarly to the previous results. The proposed Figure 8: Figure 7: The proposed converter’s equivalent waveforms in modeconverter operates with D1 = 1/3 and D = III 2 1/3 in this mode. Equation (19) shows that the output voltage in this mode mode. is 185 V,Equation (19) shows that the output voltage in which experimental results verify.this Inmode this is 185 V, which experimental results verify. In this mode diode D2 ’s and diode D1converter’s ’s currentsequivalent waveforms in mode- III . mode input’s, diode D2’s and diode D1’s input’s, The proposed Figure Figure 7: The7:proposed converter’s equivalent waveforms in modeare 18 A, 8 A and 12 A at their peaks respectively. currents are 18 A, 8 A and 12 A at their III are similar to Fig. 7 ascharging, was expected. peaks respectively. Waveforms areWaveforms similar battery, with battery and with REFERENCES: Figure 9: Experimental results for proposed converter in to Fig. 7 as was expected. battery discharging). Also, operation of the click here 4. Conclusion mode.structure Equation (19) shows the output voltage in presented in each of the Modes thatcalculated. In order to verify the theoretica CONCLUSION wasthis described, and equivalent equations mode is 185 V, which experimental results verify. Inexperimental resu In this paper, a newly developed high step-up dou- © Paper mance of the converter, courtesy of Journal of Powerthe Technologies In this paper, a newly developed high were calculated. verifying the theoretical ble input DC-DC converter presented. The also provided. results are very consisten this modeBywas input’s, diode D2per’s and diode D1 ’sThecurrents 99 (4) 2019) 264-271. formance ofperformance the proposed of converter evaluated theory and experiment. step-up double input DC-DC converter the was converter, thein are 18 A, 8without A and 12 with A at their peaks respectively. modes (namely, batwas presented. The performancethree of different the experimental results were battery, also provided. [1] Masoud Afsharikhamaneh, Payam Farhadi, are similar toInFig. tery charging, Waveforms with battery discharging). addi-7 as was expected. Abarzadeh, Jaber Ebrahimi, and Tina Sojoudi. proposed converter was evaluated in Theand results are very consistent both in Figure 9: E tion, operation of the presented structure in each of the for double flying capacitor multicell converter progre three different modes (namely, without theory and experiment.

modes was described and equivalent equations were

24 | wattnow | January 2020

4. Conclusion

— 270 —

ble flying capacitor multicell converter. IET Power E

calculate


(a) [t0 -t1 ], (b) [t1 -t2 ], (c) [t2 -t3 ], (d) [t3 -t4 ] , (e) [t4 -t5 ] Figure 8: Experimental results for proposed converter in mode-I

Journal of Power Tec

onverter’s equivalent waveforms in mode-

shows that the output voltage in hich experimental results verify. In ode D2 ’s and diode D1 ’s currents 12 A at their peaks respectively. ar to Fig. 7 as was expected. Figure 8: Experimental results converter for the Figure 9: Experimental resultsconverter for theFigure Figure 10: Experimental for proposed 10: Experimental results forresults proposed converter in mod gure 8: Experimental results for proposed Figurein9:mode-I Experimental results for proposed in mode-II proposed converter in mode-I. proposed converter in mode-II . converter in mode-III.

wly developed high step-up dounverter was presented. The perposed converter was evaluated in (namely, without battery, with batith battery discharging). In addipresented structure in each of the d and equivalent equations were

feb 2015. calculated. In order to verify the theoretical8(2):297–308, perfor[2] Mohammad Reza Banaei, Hossein Ardi, Rana Alizadeh mance of the converter, the experimental results were Amir Farakhor. Non-isolated multi-input–single-output D also provided. The results are very consistentconverter both in for photovoltaic power generation systems. theory and experiment. Power Electronics, 7(11):2806–2816, nov 2014.

[3] Hamid Behjati and Ali Davoudi. Single-stage mult [1] Masoud Afsharikhamaneh, Payam Farhadi, DC–DC Mostafa converter topology. IET Power Electronics, 6(2): Abarzadeh, Jaber Ebrahimi, and Tina Sojoudi. 403, Structure feb 2013. for double flying capacitor multicell converter progressive dou- Chen, Yubin Wang, Jih-Sheng Lai, Yuang-S [4] Chien-Liang ble flying capacitor multicell converter. IET Power Electronics, Lee, and D. Martin. Design of Parallel Inverters for Sm

Finally, a better way to save on compressed air.

Mode Transfer Microgrid Applications. IEEE Transaction Power Electronics, 25(1):6–15, jan 2010. — 270 — in mode-II [5] Yen-Mo Chen, Alex Q. Huang, and Xunwei Yu. A High gure 9: Experimental results for proposed converter Up Three-Port DC–DC Converter for Stand-Alone PV/Ba Power Systems. IEEE Transactions on Power Electro 28(11):5049–5062, nov 2013. lculated. In order to verify the theoretical perfor[6] Saeed Danyali, Seyed Hossein Hosseini, and Gevo ance of the converter, the experimental results were Gharehpetian. New Extendable Single-Stage Multiso provided. The results are very consistent both in DC–DC/AC Boost Converter. IEEE Transactions on P eory and experiment. Electronics, 29(2):775–788, feb 2014. [7] Serkan Dusmez, Xiong Li, and Bilal Akin. A new multi1] Masoud Afsharikhamaneh, Payam Farhadi, Mostafa three-level integrated DC/DC converter for renewable en Abarzadeh, Jaber Ebrahimi, and Tina Sojoudi. Structure systems. In 2015 IEEE Applied Power Electronics Confer for double flying capacitor multicell converter progressive douand Exposition (APEC). IEEE, mar 2015. ble flying capacitor multicell converter. IET Power Electronics, [8] Yanying Gao, Hongchen Liu, and Jian Ai. Novel High Up DC–DC Converter with Three-Winding-Coupled-Indu and Its Derivatives for a Distributed Generation System — ergies, 11(12):3428, dec 2018. Quickly find compressed air, gas and vacuum [9] Y.A.-R.I. Mohamed and E.F. El Saadany. Hybrid Var Structure Control With Evolutionary Optimum-Tuning leaks—the invisible energy thief rithm for Fast Grid-Voltage Regulation Using Inverter-B Did you know that compressed air can account for 40 % of wasted electricity?* Locating leaks in compressed air, Distributed Generation. IEEE Transactions on Power Elec gas and vacuum systems has been time-consuming and tedious—until now. ics, 23(3):1334–1341, may 2008. With the NEW Fluke ii900 Sonic Industrial Imager your maintenance team can quickly pinpoint [10] the location Gang Wu, Xinbo Ruan, and Zhihong Ye. Nonisolated of compressed air, gas and vacuum leaks in a matter of minutes. Step-Up DC–DC Converters Adopting Switched-Cap Cell. IEEE Transactions on Industrial Electronics, 62(1): 393, jan 2015. How much could you save if you could see leaks? [11] Qun Zhao and F.C. Lee. High-efficiency high step-up Learn more: www.fluke.com/ii900 DC converters. IEEE Transactions on Power Electro *Source: Compressed Air and Gas Institute (CAGI) wattnow | January 2020 | 25 18(1):65–73,©2019 jan Fluke 2003. Corporation. 11/2019 6012095b-en Infrared images are for illustration purposes and may not have been taken by the models shown. [12] L.-W. Zhou, B.-X. Zhu, and Q.-M. Luo. High step-up


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The Speed of the Energy Transition... - Gradual or Rapid Change? Will the global energy transition from fossil fuels to sustainable energy be gradual or rapid? This vital issue for the 2020s has profound implications for governments, energy producers, technology providers as well as industrial and private consumers. But, more importantly, the difference between a gradual and rapid transition will determine the climate future of humanity.

A gradual transition will mean that the goals of the Paris Agreement will be badly missed. A quick change will give humanity a chance to meet the purposes of the Paris Agreement and keep the temperature well below 2 degrees Celsius. Intending to both inform and spark further debate, this White Paper compares the two transition scenarios for our energy future, setting out two different narratives. The Gradual narrative is that the energy world of tomorrow will look roughly the same as that of today – implying that the global energy system has inertia incompatible with the Paris Agreement. The Rapid narrative is that current and new clean energy technologies are rapidly supplying all the growth in energy demand. Together with new policies, it will then reshape markets, business models and patterns of consumption leading to a peak in fossil fuel demand in the course of the 2020s.

BY | CHRISTINA LAMPE-ONNERUD, CO-CHAIR OF THE GLOBAL FUTURE Whether the world will follow a path of a COUNCIL ON ENERGY gradual or rapid transition will also make a JULES KORTENHORST CO-CHAIR OF THE GLOBAL FUTURE COUNCIL ON ENERGY 26 | wattnow | January 2020

significant difference to business across the energy spectrum. The rapid transition will bring new opportunities, but they need to adapt to faster change will be higher.

While the global energy system and the factors that impact it are more complex than any scenario or narrative can capture, this paper builds on different existing situations. It summarises the main ways in which they differ. It also highlights what to look for over the next decade to see which narrative plays out. The Global Future Council on Energy 2018-2020 strives to inform the debate and decisions for the near- and long-term energy future. While acknowledging lead authors Kingsmill Bond, New Energy Strategist, Carbon Tracker Initiative; Angus McCrone, Chief Editor, BloombergNEF; and Jules Kortenhorst, Chief Executive Officer, Rocky Mountain Institute, this White Paper includes significant input and insights from our Council (see the list of members at the end of the paper). The findings, interpretations and conclusions expressed herein are the results of a collaborative process facilitated by the World Economic Forum. Still, they do not necessarily represent the views of the Forum, nor the entirety of its Members, Partners or other stakeholders, nor the individual Global Future Council members listed as contributors, or their organisations.


EXECUTIVE SUMMARY The great energy debate. The energy industry is complex, and understanding the major trends changing the industry can be challenging. Investors, policy-makers, business people and other interested stakeholders require precise information about the evolution of the energy system to inform present decisions, which can have long-lasting effects. This White Paper provides a framework for navigating the mosaic of often conflicting narratives for how the energy system is evolving. The two very different narratives about the energy transition are Gradual and Rapid. This paper summarises the ways they differ and what to look for over the next decade to see which narrative is playing out. The Gradual narrative is that the energy world of tomorrow will look roughly the same as that of today. Gradual scenarios

extrapolate current patterns of policy, industry, consumption and investment, thus supporting planned carbon-intensive investment decisions and implying that the global energy system has inertia incompatible with the Paris Agreement. The Rapid narrative is that new energy technologies are rapidly supplying all the growth in energy demand, leading to peak fossil fuel demand in the course of the 2020s. Rapid scenarios suggest that current technologies and new policies will reshape markets, business models and patterns of consumption, challenging planned carbonintensive investment and leading to a lowcarbon global economy while creating considerable economic and social benefits. The narrative can become self-fulfilling. Energy systems have considerable inertia. If investors and policy-makers believe

that future energy demand and supply structures will be broadly the same as today, they will invest accordingly, helping to lock in the current system. If they believe that change is likely, they will invest in and legislate for new opportunities, speeding up the transition. The road to Paris. Gradual scenarios recognise with regret that carbon emissions will continue to rise, making compliance with the Paris Agreement ever more challenging to achieve. Rapid situations provide a framework under which global emissions can reach the goals of the Paris Agreement. Implications for the fossil fuel sectors. Gradual scenarios imply that peak fossil fuel demand is at least a generation away. Growing economies and populations will drive continued growth in demand for wattnow | January 2020 | 27


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The speed of Energy Transition continues from page 27 natural gas, oil and, to a lesser extent, coal and that the impact of the transition on these sectors will be muted with a gradual shift towards natural gas within the fossil fuel mix. Rapid scenarios imply that the demand for fossil fuels will peak in the 2020s and the same technology, policy, consumer and financial pressures that are being felt across the energy system at present will affect all fossil fuel sectors. And as technology improves, the fungibility between fossil fuels and renewables will further increase. The implications for the world’s fossil fuel sectors are significant: either they will thrive for years to come, or they are about to be disrupted and need radical change. What determines the difference. Four main features distinguish the two narratives: what matters, technology growth, policy and emerging market energy pathways. Views on these issues largely determine conclusions on where the energy markets are heading. 1. What matters – stock or flow. Gradual advocates and scenarios focus on total demand (stock) and argue that new energy technologies are relatively small and will take decades to overtake fossil fuels. Rapid advocates focus on change (flow) and say that new energy technologies will soon make up all the growth in energy supply. 2. Technology growth – linear or exponential. Gradual advocates argue that new energy technologies are expensive and face insoluble economic or technical impediments to increase, meaning that growth rates will only be linear. Rapid advocates say that solar and wind are already cheaper than fossil fuels for the generation of electricity. Electric 28 | wattnow | January 2020

vehicles (EVs) are about to challenge internal combustion engines (ICEs) on price, that the barriers to growth are soluble for the foreseeable future, and that these disruptive new energy technologies will continue to enjoy exponential growth. They anticipate the rise of new technologies, such as green hydrogen, to lead to further waves of change. 3. Policy – static or dynamic. Gradual advocates argue that it is necessary only to model policies that are certain to happen, that the forces of inertia are mighty and that policy-makers will remain cautious and slow-moving. Rapid advocates argue that the effects for change are considerably higher than those for inactivity and that technology opens up the opportunity for policymakers and regulators to design markets to better provide for all consumers’ needs. As the necessity for action becomes clear, there will be an Inevitable Policy Response.1 Modelling only the existing policy environment understates trends in policy-making. 4. Emerging market energy pathways – copy or leapfrog. Gradual advocates argue that the emerging markets (including China and India) will broadly follow the path taken by developed markets and use more fossil fuels as they get more productive and energy demand rises. Recent years’ investments in infrastructure, such as coal-fired plants, are seen to lock in consumption for years to come and increase the costs of transition, thereby slowing down its pace. Rapid advocates argue that the emerging markets will enjoy an energy leapfrog to new energy technologies and significantly less energy-intensive forms of economic development while

providing critical improvements in the quality of life. Is the energy transition just about solar and wind? Gradual advocates argue that solar and wind are too small to drive an energy transition. Rapid advocates argue that technology disruption started with solar and wind, has since spread to renewable integration technologies, is now moving into transport, and will shift into other areas of energy. As in any transition, the low-hanging fruit of change is plucked first, leaving the more problematic areas for later. How important are different fossil fuels? Gradual advocates note that coal, oil and natural gas and every fossil fuel sector in every country are different, and highlight the areas that appear to have few renewable energy alternatives. Rapid advocates argue that the energy transition will drive peaks in one fossil fuel sector after another. First coal, then oil, then gas will be impacted, in one country after another, in a pattern whose shape and trajectory will become increasingly familiar. What is the role of finance in the energy transition? Gradual advocates argue that the capital invested in the fossil fuel sectors, and the market need for fossil fuels, are so considerable that investors in aggregate will not speed up the transition. They will instead be a neutral force investing across the energy spectrum where they see the best opportunities for returns on capital. Rapid advocates argue that the financial sector as a whole will act to increase the speed of change as it searches for new growth opportunities, becomes more environmentally sustainable and restricts the flows of capital to declining industries.


