Accurate Fault Location Method of Distribution Network with Limited Number of PMUs

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2018ChinaInternationalConferenceonElectricityDistributionTianjin,17-19Sep.2018AccurateFaultLocationMethodofDistributionNetworkwithLimitedNumberofPMUsXiChen,ZaibinJiao,Member,IEEESchoolofElectricalEngineering,Xi’anJiaotongUniversity,Xi’an710000,Chinathefaultlocationisparticularlyimportant[1].FastandaccurateAbstract—Accuratefaultlocationofdistributionnetworkisoffaultlocationnotonlycanletrepairoffaultlineasquicklyasgreatsignificanceforimprovingthereliabilityofpowersupplypossible,butalsoisofgreatsignificancetoensurethesafe,andreducingthelosscausedbycontinuouspoweroutage.stableandeconomicoperationoftheentirepowersystem.However,duetothedistributionnetworkshavemultiplefeedersAtpresent,thealgorithmofdistributionnetworkfaultandshorterlengthsofeachfeeder,whicharedifferentfromthetransmissionnetwork,makingitmoredifficulttolocatefaults.Inlocationcanbedividedintoimpedancemethod,injectionthispaper,basedonthecharacteristicsofthedistributionmethodandtravelingwavemethod[2].Theimpedancemethodnetwork,anaccuratefaultlocationmethodofdistributioncalculatestheimpedanceofthefaultcircuitbyusingthenetworkisdevelopedusinglimitednumberofsynchronizationvoltageandcurrentmeasuredatthefaulttimeandfindthefaultphasemeasurementunits(PMUs).Themethodincludingtwodistanceaccordingtotheprinciplethatthelengthofthelineissteps:First,basedonthedistributionparametermodel,aftertheproportionaltotheimpedance.Themethodissimpleandeasyfaultshappen,thevoltageandcurrentinformationfromthePMUsinstalledattheendofthelinewillbecollectedtocalculatetoimplement,butgreatlyaffectedbythetransitionresistance,thevoltageattheheadendofthebranchingpoint,ifthefaultlineatthesametime,pseudo-faultpointscannotbeexcludedwithexistsfaultbranch,theheadendvoltageofthefaultbranchwillbemultiplebranchesofdistributionnetwork[3].Theinjectionabnormal.Then,thefaultdistancecouldbecalculatedbasedonmethodinjectsaspecialsignalfromsecondarydevicesuchasvoltagedistributionalongthetwoendsofthefaultbranch.Thevoltagetransformerintothesystemanddetectsthesignaltoeffectivenessoftheproposedalgorithmisverifiedbylocatethefaultafterthefaulthappen.Theinjectionmethodelectromagnetictransientsimulation.ThesimulationresultshowsthattheproposedalgorithmonlyuselimitednumberofPMUstoincludesSinjectionmethod,portfaultdiagnosismethodandlocatefaultaccuratelywithouttheneedofPMUsonbothendsoftransferfunctionalgorithm[4].TheSinjectionmethodinjectsalines,whichisnotaffectedbytransitionresistanceandfaulttype.specialsignalusingavoltagetransformerthatistemporarilyEnsuringhighaccuracy,theproposedmethodisalsoveryidleduringfault,thenlocatesthefaultaccuratelybysearchingeconomicandhaswellapplicationprospects.theinjectedsignal[5].Theportfaultdiagnosismethodbasedonthenetworkportequation,itinputsaspecificsignalandIndexTerms—Distributionnetwork,PMU,thechangeofconstructsacriterionbydetectingandcalculatingthechangeofvoltagealongtransmissionline,faultlocationthesignalbeforeandafterfailuretolocatethefault[6].TheI.INTRODUCTIONtransferfunctionalgorithmisbasedonthespectrumanalysisprincipleandthelinedistributionparametermodelandinputsaistributionnetworkislocatedattheendofthepowerDspecificsignaltoestablishatransferfunctionofthedistributionsystem,closelyrelatedtopowerconsumers.Withthenetwork.Thespectrumcharacteristicsofthetransferfunctionrapiddevelopmentofdistributionnetworks,usershaveobtainedbyeachbranchareusedtodeterminethefaultpointrequestedhigherreliabilityandqualityofpowersupply:after[7].Atpresent,portfaultdiagnosisandtransferfunctionthefaultshappen,itisnecessarytofindthefaultlocationandalgorithmaredifficulttoputintopracticalusage.OnlySrecoverthepowersupplyinthenon-faultyareaquicklyandinjectionmethodhassomeproductions[8],butspecialaccurately,reducingthepoweroutageareaandduration,thusinjectionsignalsourceandauxiliarydetectiondeviceareneededrisingtheinvestmentcost.ThetravelingwavemethodThisworkwassupportedinpartbytheKeyProjectofSmartGridTechnologyandEquipmentofNationalKeyResearchandDevelopmentPlaniswidelyusedinfaultlocationonhighvoltagetransmissionofChina.Projectno.2017YFB0902903.network[9].BymeasuringthepropagationtimeofthevoltageXiChenispursuingherM.Sc.atXi’anJiaotongUniversity,Xi’an,China.andcurrenttravelingwavebetweenthefaultpointandthebusCurrently,shefocusesonfaultlocationofdistributionnetworkandsmartdistributiongrid,xichen@stu.xjtu.edu.cntolocatethefaultwithhighaccuracy[10].DuetotheZaibinJiaoreceivedhisPh.D.degreefromXi’anJiaotongUniversity,Xi’an,distributionnetworkhasmanybranchesandshortlines,theChinaandcurrentlyworksasanAssociateProfessor.Hisresearchinteresttravelingwaveisdeflectedmultipletimes,whichmakestheincludespowersystemprotectionandnewenergy.CICED2018PaperNo.201804270000494Page1/51503

12018ChinaInternationalConferenceonElectricityDistributionTianjin,17-19Sep.2018faulttravelingwaveheaddifficulttodetect,soitisdifficulttofeederthroughtheabnormalityofthevoltageattheheadend.applythatmethodondistributionnetwork.Inaddition,theThen,basedontheprincipleofvoltagedistributionalongthedistributionnetworkfeedershavemultiplebranchesandshortfeeder,thefaultpointvoltageequationscouldrespectivelybelengthscomparedwiththetransmissionlines,whichalsorepresentedbythevoltageandcurrentinformationatbothendsincreasethedifficultyoffaultlocation.ofthefaultfeeder,andlocatefaultbysolvingtheequationWiththestudyofpowersystemsynchronizationinformationjointly.Thealgorithmproposedinthispaperrequireslessmeasurementmethods,PMU(PhasorMeasurementUnit)hasconfigurationofthePMUinthedistributionnetwork.Itonlybeenwidelyusedinfaultlocationinrecentyears[11-15].TheneedtoinstallthePMUontheexitsideofthetransformerandPMUisadevicetomeasure,outputanddynamicallyrecordtheendofthemainfeeder.Whenthereisnobranchafterthesynchronizedphasors[11].Thedevicesynchronouslycollectsmainfeederbus,ThePMUcanbeinstalledasaterminalbus,assub-secondanalogvoltageandcurrentsignalswiththehelpofshowninFigure1,whichreducesequipmentinvestmentandglobalpositioningsystem(GPS)andtransmitittodatacenter.hasgoodapplicationprospects.ThedispatchcentercanobtainthesynchronizedphasoroftheNentirepowergridinreal-time.Inref.[12],thePMUdetectsthefaultdomainbyreal-timemonitoringofthesuddenriseofthePMUPcurrent,thenlocatesthefaultinthefaultdomain.ThealgorithmGZTMO’OcanquicklyfocusonthefaultareawithoutfurtherderivingthePMUQbranchinformation.Ref.[13]proposedamethodtoaccomplishPMUdouble-endfaultlocationwithhelpofsynchronizationPMUcharacteristicsofPMU,whichimprovedtheaccuracyandRreal-timeperformanceofdynamicsynchronizedphasorPMUmeasurement.Inref.