Bidirectional Switching Characteristics Analysis Based on SiC MOSFET

Compared with Si MOSFET, the SiC MOSFET has the advantages of high temperature resistance, high voltage, high switching frequency and low switching loss. Bidirectional switches are widely used in matrix converters, T-type three-level and VIENNA rectifiers, however, the bidirectional switching characteristics based on SiC MOSFET are still less discussed. In order to explore the bidirectional switching characteristic of SiC MOSFET, the equivalent circuit of SiC MOSFET is first established, and a static model including trans-conductance, threshold voltage and pin resistance, and a dynamic model including junction capacitance and body diode are constructed. The forward and reverse conduction and turn-off characteristics of the SiC MOSFET bidirectional switch are deduced and analyzed. The reason for bidirectional switching oscillation and voltage spike are discussed in combination with the experiment. The characteristic law of SiC MOSFET and its bidirectional switch are verified through using simulation and experimental results.