Optimal dispatch of storage-assisted thermal power considering renewable uncertainties

Abstract

Energy storage systems have emerged as critical components in modern power systems, addressing the challenges of frequency regulation stability and renewable integration. Coal-fired thermal power plants have provided grid stability but now confront increasing demands for deep peak shaving services. However, energy storage systems are exposed to relatively low energy support duration while thermal power units confront slow power changing rate. This paper proposes a coordinated control strategy and a robust optimization model for storage-assisted thermal power units, addressing short-term fluctuations and long-term uncertainties imposed on thermal power units across multiple timescales. The Column-and-Constraint Generation approach is employed to improve computational efficiency, achieving convergence within three iterations for the optimal solution. Simulation results confirm that the proposed uncertainty set effectively adapts to increasing data dimensions, addressing over-conservatism in traditional models subject to multi-timescale uncertainties. By leveraging the rapid response capability of energy storage and the steady output of thermal power units, the model improves grid support and alleviates operational stress on thermal units. The results also reveal that three different energy storage systems configurations result in cost reductions of 23.50%, 41.78%, and 38.63%, respectively, while demonstrating a substantial improvement in the system’s resilience in response to short- and long-term challenges.