Distributed Secondary Control of Microgrids via a Time-Event Switching Triggered Mechanism

With the consideration of limited communication and computation resources, time-event switching triggered secondary controllers of microgrids are designed in this letter. The time-event switching triggered mechanism proposed in this letter consists of two types of triggered mechanisms and a switching rule. In each switching round of the mechanism, a time-based triggered mechanism is first activated; and after a preset period of time, an event-triggered mechanism starts to work; once control action is triggered by an event, the event-triggered mechanism switches to the time-based triggered mechanism again, and the switching loop continues. The proposed switching event-triggered secondary controllers can restore frequencies and voltages of AC microgrids and there is no Zeno behavior due to the dwell times between switching. The effectiveness of the designed controllers is verified by theoretical analysis and simulations.