SiC MOSFET Assisted Si IGBT 1200 V Switch for 3-phase DC-AC Converters with Overload Condition

Si/SiC hybrid switches are gaining popularity in overcoming the current challenges in electric power conversion, such as efficiency, cost effectiveness, and mass availability. This study demonstrates that these challenges can be resolved by parallelizing SiC-MOSFETs and IGBTs, thereby meeting the performance requirements and thermal boundaries of the power converter in overload conditions. Using static characteristics, and double pulse test to optimize the IGBT/SiC MOSFET area ratio with respect to losses, the optimal chip size trade-off was selected. The selected ratio configuration was consecutively tested in a 3-phase, Si-SiC based hybrid converter in back-to-back configuration. Discrete 1200 V rated in TO-247 (3-pin and 4-pin) packages were used in this study, adopting Infineon´s CoolSiC(TM) MOSFETs and TRENCHSTOP(TM) IGBT7 S7.