Parameters design for modular multilevel converter (MMC)

The modular multilevel converter is one of the most interesting transformerless multilevel converter topology intended for medium and high-voltage power conversion. Thus, as a new topology, a fewer design guidelines are presented in the literature, on the other hand there are many restrictions. This paper presents aims to be a design guide lines to project a MMC system. The minimum submodule capacitor requirement is presented as the capacitance related to the load displacement angle, operating frequency and output power. The arm inductor design include three parameters: current ripple, fault condition and circulating current. Semiconductor current stress are calculated using average quasi-instantaneous values and rms quasi-instantaneous values will be used. From the performed analysis some normalized abacus are derived and can be used as start point for a new MMC design. The results were validated using MATLAB simulation. Furthermore, experimental results based on 2.2 kW, 5 kHz switching frequency prototype are also include and analyzed.