demand reduction VVO typically targets a larger voltage reduction response to reduce peak demand. In order to extract the higher amount of voltage reduction, circuit conditioning may be required before implementing VVO. In order to optimize voltage and vars on the distribution system, control of all voltage and var devices is required, including load tap changers, three phase bus regulation, single phase bus regulation, single phase circuit regulation and distribution capacitor banks. With three phase regulation there are generally no voltage imbalance issues but there may be limits on optimization due to having only three phase voltage control. With single phase regulation there needs to be awareness of single phase loads and potential voltage imbalance on circuits. Optimizing voltage and vars requires specific measurements with defined accuracy. Line devices with three phase sensing are preferred. Accuracy requirements generally need to be 1% or less to allow for accurate voltage control since voltage will only be reduced a small percentage. Voltage accuracy is more critical to VVO operation, with watts and vars being more critical to power flow.
Voltage
VVO Circuits
Total Circuits
VVO Subs
Total Subs
34.5kv
58
62
21
22
12.47kv
476
556
148
153
4.16kv
0
161
0
72
totals
534
779
169
247
TABLE 1: Details circuits and substations involved in smart grid deployment
Ohio Substation Components (ITF = Inside the Fence) Total of 148 substations
Ohio Distribution Line Components (OTF = Outside the Fence) Total of 534 circuits out of 747
• 74 - Breaker Replacements
• 126 – Electronic Reclosers
• 561 - Regulation Controls
• 1947 – Capacitor Controls
• 377 – Microprocessor Relay
• 4085 – Line Sensors
Upgrades
• 30 – Self Healing Teams
RMEL EVENT SPOTLIGHT: Distribution Engineering and Design Best Practices October 11-12 RMEL is hosting a Distribution Engineers Workshop October 11-12 at the Denver Marriott South. Engineers and designers involved in distribution will find this course helpful. In addition, supervisory or management personnel who desire a review of distribution practices and standards, or who are new to power distribution, will benefit from this course. Experts from electric utilities and services and supplier companies will present on various topics during the two-day course. PRELIMINARY TOPICS INCLUDE: • Wireless
TABLE 2: Details of the Ohio substation/Distribution line components
• Fault Indicators • Utility Scale Battery Storage • 1547 transfer trip • Large EV Integration • Smart Grid • Microgrids • Construction Standards • Best Practices for Standards Panel • Emerging Technologies Workshop topics are subject to change. Visit www.RMEL.org for updates and to register.
FIGURE 5: Results achieved with VVO for 2013 to 2015 with a base line without VVO in 2012
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ELECTRIC ENERGY | SPRING 2017