Balance Control of Micro-Grid Operating Cost and ESS Life Stability Using Lyapunov Optimization-Based Energy Balancing EMS Algorithm

This paper proposes a Lyapunov optimization-based EMS (Energy Management System) algorithm aimed at improving the economic and stability of micro-grid. The proposed algorithm introduces a virtual queue to model the impact of ESS (Energy Storage System) charge/discharge cycles on its lifespan. Formulated as a Lyapunov-based optimization problem using the Drift-Plus-Penalty method, the algorithm controls a balance between micro-grid operating costs and ESS lifespan stability. The proposed algorithm was validated using real data from solar, wind, and demand resources in Jeju Island, to demonstrate its performance in a resource-variable micro-grid environment. Results showed that by adjusting a single parameter V, the proposed algorithm offers flexible control for managing operating costs and ESS lifespan stability aligned with the operator's objectives. The proposed algorithm overperforms in terms of both micro-grid operating costs and ESS lifespan stability against conventional algorithms, achieving a 99.99% energy balance satisfaction rate index. Moreover, the proposed algorithm guarantees the stable operation of multi-ESS units amid the dynamic resource variability in the micro-grid, securing both economic efficiency and operational stability. Therefore, this research can contributes to the advancement of EMS, providing effective solutions for optimizing micro-grid operating cost and enhancing the longevity of ESS. Copyright © The Korean Institute of Electrical Engineers.