A Communication-independent Reactive Power Sharing Scheme with Adaptive Virtual Impedance for Parallel Connected Inverters

Droop control method has been widely applied to achieve equal power sharing among distributed generations in microgrids. However, the reactive power sharing performance is barely satisfactory for the absence of sharing accuracy under conditions of imbalanced line impedances. This paper proposed a communication-independent reactive power sharing scheme for parallel connected inverters. In this scheme, constant voltage control is applied to inverters, and the changing rate of virtual impedance is drooped with reactive power, hence accurate reactive power sharing could be achieved with no impact on voltage regulation performance. In addition, since the virtual impedance is adaptive to changing of reactive power, extra information from PCC voltage, line impedance or other communications is not needed in the implementation. The effectiveness of the proposed method is verified by simulations.