基于EMD的绝缘子泄漏电流去除噪声研究

针对绝缘子泄漏电流信号在安全区阶段信噪比较低,传统去噪方法去噪效果不佳的问题,结合经验模态分解(Empirical Mode Decomposition,EMD)的特点,设计了基于白噪声统计特性的EMD滤波器和EMD阈值滤波器。利用设计的两种EMD滤波方法对泄漏电流信号的仿真模型进行去噪,从除噪后信号的波形形状和信噪比等方面对去噪效果进行评价。研究表明EMD去噪方法去噪性能优于小波去噪。同时还发现,针对不同信噪比的含噪信号,基于白噪声统计特性的EMD去噪和EMD阈值去噪各具有优势,可根据信噪比的不同,选取最适合的滤波方法。

Study on de-noising method based on EMD used in insulator leakage current

According to the problem that the SNR(Signal-to-Noise Ratios) of insulator leakage current in safety stage is low and traditional de-noise methods are ineffective,and combining with the characteristics of EMD(Empirical Mode Decomposition),the EMD filter based on the characteristics of white noise and the threshold filter based on EMD were designed.In this paper,two de-noising methods based on EMD which we have been designed and wavelet de-noising method have been applied and tested in the simulated leakage current.Through evaluating the de-noising result in terms of waveform and the SNR of the de-noised signal,it is found that the de-noising performance of de-noising method based on EMD is much superior to wavelet de-noising method.It is also concluded that two de-nosing methods based on EMD have respective superiorities under the circumstances of different SNR,so we should chose the best de-noising method based on different SNR.