What about countries that resist the energy transition? Gradual advocates note that many fossil fuel exporters and the current US administration are resistant to an energy transition, and large emerging economies like China and India will continue to fuel demand growth for all energy sources. Rapid advocates note that four out of five people live in countries that import fossil fuels, meaning that they would stand to benefit from a transition to local renewable energy sources. In particular, China and India are the largest and third-largest fossil fuel importers and are strongly committed to a change. Can technology solve everything? While technology is increasingly devising costeffective solutions that will drive an energy transition, the forces of inertia are mighty. Therefore, policy-makers will need to play an active role in the goals of the Paris Agreement to be achieved in time. Don’t shoot the messenger. In an increasingly fraught world, it is essential to note that some organisations whose data is referred to in this paper are providers of scenarios, not necessarily advocates of one narrative or the other. Recent developments. Gradual advocates point to a rapidly rising energy demand, the roll-back of environmental protection in the US and the fact that renewable energy capacity growth in 2018 was similar to that in 2017. Rapid advocates point to the continued and unexpected fall in renewable costs, the continued S curves of new energy technology growth, and the rising pressure from financial markets and society for policy-makers to take more aggressive action. They note that disruption is already happening in a series of energy

and related sectors, from coal to electricity, turbines to cars. What to watch out for. The key issues to watch over the next decade have been laid out to see which narrative will prevail. In technology, the focus is on the cost and growth rates of the key disruptive technologies – solar, wind, batteries, EVs and green hydrogen. In policy, the focus is on whether politicians implement more rigorous actions to make fossil fuel users pay for their greenhouse gas externalities. In the emerging markets, the question is whether China and India will be able to continue to implement new clean energy and energy efficiency technologies at scale and whether South-East Asia and Africa will follow the path they are setting. Signposts. A series of signposts are presented. Pass these, and the Rapid narrative is on track. Fail to pass them, and the Gradual narrative is playing out. Three targets have been set for 2030: solar electricity at $20-30 per megawatt hour (MWh); advanced lithium-ion batteries at $50-100 per kilowatt hour (kWh); and carbon taxes implemented on around half of emissions at $20 per tonne, with three peaks to take place in the 2020s in the event of Rapid transition: peak demand for new ICE cars; peak demand for fossil fuels in electricity; and peak demand for all fossil fuels.

ENERGY TRANSITION NARRATIVES There are as many scenarios for the future of energy as there are forecasters, and it is of course not possible to know in advance which one is optimal. Paul Warde, the Cambridge energy historian, notes2 that most long-term energy projections have

been consistently wrong,3 that projections have tended to have a significant bias in favour of the person asking the question, and that most forecasts have overestimated future demand. Nevertheless, scenarios can be grouped into two primary narratives about the speed of the energy transition:4 a gradual transition (Gradual); and a rapid transition (Rapid). In discussions about the future of energy, advocates of both sides will tend to select those scenarios and models that fit with their narrative. It is important to note that some organizations do not publish forecasts but scenarios; these scenarios can be used by advocates on both sides of the debate. It is the narrative that sets expectations for the future, and this in itself is important because it determines how governments, companies and individuals allocate their resources.5 Gradual Gradual scenarios include those from Exxon,6 the Organization of the Petroleum Exporting Countries (OPEC),7 the World Energy Council8 and the Energy Information Administration,9 as well as the IEA New Policies Scenario (NPS),10 and the BP Evolving Transition Scenario (ETS).11 These scenarios imply that the energy world of tomorrow will look roughly the same as that of today. Fossil fuel demand will rise for the foreseeable future and, when it does start to decline, the decline will be gradual. Regrettably, this means that the goals of the Paris Agreement will become increasingly unachievable. Figure 1 shows an example from BP’s ETS. wattnow | January 2020 | 29


increasingly unachievable. Figure 1 shows an example from BP’s ETS.

of both sides will tend to select those scenarios and models that fit with their narrative. It is important to note Fthat EATsome UR E organizations do not publish forecasts but scenarios; these scenarios can be used by advocates on both sides of the debate.

The speed of Energy Transition

It is the narrative that sets expectations for the future, and this in itself is important because it determines how governments, companies andpage individuals allocate their resources.5 continues from 29

Figure 1: Energy supply (EJ), Gradual narrative, 2015-2040

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Rapid scenarios include normative scenarios,12 such as the IEA 300 Sustainable Development Scenario (SDS),13 the International Renewable Energy Agency (IRENA) REMap,14 200 the Intergovernmental Panel on Climate Change (IPCC) less than two-degree models,15 the BP Rapid Transition Scenario,16 100 the International Institute for Applied Systems Analysis (IIASA) Low Energy Demand Scenario17 and the Shell Sky Scenario,18 0 primary scenarios of organizations such as as well as the 20 2015 2017(BloombergNEF), 2020 19 DNV GL, 2025 Bloomberg New Energy Finance 21 22 McKinsey and the Energy Transitions Commission.

As a rule, these scenarios seek to achieve the goals of the Paris Agreement,23 and imply that the energy sector is about to be disrupted. They forecast rapid growth in solar and wind electricity, the gradual electrification of transport, industry and heat, greater efficiency, policy action to tax fossil fuel users for their environmental externalities, and the development of new technologies like green hydrogen. They imply that demand for fossil fuels will soon peak and then enter a long period of decline. Figure 2 shows the example of the DNV GL energy forecast.

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Figure 2: Energy supply (EJ), Rapid narrative, 2016-2050

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Rapid Rapid scenarios include normative scenarios,12 such as the IEA Sustainable Development Scenario (SDS),13 the International Renewable Energy Agency (IRENA) REMap,14 the Intergovernmental Panel on Climate Change (IPCC) less than two-degree models,15 the BP Rapid Transition Scenario,16 the International Institute for Applied Systems Analysis (IIASA) Low Energy Demand Scenario17 and the Shell Sky Scenario,18 as well as the primary scenarios of organizations such as Bloomberg New Energy Finance (BloombergNEF),19 DNV GL,20 McKinsey21 and the Energy Transitions Commission.22 As a rule, these scenarios seek to achieve the goals of the Paris Agreement,23 and imply that the energy sector is about to be disrupted. They forecast rapid growth in solar and wind electricity, the gradual electrification of transport, industry and heat, higher efficiency, policy action to tax fossil fuel users for their environmental externalities, and the development of new technologies like green hydrogen. They imply that demand for fossil fuels will soon peak and then enter a long period of decline. Figure 2 shows an example of the DNV GL energy forecast. It is important to emphasize that the Rapid path is the more difficult of the two. It will require a significant coordinated effort of policy, technology development and behaviour from all sections of society to drive change across the whole of the economy on the timescale needed to achieve the goals of the Paris Agreement.

DIFFERENCES BETWEEN THE TWO NARRATIVES The differences between the two narratives can be summarised concerning four key features: what matters, technology growth, policy and emerging market energy pathways. Of course, many other important drivers of the energy transition exist, such as efficiency or digitization. Still, these tend to be a feature of both narratives and are not the focus of this paper. The energy sector is highly complex, and a large number of variables in any scenario makes them hard to compare; as a result, examples seek to illustrate rather than to be comprehensive in this analysis. Not all scenarios fit neatly into the divisions describe below, and each needs to be judged on its own merits. Moreover, some situations will, of course, be more extreme than others. Nevertheless, the chasm between the two narratives is sufficiently wide to merit some analysis. What Matters At the start of this review, the assumption was that it would be possible to have a common starting point based on the facts for 2018. However, the facts can be interpreted very differently, depending on the narrative. The focus is on four main points of difference: what matters for the energy transition; the importance of electricity; the importance of solar and wind; and the importance of distinguishing between fossil fuels. Total Supply or Change in Supply? What is the issue? Should analysts focus on total supply or change in supply? For example, the total supply of a product may be 100 units, projected to fall to 90 units in a decade.

The analyst looking at total supply will argue that supply is still high, at 90 units. The analyst looking at change will say that supply has peaked and fallen by ten units. Total energy supply growth is usually 1-2% per annum, so the difference between aggregate supply and the change in supply is significant – nearly two orders of magnitude. In 2017, for example, the total primary energy supply was 13,475 million tonnes of oil equivalent (Mtoe), and the change in supply was 246 Mtoe, according to BP.24 Gradual approach The Gradual approach focuses on total supply and notes that, even with relatively high renewable growth, total supply for fossil fuels will remain high with a gradual shift towards natural gas within the mix of fossil fuels as a cleaner option to coal.25 The energy historian Vaclav Smil comments that it will take many decades for renewable energy to overtake fossil fuels in terms of market share, and he argues that the move away from fossil fuels will be a protracted affair.26 In Figure 3 from BP showing total energy supply over the last decade, it is tough to see any impact from solar and wind, for example. Rapid approach The Rapid approach does not deny that fossil fuels will continue to play a significant role in energy markets for decades to come. The difference lies in the fact that the Rapid approach focuses on the change in supply and notes that the effects of evolution are felt by companies in these sectors as growth in their core markets turns to decline,27 and are priced by financial markets even before supply peaks. Moreover, once a tipping point is reached, financial markets wattnow | January 2020 | 31


be possible to have a common starting point based on the facts for 2018. However, the facts can be interpreted F EAT UR E very differently depending on the narrative. The focus is on four main points of difference: what matters for the energy transition; the importance of electricity; the importance of solar and wind; and the importance of distinguishing between the fossil fuels.

that, even with relatively high renewable growth, total supply for fossil fuels will remain high with a gradual shift towards natural gas within the mix of fossil fuels as a cleaner option to coal.25 The energy historian Vaclav Smil comments that it will take many decades for renewable energy to overtake fossil fuels in terms of market share, and he argues that the move away from fossil fuels will be a protracted affair.26 In Figure 3 from BP showing total energy supply over the last decade, it is very hard to see any impact from solar and wind, for example.

The speed of Energy Transition continues from page 31

Figure 3: Total energy supply (Mtoe), 2010-2018

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Source: Authors, based on data from BP, BP Statistical Review of World Energy 2019, 68th edition.

will tend to speed up the pace of change by constraining capital to declining industries and reallocating to those that are growing. 10 The Speed of theitEnergy Transition

Chinese coal demand peaked in 2013 and has fallen by 3%, and Japanese gas demand peaked in 2013 and is since down by 6%.

The four most well-known examples of this process in recent years are electricity in Europe, coal, fossil fuel turbines and the car sector. In each case, incumbents were disrupted, and stock prices impacted at around the time that demand for their product peaked. Advocates, therefore, focus on how long it will take for new energy technologies to supply all the growth.

Taking the same data as that set out above, but for the change in energy supply, a very different picture emerges (Figure 4). Nonfossil sources made up nearly one-third of the growth in energy supply in 2018, and the amount of energy they produce continues to snowball. Energy demand growth in 2018 was unusually high; if it had been the same level as in 2015, for example, then non-fossil sources would already be supplying all the growth in energy demand.

If total supply growth is 246 Mtoe and non-fossil supply growth is 90 Mtoe, there will be many countries and sectors where fossil fuel supply has already peaked and is falling. To take three examples from the BP statistical review: European oil demand peaked in 2007 and has since fallen by 14%; 32 | wattnow | January 2020

How Important is Electricity? What is the issue? Final energy consumption includes both electricity (a high-quality energy carrier) and other energy sources, such as coal, oil and gas. However, electricity can be used with minimal losses for energy services

(like turning on a light). At the same time, fossil fuels lose about two-thirds of their energy in thermodynamic losses when they are converted into most forms of useful energy. The question then is how to compare the two.28 In 2017, electricity was 19% of total final energy consumption and 38% of total primary energy demand, according to the IEA.29 Because of the continued electrification of a range of sectors, electricity was 56% of the increase in total primary energy demand. The question is: which of these numbers is more relevant? Gradual approach The Gradual approach compares electricity with fossil fuels as if they were equivalent and notes that a profound restructuring of the entire energy system is needed. Advocates argue that electricity is a small share of total final consumption, so growth


a tipping point is reached, financial markets will tend to speed up the pace of change by constraining capital to declining industries and reallocating it to those that are growing. The four most well-known examples of this process in recent years are electricity in Europe, coal, fossil fuel turbines and the car sector. In each case, incumbents were disrupted and stock prices impacted at around the time that demand for their product peaked. Advocates therefore focus on how long it will take for new energy technologies to supply all the growth.

Taking exactly the same data as that set out above, but for the change in energy supply, a very different picture emerges (Figure 4). Non-fossil sources made up nearly one-third of the growth in energy supply in 2018 and the amount of energy they produce continues to grow rapidly. Energy demand growth in 2018 was unusually high; if it had been the same level as in 2015 for example, then non-fossil sources would already be supplying all the growth in energy demand.

Figure 4: Change in energy supply (Mtoe), 2010-2018

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2013

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Source: Authors, based data BP, BP Statistical Worldfossil Energy 68th edition. in that area is likely to be on offset byfrom continued be higherReview than of rising fuel2019, demand Rapid approach fossil demand growth in other areas. in all the other sectors (one-third of the The Rapid approach seeks to adjust for growth in demand). In 2017, electricity was the19% gap ofbytotal multiplying solar and wind 3.1.2 How important is electricity? final energy consumption and 38% energywhen demand, Rapid approach byofa total factorprimary of 2-3 times converting 29 What is the issue? according to the IEA. Because of the continued The Rapid approach seeks to adjust for the How Important are Solar and Wind? them into primary energy equivalents. electrification of a range sectors,BPelectricity thermodynamic losses of fossil fuels by What is the issue? Forofexample, increaseswas solar56% and of wind Final energy consumption includes both electricity (a highthe increase in total primary energy demand. The question looking at total primary energy demand. The issue is how to count solar and wind electricity by 2.6 when turning them into quality energy carrier) and other energy sources, such as is: which of these numbers is more relevant? From electricity used electricity (a high- quality energy carrier) Mtoe, and calculates that the share of solar coal, oilthat andperspective, gas. However, electricity can be used with 30 38% of all primary energy services in 2017. (like Theyturning as a share global energy supply.approach Because and wind power in global primary energy minimal losses for energy on aof light), Gradual looked at the change in demand, where of thermodynamic losses, this is a real issue supply is more than twice as large as the while fossil fuels lose about two-thirds of their energy in thermodynamic losses into The Gradual approach compares electricity was 56% in 2017 when and is they likelyare to converted – the introduction of 100 MWh of solar will IEA estimates,electricity at 2.6%.32 with fossil most forms of useful energy. The then isprimary how to energyfuels as ifofthey were equivalent and notes that a deep increase to two-thirds as a result of question rising replace supply 200-300 compare the two.28 restructuring of the entire energy system is needed. electrification of end-use sectors, such as MWh of coal. The gap between the two does not appear Advocates argue that electricity is a small share of total final transport and heat. to be veryarea material until theoffset argument consumption, so growth in that is likely to be by Gradual approach shiftsgrowth to thein change in supply. BP data continued fossil demand other areas. Electricity, therefore, assumes a much The Gradual approach counts solar show that solar and wind made up 27% more important role in the discussion. And electricity in the same way it counts coal, of the difference in total energy supply in The Speed of the Energy Transition 11 a transition of the electricity sector alone without any adjustment. As a result, the 2017. If current solar and wind growth will be sufficient to drive peak demand for new energy technologies of solar and wind rates of 15-20% are maintained, Carbon fossil fuels (but not the Paris Agreement). appear relatively small. For example, the Tracker calculates that they will supply all The math is not complicated. Falling fossil IEA implies that solar and wind electricity incremental energy (not just electricity) fuel demand in electricity generation (two- was just over 1% of global primary energy in the early 2020s.33 This makes them thirds of the growth in demand) needs to supply in 2017.31 extremely material as agents of change. wattnow | January 2020 | 33


F EAT UR E

The speed of Energy Transition continues from page 33 Differences Between Fossil Fuels Rapid approach Gradual approach What is the issue? The Rapid approach argues that it is Gradual advocates argue that the forces of The three primary fossil fuels, of course, are necessary to take a more straightforward disruption are small and therefore unlikely coal, oil and gas. Each is used in different modelling approach at times of disruption. to have much of an impact. applications in each of the world’s countries, The technology and policy pressures that in a bewildering amount of complexity. The are being felt across the complex concede that changes Theenergy Gradual narrativeThey focuses on the point where are non-taking Rapid approach fossils half of all supply. This, even under question is whether it makes any sense to at present will affect all fossilmake fuels. up And place in the electricity sector, butthe noteShell that Sky the Scenario, is not until 2050.isFurthermore, advocates Rapid advocates note non-fossils 51% of the talk about fossil fuels as athat whole or look atprovided as technology improves, fungibility electricity only 19% of total final energy and 28% of fuels the is also pointincreasing out that even 2100, the demand for fossil still growth in fuel global electricity supply in 201834between each fossil in each country separately. fossil (for inconsumption. Meanwhile, they fuels argueisthat growth in global energy supply, and that solar and wind are quite high. instance cheap batteries make solar more solar and wind are only 1% of total energy still growing very rapidly. Electricity is 38% of primary energy Gradual fungible with oil to power vehicles scale). focuses supply and carswhere are only 0.5% of the The Rapidatnarrative onelectric the point non-fossils demandapproach and will be two-thirds of the growth in primary The Gradual approach is built upon highly Therefore, the peak in coal demand is likely global car fleet. energy demand as the world continues to electrify. As a make up all incremental supply. This is in 2025, which is a complex models and seeks to taking model place each intothe be electricity the first of these peaks, to be followed result, the disruption that is generation earlier, and when non-fossils are just a quarter sector will and be sufficient peak in demand all demandof total energyby supply. Advocates that theof remaining end sector each fuel to in drive each acountry. by a peakfor in oil and eventually a They focus onargue the difficulty providing fossil fuels because declining demand in fossil fuels for amount of demand for fossil fuels in 2100 is both hard The advantage of this method is that it peak in gas demand. And as companies and renewable energy solutions in sectorstolike forecast with any certainty and is part of the “endgame�, the electricity generation will outweigh rising demand for fossil enables forecasters to understand the financial investors see the pattern of these heat and petrochemicals and argue that fuels elsewhere in the energy complex. final areas of fossil fuel demand that may survive and will impact of detailed changes. peaks, they will invest need accordingly, which developments electricity necessary to be replaced, but which areinnot enough are to sustain will in turn speed up the transition. but not sufficient. They note that in 2017, the industry at its current size. The gap fossil fuels provided 81% of primary energy Moreover, the argument is often made that It is disruption instructive striking to consider the gapsector between the two supply, and coal provided 38% of electricity, the the energy The Starting Point of the Two Narratives narratives with regard to the importance and timing of the applies much more to coal than it does to These four issues mean that there are about the same as 30 years ago. It will take moment when the transition felt. To illustrate this, differences Figure oil and gas. Therefore, a coalistransition significant in the way the energy decades for renewable energy sources to 5 shows energy supply in the Shell Sky Scenario split into rather than an energy transition affecting environment is perceived today, before the become dominant in energy supply. fossil fuels and non-fossils. all fossil fuel sectors is being witnessed. discussion on the future even starts.

