Distributed Event-triggered Secondary Control for Average Bus Voltage Regulation and Proportional Load Sharing of DC Microgrid
Zhongwen Li, Zhiping Cheng, Jikai Si, Shuhui Li
Abstract
This paper proposes a novel distributed event-triggered secondary control method to overcome the drawbacks of primary control for direct current (DC) microgrids. With event-triggered distributed communication, the proposed control method can achieve system-wide control of parallel distrubted generators (DGs) with two main control objectives: ① estimate the average bus voltage and regulate it at the nominal value; ② achieve accurate current sharing among the DGs in proportion to their power output ratings. Furthermore, the proposed control strategy can be implemented in a distributed way that shares the required tasks among the DGs. Thus, it shows the advantages of being flexible and scalable. Furthermore, this paper proposes a simple event-triggered condition that does not need extra state estimator. Thus, limited communication among neighbors is required only when the event-triggered condition is satisfied, which significantly reduces the communication burden at the cyber layer.