Abstract：The capacitor voltage fluctuations and the arm currents will be higher when under unbalanced grid conditions.It always affects the security and stabilization of MMC system.For analyzing the peak value of arm currents and capacitor voltages fluctuation under unbalanced grid voltage conditions,the multi-objective adjustment coefficient k and unbalance factor ε are variables in this paper.Based on the variables,the expressions peak values of arm currents and capacitor voltages fluctuations of three phases are calculated.Meanwhile,the 3D plots of electrical quantities and variables k and ε are drawn.The analysis results indicates that when k=0,the gain of electrical quantities is less than k=-1 by the increase of unbalance factor.Finally,the simulation results by Matlab verify the validity of the oretical analysis,and provide a reference for the safe operation of the system under unbalanced grid conditions.
李金科,金新民,吴学智,荆龙,施恩泽. 网压不平衡下系统控制目标对MMC运行性能的影响[J]. 电工技术学报, 2016, 31(增刊2): 39-48.
Li Jinke, Jin Xinmin ,Wu Xuezhi, Jing Long, Shi Enze. The Influence of System Operation Objectives on Operation Characteristics for MMC under Unbalanced Grid Conditions. Transactions of China Electrotechnical Society, 2016, 31(增刊2): 39-48.
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2016, Vol. 31 
