Influence of turbulence intensity on wind turbine power curves

In this study the effect of turbulence on wind turbine performance measurements has been investigated, and the turbulence normalization method introduced in a draft for the second edition of the IEC 61400-12-1 standard has been evaluated. Experimental data has been collected from a wind turbine test site at the coast of Norway over a 10 month period from a Windcube v2 ground-lidar, and a 3MW wind turbine, and the effect of turbulence intensity on power curves and annual energy production (AEP) has been studied. The range of turbulence conditions experienced at this coastal site has a significant influence on the power curve and calculated AEP. The measured dataset was split into two subsets featuring different turbulence conditions, and AEP was then calculated for each of these based on power curves from the opposite subset. Using the zero turbulence power curve method the difference in calculated AEP is reduced by 50% compared to using traditional power curves. The method only considers the effect of 10-minute averaging and not the direct influence of turbulence on rotor aerodynamics.