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TransientAnalysisofPowerSystems

TransientAnalysisofPowerSystems

APracticalApproach

RetiredProfessor

PolytechnicUniversityofCatalonia

Barcelona

Spain

Thiseditionfirstpublished2020 ©2020JohnWiley&SonsLtd

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LibraryofCongressCataloging-in-PublicationData

Names:Martinez-Velasco,JuanA.,editor.

Title:Transientanalysisofpowersystems:apracticalapproach/edited byJuanA.Martinez-Velasco,RetiredProfessor,PolytechnicUniversity ofCatalonia,Barcelona,Spain.

Description:Hoboken,NJ:Wiley-IEEEPress,2020.|Includes bibliographicalreferencesandindex.

Identifiers:LCCN2019027811(print)|LCCN2019027812(ebook)|ISBN 9781119480532(hardback)|ISBN9781119480303(adobepdf)|ISBN 9781119480495(epub)

Subjects:LCSH:Transients(Electricity)–Simulationmethods.

Classification:LCCTK3226.T762020(print)|LCCTK3226(ebook)|DDC 621.319/21–dc23

LCrecordavailableathttps://lccn.loc.gov/2019027811

LCebookrecordavailableathttps://lccn.loc.gov/2019027812

CoverDesign:Wiley

CoverImage:©kentoh/Shutterstock

Setin10/12ptWarnockProbySPiGlobal,Chennai,India

10987654321

Contents

AbouttheEditor xv

ListofContributors xvii

Preface xix

AbouttheCompanionWebsite xxi

1IntroductiontoTransientsAnalysisofPowerSystemswithATP 1

JuanA.Martinez-Velasco

1.1Overview 1

1.2TheATPPackage 3

1.3ATPDocumentation 5

1.4ScopeoftheBook 6 References 8

2ModellingofPowerComponentsforTransientsStudies 11

JuanA.Martinez-Velasco

2.1Introduction 11

2.2OverheadLines 12

2.2.1Overview 12

2.2.2Multi-conductorTransmissionLineEquationsandModels 13

2.2.2.1TransmissionLineEquations 13

2.2.2.2CoronaEffect 15

2.2.2.3LineConstantsRoutine 15

2.2.3TransmissionLineTowers 16

2.2.4TransmissionLineGrounding 17

2.2.4.1Introduction 17

2.2.4.2Low-FrequencyModels 17

2.2.4.3High-FrequencyModels 18

2.2.4.4TreatmentofSoilIonization 20

2.2.5TransmissionLineInsulation 21

2.2.5.1Voltage-TimeCurves 21

2.2.5.2IntegrationMethods 22

2.2.5.3PhysicalModels 22

2.3InsulatedCables 23

2.3.1Overview 23

2.3.2InsulatedCableDesigns 24

2.3.3BondingTechniques 25

2.3.4MaterialProperties 26

2.3.5Discussion 27

2.3.6CableConstants/ParametersRoutines 27

2.4Transformers 28

2.4.1Overview 28

2.4.2TransformerModelsforLow-FrequencyTransients 31

2.4.2.1IntroductiontoLow-FrequencyModels 31

2.4.2.2Single-PhaseTransformerModels 32

2.4.2.3Three-PhaseTransformerModels 36

2.4.3TransformerModellingforHigh-FrequencyTransients 37

2.4.3.1IntroductiontoHigh-FrequencyModels 37

2.4.3.2ModelsforInternalVoltageCalculation 39

2.4.3.3TerminalModels 41

2.5RotatingMachines 45

2.5.1Overview 45

2.5.2RotatingMachineModelsforLow-FrequencyTransients 46

2.5.2.1Introduction 46

2.5.2.2ModellingofInductionMachines 46

2.5.2.3ModellingofSynchronousMachines 51

2.5.3High-FrequencyModelsforRotatingMachineWindings 55

2.5.3.1Introduction 55

2.5.3.2InternalModels 56

2.5.3.3TerminalModels 58

2.6CircuitBreakers 58

2.6.1Overview 58

2.6.2CircuitBreakerModelsforOpeningOperations 59

2.6.2.1CurrentInterruption 59

2.6.2.2CircuitBreakerModels 60

2.6.2.3Gas-FilledCircuitBreakerModels 61

2.6.2.4VacuumCircuitBreakerModels 62

2.6.3CircuitBreakerModelsforClosingOperations 64

2.6.3.1Introduction 64

2.6.3.2StatisticalSwitches 65

2.6.3.3PrestrikeModels 66 Acknowledgement 66 References 66

3SolutionTechniquesforElectromagneticTransientAnalysis 75 JuanA.Martinez-Velasco

3.1Introduction 75

3.2ModellingofPowerSystemComponentsforTransientAnalysis 76

3.3SolutionTechniquesforElectromagneticTransientsAnalysis 78

3.3.1Introduction 78

3.3.2SolutionTechniquesforLinearNetworks 78

3.3.2.1TheTrapezoidalRule 78

3.3.2.2CompanionCircuitsofBasicCircuitElements 79

3.3.2.3ComputationofTransientsinLinearNetworks 85

3.3.2.4Example:TransientSolutionofaLinearNetwork 86

3.3.3NetworkswithNonlinearElements 87

3.3.3.1Introduction 87

3.3.3.2CompensationMethods 87

3.3.3.3PiecewiseLinearRepresentation 89

3.3.4SolutionMethodsforNetworkswithSwitches 90

3.3.5NumericalOscillations 91

3.4TransientAnalysisofControlSystems 96

3.5Initialization 97

3.5.1Introduction 97

3.5.2InitializationofthePowerNetwork 97

3.5.2.1OptionsforSteady-StateSolutionWithoutHarmonics 97

3.5.2.2Steady-StateSolution 98

3.5.3LoadFlowSolution 99

3.5.4InitializationofControlSystems 100

3.6Discussion 100

3.6.1SolutionTechniquesImplementedinATP 101

3.6.2OtherSolutionTechniques 101

3.6.2.1TransientSolutionofNetworks 101

3.6.2.2TransientAnalysisofControlSystems 102

3.6.2.3Steady-StateInitialization 102 Acknowledgement 103 References 103 ToProbeFurther 106

