Research on Improved Low Frequency Control Strategy of MMC Driven Permanent Magnet Synchronous Motor

Modular multilevel converter (MMC) has large voltage fluctuation of sub module capacitor under low-frequency working conditions, which limits its application range. This paper improves the control strategy of modular multilevel controller under low-frequency working conditions, supplemented by the necessary sub module hardware matching selection method, which can further reduce the circulating current and improve the system performance. The effectiveness of the control strategy and selection method is verified by simulation.