Comparing 650V and 900V SiC MOSFETs for the application in an automotive inverter

This paper researches the performance benefits of replacing the Si IGBTs and diodes in a power module for automotive drives with either 650 V or 900 V SiC MOSFETs. Evaluating the mean conduction and switching losses in a load profile allows a comparison of both voltage classes in order to show which class offers the lower overall losses in the given application. Furthermore, the influence on the switching losses of different gate driving methods and stray inductance of the commutation loops is investigated. It can be found that 900 V chips offer lower overall losses in combination with standard packages (middle to high commutation loop inductance) and standard gate driving methods (using only the gate resistance to control the switching speed). 650 V chips, however, profit from low inductive setups and smarter gate driving strategies, while at the same time displaying less oscillations during switching.