Testing Controls to Mitigate Fatigue Loads in the Controls Advanced Research Turbine

Conference · Thu Jan 01 04:00:00 EST 2009

DOI:https://doi.org/10.1109/med.2009.5164722· OSTI ID:982286

Wright, A D; Fingersh, L J; Stol, K A

Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional (3D) turbulent wind inflow field with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, maximize energy capture, and add active damping to maintain stability for these dynamically active structures operating in a complex environment. Researchers at the National Renewable Energy Laboratory are designing, implementing, and testing advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on a linear model of the turbine that is generated by specialized modeling software. This paper describes testing of a control algorithm to mitigate blade, tower, and drivetrain loads using advanced state-space control methods. The controller uses independent blade pitch to regulate the turbine's speed in Region 3, mitigate the effects of shear across the rotor disk, and add active damping to the tower's first fore-aft bending mode. Additionally, a separate generator torque control loop is designed to add active damping to the tower's first side-side mode and the first drivetraintorsion mode. This paper discusses preliminary implementation and field tests of this controller in the Controls Advanced Research Turbine at the National Renewable Energy Laboratory. Also included are preliminary comparisons of the performance of this controller to results from a typical baseline Proportional-Integral-Derivative controller designed with just Region 3 speed regulation as the goal.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO.
• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 982286
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
AERODYNAMICS
ALGORITHMS
AUTOMATION
BENDING
CAPTURE
CONTROL
DAMPING
DESIGN
DYNAMIC LOADS
DYNAMICS
ENERGY
ENVIRONMENT
EXTRACTION
FATIGUE
NATIONAL RENEWABLE ENERGY LABORATORY
ROTORS
SHEAR
SIMULATION
STABILITY
TESTING
TORQUE
TURBINES
VELOCITY
VORTICES
WEIGHT
WIND
WIND TURBINES
Wind Energy