[14],basedonthefinitePMU,thesystemStopologyandthePMUnodeareusedtodividethelocalizationPMUdomain.ThealgorithmhasstrongadaptiveabilityandgoodFigure1.AnexampleofsettinglimitednumberofPMUsindistributionpositioningresults.Inref.[15],alocationmethodisproposednetworkthat,traversethedistributionnetworklinefirst,usingPMUdatatocalculatepossiblefaultpoints,thenexcludepseudo-faultII.DISTRIBUTIONNETWORKFAULTLOCATIONBASEDONpointsbythephasechangefrommeasuringpointandfaultPMUS’MEASUREMENTpointtoachievefaultlocation.Consideringasymmetricload,asymmetricalfaultandWiththeapplicationofPMUinfaultlocation,itispossiblenon-asymmetricfeeder,thesymmetrycomponentmethodistolocatethefaultbycollectingsynchronizedphasorsatbothadoptedinthispaper,andthephase-sequencetransformationisendsoftheline[13-15].Thefaultlocationalgorithmbasedonperformedbytheequation(1).ThenetworkisdecomposedintothePMUmeasurementresultsatbothendsofthelinehastheasymmetricthree-ordernetworktorealizethedecouplingadvantagesofstrongadaptiveability,highaccuracyandlessbetween3-phasefeeders.calculation[16-17].However,whenapplyingthismethodonlarge-scalepowergrid,allnodesoftheentirenetworkneedtoFa111Fa(1)beconfiguredwithPMU.Thedistributionnetworkhasmultiple2FaaF=1(1)ba(2)branches,consideringtheinvestmentcost,itisimpossibletoFaa21Fca(0)installPMUatbothendsofeachfeeder[18].Thoughtheinvestmentcostislimited,itisnecessarytoensuretheaccuracy13Whereaistransformationfactorandaj=−+，ofthefaultdistance,soitisneedtostudythepreciselocation22algorithmwhenconfiguringalimitednumberofPMUsinthe213distributionnetwork.aj=−−.AccordingtothenewlimitationofPMUinthecurrent22distributionnetwork[19],thispaperstudieshowtojudgetheAccordingtothepowersystemnetworklaw:nomatterwhatfaultfeederbasedonalimitednumberofPMUsfirst[20],thentypeoffaultoccurs,theremustbeapositivesequencenetwork.calculatethefaultdistance,andfinallyrealizetheaccuratefaultThispaperonlyanalyzespositivesequencecomponentnetworklocationofdistributionnetwork.Thealgorithmproposedinthisatthemomentoffault.paperfirstlyusesthePMUstomeasurethesynchronousA.Faultfeederjudgmentvoltageandcurrentinformationofeachfeeder,calculatestheInthedistributionnetworkgriddiagramofFigure1,thevoltageattheheadendofeachfeeder,andjudgesthefaultyPMUisinstalledattheendofthefeeder.Foranyfeeder,iftheCICED2018PaperNo.201804270000494Page2/51504

22018ChinaInternationalConferenceonElectricityDistributionTianjin,17-19Sep.2018voltageUandcurrentIattheendofthefeederareknown,InputPMUsupload22electricmeasurementsthecircuittheoremcanbeusedtocalculatethevoltageUat1thefirstendofthefeeder:CalculatethefurthestbranchlineP,QtothebranchpointU=+⋅ULZI(2)122O'terminalvoltagewhereListhefeederlength,Zisunitlengthimpedance.TheheadendvoltageofthefeederunderthesamebranchThepointisequal,thatis,thevoltagevalueatthebranchpointisNheadendvoltagesuniquelydetermined.ThecircuitdiagramofthefaultfeederiscalculatedbyPandQareshowninFigure2.equalP,QlinefailYI′1I′xZ⋅f()LxZ−⋅2CalculatetheOheadendvoltageofbranchlineM、N、R、SCalculatethevoltageofU′anynon-faultbranchlineU′21IftothebranchpointOTheNheadvoltagescalculatedbyeachlinecalculatetheO'voltageareequalYFailureofM,Figure2.ThecircuitdiagramofthefaultfeederN,R,SlinesPorQheadendvoltageThefaultoccursatpointfwhichisxlengthfromfeederisdifferencewiththeO'ThelineOO'failvoltagesisdeterminedastheheadendvoltagethefaultlinehead,andthevoltageU′attheheadofthefaultfeederisdiffersisthefaultline1fUUlZIx′′=′+⋅+⋅ZI(3)12020fOutputthejudgmentresultwhereU′isthevoltageoffaultfeederhead,U′isthevoltage12Figure3.Theflowchartfordeterminingthefaultfeederoffaultfeederend,I2′isthecurrentoffaultfeederend,IfisB.Faultlocationmethodbasedonvoltagedistributionthefaultcurrent.theoryalongtransmissionlineWhenfaultfeederisunknown,calculatetheheadendvoltageAfterthefaultyfeederjudgedbytheproposedmethod.ofthefeederatsamebranchpoint,thevoltageattheheadendAccuratefaultlocationcouldbeachievedbasedonthelocationofthefaultyfeedercalculatedbyequation(2)is:ofthefaultyfeeder.ThevoltageandcurrentattheheadendofthefaultfeedercouldbeobtainedbyusingthecircuittheoremU′=+⋅U′′lZI(4)1f202withthenormalandadjacentnode,andtheterminalvoltageandBecausethefaultybranchcontainsfaultyfeederisnottakencurrentarecollectedbythePMU.intoaccount,thereisanerrorbetweenthecalculatedvalueandIfthevoltageandcurrentatoneendofthelineareknown,thetruevalueoftheheadendvoltage:accordingtothetransmissionlineequation(6),thevoltageandcurrentatthepointdistancelfromtheOcanbecalculatedas:∆=−UU′U′=⋅xZI(5)11ff0UcoshγγlZcsinlUTherefore,thefaultyfeederhaserroroftheheadendvoltage=sinhγlo(6)calculatedbytheformula(2)comparedwiththetruevalue.IIcosγloZComparingtheheadendvoltagecalculatedbyformula(2)onceachfeederfromsamebranchpoint,becausethecalculatedwhereZispositivesequenceimpedanceandZ=ZY/，ccvalueonfaultyfeederhasanerrorfromthetruevalue,theandYisgroundadmittanceofunitlength,γispropagationjudgmentofthefaultfeedercanberealized.FortheexampledistributionnetworkinFigure1,afterthefailure,theflowchartcoefficientandγ=ZY.ofdeterminingthefaultyfeederisshowninFigure3:ForthefaultdiagraminFigure4,theheadendofthefeederismarkedM,theendismarkedasN,whilethefeederlengthisL.ItisassumedthatfaultpointfdistancesxtopointM.CICED2018PaperNo.201804270000494Page3/51505

32018ChinaInternationalConferenceonElectricityDistributionTianjin,17-19Sep.2018UMUNb0=0.007μF/km.II1NNfNMN端端xGZTPMUPMO2O’1234mQPMUPMU2000mFigure4.ThediagramofthefaultfeederAccordingtothetransmissionlineequation(6),thevoltageRPMUphasoroffaultpointfcouldbeexpressedbythevoltageUMandcurrentIas:PMUSMFUxUchxIZshx()=γγ−(7)MfMMcandthevoltagephasorofthefaultpointcouldalsobeexpressedPMUbythevoltageUandcurrentIas:Figure5.SimulationdistributionnetworkwithlimitedPMUsNNThepowerdistributionsystemisusuallyaneutralpointUxUchLxIZshLx()=γγ()−−()−(8)NfNNcungroundedsystem,thustheexampleinthispapermainlyThevoltageatsamepointshouldbeequal:analyzesphase-to-phasefaultsandthree-phasefaults.SetUxUxMf()=Nf()(9)differentfaultscenariosofcorrespondingfaultlocationsand1faulttypesasshowninTable1:γγxx−Bringintothehyperbolicfunctioncoshxee=(+)Table1.Differentfailurescenarios2FaultscenarioFaultlocationFaulttype1γγxx−andsinhxee=(−),theequationaboutthefaultSONAB21distancexcouldbeexpressedas:S2OO′ABG(U−IZe)(γl−+UIZ)e2γx=NNcMMc=A+jB(10)S3O′PABC−+(UIZe)(−γl+−UIZ)NNcMMcSOSAB4Noteγasγαβ=+j,findthefaultdistancebyequalizingA.Faultfeederjudgmenttherealandimaginarypartsonbothsidesoftheequation(10):BApplythefaultscenariosinTable1tothemodeldiagram2βx=arctan()(11)showninFigure5andjudgethefaultfeederbasedontheflowAchartinFigure3