Integrated control method of modular multilevel converter

This paper proposes a new integrated control method for modular multilevel converter (MMC). Common mode and differential mode of MMC system are established in this work. As the effect of voltage and current at different frequencies does not produce active power exchange, it is possible to use a set of orthogonal currents to achieve the balancing control of sub-module voltages based on the above modes. The proposed method can simultaneously achieve the tracking control of the output current, circulating current and the balancing control of sub-module voltages. MATLAB / Simulink simulation results validate the effectiveness and feasibility of the proposed control method.