Figure 5: Global energy demand (EJ), 2000-2080

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Rapid approach Rapid advocates note that non-fossils provided 51% of the growth in global electricity supply in 201834 and 28% of the increase in global energy supply and that solar and wind are still increasing. Electricity is 38% of primary energy demand and will be two-thirds of the growth in primary energy demand as the world continues to electrify.

will need to be replaced, but which are not enough to sustain the industry at its current size.

As a result, the disruption in the electricity sector will be sufficient to drive a peak in demand for all fossil fuels because declining demand in fossil fuels for electricity generation will outweigh rising demand for fossil fuels elsewhere in the energy complex.

Cost of variable renewables in electricity The reason why variable renewable costs are so significant is that prices are the agents of disruption. In the discussion below, the focus is on the cost of electricity from solar. However, the story is similar for other disruptive technologies, such as wind, batteries and smart demand-side technologies.

The gap We have to consider the difference between the importance and timing of the moment when the transition is felt. To illustrate this, Figure 5 shows the energy supply in the Shell Sky Scenario split into fossil fuels and non-fossils. The Gradual narrative focuses on the point where non-fossils make up half of all supply. This, even under the Shell Sky Scenario, is not until 2050. Furthermore, advocates point out that even in 2100, the demand for fossil fuels is still quite high. The Rapid narrative focuses on the point where non-fossils make up all incremental supply. This is in 2025, which is a generation earlier, and when non-fossils are just a quarter of total energy supply. Advocates argue that the remaining amount of demand for fossil fuels in 2100 is hard to forecast with any certainty. The final areas of fossil fuel demand that may survive and

Technology Growth Technology differences between the two narratives include the cost of existing new energy technologies, expectations for future technologies, the impediments to change and expected future growth rates.

What is the issue? The question relates to what the costs of variable renewables are today and in the future. It might seem strange that there is dispute even over facts that are known, but this is indeed the case. Gradual approach The Gradual approach tends to be relatively conservative.35 It takes peer-reviewed data (which is by definition, backwards-looking) and is cautious about future changes in costs. For example, the IEA NPS argues that the Levelized cost of energy (LCOE) of solar in 2017 in the United States was $105 per MWh,36 and that it would fall to $50 per MWh by 2040. Furthermore, the NPS argues that there are additional expenses for the deployment of solar (because of connection costs and intermittency costs), known as system costs, which make the real

cost even higher. The total US cost of solar with system costs is calculated as $105 per MWh in 2017 (the same as without system costs) and $55 per MWh in 2040 (so 10% higher than without system costs). Rapid approach The Rapid approach tends to take forwardlooking costs, to use actual projects37 and to be more optimistic about future cost falls. It is accepted that solar electricity costs have been falling at over 15% a year since 2009 and that solar modules have enjoyed a learning rate of 28% for every doubling in capacity.38 Advocates argue that it makes sense to look forward because of the speed of change and that costs are likely to continue to fall in line with the learning rate. They argue that the values used by the Gradual approach are demonstrably incorrect and that the Gradual approach fails to incorporate the cost of externalities. Moreover, they note that many renewable technologies have enjoyed rapid cost falls thanks to learning by doing, the scale effect and the virtuous learning circle. As costs have fallen, consumers have embraced the new technologies and governments have encouraged them, leading to lower costs and a new round of adoption. Hence, they argue that the growth should be modelled in a dynamic manner, not a static one.39 The upshot is that Rapid models have very different costs even for today. For example, BloombergNEF argues that the 2018 LCOE of solar in the United States was $42-65 per MWh, and it expects this to fall to $20-25 per MWh by 2040.40 wattnow | January 2020 | 35


F EAT UR E

2040. Furthermore, the NPS argues that there are additional expenses for the deployment of solar (because of connection costs and intermittency costs), known as system costs, which make the real cost even higher. The total US cost of solar with system costs is calculated as $105 per MWh in 2017 (the from samepage as without system costs) and $55 per MWh continues 35 in 2040 (so 10% higher than without system costs).

leading to lower costs and a new round of adoption. Hence, they argue that the growth should be modelled in a dynamic manner not a static one.39

The speed of Energy Transition

The upshot is that Rapid models have very different costs even for today. For example, BloombergNEF argues that the 2018 LCOE of solar in the United States was $42-65 per MWh, and it expects this to fall to $20-25 per MWh IEA40NPS and costs to fall, so these technologies are ready Rapid Rapidadvocates approachnote that system costs vary US LCOE, according to bythe 2040. with the level of penetration of variable BloombergNEF. The forecast IEA NPS by the time they are required. The question The Rapid and approach tends toare take forward-looking costs, Rapid the advocates that system costs vary the to 2040 solar coststoare almost same asnote renewables argue that they unlikely is whether it is feasible and with reasonable use actual projects37 and to be more optimistic about future level of penetration of variable renewables and argue that to impose a significant burden on the cost the real average BloombergNEF 2018 cost forecast technology evolution. they are unlikely to impose a major burden on the cost cost falls. It is accepted that solar electricity costs have been (Figure 6).modules structure for the foreseeable future. Even as penetration structure for the foreseeable future. Even falling at over 15% a year since 2009, and that solar as penetration technologies suchforasevery doubling in Gradual approachand demand rises, technologies such as storage have enjoyed arises, learning rate of 28% 38 Technologies storage and Advocates demand response are likely to New Gradual approach is relatively argue that it therefore makes sense response are likely toThe make higher levels of penetration capacity. to lookhigher forward because of the speed of change, cheaper. It is notable, for example, solar plus storage What isand the that issue? make levels of penetration cheaper. conservative on that the development of new costs are likely to continue to fall in line with the learning rate. projects are already starting to compete with fossil fuels It is notable, for example, that solar plus The Energy Transitions Commission points technologies, preferring to focus on what 41 They argue that the used by the to Gradual approach arenew energy in the United States.is out that existing technologies storage projects are costs already starting known rather than what may happen.43 demonstrably incorrect, and that the Gradual approach fails compete with fossil fuels in the United will be able to accomplish much of the Advocates point out that the evolution The gap to incorporate the cost of externalities. energy transition. However, improved of technologies is a complex and slowStates.41 technologies will be required replacethemoving process, requiring long nicely lead times The gap to between two approaches is captured by Moreover, they note that a number of renewable The gap fossil fuels in hard-to-solve sectors, such as and significant amounts of capital. The technologies have enjoyed rapid cost falls thanks to learning the actual and forecast US LCOE, according to the IEA NPS and BloombergNEF. forecastisIEAthat NPSthese 2040hard-to-solve solar costs by doing, the scale the virtuous learning circle. airlines, The gap between theeffect two and approaches is petrochemicals, winter heating or The implication 42 almosttoday the same the not actual average BloombergNEF As costsnicely have fallen, have embraced new captured by the consumers actual and forecast cement.the Investment isareneeded for as areas merely remain insoluble but 2018 cost (Figure 6). technologies and governments have encouraged them, Figure 6: US solar (LCOE, US$/MWh) $

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IEA 2040

BNEF 2040

Sources:| Authors, based on data from International Energy Agency, World Energy Outlook 2018, New Policies Scenario, and BloombergNEF, New Energy 36 | wattnow January 2020 Outlook 2018.


will also grow. For example, most Gradual scenarios see rising demand for trucks and petrochemicals as the primary driver of rising oil demand over the next 20 years. Rapid approach Advocates note that energy technology developments over the last decade have already been rapid as technologies progressed on learning curves. In 2009, lithium-ion batteries cost over $1,000 per kWh and solar cost over $350 per MWh; by 2019, the cost of lithium-ion batteries had fallen to $160 per kWh and solar to $50 per MWh. Change has indeed been possible. The advocates use this to make three principal arguments: – Current disruptive technologies, such as solar and batteries, continue on their learning curves. This will enable them to penetrate ever more sectors. – Technologies will continue to evolve to allow deeper penetration of existing disruptive technologies. For example, variable renewable energy will be able to increase its share of the total electricity supply. Or electricity will be able to increase its share in the transport, heat and industry sectors. The speed with which companies are developing etrucks, and the many new solutions being put forward to reduce the demand for plastics are examples. – New technologies will be designed to address the more intractable hard-tosolve sectors, such as petrochemicals or airlines. A series of solutions were put forward in the Energy Transitions Commission’s Mission Possible publication. Meanwhile, the IEA notes that cheap solar can be used to create green hydrogen through electrolysis and that hydrogen can substitute for gas or oil in many areas of the energy system.44

This is not to say that a shift will be easy. Success will be the result of a combination of sound policies and technologies following learning curves. Not all renewable technologies have succeeded, and not all promising technologies will achieve.

carbon-free energy. However, they make two observations: most countries are well below the feasibility ceiling, and it keeps rising as the result of the continued improvements in technology and emerging business models.

Impediments To Growth What is the issue? The impediments to the implementation of the new energy technologies are the issue: at what point will technologies be unable to grow any further because of some insurmountable technological, economic or physical barrier? Social and political boundaries are dealt with in the next section.45

This can be illustrated concerning wind and solar. In 2018, solar and wind provided 7% of the supply of electricity globally, ranging from many countries with minimal amounts (in 27% of global electricity supply, solar and wind country penetration is under 5% and, in 94% of the total, country penetration is under 15%) to several countries with more than 25% solar and wind, and some regions with more than 50%.

Gradual approach Gradual scenarios tend to be relatively cautious regarding the difficulty of implementing new energy technologies. They have a wide range of concerns, including the lack of space for renewable energy technologies to be deployed; the challenges inherent in reaching 100% carbon-free energy; the problems of setting up EV infrastructure; or the lack of supply of various minerals, from cobalt to nickel to rare minerals. Moreover, in many cases, the widespread adoption of new technologies proves prohibitively challenging to model with existing modelling practices. Current models are built to balance supply and demand in fossil-fuel-based markets, which are fundamentally distinct from emerging renewables and high asset-utilization service-based markets. Rapid approach Rapid models do not deny that impediments exist in most countries to implement 100%

Then, the feasibility ceiling is above 25%, and the IEA notes that there are phases in the process.46 Many examples of the rising feasibility ceiling exist. Innovations in electricity distribution systems have dramatically increased the feasible levels for the implementation of solar and wind, from under 5% some 20 years ago to over 50% today, and these systems continue to evolve.47 Outside the electricity sector, the picture differs, but the approach assumes that solutions will be found. In light transport, for example, there seemed to be many impediments to the growth of the EV. But as battery costs fall and expertise increases, range anxiety is diminishing as an issue. Meanwhile, it has become more likely that EV infrastructure will be rolled out as EV sales rise; some companies are now offering free home charger installation in return for access to the battery as a storage device. wattnow | January 2020 | 37


F EAT UR E

The speed of Energy Transition continues from page 37 Meanwhile, economic impediments reduce as costs fall. It is possible to build marginal abatement cost curves to calculate the cost per tonne of reducing carbon dioxide emissions. The Global Commission on the Economy and Climate argues that when the co-benefits of an energy transition are taken into account, two-thirds of greenhouse gas emissions (25 gigatonnes (Gt) per year) can be eliminated at zero cost by 2030.48 Without co-benefits, its analysis suggests that half the emissions can be reduced at zero cost. As a result, advocates argue that the technological and economic impediments to the growth of renewables can be solved for the foreseeable future. No change is easy, nothing can be accomplished without effort, but that does not mean it is unachievable.

The gap For each perspective, it is possible to show the ceiling of technological possibility graphed against today’s levels of penetration. Neither view argues that the ceiling has been hit today. The Gradual narrative explains that we will shortly bump up against it; the transition will peter out as the low-hanging fruits are plucked. The Rapid narrative argues that the ceiling is high above our heads and will continue to rise as the result of technological improvements. The argument is illustrated in Figure 7 about solar and wind as a share of electricity generation with an illustrative depiction of the ceiling. Still, it could apply to many other sectors as well.

The Growth Rate of Existing New Energy Technologies What is the issue? Different assumptions regarding costs, barriers to growth and technology evolution drive very different projections of the growth rate of renewables. Will the growth rate of new technologies be linear or exponential? Gradual approach Gradual models assume that the renewable energy growth rate is linear. An example is the projection of annual installations of solar capacity in the IEA NPS. In the 2018 forecast, for example, it is assumed that solar panel installations will remain at around 100 gigawatt (GW) per annum until 2040 (Figure 8).

Figure 7: Solar and wind as a share of electricity generation and the ceiling level, 2015-2050

Gradual ceiling

DNV GL

IEA NPS

Rapid ceiling

90%

74% in 2050

80% 70% 60% 50% 40% 30%

21% in 2040

20% 10% 0% 2015

2020

2025

2030

2035

2040

2045

2050

based on data from International Energy Agency, World Energy Outlook 2018, New Policies Scenario, and DNV GL, Energy Transition 38 |Sources: wattnow |Authors, January 2020 Outlook 2018; Carbon Tracker Initiative estimates for the “ceiling� level.


Professional Forum

An exciting time to be in engineering in South Africa.

What is the Professional Forum?

Speakers to look forward to:

South African engineers are sought after around the world, globally respected for their "can-do" attitude. Why then do we so frequently seek international assistance on South African projects? That question keeps us up at night. Join us at the Professional Forum, a platform for us to explore how South African professionals are bringing a "can do" attitude to solving industrial problems.

Herman Warren, Network Director, Africa, The Economist Roula Inglesi-Lotz, Professor of Economics, University of Pretoria Elizma van der Walt (Pr.Eng), Proconics

Who should attend? "Can do" engineering professionals. A variety of single and multidisciplinary projects will be discussed.

Who are affiliated members and why do they get special treatment? A strong engineering fraternity is at the heart of what we believe can help create a brighter future in South Africa. As a company, Proconics takes pride in being associated with affiliate organisations. As a result, we will sponsor 50% of the entry fee for any affiliated member who would like to attend the Professional Forum. Affiliate members viable for a discounted entry are: ECSA Registered Professionals SAIMC Members SAIMechE Members SAIEE Members SAICE Members PMI Members

Engineer. Procure. Construct. www.proconics.co.za

A word from our CEO "When I cast my mind back to why I decided to become a chemical engineer the overwhelming memory is one of excitement. I was going to get to build monuments, do projects, change the world. The reality is more exciting than I could have imagined. Can't wait to rub shoulders with other "can-do" engineers."

