《Nonlinear Response Analysis for Insulation Diagnosis of Water-tree Aged 10 kV XLPE Cable Using Pulse Voltage》.pdf

高电压技术 第39卷 第8期 2013年8月31日 1852 HighVoltageEngineering，Vo1．39，No．8，August31，2013 NonlinearResponseAnalysisforInsulationDiagnosisof ‘ ter-treeAged10kV XLPECableUsingPulseVoltage DuBoxue．WANGLi (SchoolofElectricalEngineeringandAutomation，TianjinUniversity,Tianjin300072，China) Abstract：Thediagnosisofwatertreesofcableinsulationisofgreatimportanceasthewater-treeingisaprimarycauseofagingbreakdown forthemiddlevoRagecables．Inthispaper,itisdescribedhow thewater-tree-aged10kVXLPEcableswerediagnosed．Th ecableswere subjectedtoelectricalstressof5．9kVm／mandathermalloadcycleniacurvedwater-filledtubeofr3，6and12monthsofagingniaccor- dancewiththeacceleratedwater-treetestmehtod．Theagedcableswere usde ashtesamplesofrwater-fleediagnosis．First，htewater-tree degradedcable，waschargedbyaDC voltage，andthenhtecablewasgroundedwhileapulsevolatgewasappliedtoitofrreleasnighte spacechargetrappedinhtewatertrees．Th ema ountofhtespacecharge，whichco~espondstohtedeteriorationdegreeofhtewatertrees， wascalculated．TheeffectsofDCvoltageampliutde，pulsevoltagerepetitionratenadagingconditionsonhteamountofhtespacecharge were sutdied．Obatniedresultsshow htathtema oun tofhtespacechargehasapositivecorrelation、mhteappliedDCvolatgenadhteag- nigtimeofhtecables，andhtatapeakvalueofspacect~ geappearswihthtenicreaseofthepulsevolatgerepetitionrate．Anoptmium pulsevoltagerepetitionrateunderwhichthespacechargecna bereleasedr~idlyisobtained．Furthermore，htereleasingmechnaism of spacechargebythepulsevolatgeisdiscussed．Accumulatedresultsshow thathtepresemedmehtodhasahighresolutionforhtediangosis ofwatertreedegradationdegreeandisexpectedtobeappliedinpracticeinfuture． Keywords：insulationdiagnosis；XLPEcable；watertree；pulsevoltage；nonlinearresponse；spacecharge DoI：10．39698．issn．1003-6520．20