Optimized design of a hybrid-MMC and evaluation of different MMC topologies

This paper investigates the combined use of basic cell types (half and full bridges) in a Modular Multilevel Converter in order to achieve an improved MMC performance. Based on an MMC without any additional features (only considering the power transmission capability), an optimal design is presented for additional capabilities such as DC fault ride-through capability or safe operation during reduced DC voltage. These different MMC configurations are compared to a Half and a Full Bridge MMC with regard to the total cost per transmitted power, which includes semiconductor losses and basic power electronic costs.