A new family of modular multilevel converters

In this work, a new family of modular multilevel converters is introduced. The proposed topologies are named as bifurcate MMCs (BMMCs) due to their bifurcate arm structure. The topologies are derived from conventional MMCs, and thus can be seen as the generalized topologies of MMCs. The derivation of multi-bifurcate MMCs and a modified control scheme are given in this paper. According to the analysis, BMMCs are suitable for low-modulation-ratio applications, and compared with the conventional MMCs, BMMCs have lower losses and submodule capacitance, so a possible application of BMMCs is the AC/DC converters with high conversion ratio in the future AC/DC hybrid grids.

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