DOUBLE SUBMODULE FOR A MODULAR MULTILEVEL CONVERTER AND MODULAR MULTILEVEL CONVERTER COMPRISING SAME

摘要

There is provided a dual submodule (18) for a modular multipoint power converter (8), the dual submodule (18) having two interconnected submodules (19, 21), each submodule having an asymmetric H-bridge circuit (22, 32). with two parallel bridge branches (24, 26, 34, 36) connected between a first and a second pole terminal (27, 28, 37, 38) of the submodule (19, 21), each bridge branch being connected in series by a power semiconductor switch (T1, T4, T6, T7) and a diode (D2, D3, D5, D8), the power semiconductor switch having an antiparallel freewheeling diode (D1, D4, D6, D7) associated therewith, and a capacitor (23; ) connected in parallel to the asymmetric H-bridge circuit (22; 32) between the first and second pole terminals of the module. The submodules (19, 21) are connected to each other via their AC terminals (29, 31; 39, 41) to form the double submodule (18). Further provided is a modular multipoint power converter (8) having a number of such dual sub-modules (18) in each of its power converter branches (9a-9f).