基于广义S变换和随机子空间的局放窄带干扰抑制方法

Partial discharge narrowband interference suppression method based on generalized S-transform and stochastic subspace

为了解决传统方法难以有效抑制局部放电中周期性窄带干扰的问题,本文提出了一种基于广义S变换和随机子空间的局部放电窄带干扰抑制方法。该方法首先利用广义S变换将染噪局放信号从时域变换到时频域中,接着利用局放信号和窄带干扰不同的时频特征确定窄带干扰数目和无局放时间片段,最后利用随机子空间算法估计窄带干扰参数,实现染噪局放信号的窄带干扰抑制。仿真和实际测试结果表明:相比于传统的广义S变换模矩阵方法和频率切片小波变换方法,本文所提方法对窄带干扰抑制效果更好,能更好地恢复原始局放波形。

In order to solve the problem that traditional methods are difficult to effectively suppress the periodic narrowband interference in partial discharge(PD),a PD narrowband interference suppression method based on generalized S-transform and stochastic subspace is proposed.Firstly,the generalized S-transform is used to transform the PD signal with noise from time domain into time-frequency domain.Because the PD signal and the narrowband interference have different time-frequency characteristics,both the number of narrowband interference and the time segment without PD are obtained in time-frequency domain.Finally,the stochastic subspace algorithm is used to estimate the parameters of narrowband interference,suppressing the narrowband interference.From the simulated and experiment results,compared with the traditional generalized S-transform modular matrix method and frequency slice wavelet transform method,the proposed method has a better suppression effect on narrowband interference,and it can restore original PD signal well.