Distributed Secondary Control for DC Microgrid with Dynamic Event-Triggered Strategies

This study explores a distributed event-triggered cooperative control method for achieving accurate voltage regulation and current sharing in a DC microgrid. In this method, an average voltage is derived using a voltage observer, followed by secondary control to synchronize the voltages of each Distributed Energy Resource (DER) to the desired values, achieving current sharing among the DERs. Significantly, the proposed scheme does not require global information; rather, it relies solely on information exchange between adjacent DERs during event-triggered control periods. The controller's update is determined by checking if the measurement error reaches a specified threshold (i.e., the event-triggering condition), thereby avoiding unnecessary information exchange between adjacent DERs and reducing the communication load at the network layer of the DC micro grid system. Furthermore, control conditions are derived using Lyapunov functions, and the stability of the approach is verified. Ultimately, the designed control strategy is validated through simulations in Matlab/Simulink and experiments in a laboratory DC micro grid system. The experimental results confirm the efficacy of the proposed control strategy.