A Distributed Control Strategy for MMC with Low Capacitor Voltage Transmission Requirement

Abstract

In most MMC distributed control strategies, the central controller needs to know the capacitor voltage of all sub-modules (SMs) in real-time to complete the average voltage control, which causes a heavy burden on the communication network, especially in the MMC with numerous SMs. With the distributed control proposed in this paper, the average voltage control can be achieved by only returning two capacitor voltages from two arms in the same phase within one control cycle, which significantly eases the communication stress. The effectiveness of the proposed method to regulate the arm voltage with only two capacitor voltages is given. The experimental results demonstrate the effectiveness of the proposed distributed control method.