A Low-Loss Compact Reflected Wave Canceller for SiC Motor Drives

Abstract

The overvoltage caused by reflected wave phenomenon in motor drives becomes worse with the application of SiC devices due to the significantly higher $dv/dt$ compared with that of Si devices. This letter presents a low-loss and compact active reflected wave canceller (ARWC) to suppress the overvoltage at the motor terminal. The proposed ARWC circuit uses low current devices to break the rising and falling edges of the pulsewidth modulation voltage waveforms to two steps, whereas the second step cancels the first step reflection. In addition, the ARWC circuit does not require an additional dc power supply that allows the ARWC self-sustained. The experimental results on one phase 6 kVA application with and without proposed ARWC are provided and compared to verify the validity of proposed method.