Abstract：U/f controlled inverter-based distributed generator (U/f-DG) supports the grid voltage and frequency in islanded microgrid, thus its control strategy has a significant influence on fault ride-through capability of microgrid. In this paper, a fault control strategy of U/f-DG is designed by introducing virtual impedance. Control principle of U/f-DG based on virtual impedance is briefly analyzed, and its equivalent positive and negative sequence model is deduced. Current limiting algorithm of U/f-DG under fault condition is also proposed. Considering voltage support, a design method of virtual impedance R/X ratio is proposed to minimize the voltage unbalance factor under unsymmetrical fault condition. A coordinated control strategy for U/f-DG and the subordinate DGs is presented to ensure that microgrid goes through the transient period smoothly. Finally, the validity of the proposed fault control strategy is verified by Simulink simulation software.
李松峰, 牟龙华, 郭文明, 张鑫. 基于虚拟阻抗的恒压恒频微电源的故障控制策略[J]. 电工技术学报, 2018, 33(3): 581-590.
Li Songfeng, Mu Longhua, Guo Wenming, Zhang Xin. Fault Control Strategy of U/f Controlled Micro Sources Based on Virtual Impedance. Transactions of China Electrotechnical Society, 2018, 33(3): 581-590.
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2018, Vol. 33 
