Sectional fuzzy control strategy for wind and storage coordinated frequency regulation in renewable power systems

With high renewable penetration, system inertia is reduced and frequency regulation capability is weakened, making supplementary control by wind turbines alone insufficient to meet frequency support requirements. To address this issue, a wind-storage coordinated frequency regulation scheme is proposed, in which wind power is assigned the primary role and auxiliary support is provided by battery energy storage systems (BESSs). Firstly, an overall control architecture for coordinated frequency regulation is developed, and the frequency-response characteristics of wind turbines together with the BESS capacity requirements are analyzed. Then, a controllable potential assessment method is established for different operating scenarios by considering wind-speed regions and BESS state of charge (SOC) regions. On this basis, a fuzzy-control-based strategy is designed to determine the required regulation power and allocate regulation responsibilities between wind turbines and the BESS, thereby forming a full-process framework in which preventive control before disturbances and coordinated control after disturbances are both incorporated. Case studies conducted on an IEEE 39-bus system demonstrate that the proposed method effectively improves frequency response under various wind conditions and operating scenarios.