Power Control of Repurposing-Battery Modular Multilevel Converter

This paper proposes a power control of the repurposing-battery modular multilevel converter (RBMMC) for hybrid ac/dc power distribution system. All submodules (SMs) of the MMC are constructed by RB-based half-bridge inverters. According to decoupling ac- and dc-circuit models, the RBMMC is able to convert energy from repurposing batteries to ac grid and/or to dc grid in a bidirectional manner. Most importantly, power balancing algorithms between phases and between arms are proposed to extend operational stability considering state-of-charge (SOC) of RBs, which is a significant feature to increase reliability of RBMMC in the power distribution system. Simulation results are provided to verify the control method.