A central control strategy of parallel inverters in AC microgrid

This paper focuses on the microgrid control method in different operating modes. The conventional droop control scheme is typically used to achieve autonomous voltage and frequency regulation, which considers only local information, and the global optimal performance can´t be guaranteed. In island mode, when the load or generation inside the MG changes, circulations will be generated between the inverters in case the line impedances are mismatch. Furthermore, the MG active power output does not follow the reference in grid connected mode. Dealing with the above problems, a central controller is designed to maintain the stable operation of the microgrid in different modes in this paper. Some simulations are carried out and the results validate the efficiency of the proposed method.