scholarly journals Wind Turbine Structural Path Stress and Fatigue Reductions Resulting from Use of Active Aerodynamic Load Control

2012 ◽  
Author(s):  
Brian Resor ◽  
Dale Berg ◽  
Zachary Wright ◽  
Chris Halse ◽  
Ashley Crowther
Keyword(s):  
Wind Turbine ◽  
Load Control ◽  
Aerodynamic Load ◽  
Structural Path

scholarly journals Active Aerodynamic Load Control for Improved Wind Turbine Design

2020 ◽  
Vol 1618 ◽  
pp. 052079
Author(s):  
D. Todd Griffith ◽  
Neal E. Fine ◽  
John A. Cooney ◽  
Mario A. Rotea ◽  
G. Valerio Iungo
Keyword(s):  
Wind Turbine ◽  
Load Control ◽  
Aerodynamic Load ◽  
Turbine Design

Dynamic Aeroelastic Response of Wind Turbine Rotors Under Active Flow Control

2019 ◽  
Author(s):  
Muraleekrishnan Menon ◽  
Fernando L. Ponta
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Active Flow Control ◽  
Load Control ◽  
Aerodynamic Load ◽  
Trailing Edge ◽  
Trailing Edge Flaps ◽  
Utility Scale ◽  
Active Flow

Abstract The significance of wind power and the associated relevance of utility-scale wind turbines are becoming more prominent in tapping renewable sources for power. Operational wind turbines today rated at 8 MW have rotor diameters of 164 m. Economies-of-scale factor suggest a sustained growth in rotor size, forecasting the use of longer and heavier blades. This has led to an increased emphasis on studies related to improvements and innovations in aerodynamic load-control methodologies. Among several approaches to controlling the stochastic aerodynamics loads on wind turbine rotors, most popular is the pitch control. Widely used in operational wind turbines, conventional pitch control is an effective approach for long-term load variations. However, their application to mitigate short-term fluctuations have limitations that present a bottleneck for growth in rotor size. Sporadic changes occurring within short time scales near the turbine rotor have significant impact on the aeroelastic behavior of the blades, power generation, with long-term effects on the rotor life-span. Cyclic variations occurring within few seconds emphasize the need for swift response of control methods that counter the resulting adverse effects. Current study revolves around the need to evaluate innovative active load control techniques that can swiftly handle high frequency oscillations in dynamic loading of turbine rotors. This may result from sudden changes in wind conditions due to gusts, environmental effects like atmospheric boundary layer and uneven terrain, or from turbine design features and operating conditions such as tower shadow effects. The upward surge in rotor size is linked with a down-side for existing techniques in rotor control that now need to account for heavier blades and the associated inertia. For example, the pitching operation rotates the entire blade around its longitudinal axis to regulate angle of wind at specific blade sections, involving huge inertial loads associated with the entire blade. On the other hand, active flow-control devices (FCDs) have the potential to alleviate load variations through rapid aerodynamic trimming. Trailing-edge flaps are light weight attachments on blades that have gradually gained relevance in studies focused on wind turbine aerodynamics and active load control. This computational study presents an aeroelastic assessment of a benchmark wind turbine based on the NREL 5-MW Reference Wind Turbine (RWT), with added trailing-edge flaps for rapid load control. The standard blades used on the NREL 5-MW RWT rotor are aerodynamically modified to equip them with actively controllable fractional-chord trailing-edge flaps, along a selected span. The numerical code used in the study handles the complex multi-physics dynamics of a wind turbine based on a self-adaptive ODE algorithm that integrates the dynamics of the control system in to the coupled response of aerodynamics and structural deformations of the rotor. Using the 5-MW RWT as a reference, the blades are modified to add trailing-edge flaps with Clark Y profile and constant chord. Attached at chosen sections of the blade, these devices have a specific range of operational actuation angles. Numerical experiments cover scenarios relevant to the aeroelastic response of a rotor with such adapted blades under operating conditions observed in utility-scale wind turbines. These fractional-chord devices attached along short spans of the blades make them light weight devices that can be easily controlled using low power of actuation. This overcomes the bottleneck in active aerodynamic load control, giving flexibility to study a wider ranged of control strategies for utility-scale wind turbines of the future. Preliminary outcomes suggest that rapid active flow control has high potential in shaping the future of aerodynamic load control in wind turbines.

