A Control Strategy for Load Voltage Restoration and Accurate Sharing of Active and Reactive Power in Microgrid

Authors

Faculty of Electrical and Computer Engineering, University of Birjand, Birjand, Iran

Abstract

In this paper, a new control strategy is proposed that adjusts the voltage of critical loads at nominal value in low voltage microgrids. The strategy compensates the voltage drop between the DG’s output and point of common coupling (PCC), without requiring any communication. The Q-V droop control method has been modified in order to restore the load voltage amplitude. Moreover, in the proposed method, the load is accurately shared between DGs based on their capacity. Virtual impedance along with voltage and current control loops have been used to avoid coupling between the active and reactive powers. Furthermore, this approach minimizes the circulating current between DG units. The presented control strategy has successfully been simulated for two microgrid designs with a two-DG and a four-DG unit system, where results have shown the effectiveness of this methodology.

Keywords