,theresultsofthejudgmentareshownas:Further,Table2.Faultfeederpositioningresult1Bx=arctan()(12)FaultscenariosFaultlocationresult2βASON1Solvingthefaultdistancexcanbeachievedbysubstitutingparameters.S2OO′SO′P3III.SIMULATIONSOS4Aimingatthemethodoffaultlocationinthispaper,ComparingthesimulationresultwiththefaultlocationinthePSCAD/EMTDCelectromagnetictransientsimulationfaultscenariosinTable1,itcanbeconcludedthatthealgorithmsoftwareisusedforverification.AsshowninFigure.5,thecanaccuratelydeterminethefaultyfeederandhashighdistributionnetworkwithlimitedPMUshastwobuses,attheaccuracy.outletsideofthetransformerMandthefeederterminalN,P,Q,R,SPMUsareinstalledtomonitorthefeederinformationatB.Precisefaultlocationreal-time.Gis35kVpowersupply,ZTisthetransformer,theAfterthefaultyfeederisjudged,faultlocationisperformedratedvoltageis35kV/10.5kV,ON,OO',O′P,O′Q,OR,OSareforthefaultsceneS.ThefaultyfeederOSheadendvoltage4feeders,andthelengthofthemareshowninthelabels.ThesupposesasthevoltageatM,andthecurrentcouldbeobtainedfeederparametersareassumedas:r1=0.096Ω/km，r0=0.23bytheKCLthroughtheadjacentfeeder.SetdifferentfaultΩ/km；x1=0.3833Ω/km，x0=1.15Ω/km；b1=0.011μF/km，CICED2018PaperNo.201804270000494Page4/51506

42018ChinaInternationalConferenceonElectricityDistributionTianjin,17-19Sep.2018distancesandtransitionresistances.Thefaultlocationresults[3]FWang,HZhou,WHu,etal.SummaryofDistributionNetworkFaultLocationTechnique[C].//InternationalConferenceonElectricalareshowninTable3.Engineering&ControlEngineering,2011:2604-2609.Table3.Precisefaultlocationsimulationresult[4]JITao,SUNTongjing,XUEYongrui,etal.CurrentstatusanddevelopmentFaultTransitionSimulationRelativeoffaultlocationtechniquefordistributionnetwork[J].Relay,2005,location/mresistance/Ωresults/merror/%33(24):32-37.01001.00.016[5]ZHANGHuifen,PANZhencun,SANGZaizhong.Injectingcurrentbasedf=100051002.40.039methodforfaultlocationinneutralisolatedpowersystem[J].101002.30.037AutomationofElectricPowerSystem,2004,28(3):64-66.02001.40.022[6]HOUZiliPENGLanfang.Port-faultdiagnosis:theprincipleandf=200052001.20.019algorithm[J].JournalofBeijingUniversityofPostsand102002.00.032Telecommunications,1990,13(2):66-72.03003.30.053[7]YANGXuechang,WENGYangbo,WUZhensheng.Theoreticalanalysisoff=300053002.20.035transferfunctionalgorithmforgroundedfaultlocationinthreephase103003.10.050powerdistributionlines[J].HighVoltageApparatus,2002,38(2):15-18.04000.00.000[8]MAShicong,GAOHoulei,XUBingyin,etal.Asurveyoffaultlocationf=400054001.50.024methodsindistributionnetwork[J].PowerSystemProtectionandControl,104001.60.0262009,37(11):119-124.04997.80.035[9]JITao,SUNTongjing,XUEYongrui,etal.FaultLocationforDistributionf=500055000.80.013FeedersBasedonTravelingWaves[J].AutomationofElectricPower104998.20.029System,2005,29(19):66-71.06005.90.095[10]YANFeng,YANGQixun,QIZheng,etal.StudyonFaultlocationf=600056005.70.091SchemeforDistributionnetworkbesaedonTravellingwavetheory[J].106005.70.091ProceedingsoftheCSEE,2004,24(9):37-43.