Sample records for wind turbine components

  1. A Stochastic DEVS Wind Turbine Component Model for Wind Farm Simulation

    E-print Network

    Ding, Yu

    A Stochastic DEVS Wind Turbine Component Model for Wind Farm Simulation Eduardo P´erez, Lewis, wind turbine, DEVS, STDEVS Abstract Wind farms use several wind turbines to generate electricity variations in wind speed and direction, wind turbines experience stochastic loading that of- ten lead

  2. Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component

    E-print Network

    Paris-Sud XI, Université de

    Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component Ensemble for stationary and non stationary cases. Index Terms-Wind turbine, induction generator, bearing failure, ensemble developed for wind turbine electric generator condition monitoring in order to prolong their life span

  3. 75 FR 2159 - In the Matter of Certain Variable Speed Wind Turbines and Components Thereof; Termination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ...337-TA-641] In the Matter of Certain Variable Speed Wind Turbines and Components Thereof; Termination of Investigation...United States after importation of certain variable speed wind turbines and components thereof that infringe claims...

  4. Multi-component wind measurements of wind turbine wakes performed with three LiDARs

    NASA Astrophysics Data System (ADS)

    Iungo, G. V.; Wu, Y.-T.; Porté-Agel, F.

    2012-04-01

    Field measurements of the wake flow produced from the interaction between atmospheric boundary layer and a wind turbine are performed with three wind LiDARs. The tested wind turbine is a 2 MW Enercon E-70 located in Collonges, Switzerland. First, accuracy of mean values and frequency resolution of the wind measurements are surveyed as a function of the number of laser rays emitted for each measurement. Indeed, measurements performed with one single ray allow maximizing sampling frequency, thus characterizing wake turbulence. On the other hand, if the number of emitted rays is increased accuracy of mean wind is increased due to the longer sampling period. Subsequently, two-dimensional measurements with a single LiDAR are carried out over vertical sections of the wind turbine wake and mean wake flow is obtained by averaging 2D measurements consecutively performed. The high spatial resolution of the used LiDAR allows characterizing in details velocity defect present in the central part of the wake and its downstream recovery. Single LiDAR measurements are also performed by staring the laser beam at fixed directions for a sampling period of about ten minutes and maximizing the sampling frequency in order to characterize wake turbulence. From these tests wind fluctuation peaks are detected in the wind turbine wake at blade top-tip height for different downstream locations. The magnitude of these turbulence peaks is generally reduced by moving downstream. This increased turbulence level at blade top-tip height observed for a real wind turbine has been already detected from previous wind tunnel tests and Large Eddy simulations, thus confirming the presence of a source of dangerous fatigue loads for following wind turbines within a wind farm. Furthermore, the proper characterization of wind fluctuations through LiDAR measurements is proved by the detection of the inertial subrange from spectral analysis of these velocity signals. Finally, simultaneous measurements with two LiDARs are performed over the mean vertical symmetry plane of the wind turbine wake, while a third LiDAR measures the incoming wind over a vertical plane parallel to the mean wind direction and lying outside of the wake. One LiDAR is placed in proximity of the wind turbine location and measures pointing downstream, whereas a second LiDAR is located along the mean wind direction at a downstream distance of 6.5 diameters and measures pointing upstream. For these measurements axial and vertical velocity components are retrieved only for measurement points where the two laser beams result to be roughly orthogonal. Statistics of the two velocity components show in the near wake at hub height strong flow fluctuations with magnitudes about 30% of the mean value, and a gradual reduction for downstream distances larger than three rotor diameters.

  5. Wind turbine

    SciTech Connect

    Yeoman, D.R.

    1987-03-24

    A wind turbine is described comprising: a vertical axis rotor assembly coupled to a rotatable drive shaft for driving electrical power generating means; first wind deflector means mounted on the wind turbine normally positioned generally upwind and to one side of the rotor assembly for initially deflecting wind current into the rotor assembly and second wind deflector means mounted on the wind turbine normally positioned on another side of the rotor assembly to redirect the initially deflected wind current into the rotor assembly. The first and second wind deflector means are normally spaced from each other by a certain inter-deflector spacing; mounting means for mounting the first and second wind deflector means in the normal positions, the mounting means including an outer shaft through which the drive shaft extends and which is normally fixed with respect thereto. The outer shaft has an upwardly facing circumferentially extending shoulder formed therein including a first shoulder portion extending around a major portion of the circumference of the outer shaft and a pair of upwardly sloping portions which reet at an apex.

  6. Wind turbine

    DOEpatents

    Cheney, Jr., Marvin C. (Glastonbury, CT)

    1982-01-01

    A wind turbine of the type having an airfoil blade (15) mounted on a flexible beam (20) and a pitch governor (55) which selectively, torsionally twists the flexible beam in response to wind turbine speed thereby setting blade pitch, is provided with a limiter (85) which restricts unwanted pitch change at operating speeds due to torsional creep of the flexible beam. The limiter allows twisting of the beam by the governor under excessive wind velocity conditions to orient the blades in stall pitch positions, thereby preventing overspeed operation of the turbine. In the preferred embodiment, the pitch governor comprises a pendulum (65,70) which responds to changing rotor speed by pivotal movement, the limiter comprising a resilient member (90) which engages an end of the pendulum to restrict further movement thereof, and in turn restrict beam creep and unwanted blade pitch misadjustment.

  7. Investigation of Data Fusion Applied to Health Monitoring of Wind Turbine Drive train Components

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Sheng, Shuangwen

    2011-01-01

    The research described was performed on diagnostic tools used to detect damage to dynamic mechanical components in a wind turbine gearbox. Different monitoring technologies were evaluated by collecting vibration and oil debris data from tests performed on a "healthy" gearbox and a damaged gearbox in a dynamometer test stand located at the National Renewable Energy Laboratory. The damaged gearbox tested was removed from the field after experiencing component damage due to two losses of oil events and was retested under controlled conditions in the dynamometer test stand. Preliminary results indicate oil debris and vibration can be integrated to assess the health of the wind turbine gearbox.

  8. Wind turbine acoustics

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    1990-01-01

    Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

  9. EEMD-based wind turbine bearing failure detection using the generator stator current homopolar component

    E-print Network

    Boyer, Edmond

    EEMD-based wind turbine bearing failure detection using the generator stator current homopolar turbine generators for stationary and non stationary cases. Keyword: Wind turbine, induction generator on the installed equipment because they are hardly accessible or even inaccessible [1]. 1.1. Wind turbine failure

  10. Wind turbine

    SciTech Connect

    Yeoman, D.R.

    1989-07-25

    This patent describes a wind turbine. It comprises: a vertical axis rotor assembly coupled to a rotatable drive shaft for driving electrical power generating means; first wind deflector means for initially reflecting wind current into the rotor assembly; second wind deflector means to redirect the initially deflected wind current into the rotor assembly; and mounting means for mounting the first and second wind deflector means in the normal positions. The mounting means including an outer shaft through which the drive shaft extends and which is normally fixed with respect thereto. The outer shaft having at least one lower groove winding in one of a left-hand or right-hand direction, at least one lower groove constituting a first lower groove set, and at least one upper groove winding in the other of the left-hand or right-hand direction, at least one upper groove constituting a second upper groove set, and first lower and second upper connector rings coupled to the first and second wind deflector means respectively, and mounted on the outer shaft proximate to the first and second groove sets respectively. The first and second connector rings including guide means cooperating with at least one groove of the first and second groove sets respectively. The mounting means allowing at least one of the first and second wind deflector means to automatically move relative to each other and from its respective normal position when the velocity of the wind current exceeds a first predetermined value to increase the inter-deflector spacing and causing at least one of the first and second wind deflector means to automatically return to its respective normal position when the velocity of the wind current diminishes to a value below the first predetermined value.

  11. Damage predictions for wind turbine components using the LIFE2 computer code

    NASA Astrophysics Data System (ADS)

    Sutherland, Herbert J.

    The LIFE2 computer code is a fatigue/fracture analysis code that is specialized to the analysis of wind turbine components. It is a PC-compatible FORTRAN code that is written in a top-down modular format. The service lifetime of a component can be divided into three phases: crack initiation, growth and coalescence of micro-cracks and growth of a macro-crack. In the LIFE2 formulation, a S-n fatigue analysis is used to describe the first two phases and a linear, da/dn fracture analysis is used to describe the third phase. The code is divided into five main sections. The first four describe the wind resource, the constitutive properties of the turbine material, the stress state in which the turbine operates and operational parameters for the turbine system. The fifth uses the data files written by the first four sections to calculate the service lifetime of a turbine component. In addition to the main sections, auxiliary sections are included to permit the storage of data and code calculations and to permit the plotting of results. This report describes the computational framework used in the LIFE2 code to evaluate the damage rules cited above. An example problem is presented here to illustrate the capabilities of the code.

  12. Fixed pitch wind turbines

    Microsoft Academic Search

    D. B. Fenn; L. A. Viterna

    1978-01-01

    Wind turbines designed for fixed pitch operation offer potential reductions in the cost of the machine by eliminating many costly components. It was shown that a rotor can be designed which produces the same energy annually as Mod-0 but which regulates its power automatically by progressively stalling the blades as wind speed increases. Effects of blade twist, taper, root cutout,

  13. Wind turbine

    SciTech Connect

    Traudt, R.F.

    1986-12-30

    This patent describes a wind turbine device having a main rotatable driven shaft, elongated blades operatively mounted on the main shaft for unitary rotation with the main shaft. The blade extends substantially radially away from the main shaft and is adapted to fold downwind under naturally occurring forces and simultaneously feather in direct response to the folding movement. A means associated with the blades is included for increasing the rate of fold relative to the rate of feather as the speed of rotation increases.

  14. Turbulence descriptors for scaling fatigue loading spectra of wind turbine structural components

    SciTech Connect

    Kelley, N.D.

    1994-07-01

    The challenge for the designer in developing a new wind turbine is to incorporate sufficient strength in its components to safely achieve a 20- or 30-year service life. To accomplish this, the designer must understand the load and stress distributions (in a statistical sense at least) that the turbine is likely to encounter during its operating life. Sources of loads found in the normal operating environment include start/stop cycles, emergency shutdowns, the turbulence environment associated with the specific site and turbine location, and extreme or ``rare`` events that can challenge the turbine short-term survivability. Extreme events can result from an operational problem (e.g., controller failure) or violent atmospheric phenomena (tornadic circulations, strong gust fronts). For the majority of the operating time, however, the character of the turbulent inflow is the dominant source of the alternating stress distributions experienced by the structural components. Methods of characterizing or scaling the severity of the loading spectra (or the rate of fatigue damage accumulation) must be applicable to a wide range of turbulent inflow environments -- from solitary isolation to the complex flows associated with multi-row wind farms. The metrics chosen must be related to the properties of the turbulent inflow and independent of the nature of local terrain features.

  15. Floating wind turbine system

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A. (Inventor)

    2009-01-01

    A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

  16. The LIFE computer code: Fatigue life prediction for vertical axis wind turbine components

    NASA Astrophysics Data System (ADS)

    Sutherland, H. J.; Ashwill, T. D.; Slack, N.

    1987-08-01

    The LIFE computer code was originally written by Veers to analyze the fatigue life of a vertical axis wind turbine (VAWT) blade. The basic assumptions built into this analysis tool are: the fatigue life of a blade component is independent of the mean stress; the frequency distribution of the vibratory stresses may be described adequately by a Rayleigh probability density function; and damage accumulates linearly (Miner's Rule). Further, the yearly distribution of wind is assumed to follow a Rayleigh distribution. The original program has been updated to run in an interactive mode on a personal computer with a BASIC interpreter and 256K RAM. Additional capabilities included in this update include: the generalization of the Rayleigh function for the wind speed distribution to a Weibull function; the addition of two constitutive rules for the evaluation of the effects of mean stress on fatigue life; interactive data input; and the inclusion of a stress concentration factor into the analysis.

  17. On risk-based operation and maintenance of offshore wind turbine components

    Microsoft Academic Search

    Jannie Jessen Nielsen; John Dalsgaard Sørensen

    2011-01-01

    Operation and maintenance are significant contributors to the cost of energy for offshore wind turbines. Optimal planning could rationally be based on Bayesian pre-posterior decision theory, and all costs through the lifetime of the structures should be included. This paper contains a study of a generic case where the costs are evaluated for a single wind turbine with a single

  18. Fixed pitch wind turbines

    NASA Technical Reports Server (NTRS)

    Fenn, D. B.; Viterna, L. A.

    1978-01-01

    Wind turbines designed for fixed pitch operation offer potential reductions in the cost of the machine by eliminating many costly components. It was shown that a rotor can be designed which produces the same energy annually as Mod-0 but which regulates its power automatically by progressively stalling the blades as wind speed increases. Effects of blade twist, taper, root cutout, and airfoil shape on performance are discussed as well as various starting technqiues.

  19. A Fatigue Approach to Wind Turbine Control

    E-print Network

    A Fatigue Approach to Wind Turbine Control Keld Hammerum Kongens Lyngby 2006 #12;Technical to the turbulent nature of wind, the structural components of a wind turbine are exposed to highly varying loads. Therefore, fatigue damage is a major consideration when designing wind turbines. The control scheme applied

  20. Energy 101: Wind Turbines - 2014 Update

    SciTech Connect

    None

    2014-05-06

    See how wind turbines generate clean electricity from the power of wind. The video highlights the basic principles at work in wind turbines, and illustrates how the various components work to capture and convert wind energy to electricity. This updated version also includes information on the Energy Department's efforts to advance offshore wind power. Offshore wind energy footage courtesy of Vestas.

  1. Large wind turbine generators

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Donovon, R. M.

    1978-01-01

    The development associated with large wind turbine systems is briefly described. The scope of this activity includes the development of several large wind turbines ranging in size from 100 kW to several megawatt levels. A description of the wind turbine systems, their programmatic status and a summary of their potential costs is included.

  2. Wind turbine wake aerodynamics

    Microsoft Academic Search

    L. J. Vermeer; J. N. Sørensen; A. Crespo

    2003-01-01

    The aerodynamics of horizontal axis wind turbine wakes is studied. The contents is directed towards the physics of power extraction by wind turbines and reviews both the near and the far wake region. For the near wake, the survey is restricted to uniform, steady and parallel flow conditions, thereby excluding wind shear, wind speed and rotor setting changes and yawed

  3. Small Wind Turbine Testing and Applications Development

    Microsoft Academic Search

    D. Corbus; I. Baring-Gould; S. Drouilhet; V. Gevorgian; T. Jimenez; C. Newcomb; L. Flowers

    1999-01-01

    Small wind turbines offer a promising alternative for many remote electrical uses where there is a good wind resource. The National Wind Technology Center (NWTC) of the National Renewable Energy Laboratory helps further the role that small turbines can play in supplying remote power needs. The NWTC tests and develops new applications for small turbines. The NWTC also develops components

  4. Wind Turbine Structural Dynamics

    NASA Technical Reports Server (NTRS)

    Miller, D. R. (editor)

    1978-01-01

    A workshop on wind turbine structural dynamics was held to review and document current United States work on the dynamic behavior of large wind turbines, primarily of the horizontal-axis type, and to identify and discuss other wind turbine configurations that may have lower cost and weight. Information was exchanged on the following topics: (1) Methods for calculating dynamic loads; (2) Aeroelasticity stability (3) Wind loads, both steady and transient; (4) Critical design conditions; (5) Drive train dynamics; and (6) Behavior of operating wind turbines.

