Rank-Based Predictive Control for Community Microgrids With Dynamic Topology and Multiple Points of Common Coupling

This article presents a rank-based model predictive control (MPC) scheme for voltage source converters (VSCs) operating in a low voltage, AC community microgrid with dynamically changing topology. The advent of mesh distribution networks with high renewable energy penetration in recent literature prompts the development of an adaptive VSC control technique for optimal performance in a changing environment. Several distributed control strategies have focused on communication less plug-and-play implementation, but the proposed ranking scheme focuses on resilient operation while minimizing physical communication requirements. The proposed framework provides intelligence to enable a fully synchronized microgrid with the ability to connect multiple VSCs to a utility grid simultaneously through multiple points of common coupling (MPCC) and disconnect from grid-forming distributed sources when islanded, attaining a higher margin of stability, robustness, and flexibility. The MPC framework features an adaptive ranking system that assigns operational modes to the VSCs, i.e., voltage control (grid-forming) or current control (grid-following), and defines leader-follower directionality for synchronization. Communication among VSCs is achieved using a topology-mirroring interaction layer. Several RTS case studies are provided to demonstrate the functionality and performance of the proposed intelligent rank-based MPC in a changing microgrid configuration with 10 VSCs.