A lookup table approach to determining wind turbine operational fatigue loading from wind field measurements

This paper investigates the potential for a lookup table approach to operational fatigue load/damage estimation for wind turbines, based on 3D wind field measurements. Simulation is used to explore consistency of wind turbine fatigue loading for turbines in different wind fields which have the same mean wind speed, turbulence intensity and shear exponent. Aeroelastic simulations are performed for two turbines. Various combinations of the above three wind field characteristics are chosen; for each of these combinations and for each turbine, six different 3D wind fields are generated which have the given value of mean wind speed, turbulence intensity and shear exponent. The turbines are simulated in the generated 3D wind fields and equivalent damage loads are calculated for the blade and tower root bending moment time histories. Means and standard deviations of the equivalent loads from each set of six wind files with their characteristics in common are presented. The results indicate there is good potential for a lookup table approach to fatigue damage prediction.