  5. Wind Turbines Benefit Crops

    SciTech Connect

    Takle, Gene

    2010-01-01

    Ames Laboratory associate scientist Gene Takle talks about research into the effect of wind turbines on nearby crops. Preliminary results show the turbines may have a positive effect by cooling and drying the crops and assisting with carbon dioxide uptake.

  6. Method and apparatus for wind turbine braking

    DOEpatents

    Barbu, Corneliu (Laguna Hills, CA); Teichmann, Ralph (Nishkayuna, NY); Avagliano, Aaron (Houston, TX); Kammer, Leonardo Cesar (Niskayuna, NY); Pierce, Kirk Gee (Simpsonville, SC); Pesetsky, David Samuel (Greenville, SC); Gauchel, Peter (Muenster, DE)

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  7. On the Fatigue Analysis of Wind Turbines

    SciTech Connect

    Sutherland, Herbert J.

    1999-06-01

    Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. Operational experiences with these large rotating machines indicated that their components (primarily blades and blade joints) were failing at unexpectedly high rates, which led the wind turbine community to develop fatigue analysis capabilities for wind turbines. Our ability to analyze the fatigue behavior of wind turbine components has matured to the point that the prediction of service lifetime is becoming an essential part of the design process. In this review paper, I summarize the technology and describe the ''best practices'' for the fatigue analysis of a wind turbine component. The paper focuses on U.S. technology, but cites European references that provide important insights into the fatigue analysis of wind turbines.

  8. Wind turbine rotor assembly

    SciTech Connect

    Kaiser, H. W.

    1984-11-20

    A vertical axis wind turbine having a horizontal arm member which supports an upright blade assembly. Bearing structure coupling the blade assembly to the turbine arm permits blade movement about its longitudinal axis as well as flexing motion of the blade assembly about axes perpendicular to the longitudinal axis. A latching mechanism automatically locks the blade assembly to its supporting arm during normal turbine operation and automatically unlocks same when the turbine is at rest. For overspeed prevention, a centrifugally actuated arm functions to unlatch the blade assembly permitting same to slipstream or feather into the wind. Manually actuated means are also provided for unlatching the moving blade assembly. The turbine arm additionally carries a switching mechanism in circuit with a turbine generator with said mechanism functioning to open and hence protect the generator circuit in the event of an overspeed condition of the turbine.

  9. An integrated modeling method for wind turbines

    NASA Astrophysics Data System (ADS)

    Fadaeinedjad, Roohollah

    To study the interaction of the electrical, mechanical, and aerodynamic aspects of a wind turbine, a detailed model that considers all these aspects must be used. A drawback of many studies in the area of wind turbine simulation is that either a very simple mechanical model is used with a detailed electrical model, or vice versa. Hence the interactions between electrical and mechanical aspects of wind turbine operation are not accurately taken into account. In this research, it will be shown that a combination of different simulation packages, namely TurbSim, FAST, and Simulink can be used to model the aerodynamic, mechanical, and electrical aspects of a wind turbine in detail. In this thesis, after a review of some wind turbine concepts and software tools, a simulation structure is proposed for studying wind turbines that integrates the mechanical and electrical components of a wind energy conversion device. Based on the simulation structure, a comprehensive model for a three-bladed variable speed wind turbine with doubly-fed induction generator is developed. Using the model, the impact of a voltage sag on the wind turbine tower vibration is investigated under various operating conditions such as power system short circuit level, mechanical parameters, and wind turbine operating conditions. It is shown how an electrical disturbance can cause more sustainable tower vibrations under high speed and turbulent wind conditions, which may disrupt the operation of pitch control system. A similar simulation structure is used to model a two-bladed fixed speed wind turbine with an induction generator. An extension of the concept is introduced by adding a diesel generator system. The model is utilized to study the impact of the aeroelastic aspects of wind turbine (i.e. tower shadow, wind shears, yaw error, turbulence, and mechanical vibrations) on the power quality of a stand-alone wind-diesel system. Furthermore, an IEEE standard flickermeter model is implemented in a Simulink environment to study the flicker contribution of the wind turbine in the wind-diesel system. By using a new wind power plant representation method, a large wind farm (consisting of 96 fixed speed wind turbines) is modelled to study the power quality of wind power system. The flicker contribution of wind farm is also studied with different wind turbine numbers, using the flickermeter model. Keywords. Simulink, FAST, TurbSim, AreoDyn, wind energy, doubly-fed induction generator, variable speed wind turbine, voltage sag, tower vibration, power quality, flicker, fixed speed wind turbine, wind shear, tower shadow, and yaw error.

  10. Build a Wind Turbine

    NSDL National Science Digital Library

    2012-03-20

    Learners build a wind turbine and test it to see how much energy is created. Learners can build a variety of wind blades, test a variety of wind speeds and see what effect these have on the energy created. Adult supervision recommended.

  11. Coalescing Wind Turbine Wakes

    NASA Astrophysics Data System (ADS)

    Lee, S.; Churchfield, M.; Sirnivas, S.; Moriarty, P.; Nielsen, F. G.; Skaare, B.; Byklum, E.

    2015-06-01

    A team of researchers from the National Renewable Energy Laboratory and Statoil used large-eddy simulations to numerically investigate the merging wakes from upstream offshore wind turbines. Merging wakes are typical phenomena in wind farm flows in which neighboring turbine wakes consolidate to form complex flow patterns that are as yet not well understood. In the present study, three 6-MW turbines in a row were subjected to a neutrally stable atmospheric boundary layer flow. As a result, the wake from the farthest upstream turbine conjoined the downstream wake, which significantly altered the subsequent velocity deficit structures, turbulence intensity, and the global meandering behavior. The complexity increased even more when the combined wakes from the two upstream turbines mixed with the wake generated by the last turbine, thereby forming a “triplet” structure. Although the influence of the wake generated by the first turbine decayed with downstream distance, the mutated wakes from the second turbine continued to influence the downstream wake. Two mirror-image angles of wind directions that yielded partial wakes impinging on the downstream turbines yielded asymmetric wake profiles that could be attributed to the changing flow directions in the rotor plane induced by the Coriolis force. The turbine wakes persisted for extended distances in the present study, which is a result of low aerodynamic surface roughness typically found in offshore conditions.

  12. Wind Turbine Blade Design

    NSDL National Science Digital Library

    Kidwind Project

    Students go through the design process and the scientific method to test the effect of blade design on power output. There is an optional extension to use the data to create an optimal set of wind turbine blades.

  13. Wind Turbine Acoustic Noise A white paper

    E-print Network

    Massachusetts at Amherst, University of

    Wind Turbine Acoustic Noise A white paper Prepared by the Renewable Energy Research Laboratory...................................................................... 8 Sound from Wind Turbines .............................................................................................. 10 Sources of Wind Turbine Sound

  14. Wind turbine gearbox technologies

    Microsoft Academic Search

    Adam Ragheb; Magdi Ragheb

    2010-01-01

    The reliability problems associated with transmission or gearbox equipped wind turbines and the existing solutions of using direct drive gearless turbines and torque-splitting, are reviewed. As alternative solutions we propose the Geared Turbofan Engine (GTF) technology, and magnetically-levitated bearings from the aerospace industry, and the consideration of Continuously Variable Transmissions (CVTs) from the automobile industry, and discuss their promise in

  15. Wind Turbine Blade Design

    NSDL National Science Digital Library

    KidWind Project

    2006-01-01

    In this activity, learners design, build and test wind turbines. Learners go through the design process and use the scientific method to test important blade variables. Learners then use this data to create an optimal set of wind turbine blades. Educators can do the basic lesson in 3-4 class periods (about 3-4 hours) or extend the activity with a larger challenge that takes 5-7 class periods in total (about 5-7 hours).

  16. Wind Turbine Blockset General Overview

    E-print Network

    Wind Turbine Blockset in Saber General Overview and Description of the Models Florin Iov, Adrian Turbine Blockset in Saber Abstract. This report presents a new developed Saber Toolbox for wind turbine, optimize and design wind turbines". The report provides a quick overview of the Saber and then explains

  17. WIND TURBINES AND EARTHQUAKES

    Microsoft Academic Search

    U. Ritschel; I. Warnke; J. Kirchner; B. Meussen

    Presenter: U. Ritschel, Physicist and Managing Director of Windrad Engineering GmbH Abstract: Modern wind turbines have been mainly erected in regions where earthquakes are rare or normally weak. More recently wind farms in Africa, Asia ad southern Europe have been developed where stability under earthquakes becomes an issue. So far earthquake loads have been analyzed with methods adapted from civil

  18. Alcoa wind turbines

    NASA Technical Reports Server (NTRS)

    Ai, D. K.

    1979-01-01

    An overview of Alcoa's wind energy program is given with emphasis on the the development of a low cost, reliable Darrieus Vertical Axis Wind Turbine System. The design layouts and drawings for fabrication are now complete, while fabrication and installation to utilize the design are expected to begin shortly.

  19. Optimization of Wind Turbine Operation

    E-print Network

    Optimization of Wind Turbine Operation by Use of Spinner Anemometer TF Pedersen, NN Sørensen, L Title: Optimization of Wind Turbine Operation by Use of Spinner Anemometer Department: Wind Energy prototype wind turbine. Statistics of the yaw error showed an average of about 10°. The average flow

  20. Wind Turbine Acoustics

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    2009-01-01

    Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

  1. Theory manual for FAROW version 1.1: A numerical analysis of the Fatigue And Reliability Of Wind turbine components

    SciTech Connect

    WUBTERSTEUBMSTEVEB R.; VEERS,PAUL S.

    2000-01-01

    Because the fatigue lifetime of wind turbine components depends on several factors that are highly variable, a numerical analysis tool called FAROW has been created to cast the problem of component fatigue life in a probabilistic framework. The probabilistic analysis is accomplished using methods of structural reliability (FORM/SORM). While the workings of the FAROW software package are defined in the user's manual, this theory manual outlines the mathematical basis. A deterministic solution for the time to failure is made possible by assuming analytical forms for the basic inputs of wind speed, stress response, and material resistance. Each parameter of the assumed forms for the inputs can be defined to be a random variable. The analytical framework is described and the solution for time to failure is derived.

  2. Wind turbine pitch optimization

    Microsoft Academic Search

    Benjamin Biegel; Morten Juelsgaard; Matt Kraning; Stephen Boyd; Jakob Stoustrup

    2011-01-01

    We consider a static wind model for a three-bladed, horizontal-axis, pitch-controlled wind tur- bine. When placed in a wind field, the turbine experiences several mechanical loads, which generate power but also create structural fatigue. We address the problem of find- ing blade pitch profiles for maximizing power production while simultaneously minimizing fatigue loads. In this pa- per, we show how

  3. Vertical axis wind turbine

    SciTech Connect

    Kutcher, H.R.

    1984-05-15

    A Darrieus-type vertical axis wind turbine is disclosed which includes a vertically extending rotor tube mounted on a support structure with two or three rotor blades of troposkein configuration on the rotor tube for rotating the tube in response to wind energy and thereby drive a generator to produce electrical power. The turbine includes an erection hinge which permits assembly of the rotor tube and blades at close to ground level followed by upward hinging of the rotor assembly to a vertical position. It also includes a system for automatically lubricating the top bearing upon erection and a system for visually tensioning the guy cables.

  4. Applied aerodynamics of wind turbines

    Microsoft Academic Search

    R. E. Wilson; P. B. S. Lissaman; S. N. Walker; W. R. McKie

    1977-01-01

    This report covers hub fairings, Giromill, Darrieus Rotor, and the Super Induced (tipvanes). Hub fairings or spinners are frequently suggested for wind turbines for reasons of aesthetics or performance. While hub fairings rarely, if ever, decrease the appearance of a wind turbine, the effects of a nose fairing may actually decrease rather than increase wind turbine rotor performance. An analysis

  5. Predicting Noise From Wind Turbines

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.

    1990-01-01

    Computer program WINDY predicts broadband noise spectra of horizontal-axis wind-turbine generators. Enables adequate assessment of impact of broadband wind-turbine noise. Effects of turbulence, trailing-edge wakes, and bluntness taken into account. Program has practical application in design and siting of wind-turbine machines acceptable to community. Written in GW-Basic.

  6. Tornado type wind turbines

    DOEpatents

    Hsu, Cheng-Ting (Ames, IA)

    1984-01-01

    A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

  7. Tornado type wind turbines

    SciTech Connect

    Hsu, Ch.-T.

    1984-06-05

    A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

  8. Experimental Research on Vertical Axis Wind Turbine

    Microsoft Academic Search

    Guoying Feng; Zhizhang Liu; Bao Daorina; Zheng Gong

    2009-01-01

    In China, researches on vertical axis wind turbine focus on aerodynamic design mostly. This paper presents the wind tunnel test data of a Darrieus wind turbine. The output powers of wind turbine systems with and without optimal power controller are tested separately. The factors influencing the output power of the wind turbine are analyzed and design methods for wind turbine

  9. Stability Simulation of Wind Turbine Systems

    Microsoft Academic Search

    P. M. Anderson; Anjan Bose

    1983-01-01

    A simulation and digital computer modeling effort is described in which a wind turbine-generator system is adapted for stability evaluation using a large scale transient stability computer program. Component models of the MOD-2 wind generator system are described and their digital model equations are provided. A versatile wind velocity model is described, which provides the capability of simulating a wide

  10. Build a Wind Turbine

    NSDL National Science Digital Library

    2007-10-25

    This hands-on project provides step-by-step instructions for building a vertical axis wind turbine in secondary classrooms. The 17-page construction plans may be freely downloaded and are organized for first-time builders. Comprehensive background information on wind energy and renewable energy are provided. Registered teacher-users also have access to supporting lesson plans. All of the materials are readily available in hardware or grocery stores. This resource, which meets multiple national science standards, was developed to spark students' interest in learning more about renewable energy sources and the science and engineering principles that underlie the harnessing of renewable power. Editor's Note: Wind turbines work by using an internal generator to convert the mechanical energy of the spinning turbine shaft into electricity. This particular project is modeled after the Savonius rotor system, which uses uses drag -- not lift -- to capture energy for making electricity. Although it isn't as efficient as a conventional horizontal axis turbine, it is much easier to build.

  11. The identification of inflow fluid dynamics parameters that can be used to scale fatigue loading spectra of wind turbine structural components

    SciTech Connect

    Kelley, N.D.

