Delayed inertial control-based coordinated frequency support using wind turbine generators

• Reveals that the optimal timing of WTG releasing energy in frequency control should lie between the inertia response and the full response of PFR. • A novel delayed inertia control is proposed for WTGs to compensate for the energy deficiency caused by the time delay of PFR. • A heuristic-based configuration method is developed to determine which WTGs should employ DIC in a fast and energy-efficient manner. • An adaptive strategy is proposed for WTGs to regulate the energy release in DIC while ensuring the rotor speed safety in fluctuating winds. This paper proposes a novel delayed inertia control (DIC)-based coordinated frequency support framework for wind turbine generators (WTGs), effectively utilizing their limited energy storage (LES) in rotating mass to support system frequency following power disturbances. A theoretical energy balance analysis is first conducted, revealing that the optimal timing for utilizing the LES in enhancing frequency nadir should lie between the inertia response and the full responses of primary frequency regulation (PFR) of synchronous generators (SGs). Based on this, the DIC concept is proposed to compensate for the energy deficiency caused by the time delay of PFR. Then, coordinated with PFR, a heuristic-based configuration method for DIC-based WTGs is proposed. By evaluating the wind power loss per unit released LES and ranking the priority of WTGs in DIC, it can determine which WTGs should employ DIC in a fast and energy-efficient manner. Finally, an adaptive frequency control strategy is proposed for DIC-based WTG. An explicit functional relationship between key DIC parameters and LES is established, enabling adaptive energy release to support frequency against fluctuating wind conditions. Simulations on a modified IEEE 39-bus power system validate the effectiveness of the proposed framework in enhancing system frequency nadir while ensuring the WTG’s rotor speed safety.