Experimental efficiency comparison of a superjunction MOSFET, IGBT and SiC MOSFET for switched reluctance machine drives

The IGBT and fast recovery diode are normally the preferred power semiconductor devices in machine drive power converters. High efficiency in the power converter reduces its cooling requirements and its consequent mass and volume. To attain high efficiencies, SiC devices are increasingly being considered as alternatives to the silicon IGBT and fast recovery diode. Another alternative would be the silicon SJ MOSFET, but because of its intrinsic diode and output capacitance characteristics, it is normally precluded from use in simple hard-switched machine drive applications. In switched reluctance machine drives, which differ from most machine drive power converters, the performance advantages of devices which may be considered the obvious choice are not distinct. This study compares the performance and power losses of three switching devices in a practical switched reluctance machine drive and shows that the silicon SJ MOSFET is the most suitable choice.