Melvin Jones EVENT DETAILS

PRICE

RSVP

WHEN: 30 JANUARY 2020

AFFILIATE MEMBERS: R500 - When you RSVP with your membership number

E-MAIL: zonia.rossouw@ proconics.co.za or

WHERE: The Lakes Hotel & Conference Center 1 Country St, Lakefield, Benoni, 1501

NON-AFFILIATE MEMBERS: R1000

A ticket will be issued with your unique entrance number

wattnow | January 2020 | 39


Growth F EAT URrate E of existing new energy technologies

Gradual approach

What is the issue?

Gradual models assume that the renewable energy growth rate is linear. An example is the projection of annual installations of solar capacity in the IEA NPS. In the 2018 forecast, for example, it is assumed that solar panel installations will remain at around 100 gigawatt (GW) per annum until 2040 (Figure 8).

The speed of Energy Transition

Different assumptions regarding costs, barriers to growth and technology evolution drive very different projections of the growthfrom rate page of renewables. Will the growth rate of new continues 38 technologies be linear or exponential? Figure 8: New solar capacity (GW), 2018-2040 120 100

solar

80 globally

60 Rapid approach

40

Rapid models assume that renewable supply continues to rise on exponential S curves of growth. In an S curve, the market share 20 of the new technology moves very rapidly from 5% to around 90%, before slowing down. This is a phenomenon that has been seen in technology diffusion many times in 0 the last century, from cars, radios and televisions to the mobile phone and internet in recent years. Advocates note 2018 that Gradual models failed to forecast the 2023 2028 rapid growth of solar and wind for many years, and that

it is necessary therefore to adopt a different approach.49 They point out that, even in 2018, the installation of solar panels (96 GW, according to BP) was much higher than the forecasts of standard Gradual models for 2018. DNV GL, for example, forecasts the rapid growth of solar, wind and EVs along S curves. Sector specialists, such as IDTechEx, have a similar perspective.50 This is illustrated in Figure 9 with the DNV GL forecast for the market share of EVs in Europe. 2033 2038

Source: Authors, based on data from International Energy Agency, World Economic Outlook 2018, New Policies Scenario.

Figure 9: Market share of electric vehicles in Europe, 2016-2050

The Speed of the Energy Transition

100% 90% 80% 70%

in Europe

60% 50% 40% 30% 20% 10% 0% 2016

2020

2025

2030

2035

Source:| Authors, based on data from DNV GL, Energy Transition Outlook 2018. 40 | wattnow January 2020

2040

2045

2050

17


Rapid approach Rapid models assume that renewable supply continues to rise on exponential S curves of growth. In an S curve, the market share of the new technology moves rapidly from 5% to around 90%, before slowing down. This is a phenomenon that has been seen in technology diffusion many times in the last century, from cars, radios and televisions to the mobile phone and internet in recent years. Advocates note that Gradual models failed to forecast the rapid growth of solar and wind for many years and that it is necessary, therefore, to adopt a different approach.49 They point out that, even in 2018, the installation of solar panels (96 GW, according to BP) was much higher than the forecasts of standard The gapmodels for 2018. Gradual

along S curves. Sector specialists, such as IDTechEx, have a similar perspective.50 This is illustrated in Figure 9 with the DNV GL forecast for the market share of EVs in Europe. The gap Different assumptions about the nature of growth lead to a massive difference between the two narratives. This is illustrated with the forecasts for electricity generation from solar photovoltaics (Figure 10). The IEA NPS forecast assumes slow linear growth, while the DNV GL forecast assumes exponential growth rates.

society. And here again, a significant gap exists between the two narratives in terms of what can be expected from the policy. Gradual models expect limited policy action, while Rapid models expect considerable policy action, encapsulated in the idea of an Inevitable Policy Response.51 The two perspectives concerning the global balance of forces are summarized, followed by the country balance of forces.

The Global Balance of Forces What is the issue? First, a look at the global balance of forces. Many forces impact policy-makers. These POLICY Developments in technology are only one include considerations on costs, jobs, health, part of the energy transition. For change to global warming, geopolitics, pressures happen rapidly, policies will need to better from civil society and the lobbying power Different assumptions about the nature of growth lead to a huge gap between the two narratives. This is illustrated with the incumbents andslow beneficiaries of the DNV GL,forfor example, forecastsfrom thesolar align the incentives(Figure of investors, businesses forecasts electricity generation photovoltaics 10). The IEA NPS of forecast assumes linear growth, fossil fuel system. rapid growth of solar, wind and EVs and individuals with the interests of while the DNV GL forecast assumes exponential growth rates. Figure 10: Solar electricity generation (PWh), 2015-2050

IEA NPS

DNV GL

30

26 PWh in 2050 25 20 15 10

3.8 PWh in 2040

5 0 2015

2020

2025

2030

2035

2040

2045

2050

Sources: Authors, based on data from International Energy Agency, World Energy Outlook 2018, New Policies Scenario, and DNV wattnow GL, Energy Transition | January 2020 | 41 Outlook 2018.


F EAT UR E

The speed of Energy Transition continues from page 41 The IEA and IRENA have shown that the capital cost of an energy transition is similar to the cost of maintaining the current fossil fuel system.52 Moreover, IRENA has been demonstrated that more jobs are required in a renewable system than a fossil fuel system.53 However, a shift from one energy source to another would reduce rents flowing to the owners of fossil fuel assets (estimated by the World Bank to be around 3% of global GDP)54 and could lead to stranded assets and communities if not handled sensitively. If these were the only considerations, then the power of inertia and lobbying would likely be able to maintain the status quo. However, many further considerations are starting to impact decision-making. – The cost of global warming, estimated by the Stern report55 at 5% of global GDP with significant tail risks from feedback loops, and by Burke, Davis and Diffenbaugh at 15-25% of global GDP56 – The dramatic human costs of heat stress, disease and migration that are hard to quantify in GDP terms – The impact on the health of outdoor air pollution (mainly from fossil fuels), estimated by the World Health Organization as killing 4.2 million people a year57 and likely to double by 206058 – The 1 million species at risk of extinction.59 When these are factored in, IRENA calculates that the benefits of an energy transition will outnumber the costs by 3-7 times.60 Gradual approach The Gradual approach argues that policies that have yet to be approved should not be forecast, and points to the repeal of the 42 | wattnow | January 2020

Clean Power Plan (CPP) in the United States.61 Moreover, the prospect of a rapid transition will create losers who want to maintain the status quo and feel relatively passionate about it. In certain countries, they can capture the government and use it to resist change. Advocates note that even after a decade of pronouncements about the need to tax fossil fuels, the average global carbon tax per tonne is under $2.62 Even if policymakers ought to act, reality suggests that they will not. Rapid approach The Rapid approach notes that societal and financial forces for change are building, as seen in the rise of civil society pressure movements, such as Extinction Rebellion, and financial pressure groups, such as Climate Action 100+. Coal plants are still closing down in the United States because of economic pressures, in spite of support from the Federal government. Advocates for this approach assume that policy will take advantage of new technological innovations to meet the aspirations of society. The falling costs of renewables have opened a window of opportunity for politicians to pursue green policies without imposing significant losses on society while garnering substantial public support.63 The rising popularity of the Green New Deal is an example of such a political shift. To quote the Committee on Climate Change: “Once a technology becomes sufficiently competitive, it starts to change the entire environment in which it operates and interacts. New supply lines are formed, behaviours shift, and new business lobbies

push for more supportive policies. New institutions are created, and old ones repurposed. As costs fall the political and commercial barriers to a transition, begin to drop away. A tipping point is eventually reached where incumbent technologies, products and networks become redundant.”64 That is to say, as the costs of renewables continue to fall, policy-makers will be able to react to the desire of voters to take action, and start to make fossil fuel users pay for their externalities. Moreover, Rapid advocates argue that there is a positive feedback loop between government, technology, finance and society (Figure 11). Society demands cleaner technology and politicians start to put on regulatory pressure to reflect this. Financial markets react to that, deploying capital towards new technologies,65 and entrepreneurs invent superior solutions. As these achieve grander scale, costs fall, society can afford more, politicians can legislate, and investors allocate more capital. Electric vehicles provide an excellent example of this positive feedback loop. They started as expensive toys for the rich, but rising sales are driving much lower battery costs and more aggressive policy action, and they are now becoming a mass-market product. As a result, Rapid scenarios assume rising costs of carbon and falling subsidies for fossil fuel usage. Even if the policy cannot be forecast in detail, they argue it is reasonable to understand that policy will evolve, encapsulated in the idea of an Inevitable Policy Response. This is the moment when governments will be forced by the deteriorating environmental


Coal plants are still closing down in the United States because of economic pressures, in spite of support from the Federal government. Advocates for this approach assume that policy will take advantage of new technological innovations in order to meet the aspirations of society. The falling costs of renewables have opened a window of opportunity for politicians to pursue green policies without imposing major costs on

politicians start to put on regulatory pressure to reflect this. Financial markets react to that, deploying capital towards new technologies,65 and entrepreneurs invent superior solutions. As these achieve greater scale, costs fall, society is able to afford more, politicians can legislate and investors allocate more capital. Electric vehicles provide an excellent example of this positive feedback loop. They started as expensive toys for the rich, but rising sales are driving much lower battery costs and more aggressive policy action, and they are now becoming a mass-market product.

Figure 11: The positive feedback loop Society

Society demands cleaner technology.

Politicians start to put on regulatory pressure to reflect this.

Technology

Government

Finance

Entrepreneurs invent superior solutions.

Financial markets react to that, deploying capital towards new technologies.

Source: Authors, based on data from Carbon Tracker Initiative.

position to take more drastic action to 20 The Speedfuel of thedemand. Energy Transition curtail fossil They point to the increasing number of countries that target 100% renewable electricity by 2050,66 and to individual states in the United States, such as California or Hawaii, which plan to move to 100% renewables. The Country Balance of Forces What is the issue? Even if the global balance of forces may favour a transition, the picture can be very different at a country level. Although the situation is more complex, the first distinction to be made is between fossil fuel exporters (which may well resist a transition) and importers (who as a rule would benefit from it). There are, of course, exceptions to this framework. Japan is the

world’s second-largest fossil fuel importer but has so far been relatively supportive of the coal sector, and Norway is one of the world’s more significant oil exporters but has embraced a transport transition. Gradual approach The Gradual approach points to recent developments in the United States and Australia as examples of countries where fossil fuel supporters have been able to take control of the political process and use it to hold back change. Rapid approach Advocates note that around 20% of the world lives in countries that are net exporters of fossil fuels, and 80% of the world lives in countries that are fossil fuel

importers. So the geopolitical and societal advantage is aligned with reducing fossil fuel usage.67 While incumbents may find it easier to prevent change in the energy exporters (such as Australia), they are likely to find it more challenging to do this in the importers of energy. And in the world’s two largest countries of China and India, the imperative is clearly to reduce fossil fuel imports. Emerging Market Energy Pathways The emerging-market energy story is singled out for special treatment because it is key to any transition. In 2018, the average US citizen used 295 gigajoules (GJ) of energy, while the average Indian used just 25 GJ. wattnow | January 2020 | 43


F EAT UR E

The speed of Energy Transition continues from page 43 What is the issue Energy demand in the OECD has been falling and is likely to continue to fall. Almost all growth in energy demand is expected; therefore, to come from emerging markets. The implication is that developments in China and India are consequently more pertinent to the question of the change in energy demand than those in the United States and Europe. The problem is whether these countries will follow the Western path of fossil-fuel-based development or take their energy path. Will countries like India or Viet Nam build their growing electricity systems on coal or on solar? Will they drive in ICE cars or EVs?

Gradual approach Gradual advocates assume that emerging market demand will mostly follow the pattern set by developed markets – the demand growth for fossil fuels will increase as GDP rises and people become richer.68 These models can point to the fact that energy demand rises with GDP, which in the past has meant more demand for fossil fuels. Rapid approach Rapid advocates do not deny the legitimate aspiration of the world’s energy-poor to enjoy the benefits of more energy. They simply argue that renewable technologies will supply this energy because they are cheaper, faster to implement, less polluting and use domestic fuel sources rather

than imports. Moreover, they take into account the high level of pollution faced by countries, such as India where 140 million people already breathe air that is ten times more toxic than the level considered safe by the World Health Organization. Polluted air is responsible for the deaths of over 1 million people a year.69 This provides extra incentive to the emerging markets to embrace energy technologies that cause less pollution. These advocates argue that there will be an energy leapfrog, similar to that observed in mobile phones or banking services. They also claim, to a greater extent than the Gradual advocates, that the introduction of energy-efficient technologies will limit energy demand growth.

Figure 12: Electricity supply (TWh), Indian subcontinent, 2016-2050

ELECTRICITY SUPPLY TWH: INDIAN SUBCONTINENT

coal

gas

12000

nuclear, hydro biomass

solar

wind

10000 8000 6000 4000 2000 0 2016 44 | wattnow | January 2020

2020

2025

2030

Source: Authors, based on data from DNV GL, Energy Transition Outlook 2018.

2035

2040

2045

2050


Rapid advocates focus on developments meant that EVs in China has already below 2 degrees Celsius - compared to prein China and India, which between them crossed the fundamental 5% market-share industrial levels, and to pursue efforts to are forecast to account for over half of the penetration level, and the demand for ICE limit the temperature increase even further growth in global energy demand. In both cars is already falling. to 1.5 degrees Celsius. China and India, solar electricity is now cheaper than that from fossil fuels, when IMPLICATIONS OF THE TWO Gradual scenarios have rising emissions, 70 comparing new projects in both. Indian NARRATIVES implying that they will be unable to achieve policy-makers, who only recently were With different modelling, assumptions the goals of the Paris Agreement. With different modelling assumptions come different Gradual scenarios have rising emissions, implying that they mocked for having a renewable capacity come to different conclusions. This focus conclusions. This focus is on three: the likelihood of achieving will be unable to achieve the goals of the Paris Agreement. target of 175 GW, recently raised itthe to 500 three: the goals of the Paris Agreement; timingisofon peak fossilthefuellikelihood of achieving Rapid scenarios have a peak in emissions in GW. As aand result, forecast that the demand. the goals of the Paris Agreement; 2020s.inThis means that they provide a demand; the models significance of peaking Rapid scenariosthe havethe a peak emissions in the 2020s. This share of electricity supply from renewables timing of peak fossil fuel demand; and the foundation to achieve the goals of the Paris means that they provide a foundation to achieve the goals of 4.1 road Paris will The multiply, as into Figure 12 from DNV GL significance of peakingthe demand. Paris Agreement.Agreement. for the Indian subcontinent. twogap narratives is captured by the The central aims of the Paris Agreement are toRoad strengthen The To Paris The gap between theThe between the two narratives is expected carbon emissions under the IEA NPS and those the global response to the threat of climate change by A similar story can be told in transport. The central aims of the Paris Agreement captured by the expected carbon emissions required to reach 2 degrees, as summarized by the IPCC keeping the global temperature rise this century well below Higher domestic petrol prices and lower are to strengthen the global response to under the IEA NPS and those required (Figure 13).71 2 degrees Celsius compared to pre-industrial levels, and to driving distances (hence smaller battery the threat of climate change by keeping the to reach 2 degrees, as summarized by the pursue efforts to limit the temperature increase even further in the United States global temperature rise, this century, well IPCC (Figure 13).71 torequirements) 1.5 degrees than Celsius.

4.

Implications of the two narratives

Figure 13: CO2 emissions (Gt), 2020-2050 IPCC Below 2ËšC median

IEA NPS

45 40 35 30 25 20 15 10 5 0 2020

2030

2040

2050

Sources: Authors, based on data from International Energy Agency, World Energy Outlook 2018, New Policies Scenario (fossil fuel sector only), and wattnow | January 2020 | 45 Intergovernmental Panel on Climate Change (total emissions for median below 2 degrees Celsius scenario).


F EAT UR E

The speed of Energy Transition continues from page 45 When Is Peak Fossil Fuel Demand? The difference between the two narratives on the timing of peak fossil fuel demand is profound. Gradual scenarios do not foresee peak fossil fuel demand for another generation. Peak demand for fossil fuels is out of the forecast range of models such as the IEA NPS, the BP ETS and those of Exxon, and is not expected until after 2040. Rapid scenarios foresee peak fossil fuel demand in the 2020s. DNV GL and McKinsey, for example, expect a peak by 2028, and the Shell Sky Scenario by 2025. How Significant Is Peak Demand? Narratives differ dramatically on the significance of peak demand. Gradual scenarios imply no significant threat to the fossil fuel sector incumbents from peak demand. This is in part because they do not see a peak for many years, and in part, because they argue the decline will be slow after the peak. After all, the market will still require fossil fuels for many years. Rapid scenarios, in contrast, imply that the fossil fuel sectors will be disrupted by the transition from growth to decline if they do not adapt quickly. They point to the experience of the European electricity sector, the global coal sector, the gas turbine sector and the auto sector. All in recent years have faced disruption when challenging technologies have had a small market share but have captured the growth in the market. For example: – The European electricity sector lost over half of its capitalization in the decade after the demand for fossil fuels stopped growing. 46 | wattnow | January 2020

At the time of writing, it is not yet clear which narrative is likely to prevail. It’s difficult for complex models to forecast systemic change because developments beyond ten years are tough to predict with any accuracy in three areas in particular: technology, policy and society. These are the three focus areas in the energy transition.

Recent Developments Gradual approach Gradual advocates point to several recent factual events to support their narrative: – Energy demand growth. High energy demand growth occurred in 2018 (2.3%), significantly higher than in the previous few years. – Growth of the hard-to-solve sectors. Demand is rising from petrochemicals and airlines. These sectors appear to have few renewable alternatives. – Peaking renewable supply. Data suggests that solar and wind capacity installations in 2018 were similar to those in 2017, implying that growth rates may have peaked. – Insufficient renewable investment. Investment in renewable capacity is not growing as rapidly as is necessary to achieve the goals of the Paris Agreement.72 – Policy rollback. Environmental protection in the US under the Trump administration has decreased, and US energy demand has increased. – More coal. Coal-fired power stations are still being built, and coal demand rose in 2018. – Not enough success. The IEA tracks progress across 45 clean energy technologies, highlighting that growth is only on track in 7 of the 45 areas to hit the targets of the Paris Agreement.73

Indisputably, growth occurs in some areas and decline happens in others; the question is how they balance. Ultimately, the path to be taken will depend on a complex series of growth and decline rates. Outlined below are recent developments that are used by advocates on the two sides of the debate as well as some of the critical factors to help establish which path the world is following.

Rapid approach Rapid advocates point to a competing set of facts: – Peaks have begun. Disruption is already happening, but not widely distributed. Each year sees peaking demand for fossil fuels in some applications within countries. For example, ICE demand may have peaked in 2018 in China, and

– Half the US coal sector went bust when global coal demand fell just 4% from its all-time high. – GE lost two-thirds of its capitalization in 2018 after it had to take a significant write-down on its turbines division. – The global auto manufacturers have been underperforming as they struggle to come to terms with a new environment. And as a result, they expect a significant impact on incumbents in the fossil fuel sectors from peaking demand in their core markets if they do not adapt quickly. However, recent history has also shown that many incumbents, especially in the electricity sector, have been able to change business models and investment strategies to take advantage of new opportunities centred more around energy services to customer, renewables and the digitalisation of energy.

CONCLUSION: WHAT TO WATCH OUT FOR


the automotive sector has transformed its strategy accordingly, pledging $300 billion to EV strategies. – Cost falls continue. The cost of new energy technologies (especially solar and batteries) has continued to fall rapidly to levels below the price of fossil fuel technologies. – Rapid renewable growth continues. EVs, batteries, solar and wind energy continue to exhibit exponential growth. This is in spite of the slowdown in investment because costs are still falling. – Some policy-makers are acting. Global carbon taxes increased by one-third in 2018 to $44 billion,74 and state and city action has shifted to 100% renewable energy and enacted bans on certain types of ICE cars. This is happening from California to Hawaii, from Paris to Berlin. – Fossil fuel CAPEX is low. Final Investment Decisions (FID) on coalfired power stations are down by 75% in the last five years and are tracking seven years ahead of the expected levels in the IEA NPS. Meanwhile, oil and gas CAPEX is in line with the IEA SDS. – Societal pressure is rising. Public concerns about the impact of global warming and pollution are rising, as manifested by Greta Thunberg and the rise of Extinction Rebellion. – Finance is mobilizing for change. This is demonstrated by the success of the CA100+ movement and the growing calls for disclosure from the Task Force on Climate-related Financial Disclosures (TCFD). Technology Issues to focus on to determine if a Gradual or Rapid narrative is playing out in coming years include:

– Cost of solar, wind and batteries. These technologies are essential because they are large enough to have a material impact, they are already challenging fossil technologies on price, and they are on well-established learning curves. Will costs continue to fall at learning rates of around 20%? If so, generation costs from solar by the end of the decade will be so low that it will be possible to use solar electricity to make hydrogen economically via electrolysis in some countries. And battery costs will be so small that it will be possible to reduce the variability of solar and wind dramatically and increase still higher their ceiling of penetration. The key numbers to focus on for 2030 would be solar and wind costs of $20-30 per MWh and battery costs of $50-100 per kWh. – The growth rate of solar, wind and EVs. Will these technologies remain on their S curves of growth? If so, they will start to supply all net new generation capacity by the early 2020s and will start to replace existing fossil fuel plants later in the same decade. By 2030, Rapid models expect to see over 300 GW a year of solar and wind installations and global EV market share of at least 30%. – Electrification. Will electricity continue its march into other sectors? A Rapid transition would need growth in the share of electricity to be at least 3-4 percentage points per decade. – New renewable technologies. Will other new technologies arise that can change the story dramatically? Those to watch, include green hydrogen, pyrolysis and next-generation biofuels. – Other energy technologies. Of course, the potential exists for significant cost falls in carbon capture and storage, which is technically available and has many

leading pilot applications at scale. With the right policy support, the technology may also enjoy learning curves. Separate to this, an enduring hope is nuclear fusion, and breakthroughs may occur in other areas. These could also alter the energy mix dramatically. Policy Areas to focus on include: – Efficiency. Governments have a pivotal role to play in the promotion of efficiency,75 through regulation on building codes, cars, appliances, and so on. Efficiency levels rose to over 2% in the years before 2017, before falling back to 1.3% in 2018, according to the IEA. The rapid change would be much easier if efficiency were to rise to over 2%, driving down global energy demand growth to around 1%. – Carbon taxation. Will policy-makers seize the opportunity of falling new energy technology costs to implement much more aggressive regulatory regimes to tax fossil fuel users for their externality? The two key metrics to focus on are the phasing out of support for fossil fuels and the widespread imposition of carbon taxes. IEA and IRENA have shown that even a relatively low carbon tax would be sufficient to make around half the world’s emissions uneconomic.76 – Electrification. Support for the electrification of the rest of the energy complex is needed, including heat, transport and industry. – The emerging-market energy leapfrog. Attention must be paid to the policy direction being set by the world’s largest growth markets, such as China, India and South-East Asia. Within these markets, whether coal is being wattnow | January 2020 | 47


F EAT UR E

The speed of Energy Transition continues from page 47 substituted by solar and whether EV sales are moving up an S curve of change. Recent examples of this include the growing number of cancellations of coal-fired power stations across Asia as well as the breakthrough of EV sales through the critical 5% market- share penetration level in China. – The just transition. Can governments devise ways to mitigate the pain of the energy transition for those individuals and communities most impacted? – The policy ratchet. The Intended Nationally Determined Contributions submitted to Paris imply global warming of 2.7 degrees Celsius, and several countries are already failing to hit their Paris commitments. By 2030, liabilities would need to be ratcheted much closer to 2 degrees Celsius. Milestones for 2030 The intention is not to be drawn into a scenario debate, but, it is useful to give a sense of the gap between the two narratives. Therefore, some pointers are summarized below that help to indicate the current path; clearly, not all targets will be reached, but a dominant narrative will likely emerge over the decade. The focus is on the year 2030 to give a sense of what needs to happen over the next decade for the Rapid narrative to be credible. Concentration is on a limited number of factors that are easy to monitor.

Under the Gradual scenario, solar capacity installations would stay at levels similar to today, around 100 GW per annum. Under the Rapid scenario, solar installations would rise to well over 200 GW per year. EV market share in 2030 Under the Gradual scenario, EVs would increase its market share to around 5-10% of sales by 2030. The Rapid scenario would see them taking a market share of over 30%. Carbon taxes In 2018, the World Bank calculated total global carbon taxes to be $44 billion,77 so under $2 per tonne for the 37 Gt of carbon dioxide emissions in that year. Only 20% of emissions are priced at all, and only 5% are rated at a level consistent with the Paris Agreement. Under the Gradual scenario, taxation would increase a little, but the difference would not be dramatic. Under the Rapid scenario, the policy response would be much more aggressive, which would see a dramatic increase in the share of emissions subject to carbon pricing and a significant increase in the level of taxation. It is hard to put a number on this, but the level of action that would be needed is around half of the emissions being taxed at average tax rates of around $20 per tonne taxed.

The Price of Solar Electricity in 2030 Under the Gradual scenario, solar prices are likely to stop falling rapidly, and average global rates will be at $50-70 per MWh in 2030. Under the Rapid scenario, they would fall to the $20-30 level, at which point they start to impact many other sectors.

Peak demand There are then three specific peaks that distinguish the two narratives. The Rapid narrative would see peaks in these areas in the 2020s; the Gradual narrative would not. – Peak demand for new ICE cars – Peak demand for fossil fuels in electricity – Peak demand for fossil fuels in total.

Solar Capacity Installations in 2030

Download full paper here.

48 | wattnow | January 2020


MORE SPARKLING ACHIEVEMENTS Highlights of Electrical Engineering

BOOK

NEW TO BE HED IS L B U P ! N O O S

Into the 21st Century from 2001

In October 2001 the South African Institute of Electrical Engineers published a coffee table book titled Sparkling achievementS. This highly successful volume was sponsored by 43 local companies and comprised 180 advertorial pages highlighting the achievements of these organisations from inception up to the year 2000.

The following list shows the number of pages sponsored by each organisation, in a range from 1 to 10 pages per sponsor: (In alphabetical order) ABB Holdings 4 ABB Powertech Transformers 3 ATC 5 Aberdare Cables 4 Alcatel Altech Telecoms 5 Allied Technologies 1 Alstom South Africa 7 Altech Card Solutions 1 Anglo Technical Division 4 Arrow Altech Distribution 1 CSIR 5 Circuit Breakers Industries 1 Conlog 2 Energy Measurements 2 Eskom 3 General Electric South Africa 1 Marconi Communications SA 4 Merlin Gerin SA 2 M-Net 10 MTN Mobile Telephone Nets 10 Multichoice Africa 2 National Data Systems 4 Orbicom 3 Potchefstroom University 2 Rand Afrikaans University 2 Reunert 2 Richards Bay Minerals 2 Rotek Engineering 6 SABC 5 Sentech 3 Siemens South Africa 2 Spescom 2 Spoornet 8

Stellenbosch University 2 Strike Technologies 2 Telkom 3 Transtel 2 UEC Technologies 1 University of Cape Town 1 University of Natal 5 University of Pretoria 4 University of the Witwatersrand 4 Vodacom Group 8

The second edition more Sparkling achievementS will include the following areas of electrical engineering activity: Electrical Research Technology Development and Standards Telecommunications Electrical Power and Distribution Electrical Traction Broadcasting Information Technology Mining Radio Astronomy RADAR Medical electronics Satellite technology

The cost of each page of advertorial will be R2000 and two books will be given free of charge, to each sponsoring company, for each group of four sponsored pages or part thereof. It is suggested that these books be placed in the company reception and CEO’s office. The book will be advertised to the Institute’s 6000 members and copies will be available at R350 each. The book is ideal to present to VIP visitors to this country who wish to learn about this country and what it has achieved. We expect school and University libraries will value the book as an indication to students of what the profession of electrical engineering is all about. The new book will match the size of the first edition (240x320mm) and will consist of between 170 and 180 full colour high quality pages.

wattnow | January 2020 | 49


F EAT UR E

Potentials of locally manufactured wind generators in SA The China-based monopoly of high-energy permanent magnet materials, used in modern wind generators, impact the economic viability and local content value of most wind turbines installed in South Africa, especially in large installations. It is possible to design, with less expensive excitation technologies, using locally-sourced woundfield electromagnets, which might promote local content. BY | U. B. AKURU M. J. KAMPER 50 | wattnow | January 2020

This study involves the optimum design performance comparison of the woundfield flux switching machine (WF-FSM) technology based on two variants – Design I and II (D-I and D-II) – the difference being in the arrangement of their DC wound-field coils. The machines are evaluated using finite element analyses (FEA) with optimum performance emphasised on design parameters such as torque density, efficiency and power factor. The selected design targets are meant to improve the performance to cost fidelity of the proposed wind generator variants. In 2D FEA, D-II can produce up to 18.8% higher torque density (kNm/m3) and 17.1% lesser loss per active volume (kW/m3) than D-I. In 3D FEA, the torque density of D-II remains higher at 10.6%, but its loss per active volume increases by 15% compared to D-I. The discrepancy observed in 2D, and 3D FEA is due to an underestimation of the end-winding effects in D-II. The power factor of D-II is higher than D-I, both in 2D and 3D FEA, which may translate to lower kVA ratings and inverter costs. A higher total active mass ensues for the studied WF-FSMs than a conventional direct-drive PMSG, but avoiding rare-earth PMs translates to significantly lower prices. The latest global status report on renewable

energy indicates that wind power led global renewable capacity for the third year in a row, with a cumulative installed total of 539 GW – 24.5 % of the world total1. The same report shows that South Africa ranked among the top counties in Africa for cumulative non-hydropower renewable energy capacity as at the end of 2017. Furthermore, it remains the only African country to have commissioned wind power projects in 20171, while also being the topmost in Africa for installed wind power capacity at 1980 MW, along with an estimated cumulative capacity of 11 442 MW by 20302. To meet its planned renewable energy targets, South Africa has benchmarked, among other things, affordable electricity and technology localisation as key objectives of its draft Integrated Resource Plan 20182. A vital component of the wind turbine architecture is the wind generator. It is commonly taken that doubly-fed induction generators (DFIGs) are the workhorse wind generators in the wind power industry3. But with the advent of bigger direct-drive wind turbines, permanent magnet synchronous generators (PMSGs) are becoming increasingly relevant due to their propensity for improved torque


density designs and operational efficiency performance4,5. However, with the growing popularity of PMSGs comes the high cost of rare-earth PMs, facilitated by a monopolised market structure, with recent impulsive price swings, is one reason for current alternative non-PM solutions so-called rare earth-free wind generator technologies5. The PM flux switching machine (PMFSM) has been commercialised for 3 MW wind turbines6. FSM is a re-emerging class of double-salient machines with statormounted and robust rotor features which makes it suitable for particular drivetrain applications7,8. Just like synchronous machines, FSMs can be excited with PM (e.g., PM-FSMs) or DC wound-field coils such as wound-field FSMs (WF-FSMs). Importantly, the design and operational characteristics of the WF-FSM topology is unlike its conventional woundrotor synchronous machine (WRSM) counterpart. It does not require slip rings and brushes for its DC field current excitation. To this end, the reliability of WF-FSMs is improved.

