基于谱减法与小波分析的电缆局部放电信号降噪方法

Cable local discharge signal denoising method based on spectral subtraction and wavelet analysis

白噪声作为电力电缆局部放电信号监测系统采集的主要环境干扰源,会对局部放电信号的检测和分类产生负面影响,因此需要一种有效的降噪技术来抑制这种环境噪声。运用传统的小波变换去噪,尽管可以达到较好的效果,但其计算复杂性给实际应用带来众多不便。针对以上问题,将计算复杂性较低的谱减法引入局放信号的处理,提出了一种功率谱减法和小波分析联合的增强算法,并通过仿真实验验证了其降噪效果。结果表明,相比小波去噪,该方法具有更好的去噪性能。

As the main environmental interference source collected by the power cable local discharge signal monitoring system,white noise will have a negative impact on the detection and classification of the local discharge signals.Therefore,an effective denoising technology is needed to suppress the environmental noise.Although the traditional wavelet transform method can achieve good effects in denoising,its computational complexity brings inconveniences to the practical application.In view of the above,the spectral subtraction with less computational complexity is introduced into the processing of local discharge signals,and an enhancement algorithm combining power spectral subtraction and wavelet analysis is proposed.Its noise reduction effect was verified by simulation experiments.The results show that the proposed method has better denoising performance than the wavelet denoising method.