基于多重自相关的局部放电信号小波去噪分解层数确定方法

Determination of the Decomposition Level in Wavelet Threshold Denoising for Partial Discharge Signal Based on Multi-layer Autocorrelation

测量系统的白噪声给电气设备局部放电信号的准确测量带来困难.小波阈值法是常用的去噪方法,其分解层数的选择会影响去噪效果.利用小波分析Mallat算法频带划分原理,提出了一种基于多重自相关的小波分解层数确定方法.仿真实验结果证明,针对混有测量系统白噪声的电气设备局部放电信号,基于所提出的分解层数确定方法使用小波阈值法可以取得较好的去噪效果.

The white noise of the measurement system brings disturbance to the accurate measurement for partial discharge signal of electrical equipment.Wavelet threshold denoising is a common method,but the decomposition level will affect the denoising effect.Based on the frequency band division principle of wavelet analysis Mallat algorithm,a new method using multi-layer autocorrelation to determine the wavelet decomposition level is proposed in this paper.The simulation results show that for the partial discharge signal of the electrical equipment mixed with white noise of the measurement system,the decomposition level determined by the method can achieve better effects in wavelet threshold denoising.