用于局部放电检测的一种小波去噪方法

A WAVELET-BASED NOISE-REDUCTION METHOD FOR PARTIAL DISCHARGE DETECTION

局放监测系统常会受到很强的外界干扰,有时局放信号甚至被噪声完全淹没,因此对采集到的信号必须进行去噪处理才能获得可靠的局放信息。笔者介绍了利用小波变换进行自动去噪处理的方法。利用相关系数选择最佳小波,通过自动阈值计算选定阈值并对高频分量进行软阈值处理,然后对信号进行重构。结果表明,这种自动去噪算法可以有效地提取局放信号的特征,可望用于局放信号在线监测。

Partial discharge(PD)detection system is often affected by external interferenc e,and sometimes the partial discharge signals are submerged in noises.So the sig nals acquired must be preprocessed to obtain reliable partial discharge inform ation.The paper presents a method to fulfil automatic noise reduction.By selecti ng an optimal wavelet and processing high-frequency components using the soft th reshold method with an automatic thresholding rule,partial discharge signals are then reconstructed with modified detailed coefficients.Results illustrate tha t this method can extract characteristics of partial discharge signals effective ly and may be used in partial discharge on-line monitoring systems.