SiC Power Module with integrated RC-Snubber Design for Voltage Overshoot and Power Loss Reduction

The maximum voltage overshoot of SiC MOSFETs in power modules limits the switching speed of voltage source inverters in electric vehicles. As the efficiency increases with faster switching transitions, decreased commutation loop inductances allow higher switching speeds at same voltage overshoot level and extend the vehicle’s range. In this research, a SiC power module including an integrated RC-snubber is designed to increase the switching speed at same voltage overshoot. The RC-snubber acts as a damped low inductance commutation loop filtering the switching transients and suppressing the ringing, whereas the low frequency components are filtered by the dc-link capacitor. To meet the target of increased system efficiency, the losses of all inverter components are analyzed for space-vector modulation (SVPWM).