Study of the effects of parasitic inductances and device capacitances on 1200 V, 35 A SiC MOSFET based voltage source inverter design

Abstract

SiC MOSFET can switch five to ten times faster compared to state of the art Si IGBT. Due to that SiC MOSFET based power converter can be lighter in weight, highly efficient, compact in size compared to Si IGBT based power converters. But the parasitic inductance in the power circuit will not allow SiC MOSFET to switch to its full potential due to very high device voltage overshoot, sustained oscillation in line currents and device voltages, high EMI noise injected in the control circuit etc. Therefore it is very important to know the behavior of the switching characteristics of the device at different parasitic condition. In this paper switching behavior of a 1200V, 35 A, SiC MOSFET is tested extensively in different parasitic condition. A limiting value of these inductances is provided to build a voltage source inverter with SiC MOSFET utilizing its full switching potential.