Currently, Modular multilevel converter (MMC) has the advantages of high modularity, strong fault tolerance, low harmonic content on AC side and so on. Si IGBT is widely used as a switching device in traditional MMC, and its power loss is high in high frequency condition, which will increase the heat dissipation cost and volume of the system. SiC MOSFET is a new wide bandgap device with low switching loss and high temperature tolerance. Its application in MMC has the potential to provide significant efficiency improvement compared with silicon devices. However, the possibility and impact of using SiC-based devices instead of Si devices for high-power conversion have not been thoroughly explored.
 This paper compares power loss characteristics of SiC-based MMC and Si-based MMC, and the result shows that the use of SiC-based devices in MMCs does not guarantee lower losses for all operating conditions.
 

MMC,Power Loss Characteristics,SiC MOSFET