Voltage Scaled Modular Multilevel Converter and Its Control for MVDC Applications

ABSTRACT The modular multilevel converter (MMC) is a widely adopted topology in high‐voltage applications due to its scalability, modularity, and superior power quality. This paper introduces a voltage scaled half‐bridge submodule (HBSM) MMC, which incorporates a hybrid submodule arrangement with 50% HBSMs/arm operating at a capacitor voltage of and 50% HBSMs/arm operating at . This MMC configuration aims to enhance the converter's performance by leveraging the advantages of voltage scaling, including reduced submodule count. Compared to traditional HBSM MMC, the proposed MMC incorporates 33.33% reduction in number of submodules (SMs), thereby reducing the number of switching devices, capacitors, and thus voltage sensors per arm by 33.33%. A SM capacitor voltage balancing algorithm is proposed for the proposed voltage‐scaled HBSM MMC to ensure stable and reliable operation. Furthermore, a detailed comparative analysis between the voltage‐scaled HBSM MMC and traditional HBSM MMC as well as FBSM MMC is conducted. Simulation results on MATLAB/Simulink and experimental results on FPGA‐based real‐time simulator configured for rapid control prototyping and hardware‐in‐the‐loop testing validate the effectiveness of the proposed balancing algorithm and demonstrate the operation of the proposed voltage‐scaled HBSM MMC in diverse operating conditions.