“…In addition, in [18][19][20] and in [10,[21][22][23][24][25][26][27], the MMC converts a single-phase and a three-phase MV grid, respectively, into a square wave mediumfrequency voltage. Furthermore, in [28][29][30][31], the MMC submodules directly connect to multiple medium-frequency transformers and ac/dc converters, and the MMC legs connect to a dc bus voltage. However, the MMC with a single-phase ac and a dc bus voltage port, as in [26][27][28][29][30][31], is not needed in this application.…”