Topology and Control of a Novel Multiplexing Arm Selection Type Modular Multilevel Converter

With the rapid advancement of DC transmission technology in offshore wind power and photovoltaic power generation, there is an increasingly urgent demand for modular multilevel converters (MMCs) in terms of economy and lightweight. This article innovatively proposes a novel multiplexing arm selection MMC (MAS-MMC) topology, which consists of cascaded switching stacks and multiplexing arms. An arm-optimized modulation voltage selection strategy is proposed to ensure its energy balance within half the fundamental period under different power factors and minimize the peak of arm modulation voltage, effectively reducing the number of sub-modules by 59.1% compared to the traditional MMC. Notably, MAS-MMC could also significantly reduce its cost and improve power density. Finally, the comprehensive validation of the proposed MAS-MMC topology and the control strategy is conducted through systematic simulation and experimental prototype, conclusively demonstrating its superiority and feasibility.