Extreme turbulence effects on wind turbine loads: A case study for the North China Plain using nacelle lidar

Extreme turbulent wind conditions are critical for wind turbine operation, as they can induce loads that threaten structural integrity and lead to power losses due to conservative operational strategies. Rapid wind energy development in China has resulted in the deployment of large-rotor turbines in northern, northwestern, and northeastern regions with relatively flat terrain, where annual mean wind speeds are typically below 7.5ms−1 and turbulence intensity is generally lower than IEC Class C. Most turbines in these regions are designed using site-specific Class S conditions; however, the applicability of the IEC site-specific extreme turbulence model for Chinese sites has not been systematically assessed. In this study, one year of nacelle lidar measurements from the North China Plain is analyzed to identify extreme turbulence events, and their impacts are evaluated through aeroelastic simulations of an onshore IEA 15 MW turbine using site-specific constrained turbulence fields as well as standard IEC Kaimal and Mann turbulence models. The results show that these extreme events can produce turbine loads comparable to those predicted by the IEC Class C model with the Kaimal spectrum, while the predicted blade and tower loads in other cases are approximately 5%–14% lower. These findings provide insights for turbine manufacturers and operators to reassess turbine design and operational strategies under extreme turbulent conditions.