Abstract：The modular multilevel converter (MMC) is a suitable topology for high-voltage high-capacity voltage source converter (VSC). The MMC topology has been used in some static synchronous compensator (STATCOM) projects. Under asymmetric bridge-arm parameters, the fundamental-frequency AC currents distribute unequally between the upper and lower arms. Meanwhile, the DC and double-frequency components also flow into the AC side. In the paper, the equivalent models of the AC side and DC side of a three-phase MMC-STATCOM are established under asymmetric bridge-arm parameters. Based on the equivalent sub-circuits at different frequencies, the effects of asymmetric conditions on MMC-STATCOM operation are analyzed in detail. A novel control strategy is further proposed to suppress the common-current of fundamental-frequency and double-frequency while keeping the voltage balance between the upper and lower arms. Both simulation and experimental results validate the feasibility of the proposed method.
秦海鸿, 赵海伟, 马策宇, 董耀文, 聂, 新. 基于模块化多电平变换器的静止同步补偿器桥臂不对称及其控制策略[J]. 电工技术学报, 2016, 31(14): 183-192.
Qin Haihong, Zhao Haiwei, Ma Ceyu, Dong Yaowen, Nie Xin. Asymmetric Bridge Arm of Static Synchronous Compensator Based on Modular Multilevel Converter and Its Control Strategy. Transactions of China Electrotechnical Society, 2016, 31(14): 183-192.
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2016, Vol. 31 