    1993-11-01

    We have recently shown that the alternating load fatigue distributions measured at several locations on a wind turbine operating in a turbulent flow can be described by a mixture of at least three parametric statistical models. The rainflow cycle counting of the horizontal and vertical inflow components results in a similar mixture describing the cyclic content of the wind. We believe such a description highlights the degree of non-Gaussian characteristics of the flow. We present evidence that the severity of the low-cycle, high-amplitude alternating stress loads seen by wind turbine components are a direct consequence of the degree of departure from normality in the inflow. We have examined the details of the turbulent inflow associated with series large loading events that took place on two adjacent wind turbines installed in a large wind park in San Gorgonio Pass, California. In this paper, we describe what we believe to be the agents in the flow that induced such events. We also discuss the atmospheric mechanisms that influence the low-cycle, high-amplitude range loading seen by a number of critical wind turbine components. We further present results that can be used to scale the specific distribution shape as functions of measured inflow fluid dynamics parameters.

  12. Wind Turbine Contingency Control Through Generator De-Rating

    NASA Technical Reports Server (NTRS)

    Frost, Susan; Goebel, Kai; Balas, Mark

    2013-01-01

    Maximizing turbine up-time and reducing maintenance costs are key technology drivers for wind turbine operators. Components within wind turbines are subject to considerable stresses due to unpredictable environmental conditions resulting from rapidly changing local dynamics. In that context, systems health management has the aim to assess the state-of-health of components within a wind turbine, to estimate remaining life, and to aid in autonomous decision-making to minimize damage to the turbine. Advanced contingency control is one way to enable autonomous decision-making by providing the mechanism to enable safe and efficient turbine operation. The work reported herein explores the integration of condition monitoring of wind turbines with contingency control to balance the trade-offs between maintaining system health and energy capture. The contingency control involves de-rating the generator operating point to achieve reduced loads on the wind turbine. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

  13. Wind tower augmentation of wind turbines

    NASA Astrophysics Data System (ADS)

    Bahadori, M. N.

    The operating principle of the 'Baud-Geers' wind towers traditionally used in Iran for ventilation and passive cooling of architectural structures is presently adapted to house a vertical axis wind turbine. Unlike annular diffuser-augmented, horizontal axis wind turbines, the 'wind tower' does not have to be trained into the wind and generates less noise. It may also be either free standing or incorporated into the structure of existing buildings. Attention is given to the continuity and energy equations of this system, and to the results of wind tunnel model testing which ascertained turbine load factor and augmentation ratio.

  14. Smart structure for small wind turbine blade

    NASA Astrophysics Data System (ADS)

    Supeni, E. E.; Epaarachchi, J. A.; Islam, M. M.; Lau, K. T.

    2013-08-01

    Wind energy is seen as a viable alternative energy option for future energy demand. The blades of wind turbines are generally regarded as the most critical component of the wind turbine system. Ultimately, the blades act as the prime mover of the whole system which interacts with the wind flow during the production of energy. During wind turbine operation the wind loading cause the deflection of the wind turbine blade which can be significant and affect the turbine efficiency. Such a deflection in wind blade not only will result in lower performance in electrical power generation but also increase of material degradation due high fatigue life and can significantly shorten the longevity for the wind turbine material. In harnessing stiffness of the blade will contribute massive weight factor and consequently excessive bending moment. To overcome this excessive deflection due to wind loading on the blade, it is feasible to use shape memory alloy (SMA) wires which has ability take the blade back to its optimal operational shape. This paper details analytical and experimental work being carried out to minimize blade flapping deflection using SMA.

  15. Application requirements for wind turbine gearboxes

    NASA Astrophysics Data System (ADS)

    Errichello, Robert; Muller, Jane

    1994-09-01

    This report is a technical guide which documents the wind turbine gearbox experience of the GEARTECH consulting firm. The report provides a reference on wind turbine gearbox applications for the gear industry, wind turbine designers, and wind turbine operators. This report will assist in selecting, designing, manufacturing, procuring, operating, and maintaining gearboxes for use on wind turbines.

  16. Sandhill Cranes Near Wind Turbines

    USGS Multimedia Gallery

    Sandhill Cranes fly in close proximity to wind turbines near Horicon National Wildlife Refuge in east-central Wisconsin, but to date no crane mortality has been associated with turbines in this area....

  17. Wind Turbine Dynamics

    NASA Technical Reports Server (NTRS)

    Thresher, R. W. (editor)

    1981-01-01

    Recent progress in the analysis and prediction of the dynamic behavior of wind turbine generators is discussed. The following areas were addressed: (1) the adequacy of state of the art analysis tools for designing the next generation of wind power systems; (2) the use of state of the art analysis tools designers; and (3) verifications of theory which might be lacking or inadequate. Summaries of these informative discussions as well as the questions and answers which followed each paper are documented in the proceedings.

  18. Airfoils for wind turbine

    DOEpatents

    Tangler, James L. (Boulder, CO); Somers, Dan M. (State College, PA)

    1996-01-01

    Airfoils for the blade of a wind turbine wherein each airfoil is characterized by a thickness in a range from 16%-24% and a maximum lift coefficient designed to be largely insensitive to roughness effects. The airfoils include a family of airfoils for a blade 15 to 25 meters in length, a family of airfoils for a blade 1 to 5 meters in length, and a family of airfoils for a blade 5 to 10 meters in length.

  19. Wind-turbine aerodynamics

    Microsoft Academic Search

    R. E. Wilson

    1980-01-01

    The aerodynamics of wind turbines is reviewed starting with effects of lift and drag on translating devices and proceeding through the performance aerodynamics of the horizontal-axis and vertical-axis machines currently in service. Horizontal-axis rotor aerodynamics is outlined and the performance limits are presented along with key assumptions and problem areas. The Darrieus rotor multiple streamtube analysis is developed and compared

  20. Make Your Own Wind Turbine

    NSDL National Science Digital Library

    National Museum of American History

    2012-06-26

    In this activity, learners create a wind turbine model using a simple pattern, a thumbtack, and a pencil with an eraser. After constructing the model, learners blow on the wind turbine to simulate the wind. Use this activity to introduce alternative energy and electricity generation.

  1. Wind response characteristics of horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Thresher, R. W.; Holley, W. E.; Jafarey, N.

    1981-01-01

    It was the objective of the work reported here, and in the companion paper 1 . A broader examination of wind turbine dynamic response to turbulence, and attempts to ascertain the features of turbulence that wind turbines are most sensitive to were made. A statistical description of the wind input including all three wind components and allowing linear wind gradients across the rotor disk, was used together with quasi-static aerodynamic theory and an elementary structural model involving only a few degrees of freedom. The idea was to keep the turbine model simple and show the benefits of this type of statistical wind representation before attempting to use a more complex turbine model. As far as possible, the analysis was kept in the simplest form, while still preserving key physical responses.

  2. Wind Power! Designing a Wind Turbine

    NSDL National Science Digital Library

    2014-09-18

    Students learn how engineers transform wind energy into electrical energy by building their own miniature wind turbines and measuring the electrical current it produces. They explore how design and position affect the electrical energy production.

  3. Lightning protection of wind turbines

    NASA Technical Reports Server (NTRS)

    Dodd, C. W.

    1982-01-01

    Possible damages to wind turbine components due to lightning strikes are discussed and means to prevent the damage are presented. A low resistance path to the ground is noted to be essential for any turbine system, including metal paths on nonmetal blades to conduct the strike. Surge arrestors are necessary to protect against overvoltages both from utility lines in normal operation and against lightning damage to control equipment and contactors in the generator. MOS structures are susceptible to static discharge injury, as are other semiconductor devices, and must be protected by the presence of static protection circuitry. It is recommended that the electronics be analyzed for the circuit transient response to a lightning waveform, to induced and dc current injection, that input/output leads be shielded, everything be grounded, and lightning-resistant components be chosen early in the design phase.

  4. Periodic pulsations from a three-bladed wind turbine

    Microsoft Academic Search

    Torbjörn Thiringer; Jan-Åke Dahlberg

    2001-01-01

    In this paper, periodic power pulsations from a three-bladed wind turbine are analyzed. The influence of wind shear, wind speed, turbulence intensity, rotor position and tower oscillation is investigated. No clear dependence between the periodic power components and the wind shear or turbulence intensity has been verified. The investigated turbine sometimes produces large power pulsations at the tower resonance frequency.

  5. Large-scale wind turbine structures

    NASA Technical Reports Server (NTRS)

    Spera, David A.

    1988-01-01

    The purpose of this presentation is to show how structural technology was applied in the design of modern wind turbines, which were recently brought to an advanced stage of development as sources of renewable power. Wind turbine structures present many difficult problems because they are relatively slender and flexible; subject to vibration and aeroelastic instabilities; acted upon by loads which are often nondeterministic; operated continuously with little maintenance in all weather; and dominated by life-cycle cost considerations. Progress in horizontal-axis wind turbines (HAWT) development was paced by progress in the understanding of structural loads, modeling of structural dynamic response, and designing of innovative structural response. During the past 15 years a series of large HAWTs was developed. This has culminated in the recent completion of the world's largest operating wind turbine, the 3.2 MW Mod-5B power plane installed on the island of Oahu, Hawaii. Some of the applications of structures technology to wind turbine will be illustrated by referring to the Mod-5B design. First, a video overview will be presented to provide familiarization with the Mod-5B project and the important components of the wind turbine system. Next, the structural requirements for large-scale wind turbines will be discussed, emphasizing the difficult fatigue-life requirements. Finally, the procedures used to design the structure will be presented, including the use of the fracture mechanics approach for determining allowable fatigue stresses.

  6. Towers for Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

    Kurian, V. J.; Narayanan, S. P.; Ganapathy, C.

    2010-06-01

    Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father offshore will be able to capture more wind energy. Currently two types of towers are considered. Cylindrical tubular structures and truss type structures. But truss type structures have less weight and flexibility in design. The construction of the offshore towers to harness the wind energy is also presented. The results will include the calculation of wind and wave forces on the tower and the design details for the tower.

  7. Parametric Modelling Of Large Wind Turbine Blades

    Microsoft Academic Search

    Paul A. Bonnet; Geoff Dutton

    Electricity production from wind energy has grown at a fast pace over the last few years. The size of individual wind turbines has also increased significantly and it is unclear if this trend can be sustained in the future for structural reasons, especially regarding rotor blade components. A research programme is being undertaken to investigate these issues, and finite element

  8. 5th International Meeting Wind Turbine Noise

    E-print Network

    Paris-Sud XI, Université de

    1 5th International Meeting on Wind Turbine Noise Denver 28 ­ 30 August 2013 Wind Turbine Noise Broadband noise generated aerodynamically is the dominant noise source for a modern wind turbine(Brooks et, clean energy. While profiting from wind energy, the noise produced by a modern wind turbine becomes

  9. Vertical axis wind turbine development

    Microsoft Academic Search

    R. E. Walters; J. B. Fanucci; P. W. Hill; P. G. Migliore

    1979-01-01

    Theoretical and experimental research accomplished in evaluating an innovative concept for vertical axis wind turbines (VAWT) is described. The concept is that of using straight blades composed of circulation controlled airfoil sections. The theoretical analysis was developed to determine the unsteady lift and moment characteristics of multiple-blade cross-flow wind turbines. To determine the drag data needed as input to the

  10. Aerodynamic performance of wind turbines

    Microsoft Academic Search

    R. E. Wilson; P. B. S. Lissaman; S. N. Walker

    1976-01-01

    The state-of-the-art of performance prediction methods is summarized for both horizontal and vertical axis wind turbines. Strip theory methods for horizontal axis wind turbines are evaluated for various tip loss models and occurrence of multiple solutions in strip theory analysis is discussed and illustrated. The performance of high-solidity turbines such as the Chalk design is also discussed. The configuration and

  11. Wind tunnel investigation on wind turbine wakes and wind farms

    NASA Astrophysics Data System (ADS)

    Iungo, G. V.; Coëffé, J.; Porté-Agel, F.

    2012-04-01

    The interaction between atmospheric boundary layer and wind farms leads to flow modifications, which need to be deeply characterized in order to relate them to wind farm performance. The wake flow produced from a wind farm is the result of a strong interaction between multiple turbine wakes, so that the wind farm configuration turns out to be one of the dominant features to enhance power production. For the present work a wind tunnel investigation was carried out with hot-wire anemometry and velocity measurements performed with multi-hole pressure probes. The tested wind farms consist of miniature three-bladed wind turbine models. Preliminarily, the wake flow generated from a single wind turbine is surveyed, which is characterized by a strong velocity defect lying in proximity of the wind turbine hub height. The wake gradually recovers by moving downstream; the characteristics of the incoming boundary layer and wind turbulence intensity can strongly affect the wake recovery, and thus performance of following wind turbines. An increased turbulence level is typically detected downstream of each wind turbine for heights comparable to the wind turbine blade top-tip. These wake flow fluctuations produce increased fatigue loads on the following wind turbines within a wind farm, which could represent a significant hazard for real wind turbines. Dynamics of vorticity structures present in wind turbine wakes are also investigated; particular attention is paid to the downstream evolution of the tip helicoidal vortices and to oscillations of the hub vortex. The effect of wind farm layout on power production is deeply investigated. Particular emphasis is placed on studying how the flow adjusts as it moves inside the wind farm and can affect the power production. Aligned and staggered wind farm configurations are analysed, also with varying separation distances in the streamwise and spanwise directions. The present experimental results are being used to test and guide the development of improved parameterizations of wind turbines in high-resolution numerical models, such as large-eddy simulations (LES).

  12. Vertical wind turbine

    SciTech Connect

    Danson, D.P.

    1988-08-16

    This patent describes a wind driven turbine of the vertical axis type comprising: (a) a support base; (b) a generally vertical column rotatably mounted to the support base; (c) upper and lower support means respectively mounted on the column for rotation therewith; wind driven blades connected between the upper and lower support means for rotation about the column and each blade being individually rotatable about a blade axis extending longitudinally through the blade to vary a blade angle of attach thereof relative to wind velocity during rotation about the column; and (e) control means for variably adjusting angles of attack of each blade to incident wind, the control means including a connecting rod means having drive means for rotating each blade about the associated blade axis in response to radial movement of the connecting rod means and control shaft pivotally mounted within the column and having a first shaft portion connected to the connecting rod means and a second shaft portion radially offset from the first shaft portion and pivotally connected to radially displace the first portion and thereby the connecting rod means to vary the blade angles of attack during rotation about the column.

