Advanced control strategy for wind-storage to compensate hammer effect based on SID and FRR

• ESS offsets reverse hydropower regulation, significantly improving frequency stability. • SOC- and deadband-based ESS strategy enables charging/discharging with self-recovery. • Dynamic regulation coefficient control improves wind turbine response at different stages. • Strategy validated using real data from a hydropower–renewable dual-entity scenario. To address the seasonal variations in frequency regulation requirements (FRRs) for a hybrid renewable hydropower system, this study proposes an advanced wind-storage coordinated control strategy to compensate for the water hammer effect, based on system inertia demand (SID) and FRRs. Firstly, the coupling mechanism and regulation requirements between power system inertia response and primary frequency regulation (PFR) were analyzed. A coordinated wind turbine frequency control strategy based on inertia support-frequency regulation demand was developed, incorporating dual frequency security constraints of minimum frequency ( f min ) and maximum rate of change of frequency ( RoCoF max ). Subsequently, an improved time-delay control method for energy storage systems (ESSs) is proposed to precisely compensate the reverse regulation power caused by hydraulic hammer effects in hydro units. Furthermore, to fully utilize the regulation capacity of ESSs, a frequency coordination control method is developed that considers both state of charge (SOC) and self-recovery requirements, achieving dual compensation both inside and outside the system’s frequency dead band. Finally, by leveraging the regulation capabilities of both wind turbines and ESSs, comprehensive frequency adjustment is achieved throughout the grid’s inertia response and PFR processes. An RT-LAB based simulation model of the wind-storage-hydro control system is established and validated using actual case data from Yunnan Power Grid. The results demonstrate: during wet season with 10 % renewable penetration: frequency violation index d 1 improves by 0.078; Frequency violation index d 2 improves by 0.223. During dry season with 55 % renewable penetration: energy storage compensates up to 0.0027p.u. reverse regulation power during initial hydro unit primary frequency response; Frequency violation index d 1 improves by 0.524; Frequency violation index d 2 improves by 0.449. The proposed strategy effectively enhances frequency regulation capability for renewable-hydro dominated power systems under different seasonal conditions.