超2f特高压输电走廊雷电绕击特征与电磁耦合特性分析

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1、西南交通大学硕士研究生学位论文第1I页AbstractWiththerapiddevelopmentofPowerGridatEx们andUltraHighVoltageLevel，thevoltagelevel，transmissionCapacityanddistanceareconstantlyincreasingwhichleadtothelightningfaultbecomingmoreseriousandcorridorresourcegettingmoreshortage．Accordingtothelong·termo

2、peratingexperienceatdomesticandinternationalshowsthatlightningtrip-outfaultofEHVismainlycausedbyshieldingfailure，SOtheaccurateevaluationofshieldingfailureperformanceoftransmissionlineplaysavitalroleforensuringthesafetyofelectricpower．Incorridorresourceshortagearea,thesit

3、uationofUHVAC／DClineoperatinginsamecorridorisinevitable．ThereareseriouscouplingeffectsbetweenACandDClinesatthattimewhichresultinlargerinductionvoltageandcurrentproducedindisconnectedlinetoseriousthreattopersonnelandequipmentsafety．Theshieldingfailuretrip—outandelectromag

4、neticcouplinginsamecorridorhasbecomethekeyissuestoaffectsafeoperationoftheEHV／UHVtransmissionlines．Inordertoquantitativelyanalyzethenumericaldistributioncharacteristicoflightningprobabilityandshieldingfailuretrip-outrateindifferentpositionoftransmissionlines，accuratelyas

5、sessthelightningshieldingfailuretrip-outlevel，andavoidtheuncontrollablee11rorresultingfrominequivalencereplacementoflightningprobabilityofeachsection，thelightningexposedwidthoftraditionalcalculationmethodisexpandedtothree-dimensionalexposedspacealoneeveryspanoftransmissi

6、onlinesbyusingcatenaryequation，thethree-dimensionalanalysismethodofshieldingfailurecharacteristicsoftransmissionlinesandthree-dimensionalcalculationmethodofexposedwidthofarbitrarysectioninexposedspaceareproposed，thethree-dimensionalcalculationformulasoflightningprobabili

7、tyandshieldingfailuretrip·outrateofarbitrarysectionarederived，andthecalculationformulaoftotalshieldingfailuretrip-outrateisrevised．Take500kVtransmissionlines、析thtwooverheadgroundwiresforexample，thethree-dimensionaldistributionoflightningexposedwidthaswellasthetwo·dimensi

8、onaldistributionoflightningprobabilityandshieldingfailuretrip—outratearecalculated．Theresearchfoundthat