第39卷第6期2023年6月电网与清洁能源PowerSystemandCleanEnergyVol.39No.6Jun.2023智能电网SmartGrid——————————基金项目：山西省科技重大专项资助项目（20181102028）；国网山西省电力公司科技项目（520530200014）。ProjectSupportedbyShanxiProvinceScienceandTechnologyKeyProjectsSupportingProgram（20181102028）；theScienceandTechnologyProgramoftheStateGridShanxiElectricPowerCompany（520530200014）.ABSTRACT：Whenapole-to-poleshort-circuitfaultoccurstotheDCdistributionsystem，theshort-circuitcurrentishighinstantly，whichthreatensthesafeandstableoperationofthesystem.Meanwhile，giventhetoleranceabilityofpowerelectronicdevices，theconverterwillbelocked，whichleadstoreductionofthefaultinformation.TheprotectionschemebecomesanimportantfactorrestrictingthedevelopmentofDCdistributionnetwork.Tosolvethisproblem，firstly，thecharacteristicsofthefaultcurrentcurveoftheflexibledirectlineafterthepole-to-poleshort-circuitfaultareanalyzed，andthentheintegraldifferenceofthefaultcurrentcurveinsideandoutsidethefaulttimezoneisrevealed.Finally，aschemeofpole-to-poleshort-circuitlineselectionbasedontheintegralratiooflinefaultcurrentisproposed.ThesimulationmodeloftheDCdistributionsystembasedonmodularmultilevelconverter（MMC）isbuiltontherealtimedigitalsimulator（RTDS）toverifytheeffectivenessofthescheme.KEYWORDS：DCdistributionsystem；pole-to-poleshort-circuitfault；integralratio；RTDS摘要：柔性直流配电系统发生极间短路故障后，系统短路电流大，对系统安全稳定运行产生威胁，同时考虑到电力电子器件的耐受能力，换流器将会闭锁，导致故障信息量减少，对保护方案的速动性和可靠性提出了很高的要求。针对此问题，文章首先分析了直流线路极间短路故障电流特性，然后揭示了故障时区内外故障电流曲线的积分差异，最后提出基于线路故障电流积分比的极间短路选线方案。在实时数字仿真器（realtimedigitalsimulator，RTDS）上搭建基于模块化多电平换流器的直流配电网仿真模型，验证了所述方案的有效性与适用性，具有较好的耐受过渡电阻和抗噪能力。关键词：直流配电网；极间短路故障；积分比；实时数字仿真器柔性直流配电系统转换效率高、供电容量大，能够支...
