IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

300 / 2017-12-08 00:12:31

Design of Gate Driver Circuit for Series-Connected Silicon Carbide MOSFETs in a Bridge Circuit

SiC,series

Plenary track > Gate drive and other auxiliary circuits

SiC MOSFET is an excellent alternative of Si IGBT for high power converters because it has low on-state resistance and can work on high switching frequency with less temperature drift. While SiC MOSFETs with higher voltage ratings have been reported, they remain in individual labs and are not available to the market. Therefore, it will be of interest for series connections of SiC MOSFET. However, for the bridge circuit in an actual converter, high dv/dt during fast switching transient of one bridge will amplify the negative influence of parasitic components and produce significant negative voltage spikes on the complementary bridge. The series-connection topology will threaten these voltage spikes. This paper proposes a novel designed gate driver for the SiC MOSFET series topology in a bridge circuit. The proposed gate driver adopts a RCD circuit to keep the active voltage balancing and a passive triggered transistor with a series capacitor to suppress the negative voltage spikes. The simulation based on LTspice software validates the analysis and shows an excellent switching operation of the proposed gate driver.