Distributed Finite-Time Cooperative Control for Microgrids Under Cyber-Physical Delays

Abstract

The integration of distributed generation into islanded microgrids necessitates robust secondary control to restore voltage and frequency deviations caused by primary droop control. While distributed consensus-based protocols have emerged as a scalable solution, they predominantly assume ideal communication networks or asymptotic convergence. In real-world cyber-physical microgrids, time-varying communication delays and the need for rapid, finite-time restoration present significant challenges, particularly when mitigating high-ramp-rate renewable fluctuations using Hybrid Energy Storage Systems (HESS). This paper proposes a distributed finite-time cooperative control framework for islanded microgrids equipped with battery-supercapacitor HESS, explicitly accounting for cyber-physical time-varying delays. A theoretical framework based on Lyapunov-Krasovskii functionals and fractional-order sliding mode dynamics is developed to guarantee finite-time stability of voltage and frequency restoration, even under delay bounds of up to 250 ms. A distributed state-of-charge (SoC) balancing and power allocation algorithm is further integrated to optimize HESS utilization, ensuring supercapacitors absorb transient high-frequency power components while batteries supply steady-state loads. The proposed methodology is validated on a modified IEEE 34-node test system. Numerical results demonstrate that the proposed controller achieves up to 65.3% faster settling times and reduces battery peak current by 42.1% compared to state-of-the-art asymptotic and uncompensated finite-time control baselines.