高压染污绝缘子泄漏电流的频谱特征

Leakage Current Spectrum Characteristics of HV Contaminated Insulators

随着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,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,以频谱理论和高阶统计量理论为基础,研究了高压污秽绝缘子泄漏电流的功率谱、功率谱频段能量变化规律;提取了泄漏电流的双谱信息,并分析了双谱对角切片和最大谱峰及其对应的频率分量的变化规律。结果表明,泄漏电流的功率谱频段能量变化能够很好地刻画泄漏电流的发展趋势。泄漏电流的双谱最大谱峰幅值总体呈现明显递增的趋势,且递增的幅值在相邻两个阶段相差2~3个数量级。泄漏电流的功率谱频段能量和双谱谱峰可作为模式识别的有效特征量对绝缘子污闪发展状态进行判别。

To realize the monitoring for the insulator surface condition through extracting the amount of the relevant characteristics of leakage current（LC） is the critical way to prevent flashover and to improve grid reliability.Consequently,not only spectrum energy and bi-spectrum of LC are calculated based on the spectrum theory and high order cumulants theory,but also the bi-spectrum slice and its corresponding frequency are analyzed.The results show that spectrum energy can describe the development of LC.The highest peak of LC bi-spectrum efficiently describes the information of arc discharge in LC,and is a good character value for flashover discriminations and risk predictions.