Wind tunnel tests on a non-rotating, dynamically scaled wind turbine blade equipped with variable trailing edge geometry were carried out. The effectiveness of the system for active load reduction purposes, with the interaction between structural dynamics, aerodynamics and control was tested. The actuation of the adaptive trailing edge was based on a piezoelectric bender actuator. The full aero...

Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine ( HAWT). A video camera mounted on the rotor was used to record night­ time and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of t...

Three different horizontal axis wind turbine (HAWT) blade geometries with the same diameter of 0.72 m using the same NACA4418 airfoil profile have been investigated both experimentally and numerically. The first is an optimum (OPT) blade shape, obtained using improved blade element momentum (BEM) theory. A detailed description of the blade geometry is also given. The second is an untapered and ...

This paper describes an easy-to-implement, proactive control strategy for wind turbines, incorporating constraints on blade loads. The control strategy is aimed for rejecting wind gusts and is based on upwind speed measurements and a new statistical wind gust detection mechanism. The control action comprises simultaneous driveline and collective pitch control with constraints on flapwise bendin...

With appropriate vibration modeling and analysis the incipient failure of key components such as the tower, drive train and rotor of a large wind turbine can be detected. In this paper, the Nonlinear State Estimation Technique (NSET) has been applied to model turbine tower vibration to good effect, providing an understanding of the tower vibration dynamic characteristics and the main factors in...

The National Renewable Energy Laboratory (NREL) has commissioned a highly modified Westinghouse 600 kW wind turbine as its Controls Advanced Research Turbine (CART). The capabilities of the original turbine have been increased through the installation of a high-speed data-acquisition and control system, a widebandwidth variable-speed generation system, and a high-speed independent blade pitch s...

This paper shows a strategy to carry out a wind turbine LPV (Linear Parameter Varying) and MIMO (Multivariable Input and Multivariable Output) model from a family of LTI (Linear Time Invariant) models. The family of LTI models is obtained from a linearization process in different operational points of the wind turbine model in GH Bladed. The procedure is valid for any family of LTI models obtai...

Modelling of wind farms using computational fluid dynamics (CFD) resolving the flow field around each wind turbine’s blades on a moving computational grid is still too costly and time consuming in terms of computational capacity and effort. One strategy is to use sub-models for the wind turbines, and sub-grid models for turbulence production and dissipation to model the turbulent viscosity accu...

When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based...

The purpose of this paper is to show an exemplary methodology for the integrated conceptioning of a floating wind turbine system with focus on the spar-type hull and the wind turbine blade-pitch-to-feather controller. It is a special interest to use a standard controller, which is easily implementable, even at early design stages. The optimization of the system is done with adapted static and d...