A VSC with 7.2kV dc bus can directly interface with a 4160V grid which can be realized in a 2-level configuration using a 10kV blocking switch. HV SiC devices such as 6.5kV and 10kV SiC MOSFETs are still in research phase, whereas 3.3kV SiC MOSFETs have already been qualified for commercial applications by multiple vendors. In this regard, an equivalent 10kV switch formed by series connection of three 3.3kV SiC MOSFETs has been proposed as a potential alternative, and it has been quantitatively compared to a single 10kV SiC MOSFET. Normalized device parameters have been considered in both cases for a fair comparison. Two types of 10kV 120mΩ switching cells have been realized through series connected 3.3kV 40 mΩ SiC MOSFETs and parallel connected 10kV 350mΩ SiC MOSFETs for effective power loss comparison. Loss modeling of 3-phase VSCs using both switching cells. The power loss and efficiency trends with load and switching frequency variation have been presented for both cases. The converter power processing capability dependence on switching frequency has also been compared for both cases.
