Distributed Predefined-Time Secondary Control for DC Microgrid with Event-Trigger Communication

This paper proposes a novel distributed control strategy for isolated DC microgrids (MGs) to address challenges arising from rapid renewable energy fluctuations and load variability. The approach integrates a predefined-time (PDT) controller with an event-triggered (ET) communication mechanism to ensure a faster power balance, voltage regulation, and economic dispatch within a user-defined convergence time. A distributed ET-PDT cost optimizer is developed to synchronize the incremental costs of all distributed generation units within the predefined time, enabling economically optimal operation. Additionally, an ET-PDT voltage regulator is introduced to maintain the MG's average voltage stability and balance power supply and demand within the specified timeframe. Unlike conventional methods, the proposed strategy guarantees convergence within the desired settling time regardless of initial conditions, while the ET mechanism significantly reduces communication overhead by transmitting updates only when necessary. Extensive simulation studies validate the effectiveness and superiority of the proposed method under diverse operating scenarios.