scholarly journals Closed loop control of aerodynamic load fluctuations on wind turbine airfoil using surface plasma actuators

2020 ◽  
Vol 53 (2) ◽  
pp. 12675-12681
Author(s):  
Dominique Nelson-Gruel ◽  
Pierrick Joseph ◽  
Alexis Paulh-Manssens ◽  
Annie Leroy ◽  
Sandrine Aubrun ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Closed Loop ◽  
Plasma Actuators ◽  
Aerodynamic Load ◽  
Closed Loop Control ◽  
Surface Plasma ◽  
Loop Control ◽  
Wind Turbine Airfoil

Simplified Procedure to Estimate the Wind Turbine Blade Aerodynamic Loadings Without Using CFD

2013 ◽  
Author(s):  
Fouad Mohammad ◽  
Emmanuel Ayorinde
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Equations Of Motion ◽  
Wind Turbine Blade ◽  
Aerodynamic Load ◽  
Horizontal Axis Wind Turbine ◽  
Cross Sectional ◽  
Flow Angle ◽  
Blade Length ◽  
The Right

The aerodynamic loadings that act on the blade of a horizontal axis wind turbine change as a function of time due to the instantaneous change of the wind speed, the wind direction and the blade position. The new contribution in this study is the introduction of a simplified non CFD based procedure for the calculation of all the aerodynamic loadings acting on a wind turbine blade. The premise of the current simplified model is that (a) the forces can be modeled by a set of point loads rather than distributed pressures, and (b) the magnitudes of these point loads can be estimated using the below load formulas, (c) an interpolation scheme needed to have all computed forces and moments as a function of the blade lengthwise x. Considering a 14m blade length and utilizing a time dependent set of parameters such as angle of attack, material and air density, wind and blade speed, flow angle, yaw, pitch angles, the centrifugal forces (along x-direction of the blade length), the cross-sectional forces (Fy and Fz) and the twisting moment of the blade (about the x-direction) were calculated for each of all the given time steps. After that the authors explain how to interpolate the calculated loadings (forces and twisting moment) and the right formulas to compute the aerodynamic load vector (the right side of the dynamic equations of motion).

Finite time estimation of actuator faults, states, and aerodynamic load of a realistic wind turbine

2019 ◽  
Vol 130 ◽  
pp. 256-267 ◽  
Author(s):  
Mostafa Rahnavard ◽  
Moosa Ayati ◽  
Mohammad Reza Hairi Yazdi ◽  
Mohammad Mousavi
Keyword(s):  
Wind Turbine ◽  
Finite Time ◽  
Time Estimation ◽  
Aerodynamic Load ◽  
Actuator Faults

Active vibration suppression of elastic blade structure: Using a novel magnetorheological layer patch

2018 ◽  
Vol 29 (19) ◽  
pp. 3792-3803 ◽  
Author(s):  
Fevzi Cakmak Bolat ◽  
Selim Sivrioglu
Keyword(s):  
Wind Turbine ◽  
Vibration Suppression ◽  
State Space Model ◽  
Interaction Model ◽  
Parametric Uncertainty ◽  
Small Scale ◽  
Aerodynamic Load ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
Blade Element

This research study proposes a new active control structure to suppress vibrations of a small-scale wind turbine blade with attached magnetorheological fluid patch actuated by an electromagnet. The blade structure is manufactured by an aluminum extrusion machine considering the airfoil data of SH3055 which is designed for use on a small wind turbine. An interaction model between the magnetorheological patch and the electromagnetic actuator is derived and a force characterization is realized. A norm-based multiobjective H2/ H∞ controller is designed using the state-space model of the elastic blade element. The H2/ H∞ controller is experimentally implemented under the steady-state aerodynamic load conditions. The results of experiments show that the magnetorheological layer patch is effective for suppressing vibrations of the blade structure and robust against parametric uncertainty.

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