Performance evaluation and control of modular multilevel converter under system fault conditions

For industrial applications requiring medium and high-power supplies modular multilevel converter (MMC) based voltage source converters (VSC) offer advantages over traditional VSCs. These include achievement of higher voltage levels with utilization of lower voltage power semiconductor devices. The control structure of MMC for fault operating condition is proposed in this paper, and dynamic performance of the MMC based on the proposed control structures is further investigated in PSCAD/EMTDC environment. Real Time Digital Simulator (RTDS) results are also presented to verify the controller performance under normal and fault operating conditions.