Time-domain characteristic site analysis for ultra-high frequency partial discharge in power transformer

The relationship between time-of-fight difference and accumulation energy is introduced to analyze the time-domain waveform of ultra-high frequency electromagnet (EM) wave induced by partial discharge (PD) from interior of transformer. Gauss function is applied to fit the waveform of EM, and the characteristics of EM are presented by the statistical analysis for all the fitting curves. It is shown that the relationship between time-of-flight difference and accumulation energy enables to identify whether the EM signals acquired by different sensors come from the same source of PD and more accurately to determine whether the EM signals come from the same source of PD due to the high similarity coefficient of EM wave induced by the same PD. And the fitted curves in time domain are beneficial to remove the interference to evaluate the PD pattern.