SiC MOSFETs connected in series with active voltage control

Abstract

Silicon Carbide (SiC) MOSFETs offer rapid switching and low on-state voltages. Connecting SiC MOSFETs in series will enable high voltage high frequency applications. Nonetheless, the output capacitances of SiC MOSFETs are often found to ring with the significant stray inductance inevitably found in circuits with series connected devices. The active voltage control gate drive method is used here to clamp the MOSFET voltages to ensure low and stable overshoot voltages, good voltage balancement and a near ideal turn on. It is concluded that SiC MOSFETs and SiC diodes may be connected in series with significant advantages compared to Silicon (Si) IGBTs and Si diode technologies, and the benefits may be realized with the use of active voltage control.