Flexible Coordination of Wind Generators and Energy Storages in Joint Energy and Frequency Regulation Market

In the future, energy storage systems (ESSs) will be widely deployed on the generation side of renewable energy to smooth its power fluctuations. To optimize the revenue of wind farm with ESSs, it is economical to combine the low operating cost of wind turbines with the high regulation accuracy of ESSs to deliver frequency regulation and energy services to the power system. In this paper, a two-stage flexible coordination scheme is proposed for the wind farm with ESSs in a joint energy and frequency regulation market. In the first stage, utilizing the day-ahead prediction results, the strategy space is optimized through dynamic programming. In second stage, taking the short-term prediction results into account, a rolling programming algorithm is proposed to revise the real-time policy and cope with the impact of day-ahead prediction errors. This scheme enables the real-time prediction and optimization with relatively low computational cost. Additionally, the internal power distribution of the wind farm for each wind turbines is also considered. The validity and real-time performance of the proposed two-stage framework is proved through numerical experiments.