  13. Wind Turbines Adaptation to the Variability of the Wind Field

    NASA Astrophysics Data System (ADS)

    Ulianov, Yuriy; Martynenko, Gennadii; Misaylov, Vitaliy; Soliannikova, Iuliia

    2010-05-01

    WIND TURBINES ADAPTATION TO THE VARIABILITY OF THE WIND FIELD The subject of our scientific research is wind power turbines (WPT) with the horizontal axis which were now common in the world. Efficient wind turbines work is largely determined by non-stationarity of the wind field, expressed in its gustiness, the presence of vertical and horizontal shifts of wind speed and direction. At critical values of the wind parameters WPT has aerodynamic and mechanical overload, leading to breakdowns, premature wear and reduce the life of the wind turbine. To prevent accidents at the peak values of wind speed it is used the regulatory system of windwheels. WPT control systems provide a process orientation of the wind turbine rotor axis in the line of the mean wind. Wind turbines are also equipped with braking device used to protect against breakdowns when a significant increase in the wind. In general, all these methods of regulation are not always effective. Thus, in practice there may be situations when the wind speed is many times greater than the stated limit. For example, if there are microbursts in the atmospheric boundary layer, low-level wind shears caused by its gust front, storms, etc. It is required for a wind power turbine adaptation to intensive short-term wind impulses and considerable vertical wind shifts that the data about them shall be obtained ahead of time. To do this it is necessary to have the information on the real structure of the wind field in the area of the blade sweep for the minimum range against the wind that is determined by the mean speed and the system action time. The implementation of acoustic and laser traditional wind sounding systems is limited by ambient acoustic noise, by heavy rain, snowfall and by fog. There are free of these disadvantages the inclined radioacoustic sounding (IRASS) technique which works for a system of remote detection and control of wind gusts. IRASS technique is realized as low-potential Doppler pulse radar including combined RF-acoustic antenna installed coaxially with the gondola of the wind power turbine. The work of the technique is synchronized with rotation of blades to eliminate their shielding action. Dangerous in terms of dynamic strength is the wind load pulse, the rise time which is comparable with the period of the natural frequency of the wind turbine elements (blade, tower, rotor, etc.). The amplitude decay of resonant vibrations at critical values of the speed of rotation can be realized through the use of mechanical elastic supports with nonlinear artificial dampers. They have a high coefficient of resistance, but may cause self-excited oscillations. We propose the way to deal with raised vibration of wind turbine elements at the expense of short-term increase of damping in the range of critical rotary axis speeds or during impulsive effects of wind loadings (wind gusts). This is possible through the use of non-linear electromagnetic dampers or active magnetic bearings. Their feature is the possibility of varying the mechanical stiffness and damping properties by changing the electrical parameters of electromagnets. The controlling of these parameters is carried out by the control system (CS) with the information feedback on the spatial-temporal structure of the wind field obtained from IRASS. In the composition of the CS can also be included the rotational speed sensor of the WPT rotor. This approach to the adaptation of wind turbines will allow to reduce vibration and to perform early compensation of the load on their components, which arise under the wind gusts. In addition, corrections about the wind field obtained with IRASS, would increase the mean power of WPT.

  14. Estimation of Wind Speed in Connection to a Wind Turbine

    E-print Network

    Estimation of Wind Speed in Connection to a Wind Turbine X. Ma #3; , N. K. Poulsen #3; , H. Bindner y December 20, 1995 Abstract The wind speed varies over the rotor plane of wind turbine making the wind speed on the rotor plane will be estimated by using a wind turbine as a wind measuring device

  15. Wind profiles for large wind turbines

    Microsoft Academic Search

    C. B. Hasager; A. Peña; S.-E. Gryning; T. Mikkelsen; M. Courtney

    2009-01-01

    The 12MW project aimed to describe wind profiles and turbulence at levels high in the atmosphere where large wind turbines operate. During the project observations up to 180 m above sea level were collected using mast and lidar offshore in the North Sea at the Horns Rev wind farm in 2006. Later also land-based observations were collected at the coastal

  16. A Review of Modern Wind Turbine Technology

    Microsoft Academic Search

    M. Balat

    2009-01-01

    This article deals with a review of modern wind turbine technology. Wind energy for electricity production today is a mature, competitive, and virtually pollution-free technology widely used in many areas of the world. Wind technology converts the energy available in wind to electricity or mechanical power through the use of wind turbines. A wind turbine is a machine for converting

  17. Fatigue and reliability analyses for wind turbines

    NASA Astrophysics Data System (ADS)

    Sutherland, H. J.

    This paper presents a summary of two areas of research into the fatigue of wind turbine components at Sandia National Laboratories. The first area is the fatigue analysis of turbine components and the second is reliability analysis. For the former, current work is addressing the examination of experimental data in the time and frequency domain. Emphasis in this paper is directed at the determination of the 'high-stress' tail of the cycle count distribution. For the reliability analysis, research is quantifying the uncertainties and the inherent randomness associated with turbine performance and the prediction of service lifetimes. Both research areas are highlighted with typical results.

  18. Analysis of the Environmental Impact on Remanufacturing Wind Turbines

    NASA Astrophysics Data System (ADS)

    Sosa Skrainka, Manuel R.

    To deliver clean energy the use of wind turbines is essential. In June 2011 there was an installed wind capacity equivalent to 211,000MW world-wide (WWEA, 2011). By the end of the year 2009 the U.S. had 35,100MW of wind energy installed capacity to generate electricity (AWEA, 2010). This industry has grown in recent years and is expected to grow even more in the future. The environmental impacts that will arise from the increased number of wind turbines and their end-of-life should be addressed, as large amounts of resources will be required to satisfy the current and future market demands for wind turbines. Since future 10MW wind turbines are expected to be as heavy as 1000 tons each, the study of the environmental response of profitable retirement strategies, such as remanufacturing for these machines, must be considered. Because of the increased number of wind turbines and the materials used, this study provides a comparison between the environmental impacts from remanufacturing the components installed inside the nacelle of multi-megawatt wind turbines and wind turbines manufactured using new components. The study methodology is the following: • Describe the life-cycle and the materials and processes employed for the manufacture and remanufacturing for components inside the nacelle. • Identify remanufacturing alternatives for the components inside the nacelle at the end of the expected life-time service of wind turbines. • Evaluate the environmental impacts from the remanufactured components and compare the results with the impacts of the manufacturing of new components using SimaPro. • Conduct sensitivity analysis over the critical parameters of the life cycle assessment • Propose the most environmentally friendly options for the retirement of each major component of wind turbines. After an analysis of the scenarios the goal of the study is to evaluate remanufacturing as an end-of-life option from an environmental perspective for commercial multi-megawatt wind turbines targeted for secondary wind turbine markets.

  19. Installing Small Wind Turbines Seminar and Workshop

    E-print Network

    Seminar and Workshop Installing Small Wind Turbines Seminar and Workshop Location: Murdoch January 2011 Details for Registration and Payment: Mr Daniel Jones, National Small Wind Turbine Test: The National Small Wind Turbine Centre at Murdoch University is holding a Small Wind Turbine short training

  20. Effective Lightning Protection For Wind Turbine Generators

    Microsoft Academic Search

    Bruce Glushakow

    2007-01-01

    A wind turbine generator is the most exposed of all types of generators connected to electric utility systems. Wind turbines are most often erected in hostile lightning environments. Lightning damage to wind turbines is costly in terms of repair and replacement of equipment. Lightning damage is the single largest cause of unplanned downtime in wind turbines, and that downtime is

  1. Effect of Surface Roughness on Wind Turbine Performance 

    E-print Network

    Ehrmann, Robert Schaefer

    2014-06-25

    Wind farm operators observe production deficits as machines age. Quantifying deterioration on individual components is difficult, but one potential explanation is accumulation of blade surface roughness. Historically, wind turbine airfoils were...

  2. Effect of Surface Roughness on Wind Turbine Performance

    E-print Network

    Ehrmann, Robert Schaefer

    2014-06-25

    Wind farm operators observe production deficits as machines age. Quantifying deterioration on individual components is difficult, but one potential explanation is accumulation of blade surface roughness. Historically, wind turbine airfoils were...

  3. Towers for Offshore Wind Turbines

    Microsoft Academic Search

    V. J. Kurian; S. P. Narayanan; C. Ganapathy

    2010-01-01

    Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy

  4. Wind Turbine Certification and Type Certification Guideline for the Certification of Wind Turbines, Edition 2003 with Supplement 2004

    Microsoft Academic Search

    Mike Woebbeking; Christian Nath; Germanischer Lloyd

    Certification of wind turbines or components is state-of-the-art and a must in most places around the world. Furthermore certification to harmonised requirements is an active support of export. Therefore it is important for manufacturers, banks and insurances of wind turbines and components to know the different certification processes as well as guidelines. The procedures to obtain Type and Project Certificates

  5. Sprayed skin turbine component

    DOEpatents

    Allen, David B

    2013-06-04

    Fabricating a turbine component (50) by casting a core structure (30), forming an array of pits (24) in an outer surface (32) of the core structure, depositing a transient liquid phase (TLP) material (40) on the outer surface of the core structure, the TLP containing a melting-point depressant, depositing a skin (42) on the outer surface of the core structure over the TLP material, and heating the assembly, thus forming both a diffusion bond and a mechanical interlock between the skin and the core structure. The heating diffuses the melting-point depressant away from the interface. Subsurface cooling channels (35) may be formed by forming grooves (34) in the outer surface of the core structure, filling the grooves with a fugitive filler (36), depositing and bonding the skin (42), then removing the fugitive material.

  6. Wind turbine testing in the NREL dynamometer test bed

    Microsoft Academic Search

    Walt Musial; Brian McNiff

    2000-01-01

    A new facility has recently been completed at the National Renewable Energy Laboratory that allows full-scale dynamometer testing of wind turbine components, from generators to complete wind turbines. This facility is equipped with a 2.5 MW motor, gearbox, and variable speed drive system to deliver shaft torque. To simulate other aspects of wind turbine loading an MTS fatigue-rated loading system

  7. The VGOT Darrieus wind turbine

    Microsoft Academic Search

    Fernando L. Ponta; Alejandro D. Otero; Lucas Lago

    2004-01-01

    We present the actual state of development of a non-conventional new vertical-axis wind turbine. The concepts introduced here involve the constructive aspects of variable-geometry oval-trajectory (VGOT) Darrieus wind turbines. The key feature of a VGOT machine is that each blade slides over rails mounted on a wagon instead of rotating around a central vertical axis. Each wagon contains its own

  8. MOD-2 wind turbine development

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.; Andrews, J. S.; Zimmerman, D. K.

    1983-01-01

    The development of the Mod-2 turbine, designed to achieve a cost of electricity for the 100th production unit that will be competitive with conventional electric power generation is discussed. The Mod-2 wind turbine system (WTS) background, project flow, and a chronology of events and problem areas leading to Mod-2 acceptance are addressed. The role of the participating utility during site preparation, turbine erection and testing, remote operation, and routine operation and maintenance activity is reviewed. The technical areas discussed pertain to system performance, loads, and controls. Research and technical development of multimegawatt turbines is summarized.

  9. Airfoils for wind turbine

    DOEpatents

    Tangler, James L. (Boulder, CO); Somers, Dan M. (State College, PA)

    2000-01-01

    Airfoils for the tip and mid-span regions of a wind turbine blade have upper surface and lower surface shapes and contours between a leading edge and a trailing edge that minimize roughness effects of the airfoil and provide maximum lift coefficients that are largely insensitive to roughness effects. The airfoil in one embodiment is shaped and contoured to have a thickness in a range of about fourteen to seventeen percent, a Reynolds number in a range of about 1,500,000 to 2,000,000, and a maximum lift coefficient in a range of about 1.4 to 1.5. In another embodiment, the airfoil is shaped and contoured to have a thickness in a range of about fourteen percent to sixteen percent, a Reynolds number in a range of about 1,500,000 to 3,000,000, and a maximum lift coefficient in a range of about 0.7 to 1.5. Another embodiment of the airfoil is shaped and contoured to have a Reynolds in a range of about 1,500,000 to 4,000,000, and a maximum lift coefficient in a range of about 1.0 to 1.5.

  10. Fast Wind Turbine Design via Geometric Programming

    E-print Network

    Abbeel, Pieter

    Fast Wind Turbine Design via Geometric Programming Warren Hoburg and Pieter Abbeel UC Berkeley the application of GP to large wind turbine design problems a promising approach. Nomenclature (·)a, (·)t axial According to the World Wind Energy Association, wind turbine installations supply approximately 3

  11. Wind Turbines Electrical and Mechanical Engineering

    E-print Network

    Provancher, William

    Wind Turbines Electrical and Mechanical Engineering Objective · Introduce students to the concept of alternative energy. · Explain the math and scientific principles behind engineering wind turbines. Standards and how it applies to wind energy · About how surface area and shape effects wind turbine efficiency

  12. Dynamics and stability of wind turbine generators

    NASA Astrophysics Data System (ADS)

    Hinrichsen, E. N.; Nolan, P. J.

    1981-05-01

    Synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Integration between adjacent wind turbines in a wind farm is also considered.

  13. Dynamics and stability of wind turbine generators

    NASA Astrophysics Data System (ADS)

    Hinrichsen, E. N.; Nolan, P. J.

    1982-08-01

    This paper describes the dynamic and stability properties of wind turbine generators connected to power systems. Both synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Interaction between adjacent wind turbines in a 'wind farm' is also considered.

  14. Torque ripple in a Darrieus, vertical axis wind turbine

    Microsoft Academic Search

    R. C. Reuter Jr.; R. C. Jr

    1980-01-01

    Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon

  15. Wind turbines and human health.

    PubMed

    Knopper, Loren D; Ollson, Christopher A; McCallum, Lindsay C; Whitfield Aslund, Melissa L; Berger, Robert G; Souweine, Kathleen; McDaniel, Mary

    2014-01-01

    The association between wind turbines and health effects is highly debated. Some argue that reported health effects are related to wind turbine operation [electromagnetic fields (EMF), shadow flicker, audible noise, low-frequency noise, infrasound]. Others suggest that when turbines are sited correctly, effects are more likely attributable to a number of subjective variables that result in an annoyed/stressed state. In this review, we provide a bibliographic-like summary and analysis of the science around this issue specifically in terms of noise (including audible, low-frequency noise, and infrasound), EMF, and shadow flicker. Now there are roughly 60 scientific peer-reviewed articles on this issue. The available scientific evidence suggests that EMF, shadow flicker, low-frequency noise, and infrasound from wind turbines are not likely to affect human health; some studies have found that audible noise from wind turbines can be annoying to some. Annoyance may be associated with some self-reported health effects (e.g., sleep disturbance) especially at sound pressure levels >40?dB(A). Because environmental noise above certain levels is a recognized factor in a number of health issues, siting restrictions have been implemented in many jurisdictions to limit noise exposure. These setbacks should help alleviate annoyance from noise. Subjective variables (attitudes and expectations) are also linked to annoyance and have the potential to facilitate other health complaints via the nocebo effect. Therefore, it is possible that a segment of the population may remain annoyed (or report other health impacts) even when noise limits are enforced. Based on the findings and scientific merit of the available studies, the weight of evidence suggests that when sited properly, wind turbines are not related to adverse health. Stemming from this review, we provide a number of recommended best practices for wind turbine development in the context of human health. PMID:24995266

  16. Wind Turbines and Human Health

    PubMed Central

    Knopper, Loren D.; Ollson, Christopher A.; McCallum, Lindsay C.; Whitfield Aslund, Melissa L.; Berger, Robert G.; Souweine, Kathleen; McDaniel, Mary

    2014-01-01

    The association between wind turbines and health effects is highly debated. Some argue that reported health effects are related to wind turbine operation [electromagnetic fields (EMF), shadow flicker, audible noise, low-frequency noise, infrasound]. Others suggest that when turbines are sited correctly, effects are more likely attributable to a number of subjective variables that result in an annoyed/stressed state. In this review, we provide a bibliographic-like summary and analysis of the science around this issue specifically in terms of noise (including audible, low-frequency noise, and infrasound), EMF, and shadow flicker. Now there are roughly 60 scientific peer-reviewed articles on this issue. The available scientific evidence suggests that EMF, shadow flicker, low-frequency noise, and infrasound from wind turbines are not likely to affect human health; some studies have found that audible noise from wind turbines can be annoying to some. Annoyance may be associated with some self-reported health effects (e.g., sleep disturbance) especially at sound pressure levels >40?dB(A). Because environmental noise above certain levels is a recognized factor in a number of health issues, siting restrictions have been implemented in many jurisdictions to limit noise exposure. These setbacks should help alleviate annoyance from noise. Subjective variables (attitudes and expectations) are also linked to annoyance and have the potential to facilitate other health complaints via the nocebo effect. Therefore, it is possible that a segment of the population may remain annoyed (or report other health impacts) even when noise limits are enforced. Based on the findings and scientific merit of the available studies, the weight of evidence suggests that when sited properly, wind turbines are not related to adverse health. Stemming from this review, we provide a number of recommended best practices for wind turbine development in the context of human health. PMID:24995266

  17. Wind Turbine Drivetrain Condition Monitoring - An Overview (Presentation)

    SciTech Connect

    Sheng, S.; Yang, W.

