染污绝缘子放电中泄漏电流的频谱变化

为更有效地预防污闪的发生,在实验室反复试验研究绝缘子交流污秽放电过程中泄漏电流的变化特性,提取了以泄漏电流为污闪预警主要特征量即利用功率谱变换对泄漏电流进行频域分析,提取出泄漏电流频域中功率谱最大谱峰值曲线增长速率作为污闪预测的有效参量从而防止污闪的发生的新思路。得出的试验结果说明此参量可以为污闪预警提供更明确的理论指导,有利于污闪预警系统更清晰地建立。

Frequency Domain Spectrum of Leakage Currents During Discharge Detection for Contamination Insulators

Contamination flashover was the extreme result of creepage discharge of contamination insulators.In order to seek a method to show definitely the various stages of creeping discharge of contamination insulators and to supply early pre-warning for contamination flashover,the artificially polluted insulators were investigated by the fog chamber method in the laboratory.For the very close relationship between the leakage current and contamination discharge of insulators,leakage currents were detected and recorded continuously by tested glass suspension insulators with different contamination degrees,and the characteristics of leakage current were researched and analyzed to obtain the characteristic parameters for preventing the contamination flashover of insulators.Power spectrum transform was used to analyze the characteristics of leakage current in frequency domain.As a result,it is found that the rising velocity of maximal peak value of power spectrum curve can be used as a prediction parameter to show the different stages of contamination discharge development.Furthermore,it is clarified that the power spectrum characteristics of leakage current can provide much clearer theoretical and practical direction for the contamination pre-warning than leakage current waveforms and effective values in engineering application.