Distinction of Partial Discharge Signal from Noisy Signal by Daubechies Wavelet Transform

Abstract

When partial discharge occurs in high voltage apparatus, it may develop into its insulation degradation or its electrical breakdown. It is important to detect partial discharge with sufficient sensitivity especially from noisy background. This paper deals with the waveform processing technology by Daubechies wavelet transform to make relief of the partial discharge from a noisy signal. The partial discharge signal was measured in the coaxial electrode arrangement with a metallic needle attached on the high voltage central electrode. By choosing suitably the Daubechies order and its level applied to the measured data, it has been demonstrated that the noise signal is reduced and the partial discharge signal is relieved with sufficient sensitivity.