Wavelet denoising of partial discharge images

Abstract

This paper presents application of wavelet based de-noising to partial discharge (PD) phase resolved images. Simulations are discussed in first part while in the second one results obtained during on-line measurements on a 6 kV motor. The basic principles of wavelet de-noising analysis, as well as examples of hard- and soft de-noising thresholding are reported. For the purposes of decomposition, the Deabuchies wavelet and wavelet packets at different levels were applied. The efficiency of the enhancement was measured by using a mean square signal-to-noise ratio and standard deviation to mean ratio.