Abstract: Interconnecting multiple AC/DC hybrid microgrids to form a hybrid microgrid cluster is a common way to supply loads, and how to utilize the autonomy of the sub-microgrids and realize the interactive power support between sub-microgrids is one of the key issues in AC/DC hybrid microgrid cluster power management. For this reason, this paper proposes a power management strategy consisting of three layers: power autonomy control layer of subgrids, power interaction support layer between neighboring subgrids, and power balance layer of the hybrid microgrid cluster for the AC/DC hybrid microgrid cluster with islanded operation. The coordinated control among the three layers can effectively improve the power supply reliability and quality of the isolated AC/DC hybrid microgrid cluster and reduce the power loss of the microgrid cluster. Finally, the proposed control strategy is verified by building an experimental platform, and the experimental results show that the proposed strategy has better robustness under normal communication and communication failure.

Key words: AC/DC hybrid multi-microgrids, power autonomy control, power interaction support, power balance