Cost comparison between SiC MOSFET and Si IGBT in use case of a MMC based delta STATCOM

This paper makes a comprehensive overall cost comparison between Si IGBT and SiC MOSFET use for a specific converter implementation, namely a MMC based delta STATCOM, consisting of series connected H-bridges in every phase leg. Not only the initial investment costs, but also the energy loss cost has been considered in this comparison, where different loading characteristics, a realistic ambient temperature profile, and the thermal behaviour of the overall equivalent thermal circuit were modelled, while different scenarios on cost figures have been tried out. Due to their low conduction and switching losses compared to Si IGBTs, the use of SiC MOSFETs for such a system turns out to be advantageous and a pay-back period for the extra investment on SiC MOSFET use seems to be as low as a couple of years, depending on the situation, which would probably be of high interest for many industrial applications and researchers in this domain.