Full Bridge Modular Multilevel Converter AC Grid Voltage Unbalance Analysis and Fault Ride through Method Research

At present, the Half Bridge Modular Multilevel Converter (HBMMC) has been studied and applied most frequently because of low cost and simple control. However, due to the topological structure, the half-bridge sub-module carried by HBMMC does not have the ability of DC short circuit fault clearing. Therefore, this paper takes Full Bridge Modular Multilevel Converter (FBMMC) with DC short-circuit fault ride through capability as the research object, and carries out the research around the topology, equivalent mathematical model, operation characteristics and system control framework of FBMMC under grid voltage unbalance. Finally, the correctness of the analysis and the effectiveness of the proposed method are verified in Matlab/Simulink simulation and the experimental platform.