In South Africa, manufacturing and installation of wind turbines translate to premium on the imported raw materials or technology, at least, of the rare earth PMs mostly deployed in such designs. Based on estimations, 23% of global installed wind turbines use PMSGs, which are designed with rare-earth elements5. Therefore, for large wind turbines, the PM content mass, implying cost, will increase as the power level increases, especially for direct-drive wind generator systems as illustrated in Figure 15,9. To this end, there is the possibility of designing wind generators with cheaper excitation technologies such as woundfield (WF) electromagnets which can be locally produced. This way, the localisation drive of wind power infrastructure could be enhanced in the long run. While a 300 kW direct-drive PMSG has been fully developed and presented for the South African wind power industry10, none which uses non-PM technology has been reported. This study involves the semi-optimised design of the FSM technology based on

two proof-of-concept wound-field variants, shown in Figure 2 as Designs I and II (D-I and D-II for short), at 300 kW power levels. The prescribed power level of the proposed wound-field machines is the so-called medium-scale power range9. In Figure 2, the DC coils of D-I overlaps transversally across the adjacent armature coils. At the same time, that of D-II displays a parallel overlap winding array between the DC and armature coils. An exhaustive characterisation of the design concept shown as D-I has been undertaken by the authors for both rare earth and rare earth-free wind generator applications, at different power levels11. Although D-II is a well-established WFFSM design concept, there is no explicit consideration of it as wind generator designs, not to mention the authors’ ignorance of any comparison existing between the designs. Over and above, the WF-FSM generator concept is nominated for this study because, unlike the WRSM, it possesses a brushless DC excitation scheme and robust rotor topology.

wattnow | January 2020 | 51


mes the fact that the high cost of rare earth PMs cilitated by a monopolised market structure, with F EAT UR E cent impulsive price swings, is one reason for rent alternative non-PM solutions, so-called rare rth-free wind generator technologies [5]. The PM flux switching machine (PM-FSM) has en commercialised for 3 MW wind turbines [6]. SM is a re-emerging class of double-salient mafrom page 51 robust rotor features ines withcontinues stator-mounted and hich makes it suitable for certain drivetrain applitions [7, 8]. Just like synchronous machines, FSMs

Wind Generators

reported. This study involves the semi-optimised design of the FSM technology based on two proof-of-concept wound-field variants, shown in Figure 2 as Designs I and II (D-I and D-II for short), at 300 kW power levels. The prescribed power level of the proposed wound-field machines is the so-called medium-scale power range [9]. In Figure 2, the DC coils of D-I overlaps transversally across the adjacent armature coils, while that of D-II displays a parallel overlap winding array between the DC and armature coils. 2D FEA solutions have been clarified based on the 3D transient FEA calculations, also undertaken in this study.

OPTIMISATION PROCESS

5 Figure designed PMSGs [5]. Figure1:1:Wind Wind turbines turbines designed withwith PMSGs .

111

Journal of Energy in Southern Africa • Vol 30 No 2 • February 2019

Figure 2: Presentation of the selected WF-FSM designs: (a) D-I, and (b) D-II.

Figure 2: Presentation of the selected WF-FSM designs: (a) D-I, and (b) D-II. An exhaustive characterisation of the design concept shown as D-I has been undertaken by the auThe proposed machines are primarily thors for both rare earth and rare earth-free wind evaluated using finite element analyses generator applications, at different power levels [11]. (FEA) Although with D-II is aoptimum well-established WF-FSM performance designemphasised concept, there no clear consideration on isdesign parameters suchofasit as wind generator designs, not to mention the audensity, efficiency and power factor, thors’ torque ignorance of any comparison existing beothers. tweenamong the designs. OverThe andstudy above,isthepatterned WF-FSM generator concept nominated for this study besimilarly to isthat performed by Potgieter cause, unlike the WRSM, it possesses brushless DC and Kamper9, and so makes no promises on excitation scheme and robust rotor topology. theproposed mechanical and thermal fidelity of the The machines are primarily evaluated using design finite element analyses (FEA) with optimum process. The selected design targets performance emphasised on design parameters are meant to improve the electromagnetic such as torque density, efficiency and power factor, performance cost isindex of thesimilarly proposedto among others. The to study patterned that performed Potgieter for and aKamper [9], and so generatorbyvariants medium-speed makeswind no promises the mechanical thermal energy on drive system, as and shown in fidelity of the design process. The selected design targets are meant to improve the electromagnetic 52 | wattnow to | January 2020 of the proposed generaperformance cost index tor variants for a medium-speed wind energy drive

As already mentioned, two WF-FSM variants are benchmarked and initially designed to achieve the reference generated output power (Pg) at 300 kW. The machines are designed with a robust static FEA tool developed in-house, the so-called SEMFEM package12, which speeds up the simulation time while maintaining reasonable accuracy on the solutions. After obtaining the reference design, the optimisation design is set up and interfaced to the FEA models using a commercial optimiser (VisualDoC13), as shown in Figure 3. The optimisation is based on a simple gradient approach called the modified method of feasible directions (MMFD). The optimisation problem is then processed as follows: Minimise: MTot (1) Subject to: Pg ≈ 300 kW (2) PF ≼ 0.8 (3) h ≼ 95% (4) ∆TL ≤ 10% (5)

package [12], which speeds up the simulation time while maintaining reasonable accuracy on the where solu- (MTot) is the total active mass, (PF) Figure 1. At the end of the study, an existing tions. After obtaining the reference design, the is optipower factor, (h) is efficiency and (∆TL) 10misation kW manufactured prototype of D-Itoisthe FEA design is set up and interfaced is the peak-to-peak torque ripple at rated models using areported commercial experimentally to optimiser validate (VisualDoC the load. [13]), as shown in Figure 3. The optimisation is results. based on a simple gradient approach called the modified method of feasible directions (MMFD). A total of 14 design parameters were Meanwhile, a possible may Further information about limitation the MMFD approach can for D-I, and 13 for D-II. In be found in [14]. optimisation problem is nominated then occur in the initialThe results of the studied processed as follows: each case, the design parameters include

machines at 300 kW because of the endwinding formulation assumed in the 2D Minimise: đ?‘€đ?‘€đ?‘€đ?‘€đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘Ąđ?‘Ąđ?‘Ąđ?‘Ą FEA procedure. Besides, because of the Subject to: đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘”đ?‘”đ?‘”đ?‘” ≈ 300 đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜ 2D nature of the initial static FEA results, the level of magnetic đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ ≼ 0.8 saturation cannot be ascertained, but in 3D transient FEA. Thus, đ?œ‚đ?œ‚đ?œ‚đ?œ‚ ≼ initially 95 % accruing from the any such doubts ∆đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ??żđ??żđ??żđ??ż ≤ 10 %

both dimensional and non-dimensional (1) variables, such as stator outer diameter (D(2) ), stator inner diameter (Di), stack 0 length (l), armature current density (Js) (3) and wound-field current density (Jec), to mention a few. The present thicknesses (4) have been varied to ensure that reasonable (5)

where (đ?‘€đ?‘€đ?‘€đ?‘€đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘Ąđ?‘Ąđ?‘Ąđ?‘Ą ) is the total active mass, (đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ) is power


(2)

Subject to: đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘”đ?‘”đ?‘”đ?‘” ≈ 300 đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘˜

(3)

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ ≼ 0.8

(4)

đ?œ‚đ?œ‚đ?œ‚đ?œ‚ ≼ 95 %

(5)

∆đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ??żđ??żđ??żđ??ż ≤ 10 %

where (đ?‘€đ?‘€đ?‘€đ?‘€đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘Ąđ?‘Ąđ?‘Ąđ?‘Ą ) is the total active mass, (đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ) is power factor, (đ?œ‚đ?œ‚đ?œ‚đ?œ‚) is efficiency and (∆đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ??żđ??żđ??żđ??ż ) is the peak-to-peak torque ripple at rated load.

describe realistic boundary conditions and were kept as similar as possible for both designs. On completion of the optimisation runs, the final designs were collected and compared, as discussed in the following section.

the end-winding effects might have been poorly attributed in D-II, thus resulting in smaller conductor losses.

Another observation in D-I which can be associated with its end-winding evaluation is the recorded lower power factor, which should inherently yield more significant RESULTS AND DISCUSSIONS The results of the 2D FEA optimisation leakage reactance compared to D-II. To process are presented in Tables 1 and 2. As this end, D-II is seen with a higher power factor, which may imply lower kVA ratings indicated, most of the targets were A total of 14 design parameters were nominated 3. design Results and discussions and optimisation inverter losses (costs), achieved, especially for D-II. After several for D-I, and 13 for D-II. In each case, the design paThe results of the 2D FEA process are and higher Figure 3: An illustration of the design rameters include both dimensional and non-dimen- it presented in difficult Tables 1 and 2. As overload indicated, most ofFurthermore, generator capability. optimisation-runs, was proving optimisation procedure. sional variables, such as stator outertodiameter (đ??ˇđ??ˇđ??ˇđ??ˇđ?‘‡đ?‘‡đ?‘‡đ?‘‡ ), the design targets for were achieved, especially D-II.18.8% higher it is observed that D-IIforyields realise the efficiency prescription Figure 3: Aninner illustration of the ), stack length (đ?‘™đ?‘™đ?‘™đ?‘™), armature stator diameter (đ??ˇđ??ˇđ??ˇđ??ˇđ?‘–đ?‘–đ?‘–đ?‘–design After several optimisation runs, it was proving 3 diffiD-I without exceeding the logical limits of torque density (kNm/m ) and 17.1% lesser optimisation current densityprocedure. (đ??˝đ??˝đ??˝đ??˝đ?‘ đ?‘ đ?‘ đ?‘  ) and wound-field current density cult to realise the efficiency prescription for D-I withdefined design optimisation space. It loss per active volume (kW/m3) than D-I. rn Africa • Vol 30 No February 2019a few. The currentthe mention densities have (đ??˝đ??˝đ??˝đ??˝đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’2),• to out exceeding the logical limits of the defined design is not a surprising been varied to ensure that reasonable thermal limits occurrence, optimisationespecially space. It is not a surprising occurrence, Meanwhile, that Tables given that the compared evaluated respected in the in final especially given total that the comparednote evaluated total 1 and 2 also thermal are limits are respected thedesigns, final notwithstanding shows the thatperformance the specific data DC of a 300 kW factthough that a failsafe thermal analysis is not anlosses ob- (Pconductor (đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘? ) display ) shows losses that the conductor designs, the even a failsafe thermal cu conductor losses of D-I is 13.03 kW, while that of Djective in this study. The airgap (đ?‘”đ?‘”đ?‘”đ?‘”), slot filling ratios specific DC conductor losses of D-I is 13.03 optimum conventional direct-drive PMSG analysis is not an objective in this study. The (đ?‘˜đ?‘˜đ?‘˜đ?‘˜ ) windII is a mere 8.64 kW, which is due to the fact that the of the wound-field DC (đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ ) and armature 9 đ?‘ đ?‘ đ?‘ đ?‘  airgap (g), slot filling ratios of the wound- kW. At the same time, that of D- II is a mere as evaluated in Potgieter and Kamper . ing slots, as well as rated generator speed (đ?‘›đ?‘›đ?‘›đ?‘›đ?‘ đ?‘ đ?‘ đ?‘  ), same slot filling factors (đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘ đ?‘ đ?‘ đ?‘  and đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ ) were assumed 8.64 kW, which is because the same slot The performance of the PMSG is carefully field DCamong (Kec) and armature (Ks) constant. winding After others, were kept defining the for both designs in 2D FEA. On a closer inspection factors (Ks and ) were assumed contrasted against that of the studied WFslots, as well as rated generatorsome speedadditional (NS), filling ec slot designs, such an assumption is naturally design parameters, formulations, of K the for both designs in 2D FEA. On closer FSM tovariants necessary forkept the optimisation process, were implemore profitable to D-II than D-I, as designed shown in in Fig-the mediumamong others, were constant. After to describe realisticsome boundary conditions, ure designs, 4. Also, the end-winding might It have been inspection of the slot such an speedeffects drivetrain. is observed that the definingmented the design parameters, and were kept as similar as possible for both designs. poorly attributed in D-II, thus resulting in smaller assumption is naturally more profitable to active masses (M ) and torque density additional formulations, necessary for the Tot On completion of the optimisation runs, the final deconductor losses. optimisation process, were implemented to D-II than to D-I, as shown in Figure 4. Also, (Tr/Vact) of D-I and D-II is much higher than signs were collected and compared, as discussed in the following section. Table 1: Optimum performance data of 300 kW wind generators. ∆đ?œ?đ?œ?đ?œ?đ?œ?đ?‘ đ?‘ đ?‘ đ?‘ đ??żđ??żđ??żđ??ż (%)

(%)

∆đ?œ?đ?œ?đ?œ?đ?œ?đ??żđ??żđ??żđ??ż

(kW)

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘?

(kW)

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘?đ?‘’đ?‘’đ?‘’đ?‘’

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ -

(%)

đ?œ‚đ?œ‚đ?œ‚đ?œ‚

(kNm)

đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘?

đ?‘€đ?‘€đ?‘€đ?‘€đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸ (kg)

đ?‘€đ?‘€đ?‘€đ?‘€đ??śđ??śđ??śđ??śđ?‘?đ?‘?đ?‘?đ?‘?

(kg)

(kg)

đ?‘€đ?‘€đ?‘€đ?‘€đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸đ??¸

���������������� (kg)

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ â „đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ (kW/m3)

(kNm/m3)

đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘? â „đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’

(kW)

D-I

7.85

8.76

15.63

3.16

0.79

94.15

9.52

74.5

61.3

2 183.5

2 319.3

41.38

20.86

303

D-II

6.62

5.56

10.52

2.32

0.98

95.91

9.43

63.9

63.9

1 744.3

1 872.1

34.29

24.79

302

PMSG

5.30

25.74

13.30

2.46

0.95

95.00

67.00

114.6

282.3

967.0

1 363.9

12.11

52.50

300

đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘”đ?‘”đ?‘”đ?‘”

Table 2: Optimum design data of 300 kW wind generators. đ??˝đ??˝đ??˝đ??˝đ?‘ đ?‘ đ?‘ đ?‘ 

đ??˝đ??˝đ??˝đ??˝đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’

(r/min)

đ?‘›đ?‘›đ?‘›đ?‘›đ?‘ đ?‘ đ?‘ đ?‘ 

(Hz)

(m)

(m)

(m)

đ??ˇđ??ˇđ??ˇđ??ˇđ?‘‡đ?‘‡đ?‘‡đ?‘‡

(mm) 2

0.45

0.45

(A/mm2) (A/mm2)

đ?‘“đ?‘“đ?‘“đ?‘“đ?‘ đ?‘ đ?‘ đ?‘ 

����

đ??ˇđ??ˇđ??ˇđ??ˇđ?‘–đ?‘–đ?‘–đ?‘–

����

đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘ đ?‘ đ?‘ đ?‘  -

đ?‘˜đ?‘˜đ?‘˜đ?‘˜đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ -

D-I

3.50

7.62

300

50

0.37

0.90

1.25

D-II

3.33

7.29

300

50

0.38

0.79

1.12

2

0.45

0.45

PMSG

4.58

-

50

114.6

0.26

2.43

2.5

-

-

-

Another observation in D-I which can be associated with its end-winding evaluation is the recorded lower power factor, which should inherently yield

and D-II is much higher than that of the PMSG. Also,| January 2020 | 53 wattnow in terms of the đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ /đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ index, the value for the PMSG is significantly lower than those conceived in


and associ- F EAT URD-II E is much higher than that of the PMSG. Also, in terms of the đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ /đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ index, the value for the orded PMSG is significantly lower than those conceived in yield the WF-FSM designs. As noted in Potgieter and o this Kamper. [9], higher loss per active volume as obwhich served in D-I and D-II can result in serious thermal losses continues from pagewhich 53 may need to be carefully adimplications, ability. dressed. 18.8% lesser Table 3: Cost analyses data of 300 kW wind isplay generators. m conđ??¸đ??¸đ??¸đ??¸đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ??¸đ??¸đ??¸đ??¸ đ??śđ??śđ??śđ??śđ??śđ??śđ??śđ??ś đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ??šđ??šđ??šđ??š đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘™đ?‘™đ?‘™đ?‘™ n Pot(USD) (USD) (USD) (USD) of the D-I 834.4 686.6 4 803.7 6 324.7 of the diumD-II 715.7 715.7 3 837.5 5 268.9 active PMSG 6 876 3 161.8 2 127.4 12 165.2 of D-I

Wind Generators

3D FEA VALIDATION AND EXPERIMENTAL PROTOTYPE This section presents the 3D FEA validation of the studied WFFSMs, as well as preliminary results achieved from an existing 10 kW prototype of D-I designed, built and tested as a wind generator in the Electrical Machines Laboratory of Stellenbosch University, South Africa, in 2017, for the first time15.