4TheATPPackage:CapabilitiesandApplications 107

4.1Introduction 107

4.2CapabilitiesoftheATPPackage 108

4.2.1Overview 108

4.2.2TheSimulationModule–TPBIG 109

4.2.2.1Overview 109

4.2.2.2ModellingCapabilities 110

4.2.2.3SolutionTechniques 117

4.2.3TheGraphicalUserInterface–ATPDraw 120

4.2.3.1Overview 120

4.2.3.2MainFunctionalities 120

4.2.3.3SupportingModulesforPowerSystemComponents 123

4.2.4ThePostprocessor–TOP 125

4.2.4.1DataManagement 125

4.2.4.2DataDisplay 126

4.2.4.3DataProcessing 127

4.2.4.4DataFormatting 127

4.2.4.5GraphicalOutput 127

4.3Applications 128

4.4IllustrativeCaseStudies 129

4.4.1Introduction 129

4.4.2CaseStudy1:OptimumAllocationofCapacitorBanks 130

4.4.3CaseStudy2:ParallelResonanceBetweenTransmissionLines 132

4.4.4CaseStudy3:SelectionofSurgeArresters 133

4.5Remarks 136

References 136 ToProbeFurther 138

5IntroductiontotheSimulationofElectromagneticTransientsUsingATP 139

5.1Introduction 139

5.2InputDataFileUsingATPFormats 140

5.3SomeImportantIssues 142

5.3.1BeforeSimulatingtheTestCase 142

5.3.1.1SettingUpaSystemModel 142

5.3.1.2TopologyRequirements 142

5.3.1.3SelectionoftheTime-StepSizeandtheSimulationTime 143

5.3.1.4Units 143

5.3.1.5OutputSelection 144

5.3.2AfterSimulatingtheTestCase 144

5.3.2.1VerifyingtheResults 144

5.3.2.2DebuggingSuggestions 144

5.4IntroductoryCases.LinearCircuits 145

5.4.1TheSeriesandParallelRLCCircuits 145

5.4.2TheSeriesRLCCircuit:EnergizationTransient 145

5.4.2.1TheoreticalAnalysis 145

5.4.2.2ATPImplementation 147

5.4.2.3SimulationResults 148

5.4.3TheParallelRLCCircuit:De-energizationTransient 150

5.4.3.1TheoreticalAnalysis 150

5.4.3.2ATPImplementation 152

5.4.3.3SimulationResults 153

5.5SwitchingofCapacitiveCurrents 155

5.5.1Introduction 155

5.5.2SwitchingTransientsinSimpleCapacitiveCircuits–DCSupply 155

5.5.2.1EnergizationofaCapacitorBank 155

5.5.2.2EnergizationofaBack-to-BackCapacitorBank 157

5.5.3SwitchingTransientsinSimpleCapacitiveCircuits–ACSupply 159

5.5.3.1EnergizationofaCapacitorBank 159

5.5.3.2EnergizationofaBack-to-BackCapacitorBank 160

5.5.3.3ReclosingintoTrappedCharge 162

5.5.4DischargeofaCapacitorBank 164

5.6SwitchingofInductiveCurrents 168

5.6.1Introduction 168

5.6.2SwitchingofInductiveCurrentsinLinearCircuits 168

5.6.2.1InterruptionofInductiveCurrents 168

5.6.2.2VoltageEscalationDuringtheInterruptionofInductiveCurrents 170

5.6.2.3CurrentChopping 172

5.6.2.4MakingofInductiveCurrents 175

5.6.3SwitchingofInductiveCurrentsinNonlinearCircuits 176

5.6.4TransientsinNonlinearReactances 178

5.6.4.1InterruptionofanInductiveCurrent 180

5.6.4.2EnergizationofaNonlinearReactance 181

5.6.5Ferroresonance 184

5.7TransientAnalysisofCircuitswithDistributedParameters 187

5.7.1Introduction 187

5.7.2TransientsinLinearCircuitswithDistributed-ParameterComponents 187

5.7.2.1EnergizationofLinesandCables 187

5.7.2.2TransientRecoveryVoltageDuringFaultClearing 191

5.7.3TransientsinNonlinearCircuitswithDistributed-ParameterComponents 195

5.7.3.1SurgeArresterProtection 195

5.7.3.2ProtectionAgainstLightningOvervoltagesUsingSurgeArresters 196

References 201

Acknowledgement 202

ToProbeFurther 202

6CalculationofPowerSystemOvervoltages 203

JuanA.Martinez-VelascoandFerleyCastro-Aranda

6.1Introduction 203

6.2PowerSystemOvervoltages:CausesandCharacterization 204

6.3ModellingforSimulationofPowerSystemOvervoltages 206

6.3.1Introduction 206

6.3.2ModellingGuidelinesforTemporaryOvervoltages 207

6.3.3ModellingGuidelinesforSlow-FrontOvervoltages 208

6.3.3.1LinesandCables 208

6.3.3.2Transformers 208

6.3.3.3Switchgear 208

6.3.3.4CapacitorsandReactors 209

6.3.3.5SurgeArresters 209

6.3.3.6Loads 210

6.3.3.7PowerSupply 210

6.3.4ModellingGuidelinesforFast-FrontOvervoltages 210

6.3.4.1OverheadTransmissionLines 210

6.3.4.2Substations 212

6.3.4.3SurgeArresters 213

6.3.4.4Sources 214

6.3.5ModellingGuidelinesforVeryFast-FrontOvervoltagesinGasInsulated Substations 214

6.4ATPCapabilitiesforPowerSystemOvervoltageStudies 216

6.5CaseStudies 216

6.5.1Introduction 216

6.5.2Low-FrequencyOvervoltages 216

6.5.2.1CaseStudy1:ResonanceBetweenParallelLines 217

6.5.2.2CaseStudy2:FerroresonanceinaDistributionSystem 219

6.5.3Slow-FrontOvervoltages 225

6.5.3.1CaseStudy3:TransmissionLineEnergization 227

6.5.3.2CaseStudy4:CapacitorBankSwitching 238

6.5.4Fast-FrontOvervoltages 243

6.5.4.1CaseStudy5:LightningPerformanceofanOverheadTransmissionLine 244

6.5.5VeryFast-FrontOvervoltages 261

6.5.5.1CaseStudy6:OriginofVeryFast-FrontTransientsinGIS 262

6.5.5.2CaseStudy7:PropagationofVeryFast-FrontTransientsinGIS 263

6.5.5.3CaseStudy8:VeryFast-FrontTransientsina765kVGIS 267 References 270 ToProbeFurther 274

7SimulationofRotatingMachineDynamics 275

JuanA.Martinez-Velasco

7.1Introduction 275

7.2RepresentationofRotatingMachinesinTransientsStudies 275

7.3ATPRotatingMachinesModels 276

7.3.1Background 276

7.3.2Built-inRotatingMachineModels 276

7.3.3RotatingMachineModelsforFastTransientsSimulation 278

7.4SolutionMethods 278

7.4.1Introduction 278

7.4.2Three-PhaseSynchronousMachineModel 278

7.4.3UniversalMachineModule 281

7.4.4WindSyn-BasedModels 284

7.5ProceduretoEditMachineDataInput 284

7.6CapabilitiesofRotatingMachineModels 285

7.7CaseStudies:Three-PhaseSynchronousMachine 287

7.7.1Overview 287

7.7.2CaseStudy1:Stand-AloneThree-PhaseSynchronousGenerator 288

7.7.3CaseStudy2:LoadRejection 288

7.7.4CaseStudy3:TransientStability 298

7.7.5CaseStudy4:SubsynchronousResonance 302

7.8CaseStudies:Three-PhaseInductionMachine 309

7.8.1Overview 309

7.8.2CaseStudy5:InductionMachineTest 310

7.8.3CaseStudy6:TransientResponseoftheInductionMachine 313

7.8.3.1FirstCase 314

7.8.3.2SecondCase 314

7.8.3.3ThirdCase 318

7.8.4CaseStudy7:SCIM-BasedWindPowerGeneration 323 References 328 ToProbeFurther 331

8PowerElectronicsApplications 333

JuanA.Martinez-VelascoandJacintoMartin-Arnedo

8.1Introduction 333

8.2ConverterModels 334

8.2.1SwitchingModels 334

8.2.2DynamicAverageModels 334

8.3PowerSemiconductorModels 335

8.3.1Introduction 335

8.3.2IdealDeviceModels 335

8.3.3MoreDetailedDeviceModels 335

8.3.4ApproximateModels 336

8.4SolutionMethodsforPowerElectronicsStudies 337

8.4.1Introduction 337

8.4.2Time-DomainTransientSolution 337

8.4.3Initialization 338

8.5ATPSimulationofPowerElectronicsSystems 338

8.5.1Introduction 338

8.5.2SwitchingDevices 339

8.5.2.1Built-inSemiconductorModels 339

8.5.2.2Custom-madeSemiconductorModels 340

8.5.3PowerElectronicsSystems 342

8.5.4PowerSystems 343

8.5.5ControlSystems 343

8.5.6RotatingMachines 344

8.5.6.1Built-inRotatingMachineModels 344

8.5.6.2Custom-madeRotatingMachineModels 344

8.5.7SimulationErrors 345

8.6PowerElectronicsApplicationsinTransmission,Distribution,Generationand StorageSystems 345

