复合绝缘子泄漏电流波形分形特征研究

Study on the Fractal Characteristics of the Leakage Current of Composite Insulators

绝缘子泄漏电流能够综合体现绝缘子电压水平、污秽状态,贯穿于绝缘子的整个闪络发展过程,提取绝缘子泄漏电流特征量对预测绝缘子闪络事故的发生尤为重要。在人工污秽试验的基础上,利用分形理论提取了复合绝缘子泄漏电流分形维数特征量,分析了闪络发展过程中泄漏电流不同区段波形和分形维数的变化特征,对比了3种不同污秽度水平下泄漏电流波形的分形特征。结果表明,在污闪发展过程中,泄漏电流波形的分形维数呈整体下降的趋势;污秽程度不同,泄漏电流波形分形特征存在微小的差异。实验分析证明,泄漏电流波形分形维数能够直接反映其波形特征,能够为绝缘子污闪提供有效预警。

Insulator leakage current can comprehensively reflect the insulator voltage level and contamination state,which takes effect throughout the entire development process of the insulator flashover, so extraction and selection of leakage current characteristics have a prominent influence on prediction of flashover. Based on artificial pollution test,fractal dimension feature quantity of composite insulators leakage current is derived by using fractal theory,the variation features of waveform and fractal dimension of leakage current in different sections is analyzed in the whole process of flashover development,and leakage current waveform fractal characteristics in three different level of contamination is compared.The results shows that in the process of flashover,fractal dimension of leakage current waveform descends on the whole;and there is a slight difference in the leakage current waveform fractal characteristics depending on different contamination level.Experimental analysis show that the leakage current waveform fractal dimension can directly reflect its waveform characteristics and provide effective early warning