A Multiplexed Modular Multilevel Converter Based Battery Energy Storage System with DC Short-Circuit Fault Ride-through Capability

Energy storage systems support electrical grid stability by enabling strategies to tackle issues, such as power fluctuations, low inertia, and insufficient damping. The present study proposes a battery energy storage system based on a modular multilevel converter with multiplexed submodule arms (M-MMC-BESS) to reduce the number of switching devices while embedding DC short-circuit fault ride-through capability. Compared to the conventional two-stage half-bridge topology, the M-MMC-BESS retains the same number of switching devices but allows uninterrupted operation under DC short-circuit faults. In addition, compared to the two-stage full-bridge topology, the proposed topology reduces the number of switching devices by one-third. The control of the M-MMC-BESS is thoroughly investigated under both normal and DC short-circuit operating conditions. Simulation and experimental results are used to demonstrate the effectiveness of the proposed system and control approach.