8.6.1Overview 345

8.6.2TransmissionSystems 346

8.6.3DistributionSystems 346

8.6.4DERSystems 347

8.7IntroductiontotheSimulationofPowerElectronicsSystems 349

8.7.1Overview 349

8.7.2One-SwitchCaseStudies 350

8.7.3Two-SwitchesCaseStudies 351

8.7.4ApplicationoftheGIFURequest 355

8.7.5SimulationofPowerElectronicsConverters 361

8.7.5.1Single-phaseInverter 361

8.7.5.2Three-phaseLine-CommutatedDiodeBridgeRectifier 362

8.7.6Discussion 365

8.8CaseStudies 367

8.8.1Introduction 367

8.8.2CaseStudy1:Three-phaseControlledRectifier 367

8.8.3CaseStudy2:Three-phaseAdjustableSpeedACDrive 369

8.8.4CaseStudy3:Digitally-controlledStaticVARCompensator 373

8.8.4.1TestSystem 375

8.8.4.2ControlStrategy 375

8.8.5CaseStudy4:UnifiedPowerFlowController 382

8.8.5.1Configuration 382

8.8.5.2Control 382

8.8.5.3Modelling 384

8.8.5.4ATPDrawImplementation 385

8.8.5.5SimulationResults 385

8.8.6CaseStudy5:SolidStateTransformer 386

8.8.6.1Introduction 386

8.8.6.2SSTConfiguration 388

8.8.6.3ControlStrategies 388

8.8.6.4TestSystemandModellingGuidelines 393

8.8.6.5CaseStudies 396

Acknowledgement 399

References 399

ToProbeFurther 404

9CreationofLibraries 405

JuanA.MartinezVelascoandJacintoMartin-Arnedo

9.1Introduction 405

9.2CreationofCustom-MadeModules 406

9.2.1Introduction 406

9.2.2ApplicationofDATABASEMODULE 406

9.2.3ApplicationofMODELS 411

9.2.4TheGroupOption 417

9.3ApplicationoftheATPtoPowerQualityStudies 419

9.3.1Introduction 419

9.3.2PowerQualityIssues 419

9.3.3SimulationofPowerQualityProblems 422

9.3.4PowerQualityStudies 423

9.4Custom-MadeModulesforPowerQualityStudies 426

9.5CaseStudies 426

9.5.1Overview 426

9.5.2HarmonicsAnalysis 426

9.5.2.1CaseStudy1:GenerationofHarmonicWaveforms 428

9.5.2.2CaseStudy2:HarmonicResonance 431

9.5.2.3CaseStudy3:HarmonicFrequencyScan 434

9.5.2.4CaseStudy4:CompensationofHarmonicCurrents 441

9.5.3VoltageDipStudiesinDistributionSystems 447

9.5.3.1Overview 447

9.5.3.2CaseStudy5:VoltageDipMeasurement 449

9.5.3.3CaseStudy6:VoltageDipCharacterization 454

9.5.3.4CaseStudy7:VoltageDipMitigation 462 References 466

ToProbeFurther 470

10ProtectionSystems 471

JuanA.Martinez-VelascoandJacintoMartin-Arnedo

10.1Introduction 471

10.2ModellingGuidelinesforProtectionStudies 472

10.2.1LineandCableModels 472

10.2.1.1ModelsforSteady-StateStudies 473

10.2.1.2ModelsforTransientStudies 473

10.2.2TransformerModels 473

10.2.2.1Low-frequencyTransformerModels 474

10.2.2.2High-frequencyTransformerModels 475

10.2.3SourceModels 475

10.2.4CircuitBreakerModels 475

10.3ModelsofInstrumentTransformers 476

10.3.1Introduction 476

10.3.2CurrentTransformers 476

10.3.3CouplingCapacitorVoltageTransformers 478

10.3.4VoltageTransformers 479

10.3.5CaseStudies 480

10.3.5.1CaseStudy1:CurrentTransformerTest 480

10.3.5.2CaseStudy2:CouplingCapacitorVoltageTransformerTest 482

10.3.6Discussion 484

10.4RelayModelling 484

10.4.1Introduction 484

10.4.2ClassificationofRelayModels 485

10.4.3ImplementationofRelayModels 486

10.4.4ApplicationsofRelayModels 488

10.4.5TestingandValidationofRelayModels 488

10.4.6AccuracyandLimitationsofRelayModels 490

10.4.7CaseStudies 490

10.4.7.1Overview 490

10.4.7.2CaseStudy3:SimulationofanElectromechanicalDistanceRelay 491

10.4.7.3CaseStudy4:SimulationofaNumericalDistanceRelay 497

10.5ProtectionofDistributionSystems 508

10.5.1Introduction 508

10.5.2ProtectionofDistributionSystemswithDistributedGeneration 508

10.5.2.1DistributionFeederProtection 508

10.5.2.2InterconnectionProtection 508

10.5.3ModellingofDistributionFeederProtectiveDevices 509

10.5.3.1CircuitBreakers–OvercurrentRelays 509

10.5.3.2Reclosers 511

10.5.3.3Fuses 511

10.5.3.4Sectionalizers 512

10.5.4ProtectionoftheInterconnectionofDistributedGenerators 513

10.5.5CaseStudies 514

10.5.5.1CaseStudy5:TestingtheModels 514

10.5.5.2CaseStudy6:CoordinationBetweenProtectiveDevices 524

10.5.5.3CaseStudy7:ProtectionofDistributedGeneration 525

10.6Discussion 531

Acknowledgement 533

References 533

ToProbeFurther 537

11ATPApplicationsUsingaParallelComputingEnvironment 539

JavierA.Corea-Araujo,GerardoGuerraandJuanA.Martinez-Velasco 11.1Introduction 539

11.2BifurcationDiagramsforFerroresonanceCharacterization 540

11.2.1Introduction 540

11.2.2CharacterizationofFerroresonance 540

11.2.3ModellingGuidelinesforFerroresonanceAnalysis 541

11.2.4GenerationofBifurcationDiagrams 541

11.2.5ParametricAnalysisUsingaMulticoreEnvironment 542

11.2.6CaseStudies 544

11.2.6.1Case1:AnIllustrativeExample 544

11.2.6.2Case2:FerroresonantBehaviourofaVoltageTransformer 545

11.2.6.3Case3:FerroresonanceinaFive-LeggedCoreTransformer 545

11.2.7Discussion 550

11.3LightningPerformanceAnalysisofTransmissionLines 550

11.3.1Introduction 550

11.3.2LightningStrokeCharacterization 551

11.3.3ModellingforLightningOvervoltageCalculations 552

11.3.4ImplementationoftheMonteCarloProcedureUsingParallelComputing 554

11.3.5IllustrativeExample 555

11.3.5.1TestLine 555

11.3.5.2LineandLightningStrokeParameters 555

11.3.5.3SimulationResults 559

11.3.6Discussion 562

11.4OptimumDesignofaHybridHVDCCircuitBreaker 563

11.4.1Introduction 563

11.4.2DesignandOperationoftheHybridHVDCCircuitBreaker 563

11.4.3ATPImplementationoftheHybridHVDCCircuitBreaker 565

11.4.4TestSystem 566

11.4.5TransientResponseoftheHybridCircuitBreaker 567

11.4.6ImplementationofaParallelGeneticAlgorithm 568

11.4.7SimulationResults 570

11.4.8Discussion 574

Acknowledgement 575

References 575

ACharacteristicsoftheMulticoreInstallation 579

BTestSystemParametersforFerroresonanceStudies 579

ToProbeFurther 580

Index 581

AbouttheEditor

JuanA.Martinez-VelascowasborninBarcelona,Spain.HereceivedtheIngenieroIndustrial andDoctorIngenieroIndustrialdegreesfromtheUniversitatPolitècnicadeCatalunya(UPC), Spain.Heisretiredandworkingasprivateconsultant.

Hehasauthoredandco-authoredmorethan200journalandconferencepapers,mostof themonTransientAnalysisofPowerSystems.HehasbeeninvolvedinseveralEMTP(ElectroMagneticTransientsProgram)coursesandworkedasconsultantforsomeSpanishcompanies. HisteachingandresearchareascoverPowerSystemsAnalysis,TransmissionandDistribution, PowerQualityandElectromagneticTransients.HehasbeenanactivememberofseveralIEEE andCIGREWorkingGroups.

Hehasbeeninvolvedaseditororco-authorinseveralbooks.HeisalsocoeditoroftheIEEE publication‘ModelingandAnalysisofSystemTransientsUsingDigitalPrograms’(1999).In 2010,hewasthecoordinatoroftheTutorialCourse‘TransientAnalysisofPowerSystems.SolutionTechniques,Tools,andApplications’,givenatthe2010IEEEPESGeneralMeeting,July 2010andheldinMinneapolis.

In1999,hewasgiventhe‘1999PESWorkingGroupAwardforTechnicalReport’,forhis participationinthetasksperformedbytheIEEETaskForceonModelingandAnalysisofSlow Transients.In2000,hewasgiventhe‘2000PESWorkingGroupAwardforTechnicalReport’, forhisparticipationintheeditionofthespecialpublication‘ModelingandAnalysisofSystemTransientsusingDigitalPrograms’.In2009hewasalsogiventhe‘TechnicalCommittee WorkingGroupAward’oftheIEEEPESTransmissionandDistributionCommittee.

