A Precharge Control Strategy for Arm Multiplexing Modular Multilevel Converter

The use of the arm multiplexing modular multilevel converter (AM-MMC) can enhance the submodule utilization rate and reduce the number of submodule assemblies to achieve MMC lightweight. In order to achieve the normal operation of the MMC converter, the precharge control is crucial, and thus, precharge research for AM-MMC is required. Therefore, this paper presents a precharge control strategy for AM-MMC. By examining the relationship between the capacitance voltages of the submodules across the arms and addressing the over-voltage and voltage imbalance issues within the submodules, the proposed precharge control strategy divides the charging process of the AM-MMC into three stages: uncontrolled charging, controllable charging, and blocking. A simulation model has been constructed in MATLAB / Simulink to confirm the viability of the suggested strategy.