An advanced architecture of multiple microgrids interfacing with UCC

With the ever-increasing penetration of distributed energy resources (DERs), the interconnection of multiple microgrids has become a trend of integrating more distribution generators. In this paper, an advanced architecture of multiple microgrids interconnection is proposed. Instead of the conventional point of common coupling (PCC), unit of common coupling (UCC), which consists of both AC and DC connection, is utilized in each microgrid, enabling multiple connection modes among microgrids and the utility grid. The UCC takes advantages of the utility grid to support the operation of multiple microgrids and the salient control features of modular multi-level converter (MMC) to optimize power-sharing. With the advanced architecture, the integration capability of DERs is significantly enhanced and the flexibility together with the reliability of the grid is also improved. A case study of multiple microgrids is built in PSCAD/EMTDC. The simulation verifies the validity and effectiveness of the proposed advanced architecture and operation strategies.