    2013-07-01

    High operation and maintenance costs still hamper the development of the wind industry despite its quick growth worldwide. To reduce unscheduled downtime and avoid catastrophic failures of wind turbines and their components have been and will be crucial to further raise the competitiveness of wind power. Condition monitoring is one of the key tools for achieving such a goal. To enhance the research and development of advanced condition monitoring techniques dedicated to wind turbines, we present an overview of wind turbine condition monitoring, discuss current practices, point out existing challenges, and suggest possible solutions.

  18. Comparison of field and wind tunnel Darrieus wind turbine data

    Microsoft Academic Search

    R. E. Sheldahl

    1981-01-01

    A 2-m-dia Darrieus Vertical Axis Wind Turbine with NACA-0012 blades was extensively tested in the Vought Corporation Low Speed Wind Tunnel. This same turbine was installed in the field at the Sandia National Laboratories Wind Turbine Test Site and operated to determine if field data corresponded to data obtained in the wind tunnel. It is believed that the accuracy of

  19. Fault-tolerant model predictive control of a wind turbine benchmark

    E-print Network

    Cambridge, University of

    Fault-tolerant model predictive control of a wind turbine benchmark X. Yang J.M. Maciejowski tolerant control problem of a wind turbine benchmark. A hierarchical controller with model predictive pre component of the wind turbine. The global MPC is used to schedule the operation of the components

  20. Large band simulation of the wind speed for real time wind turbine simulators

    Microsoft Academic Search

    Cristian Nichita; Dragos Luca; Brayima Dakyo; Emil Ceanga

    2002-01-01

    In this paper, the authors propose two modeling procedures for wind speed simulation. These procedures could be implemented on the structure of a wind turbine simulator during studies concerning stand-alone or hybrid wind systems. The evolution of a horizontal wind speed has been synthesized taking into account two components. The medium- and long-term component is described by a power spectrum

  1. Wind Turbine Blockset in Matlab/Simulink

    E-print Network

    Wind Turbine Blockset in Matlab/Simulink General Overview and Description of the Models Florin Iov, Anca Daniela Hansen, Poul Sørensen, Frede Blaabjerg Aalborg University March 2004 #12;22 Wind Turbine to model, optimize and design wind turbines" and it has been used as a general developer tool for other

  2. Computational Analysis of Shrouded Wind Turbine Configurations

    E-print Network

    Alonso, Juan J.

    Computational Analysis of Shrouded Wind Turbine Configurations Aniket C. Aranake Vinod K-dimensional simulations of shrouded wind turbines are performed for selected shroud geometries. The results are compared at the highest wind speed for which the flow over the bare turbine blade stays attached. Flow fields are examined

  3. Offshore Wind Turbines: Some Technical Challenges

    E-print Network

    Houlsby, Guy T.

    1 Offshore Wind Turbines: Some Technical Challenges Prof. Guy Houlsby FREng Oxford University House engineers concerned with installation of offshore wind turbines. The author is Professor of Civil solved, a DTI and EPSRC-sponsored research programme on foundations for wind turbines will be briefly

  4. Dynamics and Stability of Wind Turbine Generators

    Microsoft Academic Search

    E. N. Hinrichsen; P. J. Nolan

    1982-01-01

    This paper describes the dynamic and stability properties of wind turbine generators connected to power systems. Both synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed

  5. Variable speed wind turbine control system

    SciTech Connect

    Conley, E.

    1981-08-01

    Variable speed wind turbine operation is discussed for potential increased energy production if the turbine rotor is controlled to operate at constant blade tip speed to wind speed ratio. Two variable speed control systems are compared to a constant speed control system during field tests of a 5m Darrieus type wind turbine generator. 6 refs.

  6. Prototype bucket foundation for wind turbines

    E-print Network

    Prototype bucket foundation for wind turbines -natural frequency estimation Lars Bo Ibsen Morten bucket foundation for wind turbines -natural frequency estimation by Lars Bo Ibsen Morten Liingaard foundation for wind turbines--natural frequency estimation" is divided into four numbered sections

  7. Large experimental wind turbines: Where we are now

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.

    1976-01-01

    Several large wind turbine projects have been initiated by NASA-Lewis as part of the ERDA wind energy program. The projects consist of progressively large wind turbine ranging from 100 kW with a rotor diameter of 125 feet to 1500 kW with rotor diameters of 200 to 300 feet. Also included is supporting research and technology for large wind turbines and for lowering the costs and increasing the reliability of the major wind turbine components. The results and status of the above projects are briefly discussed in this report. In addition, a brief summary and status of the plans for selecting the utility sites for the experimental wind turbines is also discussed.

  8. Full-scale modal wind turbine tests: comparing shaker excitation with wind excitation

    Microsoft Academic Search

    Richard Osgood; Gunjit Bir; Heena Mutha; Bart Peeters; Marcin Luczak; Gert Sablon

    \\u000a The test facilities at the National Wind Technology Center (NWTC) of the National Renewable Energy Laboratory (NREL) include\\u000a a three-bladed Controls Advanced Research Turbine (CART3). The CART3 is used to test new control schemes and equipment for\\u000a reducing loads on wind turbine components. As wind turbines become lighter and more flexible to reduce costs, novel control\\u000a mechanisms are necessary to

  9. New guidelines for wind turbine gearboxes

    SciTech Connect

    McNiff, B. [McNiff Light Industry, Blue Hill, ME (United States); Errichello, R. [GEARTECH, Townsend, MT (United States)

    1997-12-31

    The American Gear Manufacturers Association in cooperation with the American Wind Energy Association will soon be publishing AGMA/AWEA 921-A97 {open_quotes}Recommended Practices for Design and Specification of Gearboxes for Wind Turbine Generator Systems.{close_quotes} Much has been learned about the unique operation and loading of gearboxes in wind turbine applications since the burgeoning of the modern wind turbine industry in the early 1980`s. AGMA/AWEA 921-A97 documents this experience in a manner that provides valuable information to assist gear manufacturers and wind turbine designers, operators, and manufacturers in developing reliable wind turbine gearboxes. The document provides information on procurement specification development, wind turbine architecture, environmental considerations, and gearbox load determination, as well as the design, manufacturing, quality assurance, lubrication, operation and maintenance of wind turbine gearboxes. This paper presents the salient parts of the practices recommended in AGMA/AWEA 921-A97.

  10. Economics of Small Wind Turbines

    NSDL National Science Digital Library

    This presentation from the Advanced Technology Environmental and Energy Center (ATEEC) includes instructional materials related to small wind turbines as well as lab activities. The overall learning objective is for students to understand the value of economic incentives with regard to residential wind systems. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

  11. Wind Turbine Siting: Wildlife Concerns

    NSDL National Science Digital Library

    Everhart, Roger

    The Advanced Technology Environmental and Energy Center (ATEEC) provides this document on wildlife concerns in relation to the siting of wind turbines. The material includes individual student activities and a list of web resources intended to help teachers. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

  12. The HWP-300 wind turbine

    NASA Astrophysics Data System (ADS)

    Jamieson, P.; McLeish, D.

    1983-12-01

    A 300 kW, 22 m diameter wind turbine has been designed and erected (July 1983) on the site of the North of Scotland Hydro-Electric Board at Burgar Hill in Orkney. The machine and its design concepts are described.

  13. COMPUTATIONAL MODELLING OF GIROMILL WIND TURBINES

    Microsoft Academic Search

    Francisc GYULAI

    Vertical axis wind turbines with straight blades, known as Giromill or H-Darrieus type, are of present interest for small-power scale applications. Their aerodynamics is more complicated than that of horizontal axis wind turbines due to the dependence of all kinematic parameters on the blade polar position reported to wind direction. The paper shows some aspects concerning software for Giromill wind

  14. On the biological plausibility of Wind Turbine Syndrome.

    PubMed

    Harrison, Robert V

    2014-10-01

    An emerging environmental health issue relates to potential ill-effects of wind turbine noise. There have been numerous suggestions that the low-frequency acoustic components in wind turbine signals can cause symptoms associated with vestibular system disorders, namely vertigo, nausea, and nystagmus. This constellation of symptoms has been labeled as Wind Turbine Syndrome, and has been identified in case studies of individuals living close to wind farms. This review discusses whether it is biologically plausible for the turbine noise to stimulate the vestibular parts of the inner ear and, by extension, cause Wind Turbine Syndrome. We consider the sound levels that can activate the semicircular canals or otolith end organs in normal subjects, as well as in those with preexisting conditions known to lower vestibular threshold to sound stimulation. PMID:25295915

  15. Comparison of field and wind tunnel Darrieus wind turbine data

    SciTech Connect

    Sheldahl, R.E.

    1981-01-01

    A 2-m-dia Darrieus Vertical Axis Wind Turbine with NACA-0012 blades was extensively tested in the Vought Corporation Low Speed Wind Tunnel. This same turbine was installed in the field at the Sandia National Laboratories Wind Turbine Test Site and operated to determine if field data corresponded to data obtained in the wind tunnel. It is believed that the accuracy of the wind tunnel test data was verified and thus the credibility of that data base was further established.

  16. Small-scale modular wind turbine

    NASA Astrophysics Data System (ADS)

    Bressers, Scott; Vernier, Chris; Regan, Jess; Chappell, Stephen; Hotze, Mark; Luhman, Stephen; Avirovik, Dragan; Priya, Shashank

    2010-04-01

    This study reports the design, fabrication, and implementation of a horizontal-axis, small-scale modular wind turbine termed as "small-scale wind energy portable turbine (SWEPT)". Portability, efficient operation at low wind speeds, and cost-effectiveness were the primary goals of SWEPT. The fabrication and component design for SWEPT are provided along with the modifications that can provide improvement in performance. A comparative analysis is presented with the prototype reported in literature. The results show that current version of SWEPT leads to 150% increase in output power. It was found that SWEPT can generate 160 mW power at rated wind speed of 7 mph and 500mW power at wind speeds above 10 mph with a cut-in wind speed of 3.8 mph. Furthermore, the prototype was subjected to field testing in which the average output was measured to be 40 mW despite the average wind distribution being centered around 3 mph.

  17. OPERATIONAL MODAL ANALYSIS AND WAVELET TRANSFORMATION FOR DAMAGE IDENTIFICATION IN WIND TURBINE BLADES

    E-print Network

    Paris-Sud XI, Université de

    OPERATIONAL MODAL ANALYSIS AND WAVELET TRANSFORMATION FOR DAMAGE IDENTIFICATION IN WIND TURBINE-frequency modes. KEYWORDS : Wind Turbine Blades, Debonding, Wavelet Transformation, Operational Modal Analysis. INTRODUCTION While failure can happen in any structural component of the wind turbine, one of the most common

  18. the risk issue of wind measurement for wind turbine operation

    E-print Network

    Leu, Tzong-Shyng "Jeremy"

    · Wind energy estimation at Taiwan · The risk of wind turbine from typhoon disaster · The wind exposure of wind measurement #12;3/31/2011 7 10-m height of wind measurement V10 = Vz * (10/z)1/7 __Japan resolution 10-30-50-70-250m 2000~2009 10-min wind dataset 25 km #12;THE RISK OF WIND TURBINE FROM TYPHOON

  19. Wind Turbine Manufacturing Process Monitoring

    SciTech Connect

    Waseem Faidi; Chris Nafis; Shatil Sinha; Chandra Yerramalli; Anthony Waas; Suresh Advani; John Gangloff; Pavel Simacek

    2012-04-26

    To develop a practical inline inspection that could be used in combination with automated composite material placement equipment to economically manufacture high performance and reliable carbon composite wind turbine blade spar caps. The approach technical feasibility and cost benefit will be assessed to provide a solid basis for further development and implementation in the wind turbine industry. The program is focused on the following technology development: (1) Develop in-line monitoring methods, using optical metrology and ultrasound inspection, and perform a demonstration in the lab. This includes development of the approach and performing appropriate demonstration in the lab; (2) Develop methods to predict composite strength reduction due to defects; and (3) Develop process models to predict defects from leading indicators found in the uncured composites.

  20. The new Wind Technology Test Center is the only facility in the nation capable of testing wind turbine blades up to

    E-print Network

    turbine blades up to 90 meters in length. A critical factor to wind turbine design and development is the ability to test new designs, components, and materials. In addition, wind turbine blade manufacturers the blades millions of times to simulate what a blade goes through in its lifetime on a wind turbine

  1. WindFloat: A floating foundation for offshore wind turbines

    Microsoft Academic Search

    Dominique Roddier; Christian Cermelli; Alexia Aubault; Alla Weinstein

    2010-01-01

    This manuscript summarizes the feasibility study conducted for the WindFloat technology. The WindFloat is a three-legged floating foundation for multimegawatt offshore wind turbines. It is designed to accommodate a wind turbine, 5 MW or larger, on one of the columns of the hull with minimal modifications to the nacelle and rotor. Potential redesign of the tower and of the turbine

  2. Performance of propeller wind turbines

    NASA Astrophysics Data System (ADS)

    Wortman, A.

    1983-12-01

    Presented herein is a parametric study of the performance of propeller wind turbines with realistic drag/lift ratios. Calculations were made using the complete Glauert vortex blade element theory in annular streamtube elements, with the complete turbine performance being the sum of the elemental results up to a specified tip speed ratio. The objective here is to exhibit a new computational technique which yields performance directly when tangential speed ratio and section aerodynamic characteristics are specified. It was found that for a tip speed ratio of 4, turbines with drag/lift ratios of 0.00 and 0.01 had power coefficients of 0.575 and 0.55, respectively. The off-design performance of the finite drag/lift was far better than that of their zero drag counterparts, except in a + or - 20-percent region about the design conditions. Tolerance to off-design operation increased with decreasing tip speed ratios so that the annual energy capture for tip speed ratios between 2 and 4 was about 87 percent of the ideal turbine value. The results are intended to provide a basis for re-evaluation of the power range classes of fixed pitch turbines and design tip speed ratios.

