Partial Discharge Testing Platform for PWM Voltage Source Converters in Electric Aircraft

A pulse-width modulation (PWM) voltage source converter is a vital asset in aircraft electrification. These converters operate using fast (10-100kHz) switching power semiconductors. Partial discharge (PD) that occurs in insulation due to this PWM voltage is difficult to detect due to the transient noise of the voltage switching which obscures the smaller partial discharge signal. The PWM voltage also features high dv/dt and along with the high switching frequency increases the stress on the insulation system. Partial discharge is more likely to occur in greater quantity due to PWM voltage, but more difficult to detect. This paper studies the effect that PWM voltage has on insulation due to the high switching frequency and dv/dt. In order to achieve this goal, PWM Voltage testing platform is designed and electrically isolated detection methods are examined for effectiveness in the presence of PWM voltage noise.