A synchronized current source control method for islanded microgrids

This paper presents a synchronous current source control method for islanded operation of microgrids (MGs) dominated by Inverter Interfaced Distributed Energy Resources (IIDERs). All IIDERs in a MG generate fixed-frequency currents which are phase locked to 1 Pulse Per Second (1PPS) signal from a time synchronization source, such as Globe Position System (GPS). The magnitude of voltage is mainly depending on the balance of active power, while the phase shift of voltage with respect to 1PPS signal reflects the balance of reactive power. A I/V droop control scheme is adopted to achieve even power sharing between different IIDERs according to their capacities. The proposed method is free from frequency stability and associated power angle oscillation incidents as the frequency of the MG is fixed. Physical experimental results proved the feasibility and validity of the method.