绝缘层温度对XLPE局部放电的影响特性  

Influence characteristics of insulation layer temperature on partial discharge of XLPE

作　　者：李岩 甄冠成 宋浩源 刘晓坤 梁雨薇 乔俊杰 刘鑫月 王毛桃 翟志强[2] LI Yan;ZHEN Guancheng;SONG Haoyuan;LIU Xiaokun;LIANG Yuwei;QIAO Junjie;LIU Xinyue;WANG Maotao;ZHAI Zhigang(Department of Electrical Engineering,North China Electric Power University,Baoding 071003,China;Baoding Tianwei Baobian Electric Co.,Ltd.,Baoding 071000,China)

机构地区：[1]华北电力大学电力工程系,河北保定071003 [2]保定天威保变电气股份有限公司,河北保定071000

出　　处：《电力科学与技术学报》2024年第6期260-268,共9页Journal of Electric Power Science And Technology

基　　金：中央高校基本科研业务费专项资金资助(2022MS068,20226932)。

摘　　要：交联聚乙烯(cross-linked polyethylene,XLPE)电缆是城市电网线路建设的首选。绝缘缺陷会导致局部放电,影响电缆的绝缘性能甚至导致绝缘击穿、线路跳闸,而且电缆在运行时处于不断地冷热循环中,绝缘层温度会影响XLPE局部放电特性[1-2]。为了研究这一影响,搭建针-板电极试验平台,在不同温度下测量XLPE局部放电数据,结果表明:局部放电主要发生在工频周期的-10°~100°及150°~265°时,呈“兔耳”状分布;绝缘层温度升高会导致局部放电次数增多以及局部放电起始电压下降。利用COMSOL-MATLAB联合分析法建立带气隙的针-板结构模型,对绝缘层温度影响下的局部放电现象进行仿真,验证了上述试验结论,说明了气隙的引入可以解释针-板电极中XLPE局部放电随绝缘层温度变化的规律,而XLPE介电常数会随温度变化是导致局部放电起始电压降低的关键原因。本研究有助于探究XLPE局部放电受绝缘层温度影响的机理,对电缆局部放电信号的分析及电缆状态评估有重要意义。Cross-linked polyethylene(XLPE)cables are the first choice for urban grid line construction.Insulation defects can lead to partial discharge,which affects the insulation performance of the cables and even leads to insulation breakdown and line tripping.At the same time,the cables undergo constant hot and cold cycles during operation,and the insulation layer temperature affects the partial discharge characteristics of XLPE.In order to study this effect,a pin-to-plane electrode experimental platform is set up to measure partial discharge data of XLPE at different temperatures,and the results show that partial discharge mainly occurs at-10°~100°and 150°~265°of the frequency cycle,and its distribution looks like“rabbit ears”;an increase in the insulation layer temperature will lead to an increase in the number of partial discharges and a decrease in the initial voltage of partial discharges.The above experimental findings are verified by simulating the partial discharge phenomena under the influence of insulation layer temperature by using a joint COMSOL-MATLAB analysis to model the pin-to-plate structure with an air gap.The results show that the introduction of an air gap can explain the variation of partial discharge of XLPE with insulation layer temperature in the pin-to-plate electrode,and the variation of XLPE dielectric constant with temperature is the key reason for the decrease in the initial voltage of partial discharge.The results help to explore the mechanism of partial discharge of XLPE affected by insulation layer temperature,which is important for the analysis of the partial discharge signal of cables and cable condition assessment.

关 键 词：交联聚乙烯电缆 绝缘老化 局部放电 温度特性 有限元分析 局放检测 

分 类 号：TM85[电气工程—高电压与绝缘技术]