Distributed Event-Triggered Control for Energy Storage Systems in Multi-Bus DC Microgrids

Abstract

This paper proposes an event-triggered distributed control strategy to simultaneously achieve average voltage restoration and precise current sharing in islanded multi-bus DC microgrids (MGs) formed by battery energy storage systems (BESSs). To resolve the coordination control challenges arising from multiple energy storage units, a consensus-based distributed algorithm implemented through neighborhood communication networks is developed, enabling global voltage regulation and state-of-charge (SoC) dependent current allocation. Notably, conventional average voltage observers present inherent steady-state deviations with nonzero initialization. To address this limitation, we introduce a PI consensus observer that guarantees average voltage convergence to the rated value with zero steady-state error. Moreover, based on Lyapunov stability theory, an event-triggering mechanism is developed to significantly reduce communication traffic while maintaining system stability. Theoretical proof is further provided to ensure a strictly positive minimum interval time to exclude Zeno behavior. Lastly, the simulation and hardware-in-the-loop experimental results are presented to validate the effectiveness of the proposed method. Note to Practitioners—In islanded multi-bus DC MGs, achieving voltage regulation and current sharing under limited communication resources remains a practical challenge. In particular, conventional distributed secondary control schemes often rely on continuous communication and average voltage observers that may suffer from steady-state deviations and unnecessary frequent communication. The event-triggered distributed control strategy proposed in this paper is motivated by these practical concerns. The proposed approach enables reliable average voltage restoration and SoC-dependent current sharing using only neighbor-to-neighbor communication. The event-triggering mechanism significantly reduces communication traffic while guaranteeing system stability and excluding Zeno behavior, making the method suitable for MGs with constrained bandwidth or limited communication infrastructure. In addition, the proposed approach provides an explicit formulation that directly derives triggering gains from the controller parameters, thereby simplifying parameter design for practical implementation. This control framework is especially applicable to BESS-based DC MGs in scenarios such as remote communities and industrial parks with improved scalability, robustness, and efficient utilization of distributed storage.