Loss comparison of Si- and SiC-based modular multilevel converter for medium/high-voltage applications

One of the main concerns in the operation of the modular multilevel converter (MMC), particularly for high-power applications, is its efficiency. SiC-based devices have the potential to provide significant efficiency improvement compared to Si devices. However, the possibility and benefits of using SiC-based devices instead of Si devices for high-power conversion have not been thoroughly explored. This paper reports on the results obtained from a detailed study to evaluate the performance of MMCs based on medium-voltage SiC MOSFETs and diodes with hybrid MMCs that employ Si IGBTs and SiC diodes. The results are based on detailed circuit simulations that use physics-based circuit models.