Small-Gain-Based Plug-and-Play Distributed Control Framework for DC Microgrids With Decentralized Reconfiguration

This article presents a plug-and-play (PnP) distributed control framework for DC microgrids (DCmGs) to address scalability and reconfiguration issues under dynamic network topologies. First, a decentralized control architecture is developed based on the small-gain theorem, enabling PnP operations of distributed generation units (DGUs). Specifically, the plug-in operation only requires local and neighboring state feedback without relying on global information exchange, while the plug-out operation can be performed without interunit communication. In this way, controller deployment is decoupled from the global network topology, thereby reducing reconfiguration overhead and improving the modular scalability and operational flexibility of DCmGs. Second, an optimization-based controller synthesis method is proposed to minimize the coupling effects among DGUs. The proposed method facilitates distributed controller design for heterogeneous DGUs without requiring structured Lyapunov functions or free-weighting matrices, thereby simplifying the synthesis procedure. Theoretical analysis establishes the asymptotic stability and prescribed performance of the closed-loop system under PnP operations. Finally, simulation studies on a six-DGU DCmG prototype are provided to validate the effectiveness of the proposed framework.