Series-connected SiC MOSFET drive circuit based on multi-winding transformer coupling

摘要

The present disclosure provides a series-connected SiC MOSFET drive circuit based on multi-winding transformer coupling. The drive circuit is mainly composed of a transformer, an energy storage capacitor and a push-pull circuit. The transformer plays a role of constraining a relationship between gate-source voltages of series-connected SiC MOSFETs to ensure that a drive voltage of each SiC MOSET in series is synchronously increased and decreased, and to prevent the problem of a dynamic voltage imbalance at moments of conduction and cutoff due to the desynchrony of the drive voltages. Both the energy storage capacitor and the push-pull structure are used to ensure that the SiC MOSFETs have sufficient drive currents at the moment of conduction to achieve fast conduction of the SiC MOSFETs. Meanwhile, a discharge loop is constructed for the gate-source voltages at the moment of cutoff to ensure that the drive voltages drop in a short period of time.