Optimal sampling rate for wavelet-based denoising in PD measurement

Extracting PD pulses from excessively noisy environment has been a crucial issue in PD on-line measurement. DWT as a powerful mathematical tool has proven its effectiveness in PD measurement denoising. The paper presents a method on how to achieve an improved denoising effect at an optimal sampling rate in DWT. It reveals the relationship between the sampling rate and the frequency band in wavelet analysis and contrasts the distribution of a PD signal and white noise along the decomposition levels. A set of 3 PD pulses produced by a narrow band detector immersed in white noise are processed at different sampling rates to verify the effectiveness of the proposed method.