Distributed estimator-based periodic event-triggered secondary control of islanded microgrids

This paper addresses the challenge of improving communication efficiency in the distributed secondary control of islanded microgrids. A novel periodic event-triggered communication (PETC) mechanism is proposed to reduce communication frequency while maintaining system stability. Specifically, the event-triggered (ET) moment for frequency control is jointly determined by the ET conditions of active power control, which greatly reduces the communication burden. To compensate for the absence of neighbor state updates during non-communication periods, a distributed closed-loop state estimator is incorporated. Building on this, an estimator-based PETC mechanism is developed. The stability of the proposed control schemes is analyzed, and sufficient conditions for the evaluation period are provided. Simulation results in MATLAB/Simulink and the OPAL-RT platform demonstrate that the proposed approach achieves accurate frequency restoration and active power sharing, while reducing the number of ET instants by over 50% compared to conventional periodically sampled methods.