A physical model for nanosecond partial discharge

Using an ultra-wideband detection system, the characteristics of a partial discharge are studied. The new detection results are different from traditional experimental results in the time-domain. Based on collision ionization theory, a new physical model is put forward for analyzing the new detection results in this paper. In the new model, the second emission resulting from the ion impacting cathode and photoelectron radiation is considered. The electron current and positive ion current of the first ionization, electron current resulting from the ion impacting cathode and photoelectron radiation in the nanosecond discharge process are computed in this paper. Each generation discharge current is obtained, and a computing discharge waveform is obtained. The theoretical computed current waveform is no different from the measured nanosecond discharge waveform. It is shown that the new model can interpret the detection results