  3. Frequency control and wind turbine technologies

    Microsoft Academic Search

    Gillian Lalor; Alan Mullane; Mark O'Malley

    2005-01-01

    Increasing levels of wind generation has resulted in an urgent need for the assessment of their impact on frequency control of power systems. Whereas increased system inertia is intrinsically linked to the addition of synchronous generation to power systems, due to differing electromechanical characteristics, this inherent link is not present in wind turbine generators. Regardless of wind turbine technology, the

  4. Darrieus wind turbine electric generating system

    Microsoft Academic Search

    1984-01-01

    A wind electric system intended to provide power to a power grid, for use with a wind turbine which has no starting torque. The generator is one which can function as a motor as well. When the wind is too light to permit generation, an overriding clutch mechanically disconnects the generator shaft from the turbine shaft. The clutch has also

  5. Control systems for controlling a wind turbine

    SciTech Connect

    Cousineau, K.L.

    1994-01-11

    A distributed module control system is described for controlling a wind turbine using multiple controls and monitors comprising multiple modules that include microcontrollers, and having data input terminals and data output terminals; high level logic circuitry interconnecting the modules via selected data input and data output terminals; and certain modules also connected with the turbine monitors and controls to control operation of the wind turbines in response to monitoring of turbine operation. 7 figs.

  6. Aerodynamic interference between two Darrieus wind turbines

    Microsoft Academic Search

    P. R. Schatzle; P. C. Klimas; H. R. Spahr

    1981-01-01

    The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex\\/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the

  7. Aerodynamic interference between two Darrieus wind turbines

    Microsoft Academic Search

    P. R. Schatzle; P. C. Klimas; H. R. Spahr

    1980-01-01

    The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex\\/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the

  8. Darrieus wind turbine electric generating system

    SciTech Connect

    Schwarz, E.L.

    1984-08-07

    A wind electric system intended to provide power to a power grid, for use with a wind turbine which has no starting torque. The generator is one which can function as a motor as well. When the wind is too light to permit generation, an overriding clutch mechanically disconnects the generator shaft from the turbine shaft. The clutch has also the capability of locking the generator shaft to the turbine shaft in response to a control signal. When wind speed is great enough to permit generation and the turbine is stopped, a control signal is issued locking the generator shaft to the turbine shaft. Power from the power grid causes the generator to function as a motor and accelerate the turbine to permit it to be rotated by the wind. The clutch is then returned to overriding operation and electrical generation continues until wind speed again becomes too light.

  9. Small Wind Research Turbine: Final Report

    SciTech Connect

    Corbus, D.; Meadors, M.

    2005-10-01

    The Small Wind Research Turbine (SWRT) project was initiated to provide reliable test data for model validation of furling wind turbines and to help understand small wind turbine loads. This report will familiarize the user with the scope of the SWRT test and support the use of these data. In addition to describing all the testing details and results, the report presents an analysis of the test data and compares the SWRT test data to simulation results from the FAST aeroelastic simulation model.

  10. SUSTAINABLE CONCRETE FOR WIND TURBINE FOUNDATIONS.

    SciTech Connect

    BERNDT,M.L.

    2004-06-01

    The use of wind power to generate electricity continues to grow, especially given commitments by various countries throughout the world to ensure that a significant percentage of energy comes from renewable sources. In order to meet such objectives, increasingly larger turbines with higher capacity are being developed. The engineering aspects of larger turbine development tend to focus on design and materials for blades and towers. However, foundations are also a critical component of large wind turbines and represent a significant cost of wind energy projects. Ongoing wind research at BNL is examining two areas: (a) structural response analysis of wind turbine-tower-foundation systems and (b) materials engineering of foundations. This work is investigating the dynamic interactions in wind turbine systems, which in turn assists the wind industry in achieving improved reliability and more cost efficient foundation designs. The results reported herein cover initial studies of concrete mix designs for large wind turbine foundations and how these may be tailored to reduce cost and incorporate sustainability and life cycle concepts. The approach taken was to investigate material substitutions so that the environmental, energy and CO{sub 2}-impact of concrete could be reduced. The use of high volumes of ''waste'' materials in concrete was examined. These materials included fly ash, blast furnace slag and recycled concrete aggregate. In addition, the use of steel fiber reinforcement as a means to improve mechanical properties and potentially reduce the amount of bar reinforcement in concrete foundations was studied. Four basic mixes were considered. These were: (1) conventional mix with no material substitutions, (2) 50% replacement of cement with fly ash, (3) 50% replacement of cement with blast furnace slag and (4) 25% replacement of cement with fly ash and 25% replacement with blast furnace slag. Variations on these mixes included the addition of 1% by volume steel fibers. The use of recycled concrete aggregate in the conventional and 50% slag mixes was also studied. Properties investigated included compressive and tensile strengths, elastic modulus, coefficient of permeability, thermal conductivity and durability in seawater and sulfate solutions. It was determined that the mixes containing 50% slag gave the best overall performance. Slag was particularly beneficial for concrete that used recycled aggregate and could reduce strength losses. Initial durability results indicated that corrosion of fibers in the different concrete mixes when exposed to seawater was minimal. Future research needs to include more detailed studies of mix design and properties of concrete for wind turbine foundations. Emphasis on slag-modified mixes with natural and recycled concrete aggregate is recommended. The proportion of slag that can be incorporated in the concrete needs to be optimized, as does the grading of recycled aggregate. The potential for using silica fume in conjunction with slag is worth exploring as this may further enhance strength and durability. Longer-term durability studies are necessary and other pertinent properties of concrete that require investigation include damping characteristics, pullout strength, fatigue strength and risk of thermal cracking. The properties of sustainable concrete mixes need to be integrated with studies on the structural behavior of wind turbine foundations in order to determine the optimal mix design and to examine means of reducing conservatism and cost of foundations.

  11. Modeling Smart Structure of Wind Turbine Blade

    NASA Astrophysics Data System (ADS)

    Qiao, Yin-hu; Han, Jiang; Zhang, Chun-yan; Chen, Jie-ping

    2012-06-01

    With the increasing size of wind turbine blades, the need for more sophisticated load control techniques has induced the interest for aerodynamic control systems with build-in intelligence on the blades. The paper aims to provide a way for modeling the adaptive wind turbine blades and analyze its ability for vibration suppress. It consists of the modeling of the adaptive wind turbine blades with the wire of piezoelectric material embedded in blade matrix, and smart sandwich structure of wind turbine blade. By using this model, an active vibration method which effectively suppresses the vibrations of the smart blade is designed.

  12. Installation and initial operation of a 4100 watt wind turbine

    NASA Technical Reports Server (NTRS)

    Tryon, H. B.; Richards, T.

    1975-01-01

    The results are presented of 211 days of operation of the 4.1 kilowatt wind turbine, which was the largest commercially available wind turbine. The wind turbine, electric controls and load bank, and the pivoted tower are described.

  13. WEST-3 wind turbine simulator development

    NASA Technical Reports Server (NTRS)

    Hoffman, J. A.; Sridhar, S.

    1985-01-01

    The software developed for WEST-3, a new, all digital, and fully programmable wind turbine simulator is given. The process of wind turbine simulation on WEST-3 is described in detail. The major steps are, the processing of the mathematical models, the preparation of the constant data, and the use of system software generated executable code for running on WEST-3. The mechanics of reformulation, normalization, and scaling of the mathematical models is discussed in detail, in particulr, the significance of reformulation which leads to accurate simulations. Descriptions for the preprocessor computer programs which are used to prepare the constant data needed in the simulation are given. These programs, in addition to scaling and normalizing all the constants, relieve the user from having to generate a large number of constants used in the simulation. Also given are brief descriptions of the components of the WEST-3 system software: Translator, Assembler, Linker, and Loader. Also included are: details of the aeroelastic rotor analysis, which is the center of a wind turbine simulation model, analysis of the gimbal subsystem; and listings of the variables, constants, and equations used in the simulation.

  14. Wind turbine blade tip comparison using CFD

    NASA Astrophysics Data System (ADS)

    Ferrer, E.; Munduate, X.

    2007-07-01

    The effect of wind turbine blade tip geometry is numerically analysed using Computational Fluid Dynamics (CFD). Three different rotating blade tips are compared for attached flow conditions and the flow physics around the geometries are analysed. To this end, the pressure coefficient (Cp) is defined based on the stagnation pressure rather than on the inflow dynamic pressure. The tip geometry locally modifies the angles of attack (AOA) and the inflow dynamic pressure at each of the studied sections. However not all 3D effects could be reduced to a change of these two variables. An increase in loadings (particularly the normal force) towards the tip seem to be associated to a spanwise flow component present for the swept-back analysed tip. Integrated loads are ranked to asses wind turbine tip overall performance. It results from the comparison that a better tip shape that produced better torque to thrust ratios in both forces and moments is a geometry that has the end tip at the pitch axis. The work here presented shows that CFD may prove to be useful to complement 2D based methods on the design of new wind turbine blade tips.

  15. A wind-tunnel investigation of wind-turbine wakes in different yawed and loading conditions

    NASA Astrophysics Data System (ADS)

    Bastankhah, Majid; Porté-Agel, Fernando

    2015-04-01

    Wind-turbine wakes have negative effects on wind-farm performance. They are associated with: (a) the velocity deficit, which reduces the generated power of downwind turbines; and (b) the turbulence level, which increases the fatigue loads on downwind turbines. Controlling the yaw angle of turbines can potentially improve the performance of wind farms by deflecting the wake away from downwind turbines. However, except for few studies, wakes of yawed turbines still suffer from the lack of systematic research. To fill this research gap, we performed wind-tunnel experiments in the recirculating boundary-layer wind tunnel at the WIRE Laboratory of EPFL to better understand the wakes of yawed turbines. High-resolution stereoscopic particle image-velocimetry (S-PIV) was used to measure three velocity components in a horizontal plane located downwind of a horizontal-axis, three-blade model turbine. A servo-controller was connected to the DC generator of the turbine, which allowed us to apply different loadings. The power and thrust coefficients of the turbine were also measured for each case. These power and thrust measurements together with the highly-resolved flow measurements enabled us to study different wake characteristics such as the energy entrainment from the outer flow into the wake, the wake deflection and the helicoidal tip vortices for yawed turbines.

  16. Characteristics of wind turbine generators for wind power plants

    Microsoft Academic Search

    E. H. Camm; M. R. Behnke; O. Bolado; M. Bollen; M. Bradt; C. Brooks; W. Dilling; M. Edds; W. J. Hejdak; D. Houseman; S. Klein; F. Li; J. Li; P. Maibach; T. Nicolai; J. Patino; S. V. Pasupulati; N. Samaan; S. Saylors; T. Siebert; T. Smith; M. Starke; R. Walling

    2009-01-01

    This paper presents a summary of the most important characteristics of wind turbine generators applied in modern wind power plants. Various wind turbine generator designs, based on classification by machine type and speed control capabilities, are discussed along with their operational characteristics, voltage, reactive power, or power factor control capabilities, voltage ride-through characteristics, behavior during short circuits, and reactive power

  17. The Darrieus wind turbine for electrical power generation

    Microsoft Academic Search

    M. L. Robinson

    1981-01-01

    Aspects of wind as an energy source and the momentum theory of wind turbines are briefly examined. Types of Darrieus wind turbine are described; attention is given to a turbine with airfoil blades curved in troposkein form, and a turbine with straight blades of fixed or variable pitch. The Darrieus vertical-axis wind turbine is then considered with regard to aerodynamics,

  18. Collected Papers on Wind Turbine Technology

    NASA Technical Reports Server (NTRS)

    Spera, David A. (editor)

    1995-01-01

    R and D projects on electricity generating wind turbines were conducted at the NASA Lewis Research Center from 1973 to 1988. Most projects were sponsored by the U.S. Department of Energy (DOE), a major element of its Federal Wind Energy Program. Another large wind turbine project was by the Bureau of Reclamation of the U.S. Department of Interior (DOI). From 1988 to 1995, NASA wind energy activities have been directed toward the transfer of technology to commercial and academic organizations. As part of these technology transfer activities, previously unpublished manuscripts have been assembled and presented here to share the wind turbine research results with the wind energy community. A variety of wind turbine technology topics are discussed: Wind and wake models; Airfoil properties; Structural analysis and testing; Control systems; Variable speed generators; and acoustic noise. Experimental and theoretical results are discussed.

  19. Vertical-axis wind-turbine program

    SciTech Connect

    Braasch, R.H.

    1981-01-01

    During the interval since the Fourth Biennial Wind Energy Conference, the vertical axis wind turbine program has experienced significant progress. The purpose of this paper is to review that progress in aerodynamics research, structural dynamics research, and machine development.

  20. Wind Turbine Certification and Type Certification IEC WT 01: IEC System for Conformity Testing and Certification of Wind Turbines, 2001-04

    Microsoft Academic Search

    Mike Woebbeking; Axel Andreä; Axel Dombrowski; Germanischer Lloyd

    Certification of wind turbines or components is state-of-the-art and a must in most places around the world. Furthermore certification to harmonised requirements is an active support of export. Therefore it is important for manufacturers, banks and insurances of wind turbines and components to know the different certification processes as well as guidelines. The procedures to obtain Type and Project Certificates

  1. Sustainable Energy Solutions Task 2.0: Wind Turbine Reliability and Maintainability Enhancement through System-wide Structure Health Monitoring and Modifications to Rotating Components

    SciTech Connect

    Janet M Twomey, PhD

    2010-04-30

    EXECUTIVE SUMARRY An evaluation of nondestructive structural health monitoring methods was completed with over 132 documents, 37 specifically about wind turbines, summarized into a technology matrix. This matrix lists the technology, what can be monitored with this technology, and gives a short summary of the key aspects of the technology and its application. Passive and active acoustic emission equipment from Physical Acoustics Corp. and Acellent Technologies have been evaluated and selected for use in experimental state loading and fatigue tests of composite wind turbine blade materials. Acoustic Emission (AE) and Active Ultrasonic Testing (AUT), were applied to composite coupons with both simulated and actual damage. The results found that, while composites are more complicated in nature, compared to metallic structures, an artificial neural network analysis could still be used to determine damage. For the AE system, the failure mode could be determined (i.e. fiber breakage, delamination, etc.). The Acellent system has been evaluated to work well with composite materials. A test-rig for reliability testing of the rotating components was constructed. The research on the types of bearings used in the wind turbines indicated that in most of the designs, the main bearings utilized to support the shaft are cylindrical roller bearings. The accelerated degradation testing of a population of bearings was performed. Vibration and acoustic emission data was collected and analyzed in order to identify a representative degradation signal for each bearing to identify the initiation of the degradation process in the bearings. Afterwards, the RMS of the vibration signal from degradation initiation up to the end of the useful life of the bearing was selected to predict the remaining useful life of the bearing. This step included fitting Autoregressive Moving Average (ARMA) models to the degradation signals and approximating the probability distribution function (PDF) of remaining useful life based on the results of Monte-Carlo simulation of the ARMA models. This step was performed for different percentages of the degradation signal of each bearing. The accuracy of the proposed approach then was assessed by comparing the actual life of the bearing and the estimated life of the bearing from the developed models. The results were impressive and indicated that the accuracy of the models improved as more data was utilized in developing the ARMA models (we get closer to the end of the life of the bearing).

