A MMC hysteresis current control method based on current slope

In the situation that the modular multilevel converter (MMC) needs to maintain a good current control performance within a wide scope of operations such as the intermittent new energy grid connection and electric locomotive, etc, this paper starts from the output current slope generated after the output voltage and system voltage of MMC converter are jointly acted on the equivalent coupling reactance to analyze the mathematic relation among the current error, output voltage and other correlatives and propose the MMC current hysteresis control method based on output current slope. This method is characterized by simple algorithm, definite physical significance, high output accuracy, small output current ripple, fast dynamic response and strong robustness, etc. Finally, the effectiveness and feasibility of this method is verified by the physical controller — RTDC close-loop real-time simulation experiment.