A novel submodule concept for modular multilevel converters

Modular Multilevel Converter (MMC) topologies have been successfully employed for voltage source converters in high as well as in medium voltage applications. In the low voltage range, the success of this topology strongly depends on the capability of exploiting the best performing key components commercially available. A brief survey of the state of the art reveals that standard submodule concepts do not allow the employment of the best semiconductors and capacitors in a fully optimized design. In this paper, a novel submodule concept is presented which overcomes this constraint. The dimensioning of the capacitors and the possible modulation strategies are also discussed.