Application of modified wavelet packet transform for de-noising during partial discharge measurement on power cables

PD monitoring is an effective tool for evaluating the insulation condition of high voltage equipment. However, the major challenge during on site PD measurement is that PD signals are severely affected by external noises and disturbances like white noise, random noise, Discrete Spectral Interferences (DSI), which are generated due to broadcasting stations, stochastic noise and pulses from power electronics at site conditions. Extracting PD signals from these noises is a challenging task. A method for de-noising PD signals using a modified version of Wavelet Packet Transform (WPT) proposed earlier [1] is refined further to improve its de-noising performance. In this paper, the application of Modified Wavelet Packet Transform for de-noising partial discharge signals in power cables has been carried out. The results are presented and discussed.