Research on droop control of inverter interface in autonomous microgrid

As the distributed generators are connected together through inverter interface in the microgrid, the control of the control of the interface inverter has an important influence on the operating performance of microgrid. In the paper, the study focuses on the control of the interfaced inverter, when microgrid operates in the islanded mode. In order to make the microgrid property similar to the utility grid, the ripe control scheme of the utility grid was introduced into the interfaced inverter control; the improvement on the classic droop control was made according to the nature of the low-voltage distribution line. The influence of unequal inverters distribution line impedance on the inverter output power is analyzed in detail, the variable virtual impedance has been proposed. Finally, simulation and experiment results are presented to verify the effectiveness of the proposed control scheme.