文档名:电缆终端应力锥错位缺陷对界面温度及应力分布的影响
摘要:电缆终端内部缺陷会造成终端内部电场分布不均、局部温度升高与应力分布变化,可能引发局部放电造成绝缘击穿.为研究终端应力锥错位缺陷对电缆界面温度及应力分布的影响,分别建立了电缆终端安装不足与安装过盈情况下的电缆终端错位缺陷模型,并进行电-热-力多物理场耦合仿真分析.结果表明:电缆终端绝缘屏蔽层截断处是电缆终端的薄弱部位,终端界面温度和界面压力都会在绝缘屏蔽层截断处发生突变.当电缆终端存在安装不足缺陷时,终端屏蔽层截断处与应力锥根部之间会出现电场升高区域,在安装位置为-7.5mm时界面温度最高,绝缘界面压力值升高,且安装位置为-2.5mm时绝缘承受的压力值最大;当电缆终端存在安装过盈缺陷时,绝缘屏蔽层截断处会发生电场畸变,电场突变量随着偏移量的增加而增大,在安装位置为+5.0mm时绝缘界面压力值最大,且界面压力突变量增加发生畸变.因此,在电缆终端实际设计安装与运行维护中,额外注意应力锥错位缺陷对终端内部应力分布的影响十分必要.
Abstract:Asanimportantpartoftheprefabricatedcableterminal,thestressconestructurecanalleviatetheconcentrationoftheelectricfieldstrengthatthecut-offoftheinsulationshieldinglayerduringtheoperationofthecableterminal.However,intheinstallationandconstructionofthecableterminal,duetotheinfluenceoftheinstallationprocessandoperatingconditions,thecableterminalwillhaveastressconedislocationdefect,whichwillaffecttheuniformdistributionoftheterminalelectricfield;atthesametime,theincreaseincablecoreandinsulationtemperaturewillleadtoachangeinthethermalstressdistributionintheterminalandaffectthethermalstressdistributionintheterminal.Atpresent,theresearchoncableterminaldefectsmainlyfocusesonelectrothermalaspects,whiletherearefewstudiesontheirinternalstressdistribution.Inthispaper,theelectro-thermal-mechanicalmulti-physicalfieldcouplingsimulationanalysisofthedislocationdefectcableterminaliscarriedouttoanalyzethechangesinelectricfieldstrength,temperaturedistribution,andstressdistributionintheoperationofterminaldefects.Duringtheoperationofthecableterminal,theheatsourceisformedduetotheelectromagneticloss,whichleadstothechangeoftheinternaltemperatureoftheterminal,andthenthethermalstressanddeformationoftheterminalaregeneratedbythethermalexpansionofthematerial.Firstly,thephysicalfieldcontrolequationsofthecableterminalareestablishedandthecouplingrelationshipbetweenthephysicalfieldsisanalyzed.Then,thecableterminalmodelandthestressconedislocationdefectmodelareestablished,andthematerialparametersandboundaryconditionsaresetandsimulated.Finally,bycomparingthemaximumelectricfieldstrength,temperaturechange,andinterfacepressuredistributionundertheconditionofacableterminaldefect,theinfluenceofastressconedislocationdefectonterminaltemperatureandstressisobtained,andsuggestionsaregivenforcableterminalinstallation,operationandmaintenance.Thesimulationresultsshowthatwhenthecableterminalisinnormaloperation,theelectricfieldstrengthoftheinsulationinterfacechangesabruptlyatthecut-offpositionoftheshieldinglayer.Themaximumtemperatureoftheterminalcablecoreis312K,andthemaximumthermalstressis1.37×107N/m2.Theterminalinterfacetemperatureandinterfacepressureareabruptlychangedatthecut-offpositionoftheinsulationshieldinglayer.Whentheinstallationsizeofthecableterminalistoosmall,themaximumelectricfieldstrengthoftheinsulationinterfaceis2.25MV/m,andtheelectricfieldrisezoneappearsbetweenthecut-offoftheinsulationshieldinglayerandtherootofthestresscone.Whenthedislocationsizeofthecableterminalis-7.5mm,thetemperatureoftheinsulationinterfacereachesitshighestvalue.Whentheterminaldislocationsizeis-2.5mm,theinsulationsurfacepressurevalueisthelargest,reaching3.78×105N/m2.Whenthedislocationsizeofthecableterminalis+7.5mm,themaximumelectricfieldintensityoftheinsulationinterfaceincreasesto2.42MV/m,anddistortionoccursatthetruncationoftheinsulationshieldinglayer.Whentheinstallationsizeoftheterminalistoolarge,thesuddenchangeintheinterfacetemperaturewillincrease,thepressureofthecableterminalontheinsulationsurfacewillincrease,andthepressureoftheinsulationinterfacewillbeobviouslydistorted.Whenthedislocationsizeofthecableterminalis+5.0mm,theinsulationinterfacepressurereachesamaximumof3.46×105N/m2.Accordingtotheaboveconclusions,thedislocationdefectofthecableterminalwillseriouslyaffectthestressdistributionoftheterminalandsuperimposewiththeelectricfieldandtemperaturefield,resultinginterminalinsulationdamageandaging.Therefore,thedesignandinstallationofthecableterminalshouldpayattentiontotheoccurrenceofstressconedislocationdefects,especiallytoavoidtheelectricfielddistortionandstressdistortioncausedbytheexcessiveinstallationsizeoftheterminal.
作者:祝贺 何峻旭 郑亚松 曹煜锋 郭维Author:ZhuHe HeJunxu ZhengYasong CaoYufeng GuoWei
作者单位:东北电力大学输电工程安全技术工程实验室吉林132000
刊名:电工技术学报
Journal:TransactionsofChinaElectrotechnicalSociety
年,卷(期):2024, 39(1)
分类号:TM853
关键词:电缆终端 应力锥错位缺陷 电缆界面应力 电-热-力多物理场耦合
Keywords:Cableterminal stressconedislocationdefect cableinterfacestress electro-thermal-mechanicalmulti-physicscoupling
机标分类号:TM247TM77TM15
在线出版日期:2024年1月18日
基金项目:吉林省科技发展计划资助项目电缆终端应力锥错位缺陷对界面温度及应力分布的影响[
期刊论文] 电工技术学报--2024, 39(1)祝贺 何峻旭 郑亚松 曹煜锋 郭维电缆终端内部缺陷会造成终端内部电场分布不均、局部温度升高与应力分布变化,可能引发局部放电造成绝缘击穿.为研究终端应力锥错位缺陷对电缆界面温度及应力分布的影响,分别建立了电缆终端安装不足与安装过盈情况下的电缆...参考文献和引证文献
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