A decentralized impedance-based adaptive droop method for power loss reduction in a converter-dominated islanded microgrid

As the integration of Distributed Energy Resources (DERs) in modern grids is increasing, the microgrid concept has been established. In the case of converter-dominated microgrids without communication links, the droop control method is mainly adopted in the primary control level. Normally, the economic operation of the microgrid is incorporated in the secondary control level, requiring communication among the DERs and a central controller. On the contrary, this paper proposes an adaptive droop control method based on local measurements, which achieves a power sharing with reduced power losses within the islanded microgrid. The droop coefficients are adjusted by calculating the microgrid impedance, sensed by each DER. Therefore, the remote DERs calculate a large impedance and inject lower active and reactive power, reducing the line losses. The location and the size of the DERs and the loads can be arbitrary. Another advantage is the absence of the virtual impedance control, as the power decoupling is implemented inherently by the adaptive droop coefficients. The effectiveness of the proposed control strategy is verified by extended simulation results in comparison with the accurate sharing method for different microgrid topologies. © 2015 Elsevier Ltd. All rights reserved.