Adaptive virtual impedance control scheme to eliminate reactive power sharing errors in islanded microgrid

This paper proposes an enhanced distributed generation (DG) unit with an adaptive virtual impedance control approach in order to solve the inaccurate reactive power sharing problem. The proposed method can adaptively regulate DG units with the aid of the equivalent impedance, and the mismatching problem of the feeder impedance is compensated by sharing the reactive power accurately. The proposed control strategy can be implemented directly without any pre-knowledge of the feeder impedances. Simulations are performed to validate the effectiveness of the proposed control approach.