ListofContributors

FerleyCastro-Aranda UniversidaddelValle,LaboratoriodeAlta Tensión Cali,Colombia

JavierA.Corea-Araujo Applus+ IDIADA SantaOliva,Spain

FranciscoGonzález-Molina UniversitatRoviraiVirgili,Depto.de IngenieríaElectrónica,Eléctricay Automática Tarragona,Spain

GerardoGuerra DNVGL Barcelona,Spain

JacintoMartín-Arnedo EstabanellyPahisaEnergia, Granollers,Spain

JuanA.Martinez-Velasco Retired–FormerlywithUniversitat PolitecnicadeCatalunya Barcelona,Spain

Preface

Thetransientanalysisisanimportanttaskforpowersystemanalysisanddesign.Severalsimulationtoolsarecurrentlyavailableforthispurpose.OneofthemostpopularistheAlternative TransientsProgram(ATP).

TheATPisaroyalty-freepackageintegratedbyatleastthreetools:(i)ATPDraw,agraphicaluserinterface(GUI)forcreatingand/oreditinginputfiles;(ii)TPBIG,themainprocessorfortransientsandharmonicssimulations;and(iii)onepostprocessorforplottingsimulationresults.Actually,ATPuserscanalsotakeadvantageofseveralothertools,andcreatea custom-madeenvironmentwithlinkstootherpackages.

TheacronymATPwasoriginallyusedtonamethetoolfortransientssimulation.Formany users,ATPisstillthesimulationtool;inthisbook,ATPisusedtonameindistinctlythepackage orthetransientssimulationtool,whileTPBIGisusedtoname(whenused)thesimulationtool. ATPDrawisaninteractiveWindows-basedGUIthatcanactasashellforthewholepackage; thatis,userscancontroltheexecutionofallprogramsintegratedinthepackagefromATPDraw. Severalroyalty-freetoolswithdifferentcapabilitiesarecurrentlyavailableforpostproccesing simulationresults.

ATPuserscantakeadvantageofseveralbooksforimprovingtheirknowledgeontransient analysisandtheapplicationofthistool.Althoughthisnewbookcoverstopicsalreadycoveredbyformerlyreleasedbooks,theoverlappingwithallofthemisrathersmall;themain differencesareintheorganisationofthebookandthecasestudiesthatillustratepotentialATP applications.

Actually,somereadersmightmisssomeequationsandmathematicalartefactsneededto detailanddescribetheperformanceofpowercomponentsandsystems.Thisaspecthasbeen sacrificedtogiveroomtomorepracticalaspects.Readersarereferredtootherbooksthatsatisfactorilycoverthispartofthetransientanalysis.

Itisimportanttoemphasizethat,althoughthecontentsofthebookhonouritstitle,thebook cannotbeusedasaReferenceManualorRuleBook.Inotherwords,readerswillnotlearnhow tousethepackagewiththisbook;forthatpurpose,theyshouldusetheso-calledATPRule Book,andthemanualsofthecomplementarytools(e.g.ATPDrawandtheselectedplotting program).

Themaingoalofthisbookistoprovideaclearscopeofthestudiesthatcanbecarriedout withtheATPpackage.Althoughsomecomplexstudiesandsophisticatedcustom-madesimulationenvironments(withATPasasimulationtool)arepresented,theaveragelevelofthe casesstudiedhereisintermediate;agreatmajorityofstudiesarerelatedtosmallandmedium testsystems.However,thebookcouldalsobeusefulforbeginners;Chapter5hasbeenwritten withthatpurpose.

Thechaptersofthisbookcanbeclassifiedintotwogroups;thefirstfourchaptersarededicatedtointroducethetransientanalysisofpowersystemsanddetailATPcapabilities;therestof

thebookisdedicatedtointroducesomeofthemostcommonapplicationsoftheATPpackage withalargeenoughnumberofcasestudies.

AveryimportantaspectisthecomplementarycollectionofdatafilesavailabletoATPusers fromthewebsiteofthisbook.Foreverycasestudypresentedinthebook,readerswillfindone orseveraldatafiles.WhenATPDrawcapabilitiescansatisfactorilycreateandeditadatafile, thisoptionhasbeenused;however,thereareafewcasesforwhichthosecapabilitiescannotbe used,thenthefilehasbeenmanuallyeditedusingasimpletexteditorandtakingintoaccount theformatsdetailedintheRuleBook.ThisisaveryimportantaspectaboutwhichATPusers shouldbeaware:soonerorlatersomeknowledgeofATPformatswillberequired,mainlyfor thoseinterestedindevelopingtheirowncustom-mademodels.

Inaddition,itisworthmentioningthatalthoughthisbookusesthemostimportantcapabilitiesimplementedinthesimulationtool(eithernamedasATPorTPBIG),therearedozensof ATPoptionsandrequeststhatarenotcoveredorappliedhere.Therequiredlengthforillustratingthosemissedoptionscouldeasilydoubleortriplethatofthisbook.

Itisalsoworthmentioningthatthetoolsofthepackagearecontinuouslyupdated.Thisis importantbecause,duringthepreparationofthisbook,modelsandcapabilitieswereeither addedormodified.Notallofthesemodels/capabilitieshavebeencoveredinthisbook.

Asfortheapplications,IamawarethatsomethatareofconcernformanyATPusershavenot beenincludedinthisbook.Forinstance,verylittleissaidaboutdistributedenergyresources. Thisis,withoutanydoubt,averyimportantaspect;however,althoughmorethanonehundred datafilesareprovidedwiththebook,asimilarreasoningcouldbemadeevenforapplications thatarecoveredinthebook:sometopicscouldneedmorecasestudiesforabetterunderstanding.Attheend,someselectionhadtobemade.

Althoughallthedatefilesusedinthisbookhavebeenimplementedbythecontributors, severalcasestudiesarebasedonmodelsandparametersprovidedbyotherauthors.Ingeneral, areferencetotheoriginalsourceismadeinthechapterorintheAcknowledgement.Someof thecasestudies,eveniftheyarenowimplementedinATPDraw,wereinitiallydevelopedwhen thisGUIwasnotyetreleased.Thismeansthatthosecasestudiesareratherold.Sincethetrace totheoriginalsourcewasneitherclearnoravailableforallcases,Iapologizeifourgratitudeto someauthorsisnotmentionedinanypartofthisbook.

Finally,IwanttothankDr.W.ScottMeyerandallthosewhobecameinvolvedinthedevelopmentofanyofpackagetoolsfortheirworkandeffort,withoutwhichthisbookwouldhave notbeenpublished.

Barcelona,Spain February2019

JuanA.Martinez-Velasco

AbouttheCompanionWebsite

Thecompanionwebsiteforthisbookisat:

www.wiley.com/go/martinez/power_systems

Thewebsiteincludes:

• PCHandACPfiles

ScanthisQRcodetovisitthecompanionwebsite.

IntroductiontoTransientsAnalysisofPowerSystemswithATP

1.1Overview

Transientanalysishasbecomeafundamentalmethodologyforunderstandingtheperformance ofpowersystems,determiningpowercomponentratings,explainingequipmentfailures,or testingprotectiondevices.Thestudyoftransientsisamaturefieldthatcanhelptoanalyse anddesignmodernpowersystems.

Asignificantefforthasbeendedicatedtothedevelopmentofnewtechniquesandsoftware toolsadequatefortransientanalysisofpowersystems.Sophisticatedmodels,complexsolutiontechniques,andpowerfulsimulationtoolshavebeendevelopedtoperformstudiesthat areofparamountimportanceintheanalysisanddesignofmodernpowersystems.Current toolsfortransientanalysiscanbeappliedintoamyriadofstudies(e.g.overvoltagecalculation, flexibleACtransmissionsystems(FACTS)andCustomPowerapplications,protectiverelay performance,powerqualitystudies)forwhichdetailedmodelsandaccuratesolutionscanbe crucial.

