一起110 kV氧化鋅避雷器泄露電流超標(biāo)的原因分析

一起110kV氧化鋅避雷器泄露電流超標(biāo)的原因分析Title:AnalysisoftheCausesofExcessiveLeakageCurrentin110kVZincOxideSurgeArrestersIntroductionThe110kVzincoxidesurgearresterplaysacrucialroleinprotectingpowertransmissionanddistributionsystemsfromlightning-inducedvoltagesurges.However,incertaincases,thesearresterdevicesmayfacetheissueofexcessiveleakagecurrent.Thispaperaimstoinvestigatethecausesofexcessiveleakagecurrentin110kVzincoxidesurgearresters.1.OverviewofZincOxideSurgeArresters1.1FunctionandImportanceZincoxidesurgearrestersaredesignedtodiverthighvoltagesurgescausedbylightningstrikesorswitchingoperationstotheearth,therebyprotectingthepowersystemequipmentfromdamage.2.LeakageCurrentinZincOxideSurgeArresters2.1DefinitionandSignificanceLeakagecurrentreferstothesmallcurrentflowingthroughthearresterundernormaloperatingconditions.Excessiveleakagecurrentcanleadtoarrestermalfunctionandcompromisesystemprotection.3.CausesofExcessiveLeakageCurrent3.1HighOperatingVoltageTheoperatingvoltageofthearrestershouldnotexceeditsratedvoltage.Excessiveoperatingvoltagecanresultfromavarietyoffactors,includingsystemovervoltage,impropercoordinationamongsurgearresters,orincorrectinstallation.3.2AgingandDeteriorationOvertime,theinternalcomponentsofthearrester,suchasthezincoxidediscsandinternalprotectionelements,candegradeorfail.Thiscanleadtoanincreaseinleakagecurrent.3.3ContaminationandEnvironmentalFactorsContaminants,suchasdust,moisture,salt,orchemicals,canaccumulateonthesurfaceofthearrester.Thesecontaminantscreateconductivepaths,leadingtoincreasedleakagecurrent.Additionally,extremetemperatures,highhumidity,orexposuretocorrosiveenvironmentscanacceleratearresterdeteriorationandincreaseleakagecurrent.3.4ManufacturingDefectsDuringthemanufacturingprocess,manufacturingdefectsmayoccur,suchaspoorcontactbetweenthezincoxidediscsorimproperassembly.Thesedefectscanresultinirregularcurrentdistributionandhigherleakagecurrent.3.5InsufficientSurgeArresterMaintenanceRegularinspection,cleaning,andmaintenanceofsurgearrestersareessentialtoensuringtheirproperfunctioning.Lackofmaintenancecanleadtodegradationofinternalcomponents,increasedleakagecurrent,andeventualarresterfailure.4.ImpactofExcessiveLeakageCurrent4.1ThermalEffectsAsexcessiveleakagecurrentflowsthroughthearrester,heatisgenerated.Thebuildupofexcessiveheatcanresultinthermalstressanddamagetothearrester,compromisingitsabilitytopreventsurgeseffectively.4.2ElectricalStressontheInsulationSystemSurgearrestersareinstalledinparallelwithinsulationequipment,suchastransformersorcircuitbreakers.Excessiveleakagecurrentleadstoadditionalelectricalstressontheinsulationsystem,potentiallycausinginsulationbreakdownandsystemfailures.5.MitigationStrategies5.1ProperArresterSelectionandApplicationEngineersshouldconsidervoltagecoordination,systemrequirements,andenvironmentalconditionswhenselectingandapplyingsurgearresters.Properselectionensuresthatthearrester'sperformanceisoptimizedregardingleakagecurrent.5.2RegularMaintenanceandInspectionAcomprehensivemaintenanceprogramshouldbeimplementedtomonitortheconditionofsurgearrestersperiodically.Thisincludescleaningcontaminatedsurfaces,checkinginternalconnections,andreplacingfaultycomponents.5.3SurgeArresterMonitoringSystemsInstallingmonitoringdevicescanprovidereal-timeinformationontheperformanceofsurgearresters,includingleakagecurrentlevels.Thisallowsforproactivemaintenanceandtimelydetectionofpotentialissues.ConclusionExcessiveleakagecurrentin110kVzincoxidesurgearresterscanleadtoarrestermalfunctionsandcompromisethesafetyofpowertransmissionanddistributionsystems.Understandingthecausesofexcessiveleakagecurrent,suchashighoperatingvoltage,aginganddeterioration,contamination,manufacturingdefects,and