Denoising of Partial Discharge Signal by Common Factor Method and Wavelet Thresholding

Partial Discharge (PD) will make insulation of electrical apparatus decrease and threaten the security and stability of power system. On the other hand, it is also an indicator of insulation status of electrical apparatus. Therefore, it is important to monitor PD online. However, inevitable white noise exists and will interfere PD measurement, thus distorting it and leading to misjudging of insulation status. Therefore, denoising of PD signal is very necessary. Wavelet thresholding denoising method is one of the most commonly used method, but it lacks translation in-variance, and the denoising effect is influenced. To overcome this disadvantage, common factor method is proposed to construct dual-tree complex wavelet combined with wavelet thresholding in this paper. Finally, numeric simulation experiments have been set to verify the feasibility and effectiveness of the proposed method.