A Voltage Balancing Strategy of MMC Based on Capacitor Voltage Sorting

The problem of submodule capacitor voltage balancing is a key and difficult point in the control of the Modular Multilevel Converter (MMC), and it is also one of the important factors affecting the output characteristics of the MMC. This paper analyzes a submodule voltage balancing strategy based on capacitor voltage sorting. According to the capacitor voltage values of each submodule and the current flow direction of the arm, the corresponding pulse signals are assigned to each submodule to achieve voltage balancing control. Through the simulation analysis on the Matlab/Simulink platform, the correctness and effectiveness of this voltage balancing strategy are verified.