Wind power participation in system frequency regulation is a key measure for enhancing the frequency security and stability of power systems with high renewable energy penetration. However, existing wind turbine frequency regulation strategies struggle to cope with diverse power disturbances in such systems and fail to fully utilize wind turbines’ fast frequency support capabilities. This paper develops a generalized electromagnetic transient model for frequency regulation control of direct-drive wind turbines and examines their dynamic behaviors under current frequency regulation strategies to identify the factors that limit their regulation capability. Building on this analysis, an improved system frequency response model that incorporates wind power frequency regulation is established to assess the severity of system power disturbances. A novel active frequency support control strategy for wind turbines is then proposed based on this assessment. The strategy evaluates disturbance severity using the maximum rate of change of frequency (RoCoF) following a disturbance and selects different combinations of frequency control methods according to the wind turbine’s operational mode. This allows wind turbines to effectively provide active frequency support while significantly reducing the risk of second frequency dips. Simulation results demonstrate that compared with fixed-parameter and traditional adaptive frequency control strategies, the proposed strategy offers superior frequency regulation performance under varying levels of disturbance, demonstrating its effectiveness.