IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

266 / 2017-11-29 11:16:08

Common Mode Votage Compensation for 7kV SiC-based Modular Multilevel Converter to Reduce Capacitor Voltage Ripple

motor drive,SiC device,modular multilevel converter

Plenary track > Applications in renewable energy and storage, transportation, industrial drives, and grid power

Modular multilevel converters (MMCs), with the filter-less and transformer-less features, are considered as a promising topology for high-efficiency medium voltage (MV) high voltage (HV) drive systems. However, a large current ripple flowing through the capacitors of each submodule will cause significant capacitor voltage fluctuation. This paper proposes a new compensation method in common mode voltage injection to further reduce the magnitude of the fundamental component in capacitor voltages. The capacitor voltage ripples are reduced significantly by using the proposed control method, which means that smaller size of capacitors can be used for same voltage ripple requirements. Simulation and experimental test results verify the proposed compensation method.