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Blade pitch

About: Blade pitch is a research topic. Over the lifetime, 5321 publications have been published within this topic receiving 63134 citations.


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Journal ArticleDOI
TL;DR: In this paper, a robust optimization strategy for the aerodynamic design of horizontal axis wind turbine rotors including the variability of the annual energy production due to the uncertainty of the blade geometry caused by manufacturing and assembly errors is presented.
Abstract: Presented is a robust optimization strategy for the aerodynamic design of horizontal axis wind turbine rotors including the variability of the annual energy production due to the uncertainty of the blade geometry caused by manufacturing and assembly errors. The energy production of a rotor designed with the proposed robust optimization approach features lower sensitivity to stochastic geometry errors with respect to that of a rotor designed with the conventional deterministic optimization approach that ignores these errors. The geometry uncertainty is represented by normal distributions of the blade pitch angle, and the twist angle and chord of the airfoils. The aerodynamic module is a blade-element momentum theory code. Both Monte Carlo sampling and the univariate reduced quadrature technique, a novel deterministic uncertainty analysis method, are used for uncertainty propagation. The performance of the two approaches is assessed in terms of accuracy and computational speed. A two-stage multi-objective evolution-based optimization strategy is used. Results highlight that, for the considered turbine type, the sensitivity of the annual energy production to rotor geometry errors can be reduced by reducing the rotational speed and increasing the blade loading. The primary objective of the paper is to highlight how to incorporate an efficient and accurate uncertainty propagation strategy in wind turbine design. The formulation of the considered design problem does not include all the engineering constraints adopted in real turbine design, but the proposed probabilistic design strategy is fairly independent of the problem definition and can be easily extended to turbine design systems of any complexity.

32 citations

Patent
Bertelsen Kim1
07 Nov 2008
TL;DR: In this paper, a wind turbine rotor blade comprising a blade tip and a lightning protection system is described, and the rotor blade includes at least one lightning receptor at the surface of the blade in an external distance (L ex ) from the distal end of the rotor tip.
Abstract: The invention relates to a wind turbine rotor blade comprising a blade tip and a lightning protection system. The rotor blade includes at least one lightning receptor at the surface of the blade in an external distance (L ex ) from the distal end of the blade tip, and a lightning receptor base inside the rotor blade arranged at an first internal distance (L i1 ) from the distal end of the blade tip. The rotor blade further includes means for changing at least one electric property of the rotor blade at the lightning receptor base, as compared to the electric properties of the ambient air by increasing the electric field supported between the lightning receptor base and the inner surface of the rotor blade. The invention further relates to a method for manufacturing a wind turbine rotor blade.

32 citations

Journal ArticleDOI
TL;DR: Numerical results show that the proposed controller offers improved performance in optimizing power production and reducing wind turbine and platform loads compared with the BC over an envelope of wind-wave loading environment.
Abstract: This article proposes a new strategy for individual blade pitch control to regulate power production while simultaneously alleviating structural loads on spar-type floating offshore wind turbines. Individual blade pitch control types of algorithms for offshore wind turbines are sparse in the literature though there are expected benefits from experience on such types of controllers for onshore wind turbines. Wind turbine blade pitch actuators are primarily used to maintain the rated power production at the above-rated wind speeds, and therefore, control algorithms are usually developed only to regulate power production. The scope of reducing structural loads using individual pitch control has been proven to be very promising over the last decade, and numerous individual pitch control algorithms have been proposed by researchers. However, reduction in structural loads often results in a degradation in power production and regulation. Furthermore, improving power regulation often has a detrimental effect on the floating platform motion. In this article, a new control strategy is proposed to achieve the two competing objectives. The proposed controller combines a low-authority linear-quadratic (LQ) controller with an integral action to reduce the 1P (once per revolution) aerodynamic loads while regulating power production using the same pitch actuators that are traditionally used only to optimize power production. The proposed controller is compared against the baseline controller (BC) used by the state-of-the-art wind turbine simulator FAST using a high-fidelity aeroelastic offshore wind turbine model. Numerical results show that the proposed controller offers improved performance in optimizing power production and reducing wind turbine and platform loads compared with the BC over an envelope of wind-wave loading environment.

32 citations

12 Oct 1992
TL;DR: In this paper, only propeller blades were considered and the effect of any AM on the return signal was investigated and simulated returns and frequency spectra were discussed, showing that rotor blades are large and their pitch is small.
Abstract: The analysis considers only propeller blades. This is partly because rotor blades will also have cyclic pitch, in order to reduce the roll caused by the asymmetry of lift between advancing and retreating blades, and partly because rotor blades are so large and their pitch is so small that the effect of any AM on the return signal will be small in comparison. Simulated returns and frequency spectra are plotted and discussed.

32 citations

Journal Article
TL;DR: In this paper, the effect of preset pitch angle on the performance of a three-bladed H-Darrieus VAWT has been considered for the study and the equations governing the flow are solved using a commercial CFD code ANSYS CFX 13.
Abstract: The current work involves a numerical study of the effect of preset pitch angle on the performance of a Vertical Axis Wind Turbine (VAWT). A three bladed H-Darrieus VAWT has been considered for the study. The equations governing the flow are solved using a commercial CFD code ANSYS CFX 13. The turbine with NACA 0015 profile and zero pitch angle as the reference case for comparison. The analysis has been done for three pitch angles -6 o , 0 o , +6 o , tip speed ratios (TSR) from 1 to 2.2 and wind velocities of 6, 8 and 10 m/s. Of the pitch angle considered, the best performance is observed with -6 o for all tip speed ratios and wind velocities. This has been explained by studying the instantaneous torque characteristics of the turbine. It is seen that at any given instant, the blade in the upwind region contributes significantly to the positive torque with other blades either contributing less or negating the positive torque. The pressure coefficient distributions over the upwind blade and stream lines at different azimuthal angles have also been analysed to understand the effect of pitch.

32 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202377
2022163
202184
2020110
2019105
2018109