高压绝缘子泄漏电流的分形特征

在电网电压等级的提高和各类污染的加剧,绝缘子污闪事故日益严重的情况下,通过有关特征量提取来实现绝缘子表面状态的监测是预防污闪、提高电网可靠性的关键。为此,以分形理论为基础研究了高压污秽绝缘子泄漏电流的盒维数、功率谱维数和小波分维数。应用不同算法提取了高压绝缘子闪络过程中泄漏电流的分形特征。研究结果表明,小波分维数比之盒维数和功率谱维数能够更好的表征泄漏电流信号中的电弧放电信息,并为绝缘子的污闪判别提供了有效的特征量。

Fractal Characteristics of Leakage Current on HV Insulators

The flashover of contaminated insulators in HV and UHV system threatens the security of power transmission severely.The key of improving the security of system is exploring the methods of monitoring states of insulator's surface by some characteristic values.In this paper,different fractal characteristics of leakage current(LC) are calculated,including box dimension, spectrum dimension and wavelet-fractal dimension.The results show that wavelet-fractal dimension describes the information of arc discharge in LC more efficiently than other two dimensions,and provides a good characteristic value for flashover discriminations and risk predictions.