Characterization of acoustic signal produced by partial discharge in insulation oil

Insulation failure is one of the major causes of catastrophic failure of high voltage apparatus. It is important for the study of partial discharge behavior in electrical apparatus to know the degration of insulating materials. This paper focuses on the analysis of acoustic signal produced by partial discharge in insulation oil. The needle-plane electrode system is assembled to simulate the partial discharge in insulation oil. Wavelet transform is used to analyze acoustic signal. The energy distribution of each level and time domain waveform is analyzed. A low-noise amplifier and a de-coupler are used to detect the acoustic signal with high-sensitivity. A digital acquire card is used to get the acoustic signal and save data in computer.