Observation of partial discharge current waveform under inverter surge application

The partial discharge (PD) generated by the surge voltage is a issue in inverter-fed motor for the reliability of the electrical insulation. The measurement of PD waveform with a wide frequency range is one way to investigate this PD. The PD waveform with a wide frequency range may imply information such as mechanisms beginning from initiation of avalanche and its propagation. However, measurement of the PD waveform under inverter surge voltage is not easy, because of the rapid rising time of the applied voltage. In this paper, the detecting circuit and the analysis method were studied to construct a novel analysis system for the PD current waveform with wide frequency range under the application of rapid rising voltage.