• Propose a clustering-based strategy to coordinate primary frequency regulation in large wind farms. • Classify turbines into three control categories to better utilize regional operating characteristics. • Develop a hierarchical power‑allocation scheme that prioritizes overspeed‑deloaded clusters. • Reduce pitch‑actuation events and mechanical stress while maintaining effective frequency support. As wind power penetration continues to increase, primary frequency regulation (PFR) in large-scale wind farms faces growing challenges due to the large number of turbines and the diversity of their operating conditions. These factors complicate coordinated control and may lead to unnecessary pitch activity during frequency regulation. To address these issues, this study investigates a coordinated PFR strategy for a single doubly fed induction generator (DFIG) wind farm based on dynamic clustering and hierarchical power allocation. First, an improved fuzzy c-means clustering method enhanced by the Sparrow Search Algorithm (SSA-FCM) is used to group turbines with similar operating characteristics and identify abnormal operating data. Based on the clustering results, turbines are assigned to non-deloaded, over-speed-deloaded (OSD), and pitch-angle-deloaded (PAD) groups. Then, a hierarchical regulation framework is established in which OSD turbines are prioritized to provide fast reserve support, while PAD turbines are activated only when additional regulation power is required. To reduce unnecessary pitch activity, the regulation power assigned to PAD turbines is further optimized using a hybrid Grey Wolf Optimizer–Particle Swarm Optimization (GWO-PSO) method with the objective of minimizing total pitch-angle variation. Simulation studies based on measured WF operating data show that the proposed strategy can satisfy PFR requirements while reducing unnecessary pitch-angle movements and improving the coordination of turbine participation. The results demonstrate the effectiveness and engineering applicability of the proposed strategy for frequency support in a single DFIG wind farm.
Yuan et al. (Wed,) studied this question.