Topology Analysis and Parameter Calculation of a Novel MMC Sub-module

In this paper, a Damped Series Double Sub-Module (D-SDSM) topology with DC fault damping capability is proposed. The topology adds a damping resistor inside the series double sub-module and replaces the IGBT on the internal series branch with a lower-cost IGCT. Compared with other sub-modules with fault current blocking ability, D-SDSM can clear DC fault current faster; and has the advantages of high economy and simple control. The blocking MMC with DC fault clearing ability is built by using D-SDSM and HBSM. Under the background of actual engineering parameters, the blocking MMC can realize the selection of various internal devices, which verifies the feasibility of its application in practical engineering.