Fundamental Comparison of Efficiencies of Voltage Source Converter Phase-Leg Configurations with Super-Junction MOSFETs

High-efficiency power conversion systems are desirable in transportation systems to reduce cooling requirements, and hence mass. Alternatives to the IGBT for high-efficiency power conversion include the silicon super-junction MOSFET and SiC devices. The super-junction MOSFET can be used in voltage source converters provided the challenges presented by its intrinsic diode and output capacitance are addressed. The intrinsic diode can be deactivated with auxiliary components and the output capacitance can be addressed with an inductive turn-on switching-aid (‘snubber’) circuit. A comparison of losses is performed for a phase-leg based around super-junction MOSFETs when hard-switched, used with a dissipative snubber, and used with a snubber with energy recovery.