Capacity Configuration of Flywheel–Thermal Power System for Primary Frequency Regulation Based on OCSSA-VMD

In the coordinated primary frequency regulation process of flywheel–thermal power systems, the capacity configuration of flywheel energy storage often faces problems such as strong parameter dependence, ambiguous decomposition boundaries, and single-objective economic optimization. This paper proposes an improved method based on the Osprey-Cauchy-Sparrow Search Algorithm (OCSSA). OCSSA is first employed to optimize the parameters of Variational Mode Decomposition, thereby enhancing the decomposition accuracy of primary frequency regulation power commands. A mutual information entropy criterion is subsequently adopted to determine the high–low frequency boundary, enabling rational power allocation between flywheel units and thermal units. Finally, a life-cycle economic model is constructed, and OCSSA is employed to jointly optimize flywheel capacity and rated power. Simulation results based on data from a 600 MW thermal unit in Ninghai demonstrate that the proposed method reduces investment costs by 11.41% while increasing life-cycle benefits by 3.19%, improving the economic performance of the flywheel energy storage configuration system.