Research on Energy Storage Capacity Configuration of Grid-Forming Wind-Storage Systems Based on Frequency Constraints

With the rapid development of high-penetration renewable energy power systems, the stability of grid frequency faces significant challenges. This paper proposes an optimized energy storage capacity configuration method for grid-forming wind-storage systems under grid frequency mutation scenarios, considering multiple damping states. By establishing a smallsignal model of a virtual synchronous generator (VSG) under grid disturbances, the power-capacity configuration boundaries of energy storage under overdamped, critically damped, and underdamped states are quantitatively derived. A configuration criterion based on frequency dynamic response is further proposed. Simulation results demonstrate that the regulation time under underdamped states is shorter than other damping modes during grid frequency disturbances, while the critically damped state requires the minimum energy storage capacity. The research findings provide theoretical support for the engineering-oriented configuration of grid-forming energy storage, contributing to enhanced stability in power systems with high renewable energy integration.