Spatial mask filtering algorithm for partial discharge pulse extraction of large generators

【Abstract】 A spatial mask filter algorithm (SMF) for partial discharge (PD) pulse extraction is proposed in this paper. In this algorithm, firstly, a ‘Teager’ operator is used to strengthen wavelet coefficient local energy; then direct multiplication of coefficients at two adjacent scales is used to detect singularity points of the signal and to obtain scale based spatial mask filter; finally, an ‘AND’ logic operator is used in different filters to obtain the last spatial mask filter. By multiplication of wavelet coefficients with the final mask filter and wavelet reconstruction process, partial discharge pulses are extracted. The results of digital simulation and practical experiment show that this method is superior to traditional wavelet shrinkage method (TWS). This algorithm not only can increase the signal to noise ratio (SNR), but also can preserve the energy and pulse amplitude.更多还原