Abstract：This paper applies the topology of modular multilevel converter(MMC) to the unified power quality conditioner(UPQC). In order to improve the comprehensive compensation functions of MMC-UPQC at the high voltage, large capacity power quality environment, the paper analyzes the voltage sag compensation capability of UPQC’s series MMC theoretically in detail. The topology mechanism of MMC-UPQC is given; the time domain expressions are calculated with the voltage sag value, the compensation duration, the main circuit and MMC parameters and so on, a coordinated control design method for UPQC is proposed, which is the fixed active current limit value control allowing the reduction of the common DC link voltage based on the traditional fixed DC voltage control. Define and calculate two voltage thresholds dividing the MMC-UPQC operation into the aforementioned states. The MMC-UPQC system simulation results under PSCAD/EMTDC indicate that the theoretical analysis is effective and correct. The simulation results also illustrates that the proposed coordinated control could improve voltage sag compensation time and amplitude supplied by UPQC.
陆晶晶,肖湘宁,张剑,徐云飞. 基于定有功电流限值控制的MMC型UPQC协调控制方法[J]. 电工技术学报, 2015, 30(3): 196-204.
Lu Jingjing,Xiao Xiangning,Zhang Jian,Xu Yunfei. MMC-UPQC Coordinated Control Method Based on Fixed Active Current Limit Value Control. Transactions of China Electrotechnical Society, 2015, 30(3): 196-204.
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