Optimizing Switching Performance of Cascode-Light SiC JFET Bidirectional Switch for Matrix Converter

Bidirectional Switches (BDSs) are basic elements in Matrix Converters (MCs). Its switching characteristics determine the performances of the converter. Changing the equivalent impedance of the BDS is propitious to damping the parasitic ringing during switching transient and scaling it for higher voltage applications. A Silicon Carbide Junction Field Effect Transistor (SiC JFET) BDS structure based on the cascode-light configuration is proposed in this paper. We equally present equivalent circuit model of SiC JFET BDS at turn-off and investigate the impact of snubber capacitors (C
_s
) paralleled across JFETs on the equivalent impedance of the BDS circuit. Theoretical analysis and experimental results of turn-off performance with and without C
_s
show that the proper selection of C
_s
is favourable to increasing the equivalent impedance of the BDS circuit and reducing the voltage overshoot at turn-off transient for high voltage applications.