基于EEMD的绝缘子泄漏电流消噪方法

A de-noising method based on EEMD for insulator leakage current

针对绝缘子泄漏电流测量过程中噪声干扰严重、传统消噪方法效果不佳的问题,根据经验模态分解(Empirical Mode Decomposition,EMD)的滤波特性,结合泄漏电流的特点,提出了总体经验模态分解(En-semble Empirical Mode Decomposition,EEMD)阈值消噪方法。为评价消噪效果,选择小波消噪作为对比,对仿真和实测泄漏电流进行消噪处理。研究表明,EEMD阈值方法消噪后泄漏电流有效值和三次谐波与基波幅值比都接近真实值,能准确反映泄漏电流特征。同时,EEMD阈值消噪方法具有自适应性,适合污湿和覆冰状况下的泄漏电流消噪处理。

There is a large amount of noise in the process of measuring insulator leakage current,and the traditional de-noising methods are ineffective.Therefore,combining with the characteristics of leakage current,EEMD（Ensemble Empirical Mode Decomposition） threshold de-noising method based on the filtering characteristics of EMD（Empirical Mode Decomposition） is given in the paper.In order to evaluate de-nosing effects,EEMD threshold de-noising method and wavelet threshold de-nosing method are used respectively to filter the noises from both simulated and measured leakage currents.It is shown by analysis that the amplitude value ratio of triple-harmonic to fundamental and the effective value of leakage current after EEMD threshold de-noising are close to the true value.At the same time,EEMD threshold de-noising method is self-adaptive,therefore is suitable to dirty wet and ice covered insulators leakage current de-noising.