【摘要】 污秽放电的极端结果是污闪,为提取反映绝缘子污秽放电发展的有效特征量,在实验室反复试验研究的基础上,利用分形理论中的变换法提取绝缘子污秽放电过程中泄漏电流波形的分形维数,分析不同污秽度下安全区、预报区和危险区3个区段内泄漏电流分形维数的差异,提取预报区分形维数的均值和标准差来预测污秽度。得出污秽放电不同阶段分形维数的变化特征明显,且不同污秽度的分形维数大小不同。试验证明泄漏电流分形维数的变化规律能有效预测污秽放电发展趋势及污闪的发生,分形维数的大小能有效判断绝缘子污秽的轻重,为污闪预警提供了新方法和新特征量。更多还原

【Abstract】 The extreme result of insulators contamination discharge is contamination flashover.In order to obtain effective characteristics of contamination discharge,the variation method of fractal was used to extract the fractal dimension of leakage current waveform through a number of laboratory experiments.The differences of leakage current fractal dimension in safety,forecast and danger zones under several contamination degrees were analyzed;and the typical value and the standard deviation of fractal dimension in forecast zone were extracted to predict contamination degrees.Experiments showed that variation characteristics of fractal dimension in different stages of contamination discharge are obvious,and fractal dimension values under different contamination degrees are different.These results can predict the development of contamination discharge and the occurrence of contamination flashover,estimate contamination degrees,and thus provide new methods and valid characteristics for the pre-warning of contamination flashover.更多还原