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1、上海交通大學(xué)碩士學(xué)位論文輸電線路高阻接地故障檢測(cè)的新方法研究姓名：陳佳佳申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：電力系統(tǒng)及其自動(dòng)化指導(dǎo)教師：邰能靈20070101上海交通大學(xué)碩士學(xué)位論文摘要量和與基波能量之比形成區(qū)分故障與正常投切的判據(jù)。大量ATP仿真以及RDTS實(shí)驗(yàn)結(jié)果表明，該方法具有良好的性能，能準(zhǔn)確識(shí)別高阻接地故障，并能保證在系統(tǒng)正常投切時(shí)不誤發(fā)信號(hào)，從而提高電網(wǎng)行安全性和可靠性。最后，綜合全文分析，對(duì)整個(gè)研究工作存在的問題和有待于解決的問題進(jìn)行了總結(jié)。關(guān)鍵詞：高阻接地，小波變換，模極大值，并聯(lián)電容器，空載合閘，
2、單相重合閘，諧波分量，暫態(tài)，能量上海交通大學(xué)碩士學(xué)位論文ABSTRACTANOVELTECHNIQUEFORSINGLEPHASEHIGH-IMPEDANCEFAULTDETECTIONABSTRACTGenerally,thetransmissionlinefaultcancausehighphasecurrent.Propergroundingprotectionsetcantripreliablyandcutoffthefault.However,someuniquegeographicalcha
3、racters,suchasfiregrounding,bamboogroundingandtreetopgrounding,cancausesinglephasehigh-impedancegroundingfaultfrequently,whichcauselowlevelcurrentinpractice.Especiallyinthecaseofthehigh-voltagetransmissionlines,highimpedancefaults(HIF)arecharacterizedbya
4、nintermittentArc-typenatureandlowlevelofthefaultcurrents.Thedetectionofthelow-levelgroundcurrentswiththeconventionalover-currentrelaysisdifficultandsometimesinaccurate.Toanalysisthefaultcomponent,wavelettransformcanbeseenasawell-developedmathematicaltool
5、.Itcanbeformulatedtodescribesignalsinalocalizedtimeandfrequencyformat.Analysisresultsshowthatwhenasinglephasefaulthappensinthetransmissionline,wavelettransformmodulusmaximaofthezero-sequencecurrentandthefaultphasecurrentwillpresentspecialcharacteristics.
6、AnewschemebasedonthecharacteristicsispresentedtodetecttheHIF.Furthermore,thechangesofcurrentandvoltagecausedbythenormal上海交通大學(xué)碩士學(xué)位論文ABSTRACTswitchingeventssuchasswitchingontheshuntcapacitorsmaybeidentifiedasthefaultandinducemaloperation.Inordertoenhanceth
7、ereliabilityofHIFdetection,todistinguishHIFfromthenormalswitchingeventsisapivotalproblem.Analysisresultsshowthatthedistortedcurrentcontainssignificanttransienthighfrequencycomponent.ThisishappenedbothintheHIFandthenormalswitchingevents,buttheypresentdiff
8、erentcharacteristics.SoHIFandthenormalswitchingeventscanbediscriminatedbyusingthedifferenceofthecorrespondinghighfrequencycomponent.LotsofATPsimulationresultsofHIFwithdifferentfaultresistanceanddifferentkindsofnormalswitch
