Abstract
<jats:p>As converter-interfaced wind generation replaces synchronous units, power systems become more sensitive to active-power disturbances owing to reduced inertia and weakened governor response. To enhance frequency support, this paper proposes a Rate-of-Change-of-Frequency (RoCoF)-triggered hierarchical coordinated control strategy for wind power and battery energy storage systems (BESSs) in primary frequency regulation. The coordination layer converts frequency deviation and filtered RoCoF into an active-power support demand and determines the wind–BESS power split through SOC-corrected storage participation. The lower layer tracks the allocated commands under wind reserve, converter, deadband, SOC, and power-limit constraints. When RoCoF exceeds a preset threshold, the BESS share is increased for rapid active-power support; after RoCoF falls below the threshold, the allocation returns to baseline, and wind power provides sustained regulation. MATLAB/Simulink simulations under different wind penetrations, load disturbances, and wind speeds show improved frequency nadir, reduced RoCoF, shorter recovery time, and lower BESS energy use. At 25% wind penetration and a 0.10 pu load disturbance, the nadir increases from 49.62 to 49.77 Hz, and recovery time decreases from 5.0 to 2.1 s.</jats:p>