Secondary Restoration Control of Islanded Microgrids With a Decentralized Event-Triggered Strategy

Distributed cooperative control methods attract more and more attention in microgrid secondary control because they are more reliable and flexible. However, the traditional methods rely on the periodic communication, which is neither economic nor efficient due to its large communication burden. In this paper, an event-triggered-approach-based distributed control strategy is used to deal with the secondary frequency and voltage control in the islanded microgrid. By using the outputs of estimators, which are reset to the actual values only at the event-triggered time, to replace the actual values in the feedback control laws, the proposed control strategies just require the communication between distributed secondary controllers at some particular instants while having frequency and voltage restoration function and accurate active power sharing. The stability and interevent interval are also analyzed in this paper. An islanded microgrid test system is built in PSCAD/EMTDC to validate the proposed control strategies. It shows that the proposed secondary control strategies based on the event-triggered approach can highly reduce the interagent communication.