Unbalanced and reactive power compensation for grid friendly microgrids

Microgrids are low-voltage distribution networks comprising various renewable power sources, storage units, and local loads. Microgrids can be utilized to provide different services for the main grid such as grid supporting during peak period. In microgrids single phase loads or sources can be used by the end-users and can make the grid currents unbalanced with poor power factor. This paper presents a control strategy for three-phase four-legs power converter, based on synchronous reference frame to improve the quality of power exchanged between microgrid and the main grid. The proposed control strategy is able to mitigate negative effects of grid connected microgrid such as unbalanced operation and reactive power compensation which allows the microgrid to become “grid friendly”, even it is working under highly unbalanced and poor power factor conditions. Simulation results have been carried out by using Matlab -Simulink software to verify the effectiveness of the proposed control strategy.