文档名：电容屏破损缺陷局部放电过程规律特征及仿真分析
摘要：油纸电容式变压器套管因性能好、成本低而被广泛采用.当电容屏存在边缘破损工艺缺陷时易发生局部放电,进而会改变油纸绝缘性能,缩短套管使用寿命,严重时危及电网设备安全运行.为研究电容屏破损局部放电过程变化规律,明确放电发展阶段,该文搭建了缺陷套管放电实验模型分析局放过程中相位谱图、放电量等参数发展规律,并基于实验规律及流体漂移扩散理论、固体双极电荷传输理论,建立了末屏缺陷针板沿面放电过程仿真模型,结合仿真中电荷形态变化、放电时间及油纸界面电荷密度分布对电容屏破损放电过程进行阶段划分:放电初始阶段,铝箔尖端电荷聚集发生电晕放电;放电发展阶段,尖端处带电粒子在电场作用下向油纸发展,小部分达到油纸界面产生沿面放电;放电破坏阶段,经过长时间沿面放电进入油纸发生预击穿,电场强度更大使带电粒子能量更高,冲击油纸表面造成油纸表面纤维素断裂炭化形成通道.仿真结果与实验结论相对应,证明了仿真的有效性.该文的研究成果进一步阐明了油纸套管电容屏工艺缺陷局部放电的过程及机理.
Abstract：Oil-papercapacitivetransformerbushingsarewidelyused.However,partialdischarge(PD)isaseriousthreattosafeandstableoperationofpowersystem.InordertostudythevariationlawofPDprocesswithcondenserfoillayerdamageandclarifythePDdevelopmentstage,thispaperestablishesadefectbushingPDmodeltoanalyzethedevelopmentlawofparameters.Basedonfluiddriftdiffusiontheoryandsolidbipolarchargetransfertheory,asimulationmodelforthesurfacePDprocessoftheendscreendefectneedleplateisestablished,whichcombinesthechangesinvoltage,chargemorphology,PDdurationandthechargedensitydistributionattheoil-paperinterface.Firstly,buildatestsamplebushingwithprocessdefect.Accordingtoasetof220kVtestapparatustotesttherelationshipbetweenthevoltagelevelandPDparameters,capacitance,anddischargecarbonizationtrace.Thenbasedonthehydrodynamicdrift-diffusionmodelandthebipolarchargetransportmodel,aneedle-planesurfacePDsimulationmodelwasbuilttosimulatetheprocessandspacechargedistributionofPD.Finally,withtheexperimentalphenomenonandsimulationresults,the3stagesPDprocessandspacechargedistributionatdifferentappliedvoltageareprovided.SimulationandexperimentresultsshowthatthebushingintheACelectricfieldcausesthecapacitorcoreplatetogeneratestaticelectricityandcauseselectricfielddistortion,whichresultsinchargemigrationandformingstreamer.Tipdefectivefoillayerisatextremelyinhomogeneouselectricfield,theneedletippartofthehighvoltagepositivepole,collisionionizationwilloccurfirstatthetip,collisionformationofpositiveiondensityincreasestoformstreamer,negativeionsatthetipofthecompound.Throughexperimentalverificationinneedle-planesurfacedischargesimulation,itcanbeassumedthattheprocessofPDisasfollows:(1)Attheinitialstage,coronadischargeatthetipofthefoillayercanbeobserved.Atthistimetheelectricfieldstrengthnearthetipofthefoillayeristhelargest,whichreleasesoffreeelectronsandmolecularionization.Butthecollisionenergydidnotreachtheelectronavalanche.(2)Atthedevelopmentstage,thecollisionalionizationatthetipacquiressufficientenergytomoveanddevelopcontinuouslyundertheactionofthepolarizationswimmingdynamics.Duetothelocalhightemperatureandhighfieldstrength,themoistureandgaswithintheinsulatingoilpaperformbubblesandadherestotheoilpaperinterface,andthegasinitsproductsalsoadherestotheinterfaceandformssmallbridges,leadingtothestreamertowardstothepapersurfaceandbreakdownalongthesurface.(3)Atthedamagestage,surfacePDaffectthespacechargedistributionwithintheoil-paperandstarttobreakdowndischargephenomenononpapersurface.Hightemperatureandhighfieldstrengthfromdischargeleadtopaperinsulationfailure,resultingincarbonizationtraces.Thefollowingconclusionscanbedrawnfromthesimulationanalysis:(1)BytheprocessofphysicalparameterchangesinPDexperiments,fromcoronaPDtothedevelopmentofsurfacedischarge,theamountofPDincreaseswiththeincreasingvoltage.At60kV,oilpaperbubblesprecipitate,causingacontinuousincreaseinPD.Theinsulationpapercellulosebreaksandformscarbonizationchannels,increasingconductivityandcausingafurtherdecreaseinPDcapacity.(2)BasedondiffusiondriftchargetransfertheoryandbipolarchargetransfertheorytosimulatesurfacePD,thetipPDprocessformedbythedamagededgeofthebushingcondenserfoillayerisobtained.Therearemainlythreestages.(3)BasedoncarbonizationtracesandthesimulationprocessofPD,thevoltagelevelwillcausechangesinthePDprocess,morphology,andduration.Whenthevoltagelevelislessthan40kV,thePDisinthefirstandsecondstages,andwhenthevoltagelevelishigherthan40kV,itgoesthroughthreestages.Thelargerthevoltageamplitude,themorebranchesoftheelectricaltree,theshorterthedischargetime,andthemorechargesabsorbedbytheoil-paperinterface.
作者：杨帆 张玉琛 王鹏博 吴兴旺 吴杰 Author：YangFan ZhangYuchen WangPengbo WuXingwang WuJie
作者单位：输变电装备技术全国重点实验室(重庆大学)重庆400044国网安徽省电力有限公司合肥230061
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(9)
分类号：TM216
关键词：油纸套管 电容屏工艺缺陷 针-板沿面放电 电荷分布仿真 放电过程阶段
Keywords：Oil-impregnatedpaperbushing condenserfoillayerdefect needle-planesurfacedischarge chargedistributionsimulation dischargeprocessstage
机标分类号：TM411TM835.4S157.1
在线出版日期：2024年5月13日
基金项目：国家重点研发计划，国家电网有限公司总部科技项目电容屏破损缺陷局部放电过程规律特征及仿真分析[
期刊论文] 电工技术学报--2024, 39(9)杨帆 张玉琛 王鹏博 吴兴旺 吴杰油纸电容式变压器套管因性能好、成本低而被广泛采用.当电容屏存在边缘破损工艺缺陷时易发生局部放电,进而会改变油纸绝缘性能,缩短套管使用寿命,严重时危及电网设备安全运行.为研究电容屏破损局部放电过程变化规律,明确...参考文献和引证文献
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