On the dynamics of the pitch control loop in horizontal-axis large wind turbines

2005 ◽  
Author(s):  
S. Suryanarayanan ◽  
A. Dixit
Keyword(s):  
Wind Turbines ◽  
Horizontal Axis ◽  
Control Loop ◽  
Pitch Control ◽  
Large Wind

Gain-phase margins-based delay-dependent stability analysis of pitch control system of large wind turbines

2019 ◽  
Vol 41 (13) ◽  
pp. 3626-3636 ◽  
Author(s):  
Omer Turksoy ◽  
Saffet Ayasun ◽  
Yakup Hames ◽  
Sahin Sonmez
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Wind Turbines ◽  
Time Domain ◽  
Dynamic Performance ◽  
Pitch Control ◽  
Wide Range ◽  
Delay Dependent ◽  
Delay Dependent Stability ◽  
Large Wind

This paper investigates the effect of gain and phase margins (GPMs) on the delay-dependent stability analysis of the pitch control system (PCS) of large wind turbines (LWTs) with time delays. A frequency-domain based exact method that takes into account both GPMs is utilized to determine stability delay margins in terms of system and controller parameters. A gain-phase margin tester (GPMT) is introduced to the PCS to take into GPMs in delay margin computation. For a wide range of proportional–integral controller gains, time delay values at which the PCS is both stable and have desired stability margin measured by GPMs are computed. The accuracy of stability delay margins is verified by an independent algorithm, Quasi-Polynomial Mapping Based Rootfinder (QPmR) and time-domain simulations. The time-domain simulation studies also indicate that delay margins must be determined considering GPMs to have a better dynamic performance in term of fast damping of oscillations, less overshoot and settling time.

Robust Multivariable Pitch Control Design for Load Reduction on Large Wind Turbines

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
M. Geyler ◽  
P. Caselitz
Keyword(s):  
Wind Turbines ◽  
Control Design ◽  
Fatigue Loading ◽  
Multivariable Control ◽  
Bending Moments ◽  
Pitch Control ◽  
Norm Minimization ◽  
Bending Mode ◽  
Large Wind ◽  
Minimization Approach

This paper deals with multivariable pitch control design for wind turbines, including load reducing control objectives. Different design approaches, including collective and cyclic pitch, and robustness aspects are discussed. A control design with decoupled controllers for collective and cyclic pitch is worked out in detail, based on the H∞ norm minimization approach. The control design is verified by simulations with a full nonlinear model of the wind turbine, showing the potential of multivariable pitch control to actively increase damping of the first axial tower bending mode and to reduce 1p fluctuations in blade root bending moments. Multivariable control design provides a convenient way of including additional load reducing objectives into the pitch controller of wind turbines. Fatigue loading of certain components, as tower and blades, could be reduced significantly.

scholarly journals Flow Characteristics Study of Wind Turbine Blade with Vortex Generators

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hao Hu ◽  
Xin-kai Li ◽  
Bo Gu
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Vortex Generators ◽  
Propeller Shaft ◽  
Horizontal Axis Wind Turbine ◽  
Separation Line ◽  
Blade Root ◽  
Pneumatic Power ◽  
Large Wind

The blade root flow control is of particular importance to the aerodynamic characteristic of large wind turbines. The paper studies the feasibility of improving blade pneumatic power by applying vortex generators (VGs) to large variable propeller shaft horizontal axis wind turbines, with 2 MW variable propeller shaft horizontal axis wind turbine blades as research object. In the paper, three cases of VGs installation are designed; they are scattered in different chordwise position at the blade root, and then they are calculated, respectively, with CFD method. The results show that VGs installed in the separation line upstream, with the separation line of the blade root as a benchmark, show a better effect. Pneumatic power of blades increases by 0.6% by installing VGs. Although the effect on large wind turbines is not obvious, there is a space for optimization.

On the Design of Horizontal Axis Two-Bladed Hinged Wind Turbines

1984 ◽  
Vol 106 (2) ◽  
pp. 171-176 ◽  
Author(s):  
K. H. Hohenemser ◽  
A. H. P. Swift
Keyword(s):  
Angular Velocity ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Dynamic Loads ◽  
Helicopter Rotors ◽  
Blade Tip ◽  
Velocity Variations ◽  
Large Wind

Hinged two-bladed wind turbines are not necessarily free of disturbing vibrations. The combination of elastic or built-in blade coning with blade flapping about a conventional teeter hinge produces periodic blade angular velocity variations in the blade tip path plane with associated vibrations and dynamic loads. The paper discusses and evaluates various hinge configurations for two-bladed rotors and shows why the conventional teeter hinge leads to nonuniform blade angular velocity in the blade tip path plane. The solution to this problem adopted for two-bladed helicopter rotors, though complex, could be of interest for large wind turbines. A much simpler solution, calling for the suppression of blade flapping by passive blade cyclic pitch variation produced by a strong negative pitch-flap coupling, was found to be practical for upwind tail vane stabilized two-bladed wind turbines.

Predictions of Low-Frequency and Impulsive Sound Radiation From Horizontal-Axis Wind Turbines

1982 ◽  
Vol 104 (2) ◽  
pp. 124-130 ◽  
Author(s):  
R. Martinez ◽  
S. E. Widnall ◽  
W. L. Harris
Keyword(s):  
Wind Turbines ◽  
Low Frequency ◽  
Theoretical Models ◽  
Horizontal Axis ◽  
Time Signals ◽  
Horizontal Axis Wind Turbines ◽  
Acoustic Output ◽  
Blade Loads ◽  
Large Wind ◽  
Good Agreement

This paper develops theoretical models to predict the radiation of low-frequency and impulsive sound from horizontal-axis wind turbines due to three sources: (i) steady blade loads, (ii) unsteady blade loads due to operation in a ground shear, (iii) unsteady loads felt by the blades as they cross the tower wake. These models are then used to predict the acoustic output of MOD-I, the large wind turbine operated near Boone, N. C. Predicted acoustic time signals are compared to those actually measured near MOD-I; good agreement is obtained.

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