Coordinated Switching with SiC MOSFET for Increasing Turn-off dV/dt of Si IGBT

This paper presents a solution to the excess carrier issue that limits the turn-off dV/dt of an IGBT. The method is coordinated switching of a Si IGBT and a SiC MOSFET in parallel. In this paper, the internal physics related to IGBT turn-off is summarised and the requirements to enable the reduction of excess carriers and fast switching are discussed. An experimental implementation and control strategy for the Si IGBT and SiC MOSFET are presented along with the test results that demonstrate the increasing in turn-off dV/dt and reduction in switching losses Simulation results of the dV/dt and the total turn-off loss vs. the MOSFET on-time are also presented and discussed.