Comparison of linear and non-linear blade model predictions in Bladed to measurement data from GE 6MW wind turbine

The Science of Making Torque from Wind

Collier, W.^1 ; Milian Sanz, J.^2

DNV GL, One Linear Park, Avon Street, Bristol

BS2 0PS, United Kingdom^1

GE Renewable Energy, Roc Boronat, 78, Barcelona

08005, Spain^2

关键词: Damage equivalent loads;    Dynamic behaviours;    Large deflection;    Load predictions;    Measurement data;    Small deflection;    Time-domain simulations;    Wind turbine blades;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/753/8/082004/pdf
DOI  :  10.1088/1742-6596/753/8/082004

来源: IOP

【 摘 要 】

The length and flexibility of wind turbine blades are increasing over time. Typically, the dynamic response of the blades is analysed using linear models of blade deflection, enhanced by various ad-hoc non-linear correction models. For blades undergoing large deflections, the small deflection assumption inherent to linear models becomes less valid. It has previously been demonstrated that linear and nonlinear blade models can show significantly different blade response, particularly for blade torsional deflection, leading to load prediction differences. There is a need to evaluate how load predictions from these two approaches compare to measurement data from the field. In this paper, time domain simulations in turbulent wind are carried out using the aero-elastic code Bladed with linear and non-linear blade deflection models. The turbine blade load and deflection simulation results are compared to measurement data from an onshore prototype of the GE 6MW Haliade turbine, which features 73.5m long LM blades. Both linear and non-linear blade models show a good match to measurement turbine load and blade deflections. Only the blade loads differ significantly between the two models, with other turbine loads not strongly affected. The non-linear blade model gives a better match to the measured blade root flapwise damage equivalent load, suggesting that the flapwise dynamic behaviour is better captured by the non-linear blade model. Conversely, the linear blade model shows a better match to measurements in some areas such as blade edgewise damage equivalent load.