Active Reflected Wave Canceller with Partial Discharge Suppression for MV SiC Motor Drive

The overvoltage caused by reflected wave phenomenon in motor drive will increase the risk of partial discharge, resulting in winding insulation failure. This paper proposed an active reflected wave canceller (ARWC) to suppress the overvoltage as well as partial discharge at the motor terminal. The proposed ARWC is formed by an H-bridge circuit for each phase with low-voltage low-current device as well as a coupled inductor even when motor drive adopts multilevel topology. In order to verify the proposed ARWC, a 3-level single phase active neutral point clamped (ANPC) inverter using 3.3 kV SiC MOSFET was built in the lab and the proposed ARWC was designed for this SiC inverter. In addition, a test platform to measure the partial discharge of SiC inverter with proposed ARWC and an inductive load was setup in the lab. The experimental results are provided to verify the validity of ARWC and partial discharge suppression.