In this study, distributed event‐and self‐triggered (ST) control methods are proposed for accurate load sharing and voltage control in islanded AC microgrids with resistive line impedances. The proposed control framework is comprised of a two‐level control structure. At the primary level, the V‐I droop control method is adopted. In this method, the distributed energy resources (DERs) are synchronised to a common synchronous reference frame and load sharing is accomplished through voltage‐current droop characteristics in this frame. The secondary level, which has a distributed structure, mitigates the voltage deviations induced by the primary level and eliminates the current sharing error caused by the line impedances. The data exchange among the DERs is controlled using event‐ and ST algorithms. In order to reduce the communication burden, the feedback control laws are realised using estimated variables, which are updated at certain event times. The event times are extracted based on Lyapunov stability analysis and by consideration of the V‐I droop characteristics. Comparison of event and ST algorithms shows that while the event‐triggered strategy offers superior dynamic response, the ST approach requires lower network traffic. The efficacy of the proposed scheme is verified through real time simulation results.

This paper presents a new distributed eventtriggered control mechanism for accurate load sharing and voltage regulation in islanded AC microgrids (MGs). The control structure is composed of two layers. The primary control level coordinates the output current of the Distributed Energy Resources (DERs) by utilizing the V-I droop control strategy. In this method, all DERs are synchronized to a common rotating reference frame. To realize proportional load sharing among the DERs, for each DER, the d and q components of the output voltage are determined in accordance to droop characteristics of the d and q axis currents. To eliminate the load sharing caused by the line voltage drops, the slope of the droop characteristic of each DER is altered by means of a distributed secondary control scheme. The secondary controller utilizes an event-triggered communication strategy, which remarkably decreases the exchanged data and saves bandwidth. Simulation results show that the proposed method favors smooth dynamic performance and efficient network utilization.