文档名：计及界面电荷和极性效应的油纸复合绝缘非线性电路等效模型
摘要：换流变压器是特高压直流输电工程中的关键设备,换流变压器油纸复合绝缘的界面处在直流电压下易积聚电荷,诱发局部放电甚至击穿.当前对于界面电荷的积聚分布,多采用传统的阻容模型进行计算,存在较大的误差.该文提出一种简易的非线性电路等效模型,首先,分别测量变压器油和油浸纸板的电容、电阻参数与极化电流,获得油纸的拓展Debye模型;其次,在拓展Debye模型的基础上,将变压器油和油浸纸板的恒定电阻模型改为随电场变化的非线性模型,并加入反映极性效应的界面势垒限制电流源,以此建立等效模型;最后,将电路等效模型仿真结果与实际测量结果进行对比.结果表明,与实际测量结果相比,该等效模型具有良好的适用性.该文模型为油纸绝缘的电场分布、界面电荷积聚量的计算提供了一种准确度较高的简便方法.
Abstract：Intheoperationofaconvertertransformer,theinterfaceofitsoil-papercompositeinsulationispronetochargeaccumulationunderDCvoltage.Asimplenon-linearequivalentcircuitmodelisproposedbasedontheextendedDebyemodelinthispaper,whichcancalculatetheelectricfielddistributionandinterfacechargeamountofoil-paperinsulationmoreeasilyandaccurately.Firstly,thecapacitanceandresistanceparametersofthetransformeroilandtheoil-immersedpaperboardareseparatelymeasured,andtheelectricfieldstrengthintheoilismeasuredbasedontheKerreffectmethodatappliedvoltagesfrom5to25kVrespectively.Theelectricfielddistributionintheoil-papercompositeinsulationiscalculatedfordifferentappliedvoltagesaswellasdifferentvoltagepolarities,andthemeasuredresultsarecomparedwiththecalculatedresultsfromtheRCmodel.Secondly,theconductivityofthetransformeroilandoil-immersedpaperboardaremeasuredunderdifferentelectricfieldstrengthtoestablishanon-linearconductivitymodelfortheoil-papercompositeinsulation.Thenthepolarisationcurrentsofthetransformeroilandoil-immersedpaperboardareseparatelymeasuredandfittedtoextractthebranchparametersofextendedDebyemodel.Finally,theinterfacepotentialbarriersarederivedfromthemeasuredpolarisationcurrents,andthepolaritydeterminedinterfacepotentialbarrieristhenaddedtothemodeltolimitthecurrentthroughtheinterface,thusestablishinganon-linearequivalentcircuitmodelforthetransformeroilandoil-impregnatedpaperboardwheretheresistancesaretheelectricfieldstrengthdependent.Theelectricfielddistributionintheoil-papercompositeinsulationcalculatedbytheestablishednon-linearequivalentmodeliscomparedwiththosebytheRCmodel,extendedDebyemodelandactualmeasuredresults.Thetimetosteadystatecalculatedbytheequivalentmodelisreducedtoabout500s,whichisshorterthanthatcalculatedbytheRCandDebyemodels,andisclosertothemeasuredresults.Asregardsthesteadystateelectricfieldinoilatdifferentappliedvoltages,itcanbeseenthattheerrorbetweenthosebytheequivalentmodelandmeasurmentislessthan5%forbothpositiveandnegativepolarities.TheerrorbetweentheelectricfieldinoilcalculatedbytheequivalentmodelandthemeasuredresultsisgreatestatDCvoltageof25kV,butthemaximumerroris4.8%.TheseindicatethattheaccuracyofthismodelisgreatlyimprovedcomparedtotheRCandseriesextendedDebyemodel.Comparingtheresultsofthethreemodelswiththemeasuredvaluesforpositiveandnegativepolarities,theequivalentmodelismuchclosertothemeasuredvaluesthantheRCandextendedDebyemodel,andjusttheequivalentmodelreflectsapolarityeffect.Theabsolutevalueofthemeasurednegativeinterfacechargeamountat25kVismerely1.07%higherthantheproposedequivalentmodelcalculation,andthemeasuredpositiveinterfacechargeamountis0.95%higherthantheproposedequivalentmodelcalculation.Thefollowingconclusionscanbedrawnfromtheabove:(1)ComparedwiththeRCandextendedDebyemodel,thedynamicsofelectricfielddistributionoftheoil-paperinsulationcalculatedbytheproposedmodelreachthesteadystatefasterandisclosertothemeasuredsituation.(2)Theproposedmodeltakesintoaccountthepolaritydeterminedinterfacebarriertolimitthecurrentthroughtheinterface,soitscalculationcanreflectthepolarityeffectandtheerrorbetweenthecalculatedandmeasuredelectricfieldislessthan5%.(3)Themodelhasincorporatedtheinfluenceofnonlinearconductivity,relaxationpolarisationandinterfacialpotentialbarrierlimitingcurrent,soithasagoodapplicabilitytothecalculationoftheinterfacialchargeofoil-paperinsulationunderdifferentconditionsmoreeasilyandaccurately.
作者：黄猛 李怡然 吴延宇 陈良炯 齐波Author：HuangMeng LiYiran WuYanyu ChenLiangjiong QiBo
作者单位：新能源电力系统全国重点实验室(华北电力大学)北京102206
刊名：电工技术学报 ISTICEIPKU
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(11)
分类号：TM132
关键词：油纸绝缘 界面电荷 界面极化 拓展Debye模型 电路等效模型
Keywords：Oil-paperinsulation interfacecharge interfacepolarization extendedDebyemodel equivalentcircuitmodel
机标分类号：TM721.1TM41TM855
在线出版日期：2024年6月18日
基金项目：国家自然科学基金，北京市自然科学基金资助项目计及界面电荷和极性效应的油纸复合绝缘非线性电路等效模型[
期刊论文] 电工技术学报--2024, 39(11)黄猛 李怡然 吴延宇 陈良炯 齐波换流变压器是特高压直流输电工程中的关键设备,换流变压器油纸复合绝缘的界面处在直流电压下易积聚电荷,诱发局部放电甚至击穿.当前对于界面电荷的积聚分布,多采用传统的阻容模型进行计算,存在较大的误差.该文提出一种简...参考文献和引证文献
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计及界面电荷和极性效应的油纸复合绝缘非线性电路等效模型 Equivalent Nonlinear Circuit Model with Interface Charge and Polarity Effect for Oil-Paper Composite Insulation
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