文档名：基于线芯护层过渡电阻无功特性的交叉互联电缆故障测距
摘要：高压电缆常见的接地方式是交叉互联接地,而交叉互联接地电缆故障时的测距相比单端接地或两端直接接地的电缆情况更为复杂,为此提出了基于线芯-护层过渡电阻无功特性的交叉互联电缆故障测距方法.首先,采集护层故障前后环流,构建不同电缆区段特征电流,判断故障发生区段;其次,考虑电缆金属护层对线芯的耦合作用和线路电容影响,建立交叉互联电缆的故障稳态等效阻抗模型,利用电缆首末两端线芯和护层的电压、电流推算电缆故障发生时不同区段沿线电压、电流,并基于同一位置电压相量对电缆参数进行修正;然后,利用故障点过渡电阻消耗无功功率为零的功率特性建立以故障距离为未知数的测距方程,采用二分法或弦截法等方法迭代计算求解得到故障点;最后,基于PSCAD/EMTDC仿真软件搭建了电缆故障模型,分析了故障距离、故障类型、过渡电阻、故障初相角等因素对故障测距方法的影响.结果表明,该方法的测距误差为0.4%左右,具有较高的准确性和有效性,对交叉互联接地电缆进行故障测距有一定的参考意义.
Abstract：High-voltagepowercablesarewidelyusedintheconstructionofurbanpowergrid,butthereareoftenshort-circuitfaultsmainlycausedbysingle-phasefaults.Rapidandaccuratefaultlocationisofgreatsignificancetomaintainthestableoperationofpowergrid.Thehighvoltagecablewithalengthofmorethanonekilometerusuallyadoptsthecross-connectedgroundingmode,andthecouplingbetweenthecablestructure,faultphaseandnon-faultphasebringsgreatdifficultiestofaultlocation.Atpresent,themainfaultlocationmethodsofcross-connectedcablesaretravelingwavemethodandimpedancemethod,butthereliabilityoftravelingwavemethodislow,andtheimpedancemethodhasshortcomingssuchasnotconsideringtheinfluencebetweenthethreephasesandignoringthelinecapacitance.Therefore,afaultlocationmethodforcross-connectedcablesisproposedinthispaper.Firstly,basedonthedoubleπmodel,consideringthecouplingeffectofthecablemetalsheathonthewirecoreandtheinfluenceofthelinecapacitance,anequivalentmodelisestablishedforthesingle-phaseshort-circuitfaultofthecross-connectedgroundingcable.Secondly,thevoltageandcurrentofcablecoreandsheatharecollectedbeforeandafterthefaultoccurs,andthedifferenceintegralofsheathcirculationbeforeandafterthefaultiscalculatedaccordingtothemeasuredcurrentofthecablesheathcirculationmonitoringpoint,andtheshort-circuitfaultareaisjudgedbywhetherthedifferenceintegralchangeisthelargest.Then,thecableparametersaremodifiedbasedonthepre-faultelectricalvolume,andthevoltageandcurrentalongthefirstandendofthefaultsectionarecalculatedbythepost-faultelectricalvolume.Finally,thefaultlocationequationisconstructedbasedonthezeroreactivepowerconsumedbythetransitionresistanceofthefaultbranch,andthefaultdistanceisobtainedbyiterativecalculation.Thesimulationresultsoftheproposedmethodshowthatbycalculatingtheintegralofthedifferencebetweenthemeasuredcurrentatbothendsofdifferentsectionsofcross-connectedcableasthecharacteristiccurrent,thecharacteristiccurrentvalueofthefaultsectionisobviouslygreaterthanthatofthenon-faultsection,andthefaultsectioncanbeeffectivelyjudged.Themethodoflineparametercorrectioncanmodifytheinaccurateandchanginglineparameterswithin1.1%,andreducetheelectricalparametererrorobtainedbycalculatingormeasuringtheinitialconditionsofthecable.Thefaultlocationequationisestablishedanditeratedrepeatedlytoobtainthelocationresult,whichavoidstheaccidentofthecalculationresult.Thesimulationresultsshowthatthefaultdistance,faulttype,cablearrangement,faultinitialphaseangle,transitionresistance,lineparameterchangeandgroundresistancehavelittleinfluenceonthemethod,andthemaximumdistanceerrorislessthan0.4%.Comparedwiththetwo-layerimpedancemodel,theimpedancemodelbasedonthelinedistributioncapacitancehasbetterlocationaccuracy,sothelinecapacitanceshouldnotbeignoredinthecablefaultlocation.
作者：杨明嘉 夏成军 赖胜杰 池梓斌Author：YangMingjia XiaChengjun LaiShengjie ChiZibin
作者单位：华南理工大学电力学院广州510640;广东省新能源电力系统智能运行与控制企业重点实验室广州510663
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(5)
分类号：TM247
关键词：高压电缆 交叉互联 无功特性 故障稳态 故障测距
Keywords：Highvoltagecable crossconnecting reactivepowercharacteristic steadystateoffault distanceoffault
机标分类号：TM726TM247TM427
在线出版日期：2024年3月19日
基金项目：国家重点研发计划，南方电网公司科技项目基于线芯-护层过渡电阻无功特性的交叉互联电缆故障测距[
期刊论文] 电工技术学报--2024, 39(5)杨明嘉 夏成军 赖胜杰 池梓斌高压电缆常见的接地方式是交叉互联接地,而交叉互联接地电缆故障时的测距相比单端接地或两端直接接地的电缆情况更为复杂,为此提出了基于线芯-护层过渡电阻无功特性的交叉互联电缆故障测距方法.首先,采集护层故障前后环...参考文献和引证文献
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