Consensus-based Distributed Control for Accurate Reactive, Harmonic and Imbalance Power Sharing in Microgrids

This paper investigates the issue of accurate reactive, harmonic and imbalance power sharing in a microgrid. Harmonic and imbalance droop controllers are developed to proportionally share the harmonic power and the imbalance power among distributed generation (DG) units and improve the voltage quality at the point of common coupling (PCC). Further, a distributed consensus protocol is developed to adaptively regulate the virtual impedance at fundamental frequency and selected harmonic frequencies. Additionally, a dynamic consensus based method is adopted to restore the voltage to their average voltage. With the proposed methods, the microgrid system reliability and flexibility can be enhanced and the knowledge of the line impedance is not required. And the reactive, harmonic and imbalance power can be proportionally shared among the DG units. Moreover, the quality of the voltage at PCC can be greatly improved. Simulation and experimental results are presented to demonstrate the proposed method.