Wind farm production maximization using combined layout and wake steering optimization under load constraint
Abstract
In recent years, research on wake steering has proven beneficial for increasing the power production of individual turbines as well as the Annual Energy Production (AEP) of a wind farm. By having an intentional yaw offset, the wake in the wind farm can be redirected so that the turbines downstream can capture more energy. However, misalignment of the turbines with the wind direction and change of their positions within the wind farm comes with a considerable impact on the fatigue loading for blade root and tower top loads. In addition, layout optimization by itself has been studied extensively and its benefits are more than established. Nevertheless, a combined scenario where both the layout and the turbines’ yaw angles are optimized while restricting the loads has not been explored. Thus, this thesis project aims to investigate how a coupled strategy of wake steering and layout optimization under load constraints influences a wind farm’s AEP and to explore the likely trade-off between load and power when operating the turbines under yaw misalignment. For this purpose, an already trained surrogate model of the DTU 10MW reference turbine is used to perform both the Damage Equivalent Loads (DEL) and the Lifetime Damage Equivalent Loads (LDEL) calculation via PyWake’s flow model, and TOPFARM is used to carry out the optimizations. For the layout optimization, the design variables were chosen as the inter-turbine spacing and grid rotation angle to reduce the complexity of the problem. A simple 9 turbine wind farm case is used for the study and a comparison is made between two optimization approaches: integrated and sequential. The analysis shows that an integrated optimization is highly computational expensive, even when the design variables for layout optimization are reduced to only two. On the other hand, the sequential approach yielded a higher AEP gain in substantially less time, which begs to question whether a fully integrated optimization is justifiable. For both optimization approaches a uniform distribution of the LDEL was obtained and the constraints were never reached, which means that further restriction on the maximum allowable loading could be explored.
Cite this
Araujo, Maria Virginia Sarcos. (2022). Wind farm production maximization using combined layout and wake steering optimization under load constraint.
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