Integration of Coupled Inductors for Compact Design of Flying-Capacitor Modular Multilevel Converters

In this paper, for compact design of flying-capacitor modular multilevel converters (MMCs), a utilization of coupled inductors has been proposed. In the conventional flying-capacitor MMCs, four discrete inductors are used in each leg. However, with the coupling idea of the magnetic core, the core size and inductor weight can be reduced by 37% and 39%, respectively, compared to the discrete inductors. The viability of the flying-capacitor MMCs with the coupled inductors has been verified through simulation and experimental results under wide operating frequency range of output voltage.