[11]MAShicong,GAOHoulei,XUBingyin,etal.OverviewofapplicationByanalyzingthesimulationresults,themaximumerrorresearchesbasedonsynchronousdatameasuredbyPMUsinpowerdistanceisonly3.3m,andthemaximumrelativeerrorislesssystem[J].PowerSystemProtectionandControl,2006,34(6):78-84.than0.06%.Thesimulationresultsshowthatthealgorithmcan[12]XUYan,YINGLuman,LIUZekai.ANewFaultAreaBasedMethodofPMUConfigurationandFaultLocationforLargePowerGrid[J].Powerachievefaultlocationwithhigheraccuracy,andnotaffectedbySystemTechnology,2014,38(11):3199-3204.transitionresistanceandfaulttype,meetingthedesign[13]JINXianing,WANGFuping,WANGZanji.ResearchonFaultLocationrequirements.BasedonDynamicSynchronousPhasorMeasurementbyPMU[J].PowerSystemTechnology,2013,37(10):2932-2937.[14]LUOShenzeng,LIYinhong,CHENBo,etal.AnAdaptiveWideAreaIV.CONCLUSIONFaultLocationAlgorithmforTransmissionLinesWithOptimalPMUInthispaper,thevoltageandcurrentinformationuploadedPlacement[J].ProceedingsoftheCSEE,2016,36(15):4134-4143.[15]ZHANGM,WANGY,ZHOUZ,etal.ResearchonFaultLocationbythePMUareusedtocalculatetheheadendvoltageofeachBasedonPMUforMulti-sourceDistributionNetwork[C].//Power&branchtojudgethefaultyfeeder.ThenthevoltagedistributionEnergyEngineeringConference,2016:1877-1882.alongthedouble-endfeederisusedtoachieveaccuratefault[16]JIANGJA,YANGJZ,LINYH,etal.AnadaptivePMUbasedfaultdetection/locationtechniquefortransmissionline-partI:Theoryandlocation.Thesimulationresultsshowthatthealgorithmhasalgorithms[J].IEEETransactionsonPowerDelivery,2000,15(2):goodrangingaccuracy.Comparedwiththetraditional486-493.distributionnetworkfaultlocationalgorithm,thispaperhasthe[17]AL-MOHAMMEDAH,ABIDOMA,LINYH.Anadaptivefaultlocationalgorithmforpowersystemnetworksbasedonsynchrophasorfollowingcharacteristic:1)ThereisnoneedtoinstallaPMUatmeasurements[J].ElectricPowerSystemsResearch,2014,108(3):bothendsofthefeeder,whichreducestheinvestmentofthe153-163.equipmentandensuresbettereconomywhileensuringhigh[18]MARKOSA,ELIASK.EstimationofTransmissionLineParametersUsingPMUMeasurements[C].//Power&EnergySocietyGeneralrangeaccuracy.2)Thealgorithmjudgesthefaultfeeder,whichMeeting,2015:1-5.solvestheproblemofmulti-branchfeederinfaultjudgementof[19]WANGC,DOUCX,LIXB,etal.AWAMS/PMU-basedfaultlocationdistributionnetwork.3)Basedontheprincipleofvoltagetechnique[J].ElectricPowerSystemsResearch,2007,77(8):936-945.[20]MARCOP,LORENZOZ,PAOLOR,etal.FaultDetectionandFaulteddistributionalongthedouble-end,afaultlocationalgorithmisLineIdentificationinActiveDistributionNetworksUsingestablishedwhichisnotaffectedbythetransitionresistanceSynchrophasors-BasedReal-TimeStateEstimation[J].Transactiononandfaulttype.powerdelivery,2017,32(1):381-392.Thealgorithmcanrealizemulti-branchfaultlocationunder[21]XinZhentao,ShangDeji,YinXianggen.Falserootanditsimprovementofatwo-terminalfaultlocationalgorithmontransmissionline[J].Relay,thepremiseoferror,whichhasagoodapplicationprospect.2005,33(6):36-39.REFERENCESXiChenispursuingherM.Sc.atXi’anJiaotongUniversity,Xi’an,China.Currently,shefocusesonfaultlocationofdistributionnetworkandsmart[1]TANGJinrui,YINXianggen,ZHANGZhe,etal.Surveyoffaultlocationdistributiongrid,xichen@stu.xjtu.edu.cntechnologyfordistributionnetworks[J].ElectricPowerAutomationZaibinJiaoreceivedhisPh.D.degreefromXi’anJiaotongUniversity,Xi’an,Equipment,2013,32(5):7-13.ChinaandcurrentlyworksasanAssociateProfessor.Hisresearchinterest[2]CHENYueyun,QINJian,WANGXin,etal.Asurveyonfaultlocationforincludespowersystemprotectionandnewenergy.distributionnrtwork[J].PowerSystemTechnology,2006,30(18):89-93.CICED2018PaperNo.201804270000494Page5/51507