Topology and Control Research of MMC Energy Storage System Based on Supercapacitors

This paper introduces an MMC energy storage system integrated with supercapacitors (SCs), designed to significantly enhance the power density for energy storage applications. By constructing a mathematical model to analyze the system's fundamental structure and operating principles, this paper proposes an innovative control system. The system ensures operational control and voltage balancing among submodules under both grid-connected and off-grid conditions, while maintaining the system's stability and output energy quality. The low-power prototype, constructed in simulation software, validates the proposed control and balancing strategies, demonstrating that the system successfully increases power density without compromising stability or energy output quality.