Collaborative Active and Reactive Power Control of DERs for Voltage Regulation and Frequency Support by Distributed Event-Triggered Heavy Ball Method

The increasing integration of distributed energy resources (DERs) into distribution networks draws great attention to the advanced voltage control. Meanwhile, DERs scattered in distribution networks also show potential to provide frequency support. This paper proposes a novel coordinated active and reactive control strategy of DERs by using a distributed event-triggered heavy ball method, aiming to allow DERs to offer voltage regulation and frequency support in a unified framework. In the meantime, the proposed control strategy can effectively save communication cost and accelerate the convergence rate simultaneously. Specifically, for achieving a faster convergence rate, the dual-based heavy ball method is incorporated into a traditional dual iteration scheme by adding extra momentum terms. To further reduce the communication burden, the control scheme is modified by designing event-triggered conditions on dual variables. The convergence results are provided based on a linearized power flow model to facilitate the controller design and theoretical analysis. The proposed control strategy is also numerically tested on a modified IEEE 123-bus network with a nonlinear power flow model. Finally, the simulation results illustrate that the event-triggered heavy ball approach can greatly reduce the communication cost and achieve an improved convergence rate compared with the existing methods.