Partial Discharge Detection Strategies under Fast Rise Time Voltages Generated by Wide-bandgap Semiconductor Devices

Wide-bandgap (WBG) semiconductor device is one of the leading contenders for the next generation semiconductor device. Its advantages include but not limited to: higher voltage rating, switching speed and frequency. However, when electrical applications are driven by WBG devices, the voltage stress is inevitably changed. To be more precise, the voltage stress is more likely to be enhanced based on the premature failures observed for various applications driven by WBG devices. As has been well accepted, partial discharge (PD) is considered as the main cause for insulation failure in high frequency equipment. Thus, it is necessary to study PD behaviors under the new stress introduced by WBG device. However, the issue is inherently challenging due to the nature of the equipment under test and the extremely high dv/dt (fast rise time) square-wave voltage introduced. Huge charging/discharging current would be seen at the rising/falling edges of the square-wave pulse train. The magnitude of the charging/discharging current can be hundreds of or even thousands of times larger than that of PD pulse current. In some cases, even in frequency domain, the PD pulse current would be masked by the charging/discharging current. In this paper, a summary is made on past research related to PD detection strategies under fast rise time square-wave voltage or impulse voltage. Their advantages and disadvantages would be introduced to provide a full picture about this issue for future researchers when the need of PD detection under fast rise time excitations arises.