Transientphenomenainpowersystemsareassociatedwithdisturbancescausedbyfaults, switchingoperations,lightningstrikes,orloadvariations.Thesephenomenacanstress anddamagepowerequipment.Theimportanceoftheirstudyisbasicallyduetotheeffects theycanhaveonthesystemperformanceorthefailurestheycancausetopowerequipment. Therefore,protectionagainstthesestressesisnecessary.Thisprotectioncanbeprovided byspecializedequipmentwhoseoperationisaimedateitherisolatingthepowersystem sectionwherethedisturbancehasbeenoriginated(e.g.apowercomponentfailurethatcauses short-circuit)orlimitingthestressacrosspowerequipmentterminals(e.g.byinstallingasurge arresterthatwillmitigatevoltagestresses).Inaddition,abetterperformanceagainststresses causedbytransientphenomenacanbealsoachievedwithanadequatedesignofpowerequipment(e.g.byshieldingoverheadtransmissionlinestolimitflashoverscausedbydirectlightning strokes).Thatis,althoughthepowersystemoperatesmostofthetimeundernormalconditions, itmustbedesignedtocopewiththeconsequencesassociatedtotransientphenomena.

Arigorousandaccurateanalysisoftransientsinpowersystemsisdifficultduetothesize ofthesystem,thecomplexityoftheinteractionbetweenpowerdevices,andthephysical phenomenathatneedtobeanalysed.Aspectsthatcontributetothiscomplexityarethevariety ofcauses,thenatureofthephysicalphenomena,andthetimescaleofpowersystemtransients. Inordertoselectanadequateprotectionagainstanytypeofstress,itisfundamentaltoknow theirorigin,calculatetheirmaincharacteristics,andestimatethemostadverseconditions. Disturbancescanbeexternal(lightningstrokes)orinternal(faults,switchingoperations,load variations).Powersystemtransientscanbeelectromagnetic,whenitisnecessarytoanalyse theinteractionbetweenthe(electric)energystoredincapacitorsandthe(magnetic)energy TransientAnalysisofPowerSystems:APracticalApproach, FirstEdition.EditedbyJuanA.Martinez-Velasco. ©2020JohnWiley&SonsLtd.Published2020byJohnWiley&SonsLtd. CompanionWebsite:www.wiley.com/go/martinez/power_systems

storedininductors,orelectromechanical,whentheanalysisinvolvestheinteractionbetween theenergysuppliedbysources,theelectricenergystoredincircuitelements,andthemechanicalenergystoredinrotatingmachines.Toaccuratelyanalysephysicalphenomenaassociated withtransients,itisnecessarytoexaminethepowersystemforatimeintervalasshortasafew nanosecondsoraslongasseveralminutes.Thisisachallengesincethebehaviourofpower equipmentisverydependentonthetransientphenomena;namely,itdependsontherange offrequenciesassociatedtotransients.Despitethepowerfulnumericaltechniques,simulation tools,andgraphicaluserinterfaces(GUIs)currentlyavailable,thoseinvolvedintransients studies,soonerorlater,facelimitationsofthosemodelsavailableintransientspackages, thelackofreliabledataandconversionproceduresforparameterestimation,orinsufficient studiesaimedatvalidatingmodels.

Figure1.1depictsthestepsofatypicalprocedurewhensimulatingtransientsinpower systems[1].

1. Theselectionofthestudyzoneandthemostadequaterepresentationofeachcomponent involvedinthetransient .Thesystemzoneisselectedtakingintoaccountthefrequencyrange ofthetransientstobesimulated:thehigherthefrequencies,thesmallerthezonemodelled. Ingeneral,itisadvisabletominimizethestudyzonesincealargernumberofcomponents doesnotnecessarilyincreaseaccuracy;insteaditwillincreasethesimulationtimeandthere willbeahigherprobabilityofinsufficientorincorrectmodelling.Althoughahighnumber ofworkshasbeendedicatedtoprovideguidelinesontheseaspects[2–4],someexpertiseis necessarytochoosethestudyzoneandthemodels.

Casestudy Applyingmodeling guidelines

Collectinginformation andapplyingdata conversionprocedures

Usingsoftwaretool (GUI)

Usingsoftwaretoolto obtainresults

PowerSystem

System Model-1

Selectingthestudyzone andtherepresentationof powercomponents

Determiningpower componentparameters PowerSystemModel-2

Creatingtheinputfileof thetestsystem

Simulatingthetest system

Figure1.1 Simulationoftransientsinpowersystems[1].

2. Theestimationofparameterstobespecifiedinthemathematicalmodels.Oncethe mathematicalmodelhasbeenselected,itisnecessarytocollecttheinformationthat couldbeusefultoobtainthevaluesofparameterstobespecified.Detailsaboutparameter determinationofsomepowercomponentswerepresentedin[5].Asensitivitystudyshould becarriedoutifoneorseveralparameterscannotbeaccuratelydetermined.Resultsderived fromsuchstudywillshowwhichparametersareofconcern.

3. Theapplicationofasimulationtool .Thesteadilyincreasingcapabilitiesofhardware andsoftwaretoolshaveledtothedevelopmentofpowerfulsimulationtoolsthatcancope withlargeandcomplexpowersystems.Modernsoftwarefortransientanalysisincorporates friendlyGUIsthatcanbeveryusefulwhencreatingtheinputfileofthetestsystem model.

4. Theanalysisofresults.Simulationofelectromagnetictransientscanbeused,amongothers, fordeterminingcomponentratings(e.g.insulationlevelsorenergyabsorptioncapabilities),testingcontrolandprotectionsystems,validatingpowercomponentrepresentations orunderstandingequipmentfailures.Adeepanalysisofsimulationresultsisanimportant aspectoftheentireproceduresinceeachofthesestudiesmayinvolveaniterativeprocedure inwhichmodelsandparametersvaluesmustbeadjusted.

Readersinterestedintransientsanalysiscanconsultspecializedliterature[3,6–18].

1.2TheATPPackage

ATPisanacronymthatstandsforAlternativeTransientsProgram[19].TheATPpackageis integratedbyatleastthreetools:(i)ATPDraw,aGUIforcreating/editinginputfiles[20,21]; (ii)TPBIG,themainprocessorfortransientsandharmonicssimulations;(iii)onepostprocessorforplottingsimulationresults.Actually,ATPuserscanalsotakeadvantageofothertools (e.g.ATPControlCenterandATPDesigner[22]whichcanbeusedasacontrolcenterforthe entirepackage)oraddothertoolsthatcanbeusefulforsomespecifictasks.

ATPDrawisaninteractiveWindows-basedprogramthatcanactasashellforthewhole package;thatis,userscancontroltheexecutionofallmodulesintegratedinthepackagefrom ATPDraw.Asforthepostprocessor,severaltoolshavebeendevelopedtoobtaingraphical results(e.g.PCPlot,TPPLOT,GTPPLOT,TOP,PlotXY,ATPAnalyzer),anditispossibletorun mostofthemfromATPDraw.ThemostpopularpostprocessoramongATPusersisPlotXY, developedbyMaximoCeraolo(UniversityofPisa,Italy)[23].TOP(TheOutputProgram),a royalty-freetoolcreatedbyElectrotekConcepts,isthepostprocessorusedwithmostofthe casestudiespresentedinthisbook[24].

TheacronymATPwasinitiallyusedtodenotethetransientssimulationtoolherenamed TPBIG.Presently,manyusersuseATPtoindistinctlynameeitherthetransientssimulation toolortheentirepackage.

ATPwasoriginallydevelopedforsimulationofelectromagnetictransientsinpowersystems.However,thepackagecanalsobeusedtoperformACsteady-statecalculationsand simulateelectromechanicaltransients(e.g.subsynchronousresonance,ACdrives).Solution methodstosolvesystemswithnonlinearcomponentshavealsobeenimplemented[9,19]. ATPcanrepresentcontrolsystemsandinterfacethemwithanelectricnetwork.Finally,several non-simulationsupportingroutinesarealsoavailabletocreatemodeldatafiles;thesesupportingroutinescanbeusedforcomputingparametersandcreatingmodelsoflines,cables, andtransformers.Figure1.2showsaschematicdiagramoftheconnectivitybetweensimulationcapabilities,supportingroutines,externalprograms,andalltypesoffiles.Amoredetailed descriptionofATPDrawandTPBIGcapabilitiesisprovidedinChapter4.

Time-and Frequency-Domain Simulations

Figure1.2 ATPsimulationmodules,supportingroutines,andfiles.

