Design and Control Strategy of LCL-FILTER Based on MMC-STATCOM

A new shunt STATCOM based on modular multilevel converter (MMC) is researched, but the performance of modular multilevel converters (MMC) was affected directly by higher harmonic and the circulating current. The paper presents a new topology of modular multilevel converter(MMC) which is based on LCL filter. MMC-STATCOM by combination of LCL is researched based on mathematical model of MMC-STATCOM.Based on it, the value of the leg inductance, filter inductance were redefined. And parallel filter capacitor is designed between them. Therefore, a new to- pology of MMC-STATCOM is composed which is conducive to output characteristics and the circulating current sup- pression. The paper research on the influence of elements on system, and the algorithm of elements were given. Moreo- ver, a new control strategy based onfilter capacitor feed-forward was put forward .The effectiveness and feasibility of the proposed control strategy are verified by the simulation performed based on MATLAB.