Young Gyu  Jin, Seungbeom  Ko, Sung Bo  Oh, Ho Chan  Kim, 
    Support for Primary Frequency Control by a Wind Farm
Using Wake Propagation Delay,
    Journal of Engineering and Applied Sciences,
    Volume 12,Issue 4,
    2017,
    Pages 1013-1017,
    ISSN 1816-949x,
    jeasci.2017.1013.1017,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2017.1013.1017)
    Abstract: A wind farm can be operated in the Maximum Power Point Tracking (MPPT) mode where the generation of each turbine is individually maximized. In contrast, a wind farm can be operated in the Collaborative Power Maximization (CPM) mode where the generation is maximized on a wind farm level considering wake effect. Normally, the CPM mode is obviously better than the MPPT mode in terms of the amount of generation. In this study, it is suggested that a wind farm in the CPM mode can support primary frequency control by temporarily changing into the MPPT mode. However, subsequent frequency drop is inevitable when the wind farm is returning to the CPM mode. In order to address this problem of the frequency drop, it is demonstrated that the duration between mode changes should be set sufficiently large considering wake propagation delay. For further mitigation of the frequency drop, a ramping restoration method of axial induction factors is proposed. The effectiveness of the proposed approach is verified by the simulations with a wind farm with ten turbines in a row.
    Keywords: Iterative optimization;power maximization;wake effect;wind farm control;CPM