TheapplicationsthatcanbecoveredbytheATPcanbeclassifiedasfollows:

• Time-domainsimulations.Theyaregenerallyusedforsimulationoftransients,suchas switchingorlightningovervoltages;however,theycanalsobeusedforanalysingharmonic distortioncreatedbypowerelectronicsdevices.

• Frequency-domainsimulations.ATPcapabilitiescanalsobeusedtoobtainthedrivingpoint impedanceataparticularnodeversusfrequency,detectresonanceconditions,designfilter banks,oranalyseharmonicpropagation.

• Parametricstudies.Theyareusuallycarriedouttoevaluatetherelationshipbetweenvariablesandparameters.Whenoneormoreparametercannotbeaccuratelyspecified,this analysiswilldeterminetherangeofvalueswhichmaybeofconcern.

• Statisticalstudies.SeveralATPcapabilitiescanbeappliedtoperformthesestudies(e.g.studiesbasedontheMonteCarlomethod).Theirresultscanbeofparamountimportanceinsome insulationcoordinationandpowerqualitystudies.

ATPcapabilitiescanalsobeusedtoexpandthefieldsofapplications;withthistooladata casecanbesimulatedseveraltimesbeforedeactivatingtheprogram,parametersofthesystem undersimulationcanbechangedaccordingtoagivenlaw,somecomponentscanbeeither disconnectedoractivated,andsomecalculationscanbecarriedoutbyexternalprograms.In addition,itispossible,ifrequired,tomodifythesimulationtimeonlineorthenumberofruns inaparametricstudy.

Thefollowingconceptscanbeofparamountimportanceforexpandingtheapplicationsof ATP:

• Multiplerunoption.Adatacasecanbesimulatedasmanytimesasnecessary,whilechanges areintroducedintothesystemmodelateveryrun.ThisoptionisknownasPOCKET CALCULATORVARIESPARAMETERS(PCVP);seetheATPRuleBook[19].Suchan optioncanbeusedtoperformstatisticalandparametricstudies.However,itcanalsobe usedinmanyotherapplications.Forinstance,oncethetargetofthestudyhasbeenset, PCVPcanbeusedtorunthecaseasmanytimesasrequiredwhileoneorseveralparameters aregraduallyadjustedorthesystemtopologyismodifieduntilthetargetisreached.

• Opensystem.Alinktoexternaltoolscanbeestablishedbefore,duringandafterasimulationtotakeadvantageofthecapabilitiesofthesetoolsandtoaddortestnewcapabilities. Thisoptioncanbeused,forinstance,tolinktheATPtoMATLABandtakeadvantageof itsfeatures,ortorunacustom-madeprogramthatcanderivetheparametersofapower componentusingadataconversionprocedurenotyetimplementedinthepackage.

• Datasymbolreplacement .$PARAMETERisadeclarationthatcanbeusedtoreplacedata symbolsofarbitrarylengthpriortoasimulation[19].Uptothreereplacementmodescan beused:simplecharacterreplacement(onestringisreplacedbyanotherwiththesame length),mathematicalreplacement(stringisreplacedbyanumberdeducedfromamathematicalformula),integerserialization(usedtoencodestringswithinaDOloop).Conditional branching(IF-THEN-ENDIF)isabuilt-infeaturethatcanbeusedtoselectbetweentwoor morechoices.

• Datamodule.ATP-codedtemplateshavebeenusedinthepastforthedevelopmentof datamodulesthatcouldfacilitatetheuseofthetoolbybeginners,ortosimplifytheuse ofpowercomponentsandextendmodellingcapabilitiestomorecomplexequipment[5]. Presently,custom-mademodelsarerepresentedbyamoduleanditsassociatedATPDraw icon.AlthoughthedevelopmentofnewmodulesgenerallyreliesontheroutineDATABASE MODULE,otherATPcapabilitiescanbeusedtoperformsimplecalculationswithmodule arguments,todecidewhatpartsofamodulecanbeactivatedatagivenrun,orwhatparts shouldremainsleeping.Theso-calledType94componentcouldbethebestsolutionfor developingsomenonlinearcomponents.

• Interactivity.Severalsimulationmoduleswillusuallybeinvolvedinageneralprocedure. Interactivitybetweenthemiscriticalascalculationswillbeperformedinseveralmodules. Theconnectivitybetweenapowersystemandacontrolsectiontopassvariablesinboth senseshasbeenafeaturesincetheearliestdevelopmentofcontrolcapabilities.However,it hasbeenthepossibilityofpassingalsoparameterswhathasaddedflexibilitytosomeofthe capabilitiesdescribedaboveandincreasedthetypeofapplications.

Actually,thetypeoftasksthattheATPpackagecancarryoutispracticallyunlimited. Forinstance,byusingsomesimplerulesandtakingadvantageofsomecapabilities(e.g.TO SUPPORTINGPROGRAMfeaturetorunsupportingroutines,DOloopstoserializepower components,stringreplacement),itispossibletodevelopadatasectionaimedatcreating thecodeofacomponenttakingintoaccountthetransientprocesstobesimulatedandthe informationavailable.

1.3ATPDocumentation

Thefollowingmaterialwillbeofhelpwhenusinganyofthebasictoolsthatconstitutethe package.

• Theso-called EMTPTheoryBook ,writtenbyH.W.Dommel[9],shouldbeusedbythose interestedinmodelsandsolutiontechniquesimplementedinTPBIG.Althoughthebook needstobeupdated,itisstillaveryvaluablesourceofinformationforusersofanytransients tool.

• Therulestobefollowedforcreatinganinputdatafilearepresentedinthe ATPRuleBook [19].AlthoughtheaverageuserwillcreateandruninputdatafilesbyrelyingonlyontheGUI ATPDraw,therearemanysituationsforwhichtheRuleBookwillbeanecessaryresource. ExampleswhereauserwillneedtoconsulttheRuleBookarethosecasestudiesinwhichthe controlsectionisbasedonMODELSlanguage(seeChapter4)orthoseapplicationsforwhich custom-mademodelsbasedonDATABASEMODULEmightberequired(seeChapter9).

• ATPDrawiscurrentlythegateusedbymostATPusersforcreatingandrunningcasestudies. Althoughbasedonafriendlyenvironmentandeasytouse,ATPDrawhasmanycapabilities andnotallofthemareobvious;the ATPDrawReferenceManual canbethenavaluablesource forconsultation[20,21].

Ingeneral,postprocessingtools(e.g.PlotXY,TOP)areeasytouseandthehelpcapabilities availableinmostofthemareclearenough.

1.4ScopeoftheBook

Thisbookprovidesabasicbackgroundonthemainaspectstobeconsideredwhenperforming transientsstudieswithATPandascopeofthepackageapplications.Thechaptersarededicatedto

• summarizingmodellingguidelinesintransientsimulationsandthemostbasicsolutiontechniquesimplementedinATP;

• coveringthemainapplicationfieldsofATP(overvoltagecalculation,rotatingmachine dynamics,protectionofpowersystems,powerelectronicsapplications,powerquality studies);

• describingtheprocedureandselecttheATPcapabilitiesthatcanbeusedforbuilding custom-mademodels;

• providingsomeinsightsabouttheconstructionofsimulationenvironmentsinwhichATPis thetooldedicatedtocarryouttransientcalculations.

Themantopicscoveredbyeachchapteraresummarizedinthefollowingparagraphs.

Modellingofpowercomponents.Therepresentationofpowercomponentsfortransientsstudiesdependsofthephenomenatobeanalysed(i.e.thecause,therangeoffrequencieswith whichthetransientoccurs,thecomponentsinvolvedinthetransient).Chapter2provides asummaryoftheguidelinestobefollowedwhenrepresentingsomeofthemostimportant powercomponentsinatransientstudy.Modellingguidelineswillalsobeprovidedinother chapters,andsummarizedinmostofthecasestudiespresentedinthisbook.

Solutiontechniques.ATPisanoff-linecircuit-orientedsimulationtoolthatcanbeusedtosimulatetransientsinpowersystemsusingatime-domainsolutiontechnique[9].However,the steady-stateofthesystemunderstudy,priortothecalculationofatransientprocess,isusuallyrequired,anditscalculationisperformedinthefrequency-domain.Chapter3detailsthe solutiontechniquesimplementedinATPforsteady-stateandtransientsolutionsofpower andcontrolsystems.

