This paper presents the design of a MW-level modular multilevel converter (MMC) phase-leg for 13.8 kV medium voltage (MV) grid based on Wolfspeed 10 kV 100 A SiC MOSFET XHV-9 half bridge power module. The 10 kV 20 A SiC discrete device based converter for 13.8 kV grid has been demonstrated in previous literature. Compared with the 10 kV SiC MOSFET discrete device, the 10 kV SiC MOSFET power module has higher di/dt, higher dv/dt (for loss reduction), and more stringent protection requirement, posing new challenges on the MW-level MV power converter design based on this 10 kV SiC power module. Characteristics of the 10 kV SiC MOSFET discrete device and power module are compared. Detailed MMC design to address these challenges are presented. The hardware and experimental results of the 10 kV module short circuit test, MMC submodule test, and MMC phase-leg continuous power test are demonstrated.
