Three-Phase Test Bench for Multiple Submodules in Modular Multilevel Converter System

This paper proposes a test bench targeting for submodules (SM) in power electronics, with respect to its basic structure and control strategy. By using a three-phase AC-DC converter, the proposed test bench is capable of emulating operating conditions of multiple SMs in modular multilevel converter (MMC) system. In the proposed test bench, numerical equations are used to emulate the dynamic operating conditions of SMs. Four SMs, including two in MMC inverter and two in MMC rectifier, are tested simultaneously. The comparisons between complete MMC system and test bench in the simulation, as well as experimental results, are given to verify the validity and accuracy of the proposed testing approach.