ATPcapabilitiesandapplications.ATPcapabilitiescanbeusedtosimulatepowersystems, developcustom-mademodels,orcreatenewsimulationenvironments.Asalready mentioned,ATPcanbeappliednotonlyforsimulationofelectromagnetictransients

butalsotoanextensiverangeofstudies.Chapter4detailsthecapabilitiesandbuilt-in modelsavailableinATP.Thechapterwillincludeafewexamplestoillustratetherangeof applicationsofthepackage.

Introductiontothesimulationofpowersystemstransients.Chapter5presentsthesimulation ofsomesimplecasestudiesusingtheATPpackage.Thechaptersummarizestheprocedure tobefollowedwitheachmoduleoftheATPpackage;discussesthemodellingguidelinesto beapplied,andanalysestheresultsobtainedfromeachcasestudy.Theselectedexamples willillustratetheusageofelementarylinearandnonlinearcomponents,witheitherlumpedand/ordistributed-parametercomponents.

Calculationofovervoltagesinpowersystems.Anovervoltageisavoltagehavingacrestvalue exceedingthecorrespondingcrestofthemaximumsystemvoltage.Overvoltagescanoccur withaverywiderangeofwaveshapesanddurations.Causesandmaincharacteristicsofovervoltagesarewellknown,andtheyareclassifiedinstandards(IEC,IEEE).Forinstance,the magnitudeofexternallightningovervoltagesremainsessentiallyindependentofthesystem design,whereasthatofinternalswitchingovervoltagesincreaseswiththeoperatingvoltage ofthesystem.Theestimationofovervoltagemagnitudesandshapesisfundamentalforthe insulationdesignofpowercomponents,andfortheselectionofprotectivedevices[25,26]. Chapter6analysesthedifferenttypesofovervoltagesandtheircauses,summarizesmodellingguidelinesforovervoltagecalculationwithATP,andpresentssomeillustrativecasesof overvoltages.

Simulationofrotatingmachinedynamics.TwooptionsareavailableinATPforrepresenting conventionalrotatingmachines:theThree-PhaseSynchronousMachinemodelandthe so-calledUniversalMachinemodule[19].Todate,thesecapabilitieshavemostlybeen usedtosimulateonlythree-phasesynchronousandinductionmachines.However,the applicationsareendlessandasignificantexperienceisalreadyavailable.Chapter7providesa summaryofthefeaturesavailableinthetwooptions,summarizesthemethodsimplemented forinterfacingtherotatingmachinemodelstothepowersystem,andincludesseveral illustrativeexamplesthatwillcoversomeofthemostimportantapplicationsofATPinthe studyofrotatingmachinedynamics.

Simulationofpowerelectronicsdevices.Powerelectronicsapplicationshavequicklyspreadto allvoltagelevels,fromhigh-voltagetransmissiontolow-voltagecircuitsinend-userfacilities[27–29].Modellingandsimulationofpowerelectronicsdevicesareimportanttasksfor conceptvalidationanddesignofnewdevices.Chapter8providesgeneralmodellingguidelinesandproceduresforsimulationofpowerelectronicsdevicesusingATPcapabilities, andpresentsseveralcasestudiesthatwillcoversomeimportantapplications(FACTSand CustomPowerdevices,drives,solidstatetransformer)ofthepackageinthisfield.

Developmentofcustom-mademodelsandlibraries.Severalcomponentmodelsneededinsome studies(e.g.protection,powerquality)arenotavailableintheATP.However,manycapabilitiesofthepackagecanbeusedtodevelopcustom-mademodelsaimedatrepresenting missedcomponents.Chapter9showshowATPcapabilitiescanbeusedforthedevelopment ofalibraryofcomponentmodulesthatcanbecalledfromATPDrawasbuilt-inmodels[30]. Thechapterdetailsthestepstobemadeforthedevelopmentofalibraryofmodelsaimed atcarryingoutpowerqualitystudies.Powerqualityisamultidisciplinaryarearelatedtothe assessment,analysis,characterization,andquantificationofthemutualinteractionbetween theutilityanditscustomers(i.e.theinteractionequipmentandthepowersystem).Theconceptcanbeconsideredasacombinationofvoltageandcurrentquality,soitis,therefore, concernedwithdeviationsofvoltageandcurrentfromtheidealsingle-frequencysinewaves ofconstantamplitudeandfrequency.Powerqualitydisturbancescanbegenerallyclassified intwocategories:variations(smalldeviationsofvoltageand/orcurrentcharacteristicsfrom

theirnominalordeclaredvalue/waveform)andevents(largedeviationsofvoltageorcurrentcharacteristicsfromtheirnominalordeclaredvalues/waveforms)[31,32].Thechapter showshowtheATPcapabilitiescanbeusedtoanalysetheeffectofvoltagedips,assessdistortioncausedbyharmonicsources,andsimulatetechniquesformitigatingvoltagedipsand harmoniccurrents.

Protectionsystems.Protectionsystemsarecriticalcomponentsandtheirbehaviourisanimportantpartofthepowersystemresponsetoatransientevent.Asystemaimedatprotectingagainstovercurrentsconsistsofthreemajorparts:instrumenttransformers(current, woundelectromagneticvoltage,andcapacitorvoltagetransformers),protectiverelays,and circuitbreakers[33,34].Chapter10summarizesmodellingguidelinesforrepresentingthe powersystem,instrumenttransformersandthedifferenttypesofrelays(electromechanical,static/electronic,microprocessor-based)atbothtransmissionanddistributionlevels usingATPcapabilities.Thechapterincludessomecasestudiesthatillustratethepotential ofATPinthisfield,andtheapplicationofcustom-mademodelsdevelopedforrepresenting distribution-levelprotectivedevicesfollowingtheprocedureproposedinChapter9.

Advancedapplications.ATPuserscandevelopsimulationenvironmentsinwhichATPcapabilitiesarecombinedwithcapabilitiesfromothersimulationtools.Suchcombinationscan allowuserstocreatepowerfultoolsthatareabletosignificantlyexpandATPapplications. Chapter11proposesageneralprocedurebasedonaMATLAB-ATPlinkandtheusageofa multicoreenvironmenttoexpandATPapplicationsandreducesimulationtimes.Thechapter detailsthreedifferentcasestudiesthatshowhowATPcanalsobeusedasadesigntoolthat couldbeappliedtostudiesthatrequireadditionalcapabilities.

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20 Høidalen,H.K.,Prikler,L.,andHall,J.L.(1999).ATPDraw–GraphicalpreprocessortoATP, Windowsversion.PresentedattheIPST’99inBudapest,Hungary(June1999).

21 Prikler,L.andHøidalen,H.K.(2002). ATPDrawforWindowsUser’sManual ,SEFASTR F5680.

22 Kizilcay,M.andHoidalen,H.K.(2015).EMTP-ATP.In: Chapter2ofNumericalAnalysisof PowerSystemTransientsandDynamics (ed.A.Ametani).Stevenage(UnitedKingdom):The InstitutionofEngineeringandTechnology.

23 Ceraolo,M.(2018).Experiencesincreatingasoftwaretooltoanalyzeandpostprocess simulatedandmeasureddata. Software:PracticeandExperience 48(12):2380–2388.Visit thefollowinglinkhttp://ceraolo-plotxy.ing.unipi.it/default.htm.

24 Grebe,T.andSmith,S.(1999).Visualizesystemsimulationandmeasurementdata. IEEEComputerApplicationsinPower 12(3):46–51.

25 Ragaller,K.(ed.)(1980). SurgesinHigh-VoltageNetworks.NewYork(NY,USA):Plenum Press.

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ModellingofPowerComponentsforTransientsStudies

2.1Introduction

Theaccuratesimulationoftransientphenomenarequiresarepresentationofnetworkcomponentsvalidforafrequencyrangethatvariesfromdirectcurrent(dc)todozensofMHz.On theotherhand,suchsimulationimpliesnotonlytheselectionofcomponentmodelsbutalso theselectionofthesystemareathatmustberepresented.Therulestobeconsideredwhen selectingmodelsandthesystemareaforthesimulationofelectromagnetictransientscanbe summarizedasfollows[1]:

1)Selectthesystemzonetakingintoaccountthefrequencyrangeofthetransients;thehigher thefrequencies,thesmallerthezonetobemodelled.

