Presentations

Abstract

Turbulence intensity (TI) is an important design wind quantity impacting fatigue loading on turbine components and hence their lifetime. However, the estimation of turbulence intensity from a Floating Lidar System (FLS) is biased high owing to the influence of buoy motion due to waves in addition to the measurement principle of a lidar device. In the contribution, we evaluate various motion compensation approaches for correcting FLS Turbulence Intensity Measurements based on field measurements.Two approaches are applied to the FLS wind speed data from a 6-month-long classification trail: the individual line-of-sight correction method and the compensation applied on reconstructed 1 Hz wind speed data. The effectiveness of the motion compensation is then evaluated against a lidar based reference and error metrics are derived. Results indicate that the motion compensation applied on 1 Hz reconstructed wind data provides TI estimates that can reduce the TI overestimation effect. This paves the way for the application of lidar-measured TI for applications such as fatigue load assessment, and energy yield studies. As the 1 Hz compensation method relies only on the reconstructed wind lidar data that is small enough to be transmitted every day from the buoy. This can allow projects to reduce the uncertainty in the design basis, providing an opportunity to optimize the design during the survey phase. Doing so can enable projects to reduce the uncertainty in TI therefore leading to a more accurate load and fatigue analysis and improved energy yield assessments.