Power curve measurement for large wind turbines requires taking into account more parameters than only the wind speed at hub height. Based on results from aerodynamic simulations, an equivalent wind speed taking the wind shear into account was defined and found to reduce the scatter in the power curve significantly. Two LiDARs and a SoDAR are used to measure the wind profile in front of a wind turbine. These profiles are used to calculate the equivalent wind speed. LiDAR are found to be more accurate than SoDAR and therefore more suitable for power performance measurement. The equivalent wind speed calculated from LiDAR profile measurements gave a small reduction of the power curve uncertainty. Several factors can explain why this difference is smaller than expected, including the experimental design and errors pertaining to the LiDAR at that time. This first measurement campaign shows that used of the equivalent wind speed at least results in a power curve with no more scatter than using the conventional method.
Wind energy; Test and measurements; Risø-R-1679; Risø-R-1679(EN); Test og målinger; Vindenergi
Main Research Area:
Denmark. Forskningscenter Risoe. Risoe-r
Danmarks Tekniske Universitet, Risø Nationallaboratoriet for Bæredygtig Energi, 2009