Modeling power semiconductor losses in HEV powertrains using Si and SiC devices

Silicon carbide (SiC) power semiconductor devices are known to have potential benefits over conventional silicon (Si) devices, particularly in high power applications such as hybrid electric vehicles (HEVs). Recent literature studying the use of SiC JFETs in HEV inverters indicate a substantially increased gas mileage. This paper further investigates this change in inverter efficiency due to the adoption of SiC using analytical loss models and empirical loss data obtained from experimental Cree 1200V 10A DMOSFETs and Schottky diodes. A motor inverter efficiency map is developed and used in the VEHLIB simulator to evaluate fuel consumption benefits. Distribution of conduction and switching losses in both Si and SiC inverters is explored.