Second wavelet transform automated threshold for partial discharge signal extraction

Automated threshold algorithm of second wavelet transform is used in extraction of partial discharge. Exponential damping or exponential damping oscillating etc. two kinds of partial discharges are used in numeric simulation, and effectiveness of extraction of partial discharge is studied. Simulation results show that wavelet transform can effectively extract partial discharge from random noise because it has multi-resolution, and second wavelet transform reserves more features of original partial discharge than conventional de-noise method of first wavelet transform. The method process swift, and it is adaptive to dispose on line.