  2. Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine

    SciTech Connect

    None

    2010-02-22

    Broad Funding Opportunity Announcement Project: FloDesign Wind Turbine’s innovative wind turbine, inspired by the design of jet engines, could deliver 300% more power than existing wind turbines of the same rotor diameter by extracting more energy over a larger area. FloDesign Wind Turbine’s unique shrouded design expands the wind capture area, and the mixing vortex downstream allows more energy to flow through the rotor without stalling the turbine. The unique rotor and shrouded design also provide significant opportunity for mass production and simplified assembly, enabling mid-scale turbines (approximately 100 kW) to produce power at a cost that is comparable to larger-scale conventional turbines.

  3. Microprocessor control of a wind turbine generator

    NASA Technical Reports Server (NTRS)

    Gnecco, A. J.; Whitehead, G. T.

    1978-01-01

    A microprocessor based system was used to control the unattended operation of a wind turbine generator. The turbine and its microcomputer system are fully described with special emphasis on the wide variety of tasks performed by the microprocessor for the safe and efficient operation of the turbine. The flexibility, cost and reliability of the microprocessor were major factors in its selection.

  4. Aerodynamic interference between two Darrieus wind turbines

    SciTech Connect

    Schatzle, P.R.; Klimas, P.C.; Spahr, H.R.

    1980-01-01

    The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the cases examined, the calculations showed that the downwind turbine power decrement (1) was significant only when the line of turbine centers was coincident with the ambient wind direction, (2) increased with increasing tip-speed-ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.

  5. Simulation investigation of wind turbine imbalance faults

    Microsoft Academic Search

    Xiang Gong; Wei Qiao

    2010-01-01

    This paper investigates the use of simulations to study wind turbine imbalance faults. The dynamics of a model wind turbine generator (WTG) are simulated in a combined environment of TurbSim, FAST (Fatigue, Aerodynamics, Structures, Turbulence), and Simulink in three different scenarios, i.e., normal operating conditions, blade imbalance, and aerodynamic asymmetry. The blade imbalance is simulated by scaling the mass density

  6. Modeling mechanical torque in wind turbines

    Microsoft Academic Search

    J. Villanueva; L. Alvarez-Icaza

    2009-01-01

    The mechanical torque of a wind turbine is modeled from a friction phenomenon perspective. Two models for the torque generated are proposed based on a relative speed between the wind and turbine blades. The main advantage of these models is the possibility of using real-time standard identification techniques for recovering their parameters value. Models are compared with a heuristic reference

  7. Aeroelastic stability of wind turbine blades

    NASA Technical Reports Server (NTRS)

    Kaza, K. R. V.

    1928-01-01

    The second degree nonlinear aeroelastic equations for a flexible, twisted, nonuniform wind turbine blade were developed using Hamilton's principle. The derivation of these equations has its basis in the geometric nonlinear theory of elasticity. These equations with periodic coefficients are suitable for determining the aeroelastic stability and response of large wind turbine blades. Methods for solving these equations are discussed.

  8. Blade feathering system for wind turbines

    SciTech Connect

    Harner, K.I.; Patrick, J.P.; Vosseller, K.F.

    1984-07-31

    A blade feathering system for wind turbines includes a feather actuator, control means operatively connected thereto and an adjustment means operatively connected to the control means for selectively varying the rate of operation of the feather actuator for feathering the wind turbine blades at a variable rate.

  9. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loadings

    SciTech Connect

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2012-01-01

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5-MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  10. Certification testing for small wind turbines

    SciTech Connect

    Corbus, D.; Link, H.; Butterfield, S.; Stork, C.; Newcomb, C.

    1999-10-20

    This paper describes the testing procedures for obtaining type certification for a small wind turbine. Southwest Windpower (SWWP) is seeking type certification from Underwriters Laboratory (UL) for the AIR 403 wind turbine. UL is the certification body and the National Renewable Energy Laboratory (NREL) is providing technical assistance including conducting the certification testing. This is the first small turbine to be certified in the US, therefore standards must be interpreted and test procedures developed.

  11. Model 0A wind turbine generator FMEA

    NASA Technical Reports Server (NTRS)

    Klein, William E.; Lalli, Vincent R.

    1989-01-01

    The results of Failure Modes and Effects Analysis (FMEA) conducted for the Wind Turbine Generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems which are also reflected in this FMEA.

  12. MOD-2 wind turbine farm stability study

    NASA Technical Reports Server (NTRS)

    Hinrichsen, E. N.

    1980-01-01

    The dynamics of single and multiple 2.5 ME, Boeing MOD-2 wind turbine generators (WTGs) connected to utility power systems were investigated. The analysis was based on digital simulation. Both time response and frequency response methods were used. The dynamics of this type of WTG are characterized by two torsional modes, a low frequency 'shaft' mode below 1 Hz and an 'electrical' mode at 3-5 Hz. High turbine inertia and low torsional stiffness between turbine and generator are inherent features. Turbine control is based on electrical power, not turbine speed as in conventional utility turbine generators. Multi-machine dynamics differ very little from single machine dynamics.

  13. Responses of floating wind turbines to wind and wave excitation

    E-print Network

    Lee, Kwang Hyun

    2005-01-01

    The use of wind power has recently emerged as a promising alternative to conventional electricity generation. However, space requirements and public pressure to place unsightly wind turbines out of visual range make it ...

  14. Airfoil treatments for vertical axis wind turbines

    SciTech Connect

    Klimas, P.C.

    1985-01-01

    Sandia National Laboratories (SNL) has taken three airfoil related approaches to decreasing the cost of energy of vertical axis wind turbine (VAWT) systems; airfoil sections designed specifically for VAWTs, vortex generators (VGs), and ''pumped spoiling.'' SNL's blade element airfoil section design effort has led to three promising natural laminar flow (NLF) sections. One section is presently being run on the SNL 17-m turbine. Increases in peak efficiency and more desirable dynamic stall regulation characteristics have been observed. Vane-type VGs were fitted on one DOE/Alcoa 100 kW VAWT. With approximately 12% of span having VGs, annual energy production increased by 5%. Pumped spoiling utilizes the centrifugal pumping capabilities of hollow blades. With the addition of small perforations in the surface of the blades and valves controlled by windspeed at the ends of each blade, lift spoiling jets may be generated inducing premature stall and permitting lower capacity, lower cost drivetrain components. SNL has demonstrated this concept on its 5-m turbine and has wind tunnel tested perforation geometries on one NLF section.

  15. 1Design limits and solutions for very large wind turbines Design limits and solutions for very large wind turbines

    E-print Network

    Leu, Tzong-Shyng "Jeremy"

    #12;#12;1Design limits and solutions for very large wind turbines UpWind Design limits and solutions for very large wind turbines A 20 MW turbine is feasible March 2011 Supported by: #12;March 20112 Photo:Nordex #12;3Design limits and solutions for very large wind turbines Contents 1. UpWind: Summary

  16. 36 AUGUST | 2011 EnhancEd TurbinE

    E-print Network

    Kusiak, Andrew

    36 AUGUST | 2011 EnhancEd TurbinE PErformancE moniToring comPonEnTs of wind TurbinEs are affected by asymmetric loads, variable wind speeds, and se- vere weather conditions which cause wind turbines to change their states. A typical wind turbine under- goes various states during its daily operations. The wind turbine

  17. Darrieus wind turbine: construction and testing

    SciTech Connect

    Abbott, K.; Christianson, L.L.; Hellickson, M.A.

    1982-12-01

    A Darrieus was designed and constructed to be mechanically coupled to a heat pump for agricultural applications. This design minimized the cost of a cantilevered Darrieus and was suitable for testing purposes. All turbine components operated satisfactorily during testing, but the upper bearing and torque tube may fail after extended use. Performance characteristics of a variable-speed Darrieus were found by measuring wind speed, turbine torque, and turbine rotational speed, while the Darrieus operated. A hydraulic dynamometer was used to step-wise load the Darrieus to maintain high efficiencies. Performance curves were developed by using the statistical method of bins and multiple, least square regression analysis. Optimal performance for a variable-speed Darrieus system was determined and used to evaluate the turbine performance. Cantilevered support of the Darrieus was adequate for shaft rotational speeds less than 180 r/min. Vibrations due to a mass imbalance prevented the rotational speeds from being higher. Resonance conditions were detected at rotational speeds of 50 and possibly 180 r/min. The variable-speed system operated near the predicted optimal efficiency to a rotational speed of 120 r/min but above 120 r/min efficiencies decreased because the rotor was loaded down to prevent overspeeding and because of the inertial effect of the turbine. Variable-speed operation resulted in an efficiency of 31.8 percent. Efficiency of the variable-speed system would have been higher if the turbine had operated at higher rotational speeds and if a more optimal method of loading was used.

  18. Economics of large wind turbine generators

    SciTech Connect

    Oplinger, J.L.

    1982-06-01

    This study demonstrates that established utility system planning methods are applicable to studying wind turbine generators, with minor modifications. A total utility cost approach was used to evaluate the economics of wind turbine generators. The limitations of the busbar energy cost method rule out its use. Three analytic models are studied: the wind plant performance model, the generation system reliability model, and the generation system production cost model. The results of generation, transmission, and distribution studies are interpreted. The results are then integrated to give a single measure of the value of distributed wind turbines. These results demonstrate that the value of distributed wind turbines is dominated by the generation energy and capacity value. The quality and availability of the wind resource far outweighs credits achievable from an optimal electrical location.

  19. Meteorological aspects of siting large wind turbines

    SciTech Connect

    Hiester, T.R.; Pennell, W.T.

    1981-01-01

    This report, which focuses on the meteorological aspects of siting large wind turbines (turbines with a rated output exceeding 100 kW), has four main goals. The first is to outline the elements of a siting strategy that will identify the most favorable wind energy sites in a region and that will provide sufficient wind data to make responsible economic evaluations of the site wind resource possible. The second is to critique and summarize siting techniques that were studied in the Department of Energy (DOE) Wind Energy Program. The third goal is to educate utility technical personnel, engineering consultants, and meteorological consultants (who may have not yet undertaken wind energy consulting) on meteorological phenomena relevant to wind turbine siting in order to enhance dialogues between these groups. The fourth goal is to minimize the chances of failure of early siting programs due to insufficient understanding of wind behavior.

  20. Preform spar cap for a wind turbine rotor blade

    DOEpatents

    Livingston, Jamie T. (Simpsonville, SC); Driver, Howard D. (Greer, SC); van Breugel, Sjef (Enschede, NL); Jenkins, Thomas B. (Cantonment, FL); Bakhuis, Jan Willem (Nijverdal, NL); Billen, Andrew J. (Daarlerveen, NL); Riahi, Amir (Pensacola, FL)

    2011-07-12

    A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

  1. Structural responses and power output of a wind turbine are strongly affected by the wind field acting on the wind turbine. Knowledge about the wind field and its

    E-print Network

    Stanford University

    ABSTRACT Structural responses and power output of a wind turbine are strongly affected by the wind field acting on the wind turbine. Knowledge about the wind field and its variations is essential not only for designing, but also for cost-efficiently managing wind turbines. Wind field monitoring

  2. Development of the Risø wind turbine airfoils

    Microsoft Academic Search

    Peter Fuglsang; Christian Bak

    2004-01-01

    This paper presents the wind turbine airfoil development at Risø. The design method is described together with our target characteristics for wind turbine airfoils. The use of the CFD code Ellipsys2D for prediction of final target characteristics is described together with the VELUX wind tunnel testing setup. Three airfoil families were developed; Risø-A1, Risø-P and Risø-B1. The Risø-A1 airfoil family

  3. Modeling Smart Structure of Wind Turbine Blade

    Microsoft Academic Search

    Yin-Hu Qiao; Jiang Han; Chun-Yan Zhang; Jie-Ping Chen

    2011-01-01

    With the increasing size of wind turbine blades, the need for more sophisticated load control techniques has induced the interest\\u000a for aerodynamic control systems with build-in intelligence on the blades. The paper aims to provide a way for modeling the\\u000a adaptive wind turbine blades and analyze its ability for vibration suppress. It consists of the modeling of the adaptive wind

  4. Wind turbine control system modeling capabilities

    SciTech Connect

    Pierce, K.; Fingersh, L.J.

    1998-04-01

    At the National Renewable Energy Laboratory`s (NREL`s) National Wind Technology Center the authors are continuing to make progress in their ability to model complete wind turbine systems. An ADAMS{reg_sign} model of the NREL variable speed test bed turbine was developed to determine whether wind turbine control systems could be simulated and to investigate other control strategies for this turbine. Model simulations are compared with data from the operating turbine using the current mode of operation. In general, the simulations show good agreement with test data. Having established confidence in their ability to model the physical machine, the authors evaluated two other control methods. The methods studied are a generalized predictive control method and a bias estimation method. Simulation results using these methods are compared to simulation results of the current mode of operation of the turbine.

  5. Influence of refraction on wind turbine noise

    E-print Network

    Makarewicz, Rufin

    2013-01-01

    A semi-empirical method is applied to calculate the time-average sound level of wind turbine noise generation and propagation. Both are affected by wind shear refraction. Under upwind conditions the partially ensonified zone separates the fully ensonified zone (close to the turbine) and the shadow zone (far away from the turbine). Refraction is described in terms of the wind speed linear profile fitted to the power law profile. The rotating blades are treated as a two-dimensional circular source in the vertical plane. Inside the partially ensonified zone the effective A-weighted sound power decreases to zero when the receiver moves from the turbine toward the shadow zone. The presented results would be useful in practical applications to give a quick estimate of the effect of refraction on wind turbine noise.