3D FEA VALIDATION In Figure 5, the flux density plots of the 300 kW WF- FSMs evaluated that of the PMSG. Also, in terms of the Ploss/Vact index, the value for in 3D FEA as quarter-symmetrical models are presented. The peak the PMSG is significantly lower than those conceived in the WFdensity flux in the iron cores reaches 2.3 T in trace proportions Southern • Vol No 2in•Potgieter Februaryand 2019 FSMAfrica designs. As30 noted Kamper9, higher loss per inin regions close to the airgap, at rated Figure 4: Depiction slotinfilling areas 2D FEA modelling: (a) D-I, and conditions. (b) D-II. Table 4 is then active volume as observed in D-I and D-II of canthe result serious introduced by way of comparing the 2D and 3D FEA evaluations thermal implications, which may need to be carefully addressed. The PMSG is designed with rare earth PMs, to account it may be D-II than D-I. Also,It aishuge difforworse the endforfully-winding effects. clear enough that which should result in a trade-off between the active theference in the torque ripple of D-II is also observed. end-winding effects were seriously underestimated in D-II, as The PMSG ismass designed earthConsequently, PMs, which should resultanalin andwith totalrare costs. the cost The trend, which appeared to beinsteadfast 2D and witnessed by the significant increase the total in copper losses. This a trade-off between mass and costs. Consequently, yses ofthe theactive generators aretotal contrasted as shown in 3D FEA, is that the torque density of the D-II is considerable drop has to be implicated in the discrepancy observed Tableof3.the Clearly, it is observed that although theintoslightly maintained above that of D-I, as well as atthe cost analyses generators are contrasted, as shown in the averageoftorque, efficiency. tal active mass of the PMSG is smaller than the WFtainment unitarytorque powerdensity factor and in the former. The highlight Table 3. It is observed that although the total active mass of the FSM designs, its total cost is about twice as much. PMSG is smaller than the WF- FSM designs, its total cost is about The reverse is the case for the WF-FSM designs, twice as much. The shows reversetheir is thetotal casemasses for theto WF-FSM designs, which be much higher, which shows yet their total to be much higher, yetreduced the cost of the costmasses of material is significantly bematerial is significantly because they areIt rare earth-free. cause theyreduced are rare earth-free. should be mentioned that although the comparison between the diand the geared WF-FSM between designs is It should be rect-drive mentionedPMSG that although the comparison not exactly comfortable because of their different the direct-drive PMSG and the geared WF-FSM designs is not drivetrain configurations, yet it gives insight to the precisely comfortable. Thisavoidance is because of of rare theirearth different fact that the PMsdrivetrain may posiconfigurations. Yet,impact it giveson insight to the total fact that avoidance tively the latter’s cost the of materials. of rare-earth PMs may positively impact on the latter’s total cost of materials. 4. 3D FEA validation and experimental prototype This section presents the 3D FEA validation of the studied WF-FSMs, as well as experimental results achieved from an existing 10 kW prototype of D-I designed, built and tested as a wind generator in the Electrical Machines Laboratory of Stellenbosch University, South Africa, in 2017, for the first time [15].

4.1 3D FEA Validation In Figure 5, the flux density plots of the 300 kW WFFSMs evaluated in 3D FEA as quarter symmetrical models are presented. The peak density flux in the iron cores reaches 2.3 T in trace proportions in reFigure 3D FEA predicted flux contour densityplots contour gions close to the airgap, at conditions. Table igure 4:Figure Depiction of the of slot areas in 2D FEA modelling: (a) D-I, and (b) 5: D-II. 4: Depiction thefilling slot filling areas in rated 2D FEA modelling: (a) Figure 3D5:FEA predicted flux density of the studied plots of the studied 300 kW WF-FSMs at rated 4 is then introduced by way of comparing the 2D D-I, and (b) D-II. 300 kW WF-FSMs at rated conditions: (a) D-I, and (b) D-II. conditions: (a) D-I, and (b) D-II. and rare 3D FEA fullybeaccount forD-II the endMSG is designed with earthevaluations PMs, ittomay worse for than D-I. Also, a huge dif54 | wattnow | January 2020 winding effects. It is clearference enough the end-winduld result in a trade-off between the active in that the torque ripple of D-II is also observed. 4.2 Experimental ing effects wereanalseriously underestimated in D-II, to asbe steadfast total costs. Consequently, the cost The trend, which appeared in 2D and prototype and tests


shown in Figure 7, while Figure 8 is used to me of the measured results with those pretially at the design stage. At higher loading, rs the effect of saturation becomes daring, ved in Figure 8. Other than that, a good nt is indicated. The level of agreement

achieved through the experimental testing of the 10 kW prototype yields some promise as to the feasibility of furthering the power levels to the proposed 300 kW wind generator concepts for South Africa’s wind power industry, as already being initiated in this study.

Figure 6: Manufacturing process of a 10 kW WF-FSM wind generator prototype [15].

Figure 6: Manufacturing process of a 10 kW WF-FSM wind 7: Measured electromagnetic under varying load [11]. Figure 8:Figure Measured electromagnetic torque torque under varying load current 15 generator prototype . le 4: Comparison 2DFigure and 3D7,FEA performance of 300 wind generators. . the 10 bench isbetween shown in while Figure 8 isdata used to kWachieved through the experimental current testing11of â „đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘ŽConclusions 5. the torque density and powe ∆đ?œ?đ?œ?đ?œ?đ?œ?đ??żđ??żđ??żđ??ż đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘? some ofđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’the đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘? results with đ?œ‚đ?œ‚đ?œ‚đ?œ‚ đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘? â „prototype đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ prekW some to D-I. the However, feasibilđ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘?đ?‘’đ?‘’đ?‘’đ?‘’ measured đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ those predicted initially at theyields design stage.promise ofgauge end-winding effects is the reversal of the those to theasspecified design constraints, but with 3 3 optimal design comparison has In this of proposed D-II remains steadfastly higher than D-I, ) paper, ) (%) (kWinitially at (kW (kNm) (kW/m (kNm/m - the power levels to the dicted the design stage. At(%) higher loading, ity ofanfurthering loading,forittwo appears the effect of a significant P /Vact index between the machines, which At higher discrepancy in ofthewriting, specific been initiated wound-field flux concepts switching ma3D FEA. At the time a locally m appears saturation daring, 300 for South Africa’s đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ itloss2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ the 2đ??ˇđ??ˇđ??ˇđ??ˇ effect 3đ??ˇđ??ˇđ??ˇđ??ˇ of2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇbecomes 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ kW 3đ??ˇđ??ˇđ??ˇđ??ˇ wind 2đ??ˇđ??ˇđ??ˇđ??ˇ generator 3đ??ˇđ??ˇđ??ˇđ??ˇ chine variants, profiled as D-I and D-II, at 300 kW current tured 10copper kW laboratory prototype of D-I exis saturation becomes daring. Other than suggests in reality that it may be worse for direct losses observed observed in Figure 8. Other than 93.67 that, 41.38 a good wind 19.88 power0.79industry, as already being initiated in 6 8.85 as 15.63 15.60 3.16 3.56 9.52 9.03 94.15 42.19 20.86 0.65 power ratings, in order to demonstrate the industrial suring that some experimental validation that, a good this agreement is indicated. The due to unfair approximations of the slot D-II than D-I.isAlso, a vast difference in the agreement study. 6 17.96 agreement 10.52 16.08 2.32indicated. 2.09 9.43 The 8.24 level 95.91 of 93.44 34.29relevance 48.53 24.79 22.00 0.98 1.00 of rare earth-free wind generators to the vided. In conclusion, the study uncovers so of agreement achieved the filling torque ripple of D-II is observed. The trend, level booming after undertaking South Africa windthrough power industry. In 2D factors. gree However, of design feasibility with perceived ec testing of the (FEA), 10 kWD-II prototype which appeared to be steadfast in 2D and experimental 3DperFEA, benefits the results that wind the endfinite element analyses shows better of theshow proposed generators fo credentials in response to the of specified de- effects Africa’s industry. some promise as to the feasibility 3D FEA, is that the torque density of the yieldsformance winding ofwind D-IIpower have been seriously sign constraints, but with a significant discrepancy in the power to the proposed D-II is slightly maintained above that of furthering underrated, of which the specific directlevels current copper losses observed Author rolesamong other things, wind generator concepts for South D-I, as well as attainment of unitary power 300 kW /V index increasesthe by 15% did the the P due to unfair approximations of the slot filling fac- loss U.B. Akuru designed research, act tors. However, after undertaking 3D FEA, the results and the technical report. Africa’s wind power industry, as already compared to D-I. factor in the former. show that the end-winding effects of D-II have been M.J. Kamper provided guidelines on the r being initiated in this study. seriously underrated, of which among other things, techniques and inputs on the write-up. EXPERIMENTAL PROTOTYPE AND However, the torque density and power to the đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ /đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ index increases by 15% compared TESTS CONCLUSIONS factor of D-II remains steadfastly higher The main handout from the experimental In thisReferences paper, an optimal design comparison than D-I, even in 3D FEA. At the time demonstration is that the manufacturing has been initiated for two wound-field fluxreportof(Paris: writing, locally 2018. manufactured 10 [1] REN21, Renewables 2018 global status REN21aSecretariat), Available: www.ren21.ne is 100% South African, without the need switching machine variants. It isResource profiledPlan as – Department kW laboratory prototype D-I Africa, existed, [2] Draft IRP-2018: Integrated of Energy, Republic ofofSouth August 2018 cessed online on 2018/10/16 at: http://www.energy.gov.za/IRP/irp-update-draft-report2018/IRP-Update-20 for the importation of any of the resource D-I and D-II, at 300 kW power ratings, to ensuring that some experimental validation Draft-for-Comments.pdf igure 7: components WF-FSM wind generator being testeddemonstrate on laboratorythe test bench [15]. used in prototype the fabrication relevance of rare is onprovided. In conclusion, study across th [3] Goudarzi,industrial N. and Zhu, W. D. 2013. A review the development of wind turbinethe generators Dynamics and Control 2013(1): 192–202. https://doi.org/10.1007/s4043 process. In Figure 6, the highlights earth-freeworld. windInternational generatorsJournal to the ofbooming uncovers some degree of design feasibility 0016-y of the manufacturing process are South Africa wind power industry. In 2D with perceived economic benefits of the [4] Keysan, O. 2017. Future electrical generator technologies for offshore wind turbines, Wind Power, E&T IE photographically profiled. Figure 7 is used finite element analyses (FEA), D-II shows proposed wind generators for South vices, Aug 16, 2017. Accessed online on 2018/07/12 at: https://energyhub.theiet.org/users/60216-ozanFigure 6: Manufacturing process of a 10 kW WF-FSM wind generator prototype [15]. keysan/posts/19442-future-electrical-generator-technologies-for-offshore-wind-turbines to gauge some of the measured results with better performance credentials in response Africa’s wind power industry.

[5] Pavel, C. C., Lacal-ArĂĄntegui, R., Marmier, A., SchĂźler, D., Tzimas, E., Buchert, M., Jenseit, W. and Blago 2017. Substitution strategies for reducing the use of rare earths in wind turbines. Resources Policy 52: 349 Table 4: Comparison between 2D and 3D FEA performance data of 300 kW wind generators. Š Paper courtesy of https://doi.org/10.1016/j.resourpol.2017.04.010 Journal of Energy [6] ∆đ?œ?đ?œ?đ?œ?đ?œ?đ??żđ??żđ??żđ??ż đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘? đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘?đ?‘?đ?‘?đ?‘?đ?‘’đ?‘’đ?‘’đ?‘’ đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘? VENPOWER:đ?œ‚đ?œ‚đ?œ‚đ?œ‚http://www.venpower.de/index.html đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘™đ?‘™đ?‘™đ?‘™đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘‡ â „đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ đ?‘‡đ?‘‡đ?‘‡đ?‘‡đ?‘?đ?‘?đ?‘?đ?‘? â „đ?‘‰đ?‘‰đ?‘‰đ?‘‰đ?‘Žđ?‘Žđ?‘Žđ?‘Žđ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’đ?‘’ đ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒđ?‘ƒ South Africa Vol 30 [7] Rauch, S. E.(%) and Johnson,(kW/m L. J. 1955. principles alternators. 7 3 3 No AIEE 2 MayTransactions 2019 ) Design ) of flux–switching (%) (kW (kW (kNm) (kNm/m 1261–1268. https://doi.org/10.1109/AIEEPAS.1955.4499226 2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ [8] 3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ Hua,3đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ J. and 3đ??ˇđ??ˇđ??ˇđ??ˇZhao, 2đ??ˇđ??ˇđ??ˇđ??ˇ 2đ??ˇđ??ˇđ??ˇđ??ˇ of stator–permanent 3đ??ˇđ??ˇđ??ˇđ??ˇ Cheng, M., W., Zhang, W. 2011.3đ??ˇđ??ˇđ??ˇđ??ˇ Overview magnet brushless mac For Reference, IEEE Transactions on Industrial Electronics 58(11): 5087–5101. https://doi.org/10.1109/TIE.2011.212385 download D-I 8.76 8.85 15.63 15.60 3.16 3.56 9.52 9.03 94.15 93.67 41.38 42.19 20.86 19.88 0.79 0.65 paper here. D-II 5.56 17.96 10.52 16.08 2.32 2.09 9.43 8.24 95.91 93.44 34.29 48.53 24.79 22.00 0.98 1.00 115

Journal of Energy in Southern Africa • Vol 30 No 2 • February 2019

116

wattnow | January 2020 | 55

Journal of Energy in Southern Africa • Vol 30 No 2 • February 2019


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Lightning and surge protection for electromobility DEHN Africa provides lightning and surge protection for electric vehicle charging stations

Because most electric vehicle charging stations are generally positioned outside, they are more vulnerable to the effects of direct lightning strikes, as well as the possibility of resultant surges.

In mid-2019, there were an estimated one thousand electric vehicles (EV) registered in South Africa1. In October of last year, the practicality of the local charging network was tested when seven EVs went on a road trip from Pretoria to Cape Town2. Generation.e organised the road trip – an events company with a mission to accelerate EV adoption - in partnership with the Gauteng Provincial Government, the African Alliance for Energy Productivity and the Department of Transport. As at early 2020, there are reported to be 132 designated charging stations throughout South Africa3, with brands such as Renault, Mini Cooper, Porsche and Audi preparing to add either fully electric or hybrid vehicles in 20204 to the existing offerings from Nissan (the Nissan Leaf), BMW (i3) and Jaguar(I-PACE). Most car

56 | wattnow | January 2020

experts agree that the adoption of electric cars is bound to increase in the next few years as more public charging stations become available throughout the country. Read more on the solutions offered from DEHN Africa in the below white paper on lightning and surge protection for EV charging stations.

DANGER DURING THUNDERSTORMS Several billion flashes of lightning come down in the world every year. In Germany alone, an average of 1.5 million lightning events are counted each year, and the tendency is rising. If lightning strikes nearby, buildings and the infrastructure often suffer damage: lightning strikes can cause fires and surge damage to electrical devices and systems. The latter may occur even if the actual strike was up to 2 km


away. Besides, switching electrical power, e.g. on the charging post, and switching operations in transformer stations generate switching overvoltages which can also have adverse effects. It frequently only takes a small amount of energy to cause significant damage.

DAMAGE CAUSED DURING CHARGING Constant availability of electrical power is a decisive factor for the charging process. The fact that charging stations is primarily erected outside means that they are especially susceptible to the effects of lightning discharge and the resulting surges which might exceed the dielectric strength of the electrical components within the charging post many times over. Furthermore, voltage peaks in the power grid from, e.g. switching operations or earth faults and short-circuits, should

be regarded as a possible threat. The consequences are defective electronic components and a charging post which is out of order. Should the surge occur during the charging process itself, it can even damage the actual vehicle (e.g. the charge controller or battery). It is therefore advisable to consider a reliable lightning and surge protection concept to avoid such financially damaging consequences and minimise repairs and maintenance.

