Implementation and Validation of Algorithm forEstimating the Possible Power of Curtailed Wind Turbines Exposed to WakeEffects

Abstract: In countries with high wind power penetration such as Denmark and Germany, wind farms are now requested to provide ancillary services. This implies that wind operators like Vattenfall must curtail (down-regulate) their farms from their possible power so that power reserves can be used in case of an outage in the electrical network. However, the estimation of the possible power of a farm is a complex task as it depends on many parameters such as the ambient conditions, the operational status of the turbines and the layout of the farm. The current estimation ignores these and unfortunately, this yields to an overestimation of the possible power when the farm is curtailed. Tuhfe Göçmen published recently the PossPOW algorithm whose goal was to integrate these parameters in the estimation of the possible power so that the method would still be applicable during curtailments. Here, this algorithm was studied in depth to determine if it could be employed in real cases. In particular, it was tested on different situations than the ones investigated initially. It turned out that the actual algorithm failed to consider correctly the wind direction, a crucial parameter for the quality of the estimate. Therefore, modifications in the initial algorithm were applied to deal with this issue and these led to significant improvements in its performances. The PossPOW algorithm even with the proposed corrections was not able to reach the expected accuracy. But several areas of improvement were given to enhance the performances of the algorithm in the future. In parallel, this study raised the question of optimal curtailment strategies that which according to the developed models could increase the production of wind farms. Nevertheless, real experiments on wind farms are needed to try these strategies and assess their potential in practice.