GaN Gate Driver for SiC MOSFETs in a Megawatt Inverter

Abstract:
High power inverter applications utilizing SiC MOSFETs (or IGBTs) require multiple chips in parallel. However, paralleled chips lead to a significant peak current on the gate drivers during the switching events, which could surpass the capabilities of a standard gate driver. Addressing this issue, a booster stage is implemented between the gate driver and the parallel chips. This paper presents a concept employing a GaN FET based booster stage to efficiently drive a larger number of SiC MOSFETs in parallel, which is also suitable for IGBTs. The performance of this GaN booster is analysed and compared with a Si MOSFET based booster configuration. The analysis high-lights the advantages of GaN FETs in terms of clean switching, smaller package size, lower power loss, and better thermal performance, making it an attractive solution for high-power applications.