A scalable and reconfigurable hybrid AC/DC microgrid clustering architecture with decentralized control for coordinated operation

Abstract

Microgrid clusters are effective to increase utilization of renewable energy resources (RESs), and improve reliability and stability of power systems. Facilitating flexible configurations, grid networking and coordinated operation among multiple microgrids are essential for the microgrid cluster. In view of this, this paper presents a scalable and reconfigurable hybrid microgrid clustering architecture and a corresponding decentralized control method. Initially, a new interlinking converter referred as energy networking unit (ENU) is proposed. The ENU is used to interface the AC and DC subgrid in single hybrid microgrid, and also facilitates the connection with the external power grid. Then the ENU-based hybrid microgrid clustering architecture is established, which is characterized by scalability, reconfigurability and modularity. Thanks to the reconfigurable topology of ENUs, the architecture could realize flexible AC/DC interconnection between microgrids by the same converter modules with less power conversion units. Finally, a proposed decentralized control strategy for this architecture could realize autonomous power exchange between subgrids in single microgrid with considering energy storage restrictions and smooth mode switch. And an adaptive and autonomous power interaction among neighboring microgrids is also achieved with full utilization of the compensation capacity of clusters, thus improving the system reliability, as well as the utilization and local consumption of RESs. The effectiveness of the proposed clustering architecture and decentralized control strategy is verified by comprehensive cases.