Abstract：In the islanded AC microgrid, the line impedance between the DG units are always different, which can result in circulating current and low precision of power sharing among inverters by using the traditional droop control method. Therefore, an improved droop control strategy is proposed based on synchronous compensation for reactive power sharing in microgrid. The reference voltage of droop characteristic curve can be compensated synchronously when DG units operate at reactive power sharing mode, meanwhile the accuracy of the sharing of reactive power can also be improved. And then when the output voltage of a DG unit drops to the minimum value, each DG unit switches to the voltage recovery mode, and its voltage will recover to the reference voltage synchronously. The improved coordinated operation strategy is designed for reactive power sharing mode and voltage recovery mode, which can ensure that the accurate sharing of reactive power and the output voltage is near the rated value, and then the system can operate stably. Finally, simulations and experiments are performed in MATLAB and real-time digital simulator (RTDS) respectively to verify the validity of the proposed control strategy. It is proved that the method has low communication bandwidth requirement and strong robustness, and maintains the characteristic of “plug and play” of each DG.
米阳, 蔡杭谊, 宋元元, 李振坤. 基于同步补偿的孤岛微电网无功均分研究[J]. 电工技术学报, 2019, 34(9): 1934-1943.
Mi Yang, Cai Hangyi, Song Yuanyuan, Li Zhenkun. Study on Reactive Power Sharing of Island Microgrid Based on Synchronous Compensation. Transactions of China Electrotechnical Society, 2019, 34(9): 1934-1943.
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2019, Vol. 34 
