A Distributed Control Strategy for Unbalanced Voltage Compensation in Islanded AC Microgrids Without Continuous Communication
Jinghang Lu, Bingfu Zhang, Xiaochao Hou, Josep M. Guerrero
Abstract
Due to the unbalanced load connection in the sensitive load bus (SLB), the ac microgrid may suffer from voltage unbalance in the system. To overcome this issue, this article presents a new distributed control scheme to achieve the unbalanced voltage compensation for islanded ac microgrid with limited noncontinuous communication among the distributed generation (DG) units. In this article, a two-layer control framework, including the cyber layer and the primary control layer, is employed. The proposed control strategy that is applied in the cyber layer implements an event-triggered communication to effectively compensate for the unbalanced voltage in the SLB. In contrast with the centralized control strategy, the proposed control strategy is fully distributed, and the information exchange among the DG units at only the event-triggered times. As a result, the communication burdens can be measurably reduced while the control performance is not affected. The stability is analyzed with the Lyapunov function in this article. Finally, several experimental case studies are provided to verify the effectiveness of the proposed scheme.