基于泄漏电流特性的交流悬式绝缘子覆冰闪络特性  

AC Suspension Insulatorês Ice Flashover Based on Characteristics of Leakage Current

作　　者：于昕哲[1,2] 杨晓磊[1] 唐其筠 张乔根[1] 杨昊[1] 李舟 

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]中国电力科学研究院,北京100192 [3]国网天津市电力公司城南供电分公司,天津300299

出　　处：《高电压技术》2017年第9期2943-2950,共8页High Voltage Engineering

基　　金：国家电网公司科技项目(GY71-13-034)~~

摘　　要：为了揭示覆冰闪络特性以提高闪络预测结果的准确性,对比分析了长串和短串覆冰绝缘子交流闪络过程的泄漏电流特性。根据泄漏电流时域波形将绝缘子覆冰闪络过程分为4个阶段,选取第3阶段的准恒定特征电流(IW)和第4阶段闪络前最后一周期泄漏电流峰值(IFT)作为闪络预测的2个重要特征量,并研究了其与覆冰严重程度、污秽度和覆冰水电导率的关系。结果表明:IW和IFT随覆冰水电导率的增加近似线性增大,但几乎不受污秽度影响;2者随覆冰严重程度的增加而增大,当伞裙间隙被冰棱完全桥接时达到饱和值;IW可以用于覆冰闪络的早期预警,而IFT可作为临界闪络判据。In order to clarify the features of the pre-flashover and predict ice flashover more accurately, the entire evolution of leakage current during the pre-flashover process of both AC long and short suspension insulator strings covered with ice was recorded and analyzed. The tests were carried out in two separate climate chambers, and showed that the pre-flashover processes of both ice-covered long and short insulator strings could be divided into four stages based on the time domain characteristics of leakage current. Two significant parameters were proposed as characteristic parameters for the analysis of pre-flashover characteristics, namely the characteristic current（IW） which was the quasi-constant value in stage III, and the critical current（IFT） which was the leakage current amplitude value in the last cycle before flashover in stage IV. The relationships between these two characteristic parameters and the influencing factors including ice build-up severity, the contamination degree, and the conductivity of the freezing water were also studied. It was found that IW and IFT increased with the conductivity of the freezing water almost linearly, but they were barely influenced by the contamination level. And the two parameters increased with the ice build-up severity, finally reaching a saturated level when the air gaps amid the insulator sheds were completely bridged by icicles. It was believed that the characteristic parameter IWcould be adopted as early-warning value of pre-flashover along the ice-covered suspension insulator, and IFT as the criterion of the critical flashover.

关 键 词：绝缘子闪络 覆冰 污秽 电弧长度 泄漏电流 冰棱桥接 

分 类 号：TM216[一般工业技术—材料科学与工程]