Abstract：For parallel multi-inverters in island microgrid, the difference of equivalent output impedance and line impedance effects greatly on power sharing and circulating current restraining greatly. Robust droop control can reduce the impacts on accurate power sharing due to the impedance difference. But there are large impact current and long transition time in the start transition process, which hinder the actual engineering application. Thus, in the case of resistive line impedance, an improved robust droop multiple loop control method is proposed, which includes the outer power loop and the double loop of inner voltage and current. In the voltage and current loop, the controller parameter design method considering the influences of load is applied, to suppress the adverse impact of load change. In the outer power loop,the equivalent output impedance of inverters is redesigned as resistance by virtual resistive impedance. An improved robust droop control strategy is proposed. Compared with the conventional robust droop control, the improved robust droop can improve start transition process, reduce the impact current, speed up the transition process and realize rapid smooth transition. Simulation and experimental results verify the control strategy.
王逸超, 罗安, 金国彬. 微网逆变器的改进鲁棒下垂多环控制[J]. 电工技术学报, 2015, 30(22): 116-123.
Wang Yichao, Luo An, Jin Guobin. Improved Robust Droop Multiple Loop Control for Parallel Inverters in Microgrid. Transactions of China Electrotechnical Society, 2015, 30(22): 116-123.
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