Abstract

According to the constraints of frequency safety indices, rationally utilizing the energy reserve provided by wind power and energy storage to meet the system's frequency regulation demand is inevitable for the development of a large-scale new energy power system. Firstly, frequency response characteristics and frequency regulation safety indicators required by new energy generation systems were analyzed. Secondly, the frequency dynamic response model of the system with wind power and energy storage was established, and the extreme value time for the virtual inertia response of the system was calculated. Using the extreme time at which the frequency drop is maximum, the virtual inertia time constant of the wind-storage system was evaluated. Additionally, the system inertia and the primary frequency regulation demand were obtained considering the frequency safety indices, and a novel coordinated control strategy for wind power and energy storage to provide the required frequency support was proposed. Finally, a grid-connected wind-storage simulation system was built to verify the superiority of the proposed control strategy. The obtained results indicate that the proposed control scheme flexibly meets the system frequency safety requirements.