染污复合绝缘子受潮过程中特征量K_(h10)理论分析  

Investigation on Theoretical Analysis of Characteristic Parameter K_(h10) in Wetting Process of Polluted Composite Insulators

作　　者：郑广君[1] 戴罕奇[1] 张春雷[1] 谷哲飞 赵新历[1] 王海波[1] 王黎明[2] 

机构地区：[1]国网北京市电力公司,北京市西城区100031 [2]清华大学深圳研究生院,广东省深圳市518055

出　　处：《电网技术》2017年第8期2731-2736,共6页Power System Technology

基　　金：国家自然科学基金项目(51377093)~~

摘　　要：特征量Kh用于描述复合绝缘子受潮期间的污层状态,研究了其物理意义。针对污层表面局部放电现象,提出了相应的电路模型,并结合试品受潮期间的干区形成过程,进一步探讨了电路模型的正确性。分析认为:Kh的理论值等于污层剩余电阻与总电阻之比,干区电阻越小,污层表面放电越微弱,Kh值越大。Kh值变化与污层表面局部放电相对应,间歇性放电造成Kh值频繁波动,要评价污层受潮状态,需对Kh数据进行特殊处理。通过提取周期T内10个最小的Kh值,得到平均值K_(h10),可用于研究染污复合绝缘子的受潮过程。研究发现:试品闪络电压与污秽度、污秽成分、憎水性、受潮程度等多因素有关,特征量K_(h10)表征了试品受潮期间的综合表面状态,对于污秽度、污秽成分、憎水性能、受潮方式均不同的染污试品,只要闪络试验前的K_(h10)值趋同,闪络电压也接近,由此表明特征量K_(h10)对于复合绝缘子人工污秽试验具有良好的适用性。This paper investigates physical meaning of characteristic parameter Kh describing state of pollution layer of composite insulators during wetting. A circuit model is proposed to analyse partial discharge phenomena on pollution layer. Correctness of the circuit model is discussed by studying dry band formation process of samples during wetting. According to derivation, Kh is found theoretically equal to ratio of residual resistance over total resistance of polluted layer. Kh is negatively correlated with dry band resistance. Kh change corresponds to partial discharge on polluted layer surface. Intermittent discharge causes Kh to fluctuate frequently. To evaluate wetting state of pollution layer, Kh data need to process. Average value Khlo is obtained by extracting the ten smallest Kh values in period T. Khl0 can be used to study wetting process of composite insulators. Flashover voltage is found related to various factors such as pollution grade, pollutant components~ hydrophobicity and damp state. Khl0 represents comprehensive surface state of samples during wetting. For polluted samples with different pollution grade, pollutant components, hydrophobicity and wetting method, their flashover voltages are＇similar if the samples have similar Khlo values before flashover tests. These results indicate that parameter Khl0 is valid for artificial pollution test of composite insulators.

关 键 词：放电特征量Kh10 绝缘子 泄漏电流 受潮过程 电路模型 闪络电压 

分 类 号：TM86[电气工程—高电压与绝缘技术]