An MMC-based Fully Modular Ultra-Fast Charging Station Integrating a Battery Energy Storage System

The wide diffusion of electric vehicles is possible only if charging infrastructures are adequately developed. In this context, this paper proposes a novel fast-charging structure based on a modular multilevel converter (MMC) with the battery energy storage system (BESS) integrated at the submodule level along with the charging spot. In this way, bulky output filters can be avoided, and the modularity of the converter can be exploited. Moreover, the possibility to split the BESS increases the converter reliability. Lastly, considering the possible different vehicle charging powers, an optimal size of the BESS capacity to install is provided, analyzing the power flows of the regular converter operation. The presented simulation results show the advantages and drawbacks of the analyzed MMC-BESS topology.