基于錄波信息的雙側(cè)電源輸電線(xiàn)路故障接地電阻計(jì)算方法

1、基于錄波信息的雙側(cè)電源輸電線(xiàn)路故障接地電阻計(jì)算基于錄波信息的雙側(cè)電源輸電線(xiàn)路故障接地電阻計(jì)算李輝，宋斌，許捷（國(guó)電南瑞科技股份有限公司江蘇南京211106）摘要：針對(duì)由山火、雷電、覆冰、污閃等自然因素引起輸電線(xiàn)路故障是單相或相間經(jīng)過(guò)渡電阻接地這一現(xiàn)象，首先用對(duì)稱(chēng)分量法分別對(duì)單相故障接地和相間故障接地進(jìn)行分析，得出兩種情況下故障點(diǎn)接地故障電流都等于故障點(diǎn)的總零序電流。利用故障點(diǎn)接地故障電流都等于故障點(diǎn)的總零序電流和從流入保護(hù)裝置的零序電流

2、中扣除本線(xiàn)路相對(duì)地的分布電容決定的零序電容電流，來(lái)計(jì)算故障點(diǎn)的總零序電流即接地故障電流。利用各序?qū)ΨQ(chēng)分量之間的電壓關(guān)系是相互獨(dú)立特性，首先把保護(hù)裝置的錄波數(shù)據(jù)電壓量計(jì)算出線(xiàn)路始端三序電壓分量，分別計(jì)算故障點(diǎn)故障相的各序電壓，然后疊加成故障點(diǎn)處故障相實(shí)際電壓，最后利用歐姆定律計(jì)算出接地電阻。關(guān)鍵詞：雙側(cè)電源；對(duì)稱(chēng)分量法；接地電阻；零序電容電流CalculationofEarthResistanceofBilateralPowerSuppl

3、yTransmissionLineBasedonFaultInfmationLIHuiSONGBinXUJie(NARITechnologyDevelopmentLimitedCompanyNanjing211106China)Abstract：Duetotheexistenceofearthresistancecausedbyfirelightningicepollutionflashovernaturalfactssinglepha

4、segroundingfaultinterphaseearthfaultgroundisanalyzedwithsymmetricalcomponentmethoditisconcludedthatinbothcasesfailurepointgroundingfaultcurrentisequaltothetotalzerosequencecurrentoffaultpoint.Usingfaultpointgroundingfaul

5、tcurrentisequaltothepointofzerosequencecurrentdeductedfromflowingintoprotectionofzerosequencecurrentofthiscircuitisrelativelydistributedcapacitanceofzerosequencecapacitivecurrentdecisiontocalculatethefaultpointtotalofzer

6、osequencecurrentasgroundingfaultcurrent.Usingtherelationshipbetweenthevoltagesequencesymmetricalcomponentaremutuallyindependentfeaturesfirstofalltheprotectiondeviceofvoltagewaverecddatatocalculatethelinebetweenthreeseque

7、ncevoltagecomponenteachsequencevoltageoffaultphasearecalculatedrespectivelythenintoaactualvoltagefaultpointfinallyusingohmslawtocalculatetheearthresistance.Keywds：bilateralpowersupplymethodofsymmetricalcomponentsearthres

8、istancezerosequenceCapacitivecurrent0引言引言電力系統(tǒng)輸電線(xiàn)路大多暴露于曠野之中，周邊環(huán)境復(fù)雜，引起線(xiàn)路跳閘的因素很多，主要包括：山火、雷電、覆冰、霧閃、樹(shù)障等，而這些因素導(dǎo)致輸電線(xiàn)路故障絕大多數(shù)表現(xiàn)為接地故障[1]。不同因素引起的接地故障，其接地電阻值的大小上是有差異的，計(jì)算出故障接地電阻也為分析故障起因提供了必要的依據(jù)。在現(xiàn)代電網(wǎng)保護(hù)和控制系統(tǒng)中，都包含有保護(hù)裝置、錄波裝置和故障測(cè)距裝置等，這也A

9、BCCBAM側(cè)N側(cè)系統(tǒng)電源IANIBNICNIBMICMIAMIgUAMUBMUCMUANUBNUCN圖2雙側(cè)電源線(xiàn)路BC兩相接地故障根據(jù)文獻(xiàn)[電力系統(tǒng)暫態(tài)分析]分析可知，BC兩相接地短路故障處的電流邊界條件為：0II??ANAM式（5）將此式轉(zhuǎn)換為用A相的對(duì)稱(chēng)分量表示，則：0IIIIII??????f(0)Nf(2)Nf(1)Nf(0)Mf(2)Mf(1)M式（6）將B、C兩故障相電流轉(zhuǎn)換為用A相的對(duì)稱(chēng)分量表示：???????????

10、????????????????f(0)Nf(2)Nf(1)Nf(0)Mf(2)Mf(1)MCNCMf(0)Nf(2)Nf(1)Nf(0)Mf(2)Mf(1)MBNBMIIIIIIIIIIIIIIII2222式（7）兩相接地故障短路電流為：式（8）)II(3)II(IIIIIIIIIIIIIIIIIIIIIIIIIIIIIf(0)Nf(0)Mf(0)Nf(0)M2f(0)Nf(2)Nf(1)Nf(0)Mf(2)Mf(1)Mf(0)Nf(

11、2)Nf(1)Nf(0)Mf(2)Mf(1)M2f(0)Nf(2)N2f(1)Nf(0)Mf(2)M2f(1)Mf(0)Nf(2)Nf(1)N2f(0)Mf(2)Mf(1)M2CNCMBNBMg)α(2)α()(ααααααααα??????????????????????????????????α由式（4）和式（8）分析計(jì)算可知，無(wú)論是單相接地故障或是兩相接地故障，其故障點(diǎn)接地故障電流都等于故障點(diǎn)的總零序電流。這也說(shuō)明了在110kv及