Control Strategy of Circulating Current Suppression for Modular Multilevel Converter

Abstract

The structural characteristics of modular multilevel converters (MMC) lead to circulating current problems, which increases the requirements for device capacity and withstand voltage levels. Therefore, this paper proposes a circulating current suppression strategy based on new sliding mode control. This strategy uses a variable approach rate to reduce chattering caused by sliding mode control. Compared with the circulating current suppression strategy using traditional PI control, it enhances the anti-interference of the circulating current suppression strategy. Finally, this paper builds the MATLAB/Simulink simulation model and experimental platform. The results show that the strategy has good anti-interference performance.