A microgrid cluster structure and its autonomous coordination control strategy

Microgrid cluster as an interconnected system of multiple AC subgrids and DC subgrids, its complex structure increases the difficulty of power coordination control for it. To address this issue, a microgrid cluster structure and its autonomous coordination control strategy are proposed in this paper. The proposed microgrid cluster structure is composed of AC subgrids, DC subgrids, power exchange unit (PEU) and energy pool (EP). The aim of PEU is mainly to coordinate power exchange between the subgrids and EP. Meanwhile, the power coordinated control method is proposed to design the controller of PEU, which can realize mutual power support among each sub-grid and reduce the bus voltage deviation in each subgrid. Besides, EP is mainly used to balance the system power, and the dc-link voltage stability control method of EP is proposed to stabilize the dc-link voltage and to reasonably allocate the net exchange power of PEU. The proposed autonomous coordination control strategy has been verified by the simulation results.