基于小波分解的自适应滤波算法在抑制局部放电窄带周期干扰中的应用

在局部放电在线监测中，由于窄带周期干扰的频率范围很宽，自适应滤波器的参数设置比较困难，有时甚至会导致算法不稳定。为此，文中提出了一种基于小波分解的自适应滤波算法，以用于抑制窄带周期干扰：利用小波的分频特性先将信号分解到不同的频段上，然后对各频段的信号施以自适应滤波，由于信号被分解到不同的频段，各频段内的窄带干扰频率相差有限，所以，可以根据各频段信号的特性采用最佳的滤波参数，以达到较好的滤波性能。计算机仿真分析和现场数据处理表明，该算法比普通自适应滤波算法有更好的抗干扰性能和稳定性。

STUDY OF ADAPTIVE FILTER ALGORITHM BASED ON WAVELET ANALYSIS IN SUPPRESSING PD''S PERIODIC NARROW BANDWIDTH NOISE

A new adaptive algorithm based on wavelet analysis to suppress narrow bandwidth noise is proposed. The usual adaptive filter is one of the best algorithm in suppressing sinusoidal noises in PD signal processing. But it is difficult in setting the parameters of the adaptive filter in PD on-line monitoring due to wide frequency range of narrow bandwidth noise, and it may be unstable sometimes when the parameters set improperly. Study shows that the new algorithm has better performance and stability compared to usual adaptive filters.