WHAT HAPPENS IF LIGHTNING STRIKES WHEN CHARGING? In case of a direct lightning strike, e.g. in a street lamp, a partial lightning current can flow to the charging post. This can be conducted directly into the vehicle via the attached charging cable where it may destroy the charging electronics or even the battery.

If a surge protective device has been installed, the lightning current and the overvoltage is discharged directly via the protective device and the charging equipment, and the vehicle remains intact (Figure 1).

WHAT DO THE STANDARDS HAVE TO SAY? Publication VdS 3471, issued by the VdS (German insurer for damage prevention), on ‘Charging stations for electric vehicles’ states on the topic of surge protection that, according to DIN VDE 0100-443, the evaluation of whether additional surge protective measures are necessary, depends on the overvoltage category stated by the manufacturer. Standards in the series DIN VDE 0100 are installation standards and therefore apply to fixed installations. Charging posts which wattnow | January 2020 | 57


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Lightning Protection for electromobility continues from page 57

Without surge protection

With surge protection

Figure 1 - Lightning and surge coupling when charging

M

SEMP

Figure 2 - Causes of overvoltage are not portable and are connected via fixed wiring fall under the scope of DIN VDE 0100. DIN VDE 0100-443:2016-10 deals with the protection of electrical installations against transient overvoltages of atmospheric origin. These are transmitted through the power grid, including direct lightning strikes in power lines and transient overvoltages due to switching operations. It explains whether surge protective measures are necessary, assesses the risk of the location, defines overvoltage categories and the correspondingly required rated impulse withstand voltage level for the 58 | wattnow | January 2020

equipment and defines whether additional surge protective devices are necessary. Furthermore, it expands on the required availability of the system. If the risk of direct lightning strikes needs to be considered, lightning protection standard DIN EN 62305 (VDE 0185-305) should also be applied. The technical guidance document “Charging infrastructure/ electromobility” by the DKE / AK EMOBILITY.60 (a working group of the German Commission for electrotechnology) refers that, in the interest of preventing damage and injury, these standards should be assessed

and considered. Should lightning and surge protective measures be applied in compliance with DIN VDE 0100-443 and EN 62305, these should be installed according to DIN VDE 0100-534.

CAUSES OF TRANSIENT OVERVOLTAGE A direct strike to the charging post or the supply line produces a lightning current which is simulated under test conditions with the impulse shape 10/350 μs. Distant lightning strikes or so-called indirect lightning strikes lead to conducted partial lightning currents (impulse shape 10/350 μs) in the supply lines or also to inductive/


class of LPS III: 100 kA

switchgear cabinet

30 m

30 m

30 m

30 m

30 m

U= î ∙

ρE (2 ∙ π ∙ d)

Assumption: Homogenous soil Specific earth resistance: 1000 Ωm Point of strike 30 m away from first charging post

Distance 30 m 60 m 90 m 120 m 150 m 180 m 210 m 240 m 270 m 300 m 1m Voltage to distant earth in kV 15924 kV 531 kV 265 kV 177 kV 133 kV 106 kV 88 kV 76 kV 66 kV 59 kV 53 kV

Figure 3 - Potential gradient area for a lightning strike in the immediate vicinity of a charging station wattnow | January 2020 | 59


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Lightning Protection for electromobility continues from page 59

Surge protection should be selected according to DIN VDE 0100-534 depending on the location of the charging post or wall box (Figure 4). If the charging post or its wiring is in zone 0A, both galvanic coupling and coupling of partial lightning currents must be expected in case of a nearby or distant lightning strike.

only needs to reckon with inductive and capacitive coupling from the lightning discharge. In this case, type 2 surge arresters like, for example, DEHNguard suffice. If it is not possible to reliably assess the potential threat, installing the compact and space-saving type 1 + 2 + 3 combined arrester DEHNshield is generally the best option. DEHNshield is based on spark-gap technology, has VDE and UL certification, is maintenance-free, offers protection against both the direct and indirect effects of lightning and is, therefore, a flexible and universal solution. As this arrester is purely based on spark gap technology, the wave breaker function is assured.

Type 1 + 2 + 3 combined arresters, e.g. DEHNshield, should be installed in the charging posts to control these interference impulses. If the charging posts or wall boxes and their wiring are in zone 0B, i.e. in an area protected against strikes, one

This has the effect of reducing the energy of the lightning impulse current to such an extent that even the most sensitive electronics installed downstream remain intact. This constitutes real protection of terminal devices!

capacitive coupling (impulse shape 8/20 Οs) in the charging stations themselves. Besides, overvoltage can be caused by switching operations, earth faults and short circuits or when fuses trip (SEMP – switching electromagnetic pulse) (Figure 2 and 3).

SELECTION OF SURGE PROTECTIVE DEVICES When selecting suitable lightning and surge protective devices, it is not only essential to know about the installation location but also about the local system configuration, system voltage and nominal voltage of the charging facility. A possible selection is shown in table 1.

REFERENCES 1. https://w w w.itweb.co.za/content/ mQwkoq6Kb2gv3r9A 2. https://www.wheels24.co.za/News/ Gear_and_Tech/driven-sas-3-electriccars-on-a-road-trip-is-it-possiblewithout-consequence-20191010-2 3. https://w w w.dailymaverick.co.za/ article/2020-01-15-ten-new-2020-ridesfor-south-africa/ 4. b u s i n e s s t e c h . c o . z a / n e w s / motoring/363600/8-new-cars-coming-tosouth-africa-in-2020-to-get-excited-about/

Combined lightning current and surge arrester type 1 Surge arrester type 2 Power supply Telecommunications systems

Figure 4 - Application of lightning and surge protective devices depending on location 60 | wattnow | January 2020


Table 1 - Selection aid for protecting electromobility – charging infrastructure (Figure 4)

WattNow.pdf 1 2017-05-15 03:52:31 PM

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24 HOUR ON-SITE SERVICES Breakdown repairs, removal, re-installation, on-site testing, dynamic balancing, alignment, vibration analysis, root cause analysis, condition monitoring, preventative and predictive maintenance, motor management programmes and maintenance contracts

CUSTOMISED ELECTRICAL AND MECHANICAL DESIGN Reliability improvements/enhancements, efficiency improvements, performance upgrades and root cause analyses.

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January in History January is the first month of the year in the Julian and Gregorian calendars and the first of seven months to have a length of 31 days. The first day of the month is known as New Year's Day.

2019 The long-awaited national minimum wage came into effect in South Africa.

2 JANUARY 2004 The NASA spacecraft Stardust successfully flew past Comet Wild 2, collecting samples to be returned to Earth. The primary mission was successfully completed on 15 January 2006, when the sample return capsule returned to Earth.

3 JANUARY

COMPILED BY | JANE BUISSON-STREET

FSAIEE | PMIITPSA | FMIITSPA

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years after the original mission limit, Spirit had covered a total distance of 7.73 km but its wheels became trapped in sand. The last communication received from the rover was on March 22, 2010, and NASA ceased attempts to reestablish communication on May 25 of that year.

1 JANUARY

1977 Less than one year after its founding, the world’s first personal computer company, Apple Computer, Inc. was incorporated. The original Apple Computer, Inc. logo was the “Rainbow Apple Logo” used through to 1999.

4 JANUARY 2004

Spirit, a NASA Mars Rover, landed successfully on Mars. Nearly 6

5 JANUARY 1984

Richard Stallman began developing the software for the GNU operating system, intended to be a free UNIXlike OS. The goal was to bring a wholly free software operating system into existence. Stallman wanted computer users to be free to study the source code of the software they use, share software with other people, modify the behaviour of software, and publish their own modified versions of the software. This philosophy was later published as the GNU Manifesto in March 1985.


6 JANUARY

13 JANUARY

1984

1942

Hitachi announced that they had developed the first memory chip capable of holding 1 MB of data!

7 JANUARY 1990 The Leaning Tower of Pisa was closed to the public for the first time in 800 years because it was leaning too much..

8 JANUARY 871

Battle of Ashdown: Ethelred I of Wessex and his brother Alfred the Great beat invading Danish army.

9 JANUARY 1793

1st hot-air balloon flight in the US lifts off in Philadelphia, piloted by Jean Pierre Blanchard.

10 JANUARY 1863 The first underground railway opens in London.

11 JANUARY 1838 The first public demonstration of telegraph messages sent using dots and dashes at Speedwell Ironworks in Morristown, New Jersey by Samuel Morse and Alfred Vail.

12 JANUARY 1948

Mahatma Gandhi begins his final fast.

Wartime material shortages forced manufacturers to become very creative so Henry Ford patented a Soybean car (a plastic car), which was 30% lighter than a regular car. Henry Ford came up with a unique tubular steel framework which he could bolt his plastic panels on. It is believed the plastic was made from Soybean, so that car was also called Soybean car.

14 JANUARY

assembled, which degenerated into a shoving match. Consequently, Heatherington was summoned to appear in court before the Lord Mayor and fined £50 for going about in a manner “calculated to frighten timid people.

16 JANUARY 1980 Scientists in Boston, USA produced interferon, a natural virus-fighting substance through genetic engineering.

1878 Alexander Graham Bell demonstrated the telephone for the first time to Queen Victoria at her rural retreat at Osborne House in East Cowes. He made the UK’s first publicly-witnessed long distance calls, calling Cowes, Southampton and London. When the Queen saw his telephone, she was much impressed, and ordered a private line to be laid between Osborne House, on the Isle of Wight, and Buckingham Palace.

17 JANUARY

15 JANUARY

1919

1797 The top hat was first worn in England by James Heatherington, a Strand haberdasher in London, England. An issue of the Times of that period records that when he left his shop with his extraordinary headwear, a crowd of onlookers

1874 – Twins Chang and Eng Bunker died. They were Siamese-born American twins joined at the chest and are the source of the term “Siamese Twins.” They toured Europe and the U.S., eventually settling in North Carolina where they married two sisters, who bore them 22 children. “Chang” and “Eng” is Thai for “Left” and “Right.”

18 JANUARY This was the first day of The Paris Peace Conference, also known as the Versailles Peace Conference, of the victorious Allied Powers following the end of World War I to set the peace terms for the defeated Central Powers. Two of the outcomes of this Conference

wattnow | January 2020 | 63


L OOKING B A C K . . .

January in History continues from page 63 was the creation of the League of Nations and the Treaty of Versailles.

19 JANUARY 1999 Research In Motion (RIM) introduced the BlackBerry. The original BlackBerry devices were not phones, but instead were the first mobile devices that could do real-time e-mail. They looked like big pagers. Apparently the name “BlackBerry” came from the similarity that the buttons on the original device had to the surface of a blackberry fruit.

20 JANUARY 1970

“The Super Fight“, a computerized, fictional boxing match between Muhammad Ali and Rocky Marciano “took place”. The fictional fight was created by filming Ali and Marciano acting out every possible scenario in a fight and the result was then determined using probability formulas entered into a computer.

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of Treating Foodstuffs.” Five years earlier, Spencer accidentally discovered that microwave energy could heat food when a chocolate bar in his pocket melted while he was experimenting with a microwave tube. Microwave tubes were originally designed for RADAR systems.

21 JANUARY 2000 The domain name twitter.com was registered. However, it wasn’t until 2006 that the domain was purchased by Twitter, Inc. and took the form known today.

22 JANUARY 1968

The first unmanned lunar module lifted off in Apollo 5 (also known as AS-204).

23 JANUARY 1996 The first version of the Java programming language was released (confusing many coffee drinkers). The ability of Java to “write once, run anywhere” made it ideal for Internet-based applications. As the popularity of the Internet soared, so did the usage of Java.

24 JANUARY 1950 The patent of one of the most used piece of equipment in many people’s kitchens, the microwave, was issued to Percy LeBaron Spencer under the title “Method

25 JANUARY 1905

At the Premier Mine in Pretoria, South Africa, a 3,106-carat diamond was discovered during a routine inspection by the mine’s superintendent. Weighing 603 grams, and christened the “Cullinan,” it was the largest diamond ever found.

26 JANUARY 1998 Compaq Computer purchased Digital Equipment Corporation (DEC) for $9.6 billion. DEC was a pioneering company in the early history of computers from the 1960s to the 1980s. Unfortunately, as was seen with many companies, they were slow to recognize the


rise of the PC which ultimately led to the sell-off of all the company’s business units, cumulating with the final sale to Compaq. Compaq itself was eventually merged with HP.

1988

27 JANUARY 1967

Astronauts Gus Grissom, Edward White and Roger Chaffee were killed in a fire during a test of their spacecraft at the Kennedy Space Centre. After the fire, the spacecraft and planned launch which never took place was posthumously named Apollo 1, in honour of the astronauts.

28 JANUARY 1999 Yahoo! bought GeoCities for $3.65 billion USD. GeoCities was an early web hosting service that start in 1994. As a testament to its popularity, there were at least 38 million pages remaining on GeoCities when Yahoo! shut it down in 2009.

then set to play. The 50th time the game was started, the virus was released, but instead of playing the game, it would change to a blank screen that displayed a poem about the virus.

29 JANUARY The computer game Tetris made its first appearance in the United States as a PC game. The company that released the game was Spectrum Holobyte, which had dubious licensing rights to the game. When companies became interested in licensing Tetris for other platforms besides the PC, a series of events kicked off a long legal battle, in which the big winner was eventually Nintendo, who used the game Tetris to drive sales of its new Game Boy platform.

30 JANUARY 1982 Richard Skrenta (a 15-year old school boy) wrote the first PC virus code, which was 400 lines long and disguised as an Apple II boot program called “Elk Cloner“.

Elk Cloner was spread by infecting the Apple DOS 3.3 operating system using a technique now known as a boot sector virus. It was attached to a game which was

Elk Cloner: The program with a personality It will get on all your disks It will infiltrate your chips Yes, it’s Cloner!

It will stick to you like glue It will modify RAM too

Send in the Cloner!

Twenty-five years later, in 2007, Skrenta called it “some dumb little practical joke.”

31 JANUARY 1990

The first McDonald’s was opened in Russia, in the city of Moscow. The restaurant served at least 30,000 people during its first day.

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SAIEE CENTRES Eastern Cape Centre

Chairman | Simphiwe Mbanga T|083 777 7916 E|MbangaS@eskom.co.za

Free State Centre

Chairman | Joseph George T|082 263 1213 E|joseph.george22@gmail.com

Gauteng Central Centre Chairman | Teboho Machabe T|083 692 6062 E|MachabTB@eskom.co.za

Kwa-Zulu Natal Centre Chairman | Jay Kalichuran

T|082 569 7013 E|KalichuranJ@elec.durban.gov.za

Mpumalanga Centre

Chairman | Louis Kok E| louis.kok2@sasol.com

Northern Cape Centre Chairman | Ben Mabizela

T| 073 708 0179 E| MabizeBG@eskom.co.za

Southern Cape Centre

Chairman | Steyn van der Merwe E|steynvdm@gmail.com

Vaal Centre

Chairman | Carlisle Sampson T|083 397 8021 E|Carlisle.Sampson@sasol.com

Western Cape Centre

Chairman | Heinrich Rudman E| admin.wcape@saiee.org.za

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CERTAINTY THROUGH CERTIFICATION AND COMPLIANCE

Are you an

ELPA member? IN SOUTH AFRICA, LIGHTNING IS A REAL THREAT EARTHING & LIGHTNING PROTECTION ASSOCIATION

T 086 135 7272 E info@elpasa.org.za

• •

South Africa experiences ±24 million lightning strokes annually With ± 500 related fatalities every year

The Earthing and Lightning Protection Association (ELPA) was formed to bring the industry together, reduce the burden and upskill engineers to protect the consumer, establish a uniform interpretation of the codes of practice, and help to regulate and advise the lightning protection industry.

JOIN US TODAY AND START MAKING A DIFFERENCE!

www.elpasa.org.za

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RELIABLE POWER FOR A WORLD THAT’S ALWAYS N. RELIABLE SYSTEMS. DEPENDABLE PEOPLE. LOCAL SERVICE. CUMMINS SOUTH AFRICA TEL: +27 11 451 3400 24/7 SERVICE SUPPORT LINE: +27 11 451 3400 WWW.CUMMINS.COM

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Profile for SAIEE

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