抄録
The partial discharge (PD) generated by the surge voltage is an 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. 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. A detecting circuit containing a detecting resistance, a coupling capacitor and a resistance for suppressing the ringing brought appropriate current waveform under a surge voltage application. It is also recognized that the PD current waveform is only extracted from the detected current waveform using a transfer function calculated by a voltage and current waveforms without PD. Furthermore, this system on the PD analysis may further be useful to clarify the PD mechanism under a surge voltage application because the PD current waveform, which contains information on PD mechanism, was extracted without waveform change.