2)Minimizethepartofthesystemtoberepresented.Anincreasednumberofcomponentsdo notnecessarilymeanincreasedaccuracy,astherecouldbeahigherprobabilityofinsufficient orincorrectmodelling.Inaddition,averydetailedrepresentationofasystemwillusually requirelongersimulationtime.

3)Implementanadequaterepresentationoflosses.Sincetheireffectonmaximumvoltages andoscillationfrequenciesislimited,theydonotplayacriticalroleinmanycases.However, therearesomecases(e.g.ferroresonanceorcapacitorbankswitching)forwhichlossesare criticaltodefiningthemagnitudeofovervoltages.

4)Consideranidealizedrepresentationofsomecomponentsifthesystemtobesimulatedis toocomplex.Suchrepresentationwillfacilitatetheeditionofthedatafileandsimplifythe analysisofsimulationresults.

5)Performaparametricstudyifoneorseveralparameterscannotaccuratelybedetermined. Resultsderivedfromsuchastudywillshowwhichparametersareofconcern.

Modellingofpowercomponentstakingintoaccountthefrequency-dependenceofparameterscanbeachievedcurrentlythroughtheuseofmathematicalmodelswhichareaccurate enoughforaspecificrangeoffrequencies.Eachrangeoffrequenciesusuallycorrespondsto someparticulartransientphenomena.Oneofthemostacceptedclassificationsdividesfrequencyrangesintofourgroups[2,3]:low-frequencytransients,from0.1Hzto3kHz,slowfronttransients,from50/60Hzto20kHz,fast-fronttransients,from10kHzto3MHz,very fast-fronttransients,from100kHzto50MHz.Notethatthereisoverlapbetweenfrequency ranges.

Ifarepresentationisalreadyavailableforeachfrequencyrange,theselectionofthemodel maysupposeaniterativeprocedure:themodelmustbeselectedbasedonthefrequencyrange ofthetransientstobesimulated;however,thefrequencyrangesofthecasestudyarenot usuallyknownbeforeperformingthesimulation.Thistaskcanbealleviatedbylookinginto

TransientAnalysisofPowerSystems:APracticalApproach, FirstEdition.EditedbyJuanA.Martinez-Velasco. ©2020JohnWiley&SonsLtd.Published2020byJohnWiley&SonsLtd. CompanionWebsite:www.wiley.com/go/martinez/power_systems

2ModellingofPowerComponentsforTransientsStudies

widelyacceptedclassificationtables;see[1].Muchefforthasbeendedicatedtoclarifythemain aspectstobeconsideredwhenrepresentingpowercomponentsintransientsimulations.Nowadaysusersofelectromagnetictransientstoolscanobtaininformationonthisfieldfromseveral sources[3–5].

Thischapterprovidesashortsummaryofthemodellingguidelinessuggestedforrepresenting powersystemcomponentsinvolvedinthegenerationanddeliveryofelectricenergy.

2.2OverheadLines

2.2.1Overview

Theselectionofanadequatelinemodeliscrucialinmosttransientstudies.Voltagestressesto beconsideredinoverheadlinedesigncanalsobeclassifiedintogroups,eachonehavingadifferentfrequencyrange[6–8]:(i)power-frequencyvoltagesinthepresenceofcontamination; (ii)temporary(low-frequency)overvoltagesproducedbyfaults,loadrejectionorferroresonance;(iii)slow-frontovervoltagesproducedbyswitchingoperations;(iv)fast-frontovervoltages,generallycausedbylightningflashes.

Twotypesoftime-domainmodelshavebeendevelopedforoverheadlines:lumped-and distributed-parametermodels.Theappropriateselectionofamodeldependsonthehighest frequencyinvolvedinthephenomenonunderstudyand,tolessalesserextent,ontheline length.

Lumped-parameterlinemodelsrepresenttransmissionsystemsbylumped R, L, G, and C elementswhosevaluesarecalculatedatasinglefrequency.Thesemodels,knownasPImodels, areadequateforsteady-statecalculations,althoughtheycanalsobeusedfortransientsimulationsintheneighbourhoodofthefrequencyatwhichparameterswereevaluated.Themost accuratemodelsfortransientcalculationsarethosethattakeintoaccountthedistributednature ofthelineparameters[3–5].Twocategoriescanbedistinguishedforthesemodels:constant parametersandfrequency-dependentparameters.Thenumberofspansandthedifferenthardwareofatransmissionline,aswellasthemodelsrequiredtorepresenteachpart(conductors andshieldwires,towers,grounding,insulation),dependonthecauseofthevoltagestress.The followingrulessummarizethemodellingguidelinestobefollowedineachcase[9].

1.Inpower-frequencyandtemporaryovervoltagecalculations,thewholetransmissionline lengthmustbeincludedinthemodel,butonlytherepresentationofphaseconductorsis usuallyneeded.Amulti-phasemodelwithlumpedandconstantparameters,includingconductorasymmetry,willgenerallysuffice.Fortransientswithafrequencyrangeabove1kHz, afrequency-dependentmodelcouldbeneededtoaccountforthegroundpropagationmode. Coronaeffectcanalsobeimportantifphase-conductorvoltagesexceedthecoronainception voltage.

2.Inswitchingovervoltagecalculations,amulti-phasedistributed-parametermodelofthe wholetransmissionlinelength,includingconductorasymmetry,isgenerallyrequired.Asfor temporaryovervoltages,frequency-dependenceofparametersisimportantfortheground propagationmode,andonlyphaseconductorsneedtoberepresented.

3.Thecalculationoflightning-causedovervoltagesrequiresamoredetailedmodel,inwhich towers,footingimpedances,insulatorsandtowerclearances,inadditiontophaseconductorsandshieldwires,arerepresented.However,onlyafewspansatbothsidesofthepoint ofimpactmustbeconsideredinthelinemodel.Sincelightningisafast-fronttransient phenomenon,amulti-phasemodelwithdistributedparameters,includingconductorasymmetryandcoronaeffect,isrequiredfortherepresentationofeachspan.

Thelengthextentofanoverheadlinethatmustbeincludedinamodeldependsonthe typeoftransienttobeanalysed.Asaruleofthumb,thelowerthefrequencies,themore lengthoflinetoberepresented.Forlow-andmid-frequencytransients,thewholelinelength isincludedinthemodel.Forfast-frontandveryfast-fronttransients,afewlinespanswill usuallysuffice.

Thefollowingsubsectionsarerespectivelydedicatedtopresenttheequationsneeded tomodelmulti-conductorlines,andthemodelstobeconsideredforrepresentingtowers, groundingimpedancesandinsulators.Seereference[9]formoredetailsoneverysubject.

2.2.2Multi-conductorTransmissionLineEquationsandModels

2.2.2.1TransmissionLineEquations

Figure2.1depictsadifferentialsectionofamulti-conductoroverheadlineillustratingthecouplingsamongseriesinductancesandamongstshuntcapacitances.Thebehaviourofthislineis describedinthefrequencydomainbytwomatrixequations:

d Vx (ω)

dx = Z(ω) Ix

where Z(ω)and Y(ω)arerespectivelytheseriesimpedanceandtheshuntadmittancematrices perunitlength.

Theseriesimpedancematrixofanoverheadlinecanbedecomposedasfollows:

Z(ω)= R(ω)+ jωL(ω) (2.2) where Z isacomplexandsymmetricmatrix,whoseelementsarefrequency-dependent.For transientanalysis,elementsof R and L mustbecalculatedtakingintoaccounttheskineffect inconductorsandground.ThisisachievedbyusingeitherCarson’sgroundimpedance[10],or Schelkunoff’ssurfaceimpedanceformulaeforcylindricalconductors[11].

Theshuntadmittancecanbeexpressedasfollows:

where Y isalsoacomplexandsymmetricmatrix,withfrequency-dependentelements.Ingeneral,elementsof G canbeassociatedwithcurrentsleakingtogroundthroughinsulatorstrings, whichcanmainlyoccurwithcontaminatedinsulators.Theirvaluescanusuallybeneglectedfor moststudies;however,undercoronaeffectconductancevaluescanbesignificant.Thatis,under non-coronaconditions,withcleaninsulatorsanddryweather,conductancescanbeneglected.

Figure2.1 Differentialsectionofathree-phaseoverheadline.

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