Abstract
In this paper, a community microgrid with multiple ac and dc microgrids is introduced and analyzed. Individual microgrids with different frequency and voltage requirements would operate as self-controlled entities, which could also cooperate with neighboring microgrids for providing backup operations in the community microgrid. A hierarchical coordination strategy with primary, secondary, and tertiary coordination is proposed for the economic operation of an islanded community microgrid. The hierarchical strategy is also applied to a grid-connected community microgrid and the results are discussed. The simulation results verify that the proposed hierarchical coordination strategy is an effective and efficient way for coordinating microgrid flows in an islanded community microgrid, while maintaining the rated frequency and voltage with each microgrid. The simulation results also demonstrate the economic operation of a grid-connected community microgrid in which individual microgrids operate as autonomous agents, while satisfying the community objectives.