文档名：基于动态电阻串联的高阻接地故障精确建模
摘要：现有各类高阻接地故障模型缺乏对故障发展全过程的物理解释,难以准确模拟故障的非线性特征.该文根据现场录波数据,深入研究高阻接地故障的物理过程,归纳可知故障电流波形的非线性畸变来源于两个方面:空气间隙击穿引起的非线性与接地介质本身的非线性.据此提出高阻接地故障的故障电阻由电弧电阻和接地电阻串联组成,进而建立基于动态电阻串联的高阻接地故障新模型.首先,利用汤逊原理分析空气介质击穿过程中动态电弧的产生,建立了故障点指数电弧模型;然后,研究故障电流在土壤中的流散过程,结合土壤电阻率变化规律,求解接地电阻随故障电流变化的表达式,建立接地电阻模型;最后,在PSCAD中将二者串联,搭建高阻接地故障新模型,结合现场故障数据并与其他模型对比,验证了该文所提模型能更准确地表征不同接地介质下高阻接地故障的非线性特征,为后续研究高阻接地故障辨识提供更精确的数据支撑.
Abstract：Highimpedancefault(HIF)mayoccurindistributionlinesowningtoharshweathercondition,whichisdifficulttobedetectedduetoitsoverthousandsofohmsimpedance,posingahugehazardtohumanandelectricequipment.Therefore,thesafetyrisksandthelackofactualHIFdatamakeitessentialtorequireanaccurateHIFmodel.However,onlybasedonheatbalanceordielectricbreakdowntheories,existingHIFmodelsfailtocapturenonlinearcharacteristicsduetotheinsufficientphysicalinterpretationofHIF.Thus,consideringtheentirefaultphysicalprocess,aHIFmodelbasedondynamicimpedanceinseriesisproposed.Bycomparingitwithothermodels,thesimulationresultsverifythattheproposedmodelcharacterizesHIFnonlinearcharacteristicsundervariousgroundingmediawithhigheraccuracy.TheHIFexperimentsunderlateritesoilhadbeencarriedoutinthe1:1realdistributionnetworktestingfield.Basedontherecordedwaveforms,theHIFphysicalprocessesareanalyzed,specificallyincludingthearcignitionandextinctioncharacteristicsandthecurrentdispersioninsoil.Thefindingssuggestthatthenonlinearityofgroundingmediumandairbreakdownprocessaretheprimarycontributorstothenonlineardistortionoffaultcurrentwaveforms.Correspondingly,itcanberevealedthattheHIFfaultimpedanceiscomposedofarcimpedanceandgroundimpedanceinseries.Onthisbasis,anewHIFmodelbasedondynamicimpedanceinseriesisproposed.Firstly,theThompsonTheoryisutilizedtodescribethearcignitionandextinctioncharacteristicsinairbreakdownprocess,basedonwhichthedynamicexponentialarcimpedancemodelcanbeestablished.Secondly,withtheanalysisofthefaultcurrentdispersionprocess,thevariationcurveofsoilresistivitywithelectricfieldintensityisobtained,thenthegroundingimpedancecanbecalculatedtoestablishthegroundingimpedancemodel.Thoughtheanalysisofgroundingimpedanceonlytakeslateritesoilasanexample,itisworthnotingthatthisisjustanapproachtocalculategroundingimpedance,whichisnotlimitedbythetypesofgroundingmedium.Inprinciple,theapproachappliestoallgroundingmedia.Ultimately,thenewHIFmodelisobtainedbyconnectingthesetwoimpedancemodelsinseries.ThenewHIFmodeltakestheentireHIFphysicalprocessesintoconsideration,featuringspecificphysicalsignificance.TovalidatetheeffectivenessoftheproposedHIFmodel,alargenumberofHIFsimulationswerecarriedoutandthesimulatedwaveformswerecomparedwiththefieldexperimentalwaveformsusingwaveformcorrelationcoefficients.Firstly,thesimulatedwaveformsandVoltage-Amperecharacteristicscurvearesimilartothefieldtestingrecordeddata.Furthermore,forHIFoccurringunderlateritesoil,gravel,andmicrosand,thefaultcurrentwaveformcorrelationcoefficientsbetweensimulatedandrealtestingdataare0.9762,0.9693,and0.9658respectively.Thesimulationresultsverifiedthattheproposedmodelexhibitsoutstandingperformance.Secondly,thefaultcurrentwaveformcorrelationcoefficientofproposedmodelreaches0.9762,comparedwithonlyupto0.925?6forotherexistingHIFmodels.Inotherwords,proposedmodelcanbetterreflectthenonlineardistortioncharacteristicsofHIFfaultswithhigheraccuracy,whichdemonstratesthesuperiorityofproposedmodel.Thefollowingconclusionscanbedrawnfromthetheoreticalandexperimentalanalysis:(1)TherealfieldHIFexperimentsindicatethatthefaultcurrentwaveformandvolt-amperecharacteristicscurveexhibitobviousnon-lineardistortion,andthefaultimpedancefluctuatesperiodically.(2)TheHIFphysicalprocessincludingairbreakdownandsoilcurrentdispersionareanalyzed.Correspondingly,thefaultimpedancecanbecomposedofarcimpedanceandgroundingimpedance.Onthisbasis,anewHIFmodelbasedonthedynamicarcandgroundingimpedanceinseriesisproposed,whichfeaturescharacterizingHIFphysicalprocess.(3)TheproposedmodelisconstructedinPSCAD.ComparingitwithfieldexperimentsandotherHIFmodels,thesimulationresultsverifythattheproposedmodelcanmoreaccuratelycharacterizetheHIFnonlinearfeaturesundervariousgroundingmedia,providingmorepreciseHIFdataforsubsequenceresearch.(4)However,theproposedHIFmodelhascertainlimitationsduetothediversityofgroundingmedia.Therefore,theupcomingresearchwillfocusonclassifyingthesevariousgroundingmedia,aimingatconstructingamoreaccurateandcomprehensiveHIFmodel.
作者：钟逸涵 邓丰 史鸿飞 徐帆 李鑫瑜 Author：ZhongYihan DengFeng ShiHongfei XuFan LiXinyu
作者单位：长沙理工大学电气与信息工程学院长沙410114国网湖南省电力有限公司湘潭供电公司湘潭411100
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(7)
分类号：TM77
关键词：配电网 高阻接地故障 电弧电阻 接地电阻 非线性特征
Keywords：Distributionnetwork highimpedancefault arcimpedance groundingimpedance nonlinearcharacteristics
机标分类号：TH132.41TM76TM862
在线出版日期：2024年4月12日
基金项目：国家自然科学基金，湖南省自然科学基金杰出青年项目，湖南省湖湘青年科技创新人才项目基于动态电阻串联的高阻接地故障精确建模[
期刊论文] 电工技术学报--2024, 39(7)钟逸涵 邓丰 史鸿飞 徐帆 李鑫瑜现有各类高阻接地故障模型缺乏对故障发展全过程的物理解释,难以准确模拟故障的非线性特征.该文根据现场录波数据,深入研究高阻接地故障的物理过程,归纳可知故障电流波形的非线性畸变来源于两个方面:空气间隙击穿引起的...参考文献和引证文献
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基于动态电阻串联的高阻接地故障精确建模 Accurate Modeling of High Impedance Fault Based on Dynamic Impedance Series Connection
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