  6. Numerical investigation of wind turbine and wind farm aerodynamics

    NASA Astrophysics Data System (ADS)

    Selvaraj, Suganthi

    A numerical method based on the solution of Reynolds Averaged Navier Stokes equations and actuator disk representation of turbine rotor is developed and implemented in the OpenFOAM software suite for aerodynamic analysis of horizontal axis wind turbines (HAWT). The method and the implementation are validated against the 1-D momentum theory, the blade element momentum theory and against experimental data. The model is used for analyzing aerodynamics of a novel dual rotor wind turbine concept and wind farms. Horizontal axis wind turbines suffer from aerodynamic inefficiencies in the blade root region (near the hub) due to several non-aerodynamic constraints (e.g., manufacturing, transportation, cost, etc.). A new dual-rotor wind turbine (DRWT) concept is proposed that aims at mitigating these losses. A DRWT is designed using an existing turbine rotor for the main rotor (Risoe turbine and NREL 5 MW turbine), while the secondary rotor is designed using a high lift to drag ratio airfoil (the DU 96 airfoil from TU Delft). The numerical aerodynamic analysis method developed as a part of this thesis is used to optimize the design. The new DRWT design gives an improvement of about 7% in aerodynamic efficiency over the single rotor turbine. Wind turbines are typically deployed in clusters called wind farms. HAWTs also suffer from aerodynamic losses in a wind farm due to interactions with wind turbine wakes. An interesting mesoscale meteorological phenomenon called "surface flow convergence" believed to be caused by wind turbine arrays is investigated using the numerical method developed here. This phenomenon is believed to be caused by the pressure gradient set up by wind turbines operating in close proximity in a farm. A conceptual/hypothetical wind farm simulation validates the hypothesis that a pressure gradient is setup in wind farms due to turbines and that it can cause flow veering of the order of 10 degrees. Simulations of a real wind farm (Story County) are also conducted which give qualitatively correct flow direction change, however quantitative agreement with data is only moderately acceptable.

  7. Ply design and intensity analysis of composite vertical axis wind turbine blade based on ANSYS

    Microsoft Academic Search

    Chenguang Song; Yuan Zheng; Zhengzhou Zhao

    2011-01-01

    Blade is the key component to capture wind energy. It plays a vital role in the whole wind turbine. In this paper, Ply design and intensity analysis are conducted with layered shell elements to treat a composite vertical axis wind turbine blade based on ANSYS. The results show that the ply design meets the requirements of intensity and stiffness. The

  8. SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES

    E-print Network

    Paris-Sud XI, Université de

    SUBSPACE-BASED DETECTION OF FATIGUE DAMAGE ON JACKET SUPPORT STRUCTURES OF OFFSHORE WIND TURBINES-based Damage Detec- tion (SSDD) method on model structures for an utilization of this approach on offshore wind damage in real size structural components of offshore wind turbines. KEYWORDS : Damage detection

  9. Wind Turbines and Health A Rapid Review of the Evidence

    E-print Network

    Firestone, Jeremy

    1 Wind Turbines and Health A Rapid Review of the Evidence July 2010 #12;2 Wind Turbines and Health of the evidence from current literature on the issue of wind turbines and potential impacts on human health regarding wind turbines and their potential effect on human health. It is important to note that these views

  10. innovati nNREL Computer Models Integrate Wind Turbines with

    E-print Network

    innovati nNREL Computer Models Integrate Wind Turbines with Floating Platforms Far off the shores for today's seabed-mounted offshore wind turbines. For the United States to tap into these vast offshore models that allow detailed analyses of such floating wind turbines. Coupling wind turbines and floating

  11. An experimental investigation on wind turbine aeromechanics and wake interferences among multiple wind turbines

    NASA Astrophysics Data System (ADS)

    Ozbay, Ahmet

    A comprehensive experimental study was conducted to investigate wind turbine aeromechanics and wake interferences among multiple wind turbines sited in onshore and offshore wind farms. The experiments were carried out in a large-scale Aerodynamic/Atmospheric Boundary Layer (AABL) Wind Tunnel available at Iowa State University. An array of scaled three-blade Horizontal Axial Wind Turbine (HAWT) models were placed in atmospheric boundary layer winds with different mean and turbulence characteristics to simulate the situations in onshore and offshore wind farms. The effects of the important design parameters for wind farm layout optimization, which include the mean and turbulence characteristics of the oncoming surface winds, the yaw angles of the turbines with respect to the oncoming surface winds, the array spacing and layout pattern, and the terrain topology of wind farms on the turbine performances (i.e., both power output and dynamic wind loadings) and the wake interferences among multiple wind turbines, were assessed in detail. The aeromechanic performance and near wake characteristics of a novel dual-rotor wind turbine (DRWT) design with co-rotating or counter-rotating configuration were also investigated, in comparison to a conventional single rotor wind turbine (SRWT). During the experiments, in addition to measuring dynamic wind loads (both forces and moments) and the power outputs of the scaled turbine models, a high-resolution Particle Image Velocity (PIV) system was used to conduct detailed flow field measurements (i.e., both free-run and phase-locked flow fields measurements) to reveal the transient behavior of the unsteady wake vortices and turbulent flow structures behind wind turbines and to quantify the characteristics of the wake interferences among the wind turbines sited in non-homogenous surface winds. A miniature cobra anemometer was also used to provide high-temporal-resolution data at points of interest to supplement the full field PIV measurement results. The detailed flow field measurements are correlated with the dynamic wind loads and power output measurements to elucidate underlying physics in order to gain further insight into the characteristics of the power generation performance, dynamic wind loads and wake interferences of the wind turbines for higher total power yield and better durability of the wind turbines sited in atmospheric boundary layer (ABL) winds.

  12. Effect of precipitation on wind turbine performance

    NASA Technical Reports Server (NTRS)

    Corrigan, R. D.; Demiglio, R. D.

    1985-01-01

    The effects of precipitation on wind turbine power output was analyzed. The tests were conducted on the two bladed Mod-0 horizontal axis wind turbine with three different rotor configurations. Experimental data from these tests are presented which clearly indicate that the performance of the Mod-0 wind turbine is affected by rain. Light rainfall degraded performance by as much as 20 percent while heavy rainfall degraded performance by as much as 30 percent. Snow mixed with drizzle degraded performance by as much as 36 percent at low windspeeds. Also presented are the results of an analysis to predict the effect of rain on wind turbine performance. This analysis used a blade element/momentum code with modified airfoil characteristics to account for the effect of rain and predicted a loss in performance of 31 percent in high winds with moderate rainfall rates. These predicted results agreed well with experimental data.

  13. Active load control techniques for wind turbines.

    SciTech Connect

    van Dam, C.P. (University of California, Davis, CA); Berg, Dale E.; Johnson, Scott J. (University of California, Davis, CA)

    2008-07-01

    This report provides an overview on the current state of wind turbine control and introduces a number of active techniques that could be potentially used for control of wind turbine blades. The focus is on research regarding active flow control (AFC) as it applies to wind turbine performance and loads. The techniques and concepts described here are often described as 'smart structures' or 'smart rotor control'. This field is rapidly growing and there are numerous concepts currently being investigated around the world; some concepts already are focused on the wind energy industry and others are intended for use in other fields, but have the potential for wind turbine control. An AFC system can be broken into three categories: controls and sensors, actuators and devices, and the flow phenomena. This report focuses on the research involved with the actuators and devices and the generated flow phenomena caused by each device.

  14. Wake measurements around operating wind turbines

    SciTech Connect

    Baker, R.W.; Katen, P.C.; Walker, S.N.

    1985-05-01

    Researchers at Oregon State University have conducted wind measurement programs to describe the wake behind large horizontal axis turbines at Goodnoe Hills, Washington, (MOD-2), and behind the FloWind vertical axis wind turbine near Ellenburg, Washington. Wake measurements were taken using portable kite anemometers as well as fixed place anemometers under several atmospheric stability conditions and turbine operating conditions. Centerline hub height (midrotor) measurements were taken downwind and crosswind from 3-9 diameters. These wake programs are discussed and the velocity deficits measured are compared to the estimated deficits calculated from wake models.

  15. Composite Materials for Wind Power Turbine Blades

    Microsoft Academic Search

    Povl Brøndsted; Hans Lilholt; Aage Lystrup

    2005-01-01

    Renewable energy resources, of which wind energy is prominent, are part of the solution to the global energy problem. Wind turbine and the rotorblade concepts are reviewed, and loadings by wind and gravity as important factors for the fatigue performance of the materials are considered. Wood and composites are discussed as candidates for rotorblades. The fibers and matrices for composites

  16. Operational Modal Analysis of a Wind Turbine Mainframe using Crystal Clear SSI

    Microsoft Academic Search

    Sven-Erik Rosenow; Palle Andersen

    \\u000a Experimental investigations of the dynamic behavior of wind turbine components as well as of the turbine’s overall dynamics\\u000a are important for the evaluation of applied prediction models. Operational Modal Analysis (OMA) was applied to identify resonant\\u000a frequencies, corresponding mode shapes and damping values. Experimental investigations were carried out at the main frame\\u000a of a Fuhrländer AG 2.5 MW wind turbine

  17. Estimation of power in low velocity vertical axis wind turbine

    NASA Astrophysics Data System (ADS)

    Sampath, S. S.; Shetty, Sawan; Chithirai Pon Selvan, M.

    2015-05-01

    The present work involves in the construction of a vertical axis wind turbine and the determination of power. Various different types of turbine blades are considered and the optimum blade is selected. Mechanical components of the entire setup are built to obtain maximum rotation per minute. The mechanical energy is converted into the electrical energy by coupling coaxially between the shaft and the generator. This setup produces sufficient power for consumption of household purposes which is economic and easily available.

  18. WIND TURBINE SITING IN AN URBAN ENVIRONMENT: THE HULL, MA 660 KW TURBINE

    E-print Network

    Massachusetts at Amherst, University of

    1 WIND TURBINE SITING IN AN URBAN ENVIRONMENT: THE HULL, MA 660 KW TURBINE J. F. Manwell, J. G. Mc turbine at Windmill Point in Hull, Massachusetts represents a high point in the long history of wind's performance of the wind turbine is given. The paper also presents an overview of possible future wind

  19. Simulation of a flexible wind turbine response to a grid fault Anca D. Hansen*, Nicolaos A. Cutululis*, Poul Srensen*,

    E-print Network

    Simulation of a flexible wind turbine response to a grid fault Anca D. Hansen*, Nicolaos A of a wind turbine. Grid faults generate transients in the generator electromagnetic torque, which are propagated in the wind turbine, stressing its mechanical components. Grid faults are normally simulated

  20. Influence of the Type and Size of Wind Turbines on Anti-Icing Thermal Power Requirements for Blades

    Microsoft Academic Search

    L. Battisti; R. Fedrizzi; S. Dal Savio; A. Giovannelli

    Summary. Ice accretion on wind turbine components affects system safe operation and performance, with an annual power loss up to 20–50% at harsh sites. Therefore, special design requirements, as ice prevention systems, are necessary for wind turbines to operate in cold climates. The paper presents results for evaluating the anti-icing energy requirement for wind turbine blades as a function of

  1. Danehy Park Wind Turbine Project Preliminary Assessment Report

    E-print Network

    Danehy Park Wind Turbine Project Preliminary Assessment Report Danehy Park Project Group Wind/s) 13 10 14.5 ~15 12 Table 1: Summary of basic wind turbine specifications for turbines in evaluation. Bob Paine and Scott Abbett for their thoughts and experiences with the Medford McGlynn School wind

  2. Modelling of a chaotic load of wind turbines drivetrain

    NASA Astrophysics Data System (ADS)

    Bielecki, Andrzej; Barszcz, Tomasz; Wójcik, Mateusz

    2015-03-01

    The purpose of this paper is to present a model of the load of the wind turbine gears for simulation of real, varying operational conditions for modelling of wind turbine vibration. The characteristics of the wind, which generates chaotically varying loads on the drivetrain components generating load in teeth and bearings of gears during torque transfer, are discussed. A generator of variable load of wind turbines drivetrain is proposed. Firstly, the module for generation of wind speed is designed. It is based on the approach in which the wind speed was considered as a time series approximated by the Weierstrass function. Secondly, the rotational speed of the main shaft is proposed as a function of the wind speed value. The function depends on a few parameters that are fitted by using a genetic algorithm. Finally, the model of torque of the main shaft is introduced. This model has been created by using a multi-layer artificial neural network. The results show that the proposed approach yields a very good fit for the experimental data. The fit brings about the proper reproducing of all the aspects of the load that are crucial for causing fatigue and, as a consequence, damaging of gears of the wind turbines.

  3. Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint

    SciTech Connect

    Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.

    2006-03-01

    This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts was also performed. Key cost components included the material and construction costs of the buoy; material and installation costs of the tethers, mooring lines, and anchor technologies; costs of transporting and installing the system at the chosen site; and the cost of mounting the wind turbine to the platform. The two systems were evaluated based on their static and dynamic performance and the total system installed cost. Both systems demonstrated acceptable motions, and have estimated costs of $1.4-$1.8 million, not including the cost of the wind turbine, the power electronics, or the electrical transmission.

  4. Data Analytics Methods in Wind Turbine Design and Operations 

    E-print Network

    Lee, Giwhyun

    2013-05-22

    This dissertation develops sophisticated data analytic methods to analyze structural loads on, and power generation of, wind turbines. Wind turbines, which convert the kinetic energy in wind into electrical power, are operated within stochastic...

  5. Data Analytics Methods in Wind Turbine Design and Operations

    E-print Network

    Lee, Giwhyun

    2013-05-22

    number of important tasks including predicting wind power production and assessing a turbine’s energy production efficiency. Nevertheless, actual wind power data indicate that the power output is affected by more than just wind speed. Several other...

  6. Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine

    E-print Network

    Bae, Yoon Hyeok

    2013-04-23

    floating wind turbines, so the effects of such high-frequency excitations from the tower and blades need to be checked. 5 Another concept for floating offshore wind farms is the Multiple Unit Floating Offshore Wind Turbine (MUFOWT). This model...

  7. Review of Aerodynamics for Wind Turbines

    NASA Astrophysics Data System (ADS)

    Snel, Herman

    2003-07-01

    This article reviews the state of the art of wind turbine rotor aerodynamics. It addresses present uncertainties in rotor design and load calculations, recent modelling efforts to reduce these uncertainties, and validation activities regarding the modelling and results thereof.

  8. Wind Turbine Drivetrain Condition Monitoring - An Overview

    SciTech Connect

    Sheng, S; Veers, P.

    2011-10-01

    This paper provides an overview of wind turbine drivetrain condition monitoring based on presentations from a condition monitoring workshop organized by the National Renewable Energy Laboratory in 2009 and on additional references.

  9. Darrieus wind turbine program at Sandia Laboratories

    Microsoft Academic Search

    P. C. Klimas

    1979-01-01

    The design and development of vertical axis wind turbines (VAWTs) are discussed. Aerodynamic, structural, testing, and systems analyses capabilites for the development program are reported. The aerodynamic and structural characteristics of the VAWT are presented.

  10. Flexible dynamics of floating wind turbines

    E-print Network

    Luypaert, Thomas (Thomas J.)

    2012-01-01

    This work presents Tower Flex, a structural dynamics model for a coupled analysis of offshore floating wind turbines consisting of a tower, a floating platform and a mooring system. In this multi-body, linear frequency-domain ...

  11. Advanced control strategies for wind turbines

    NASA Astrophysics Data System (ADS)

    Schluter, L. L.; Vachon, William A.

    As wind turbines become more complex and begin to incorporate variable speed operation, control algorithms that enable the wind turbine to operate as efficiently as possible will become more complicated. Also, most current control strategies do not take into account factors such as wake effects from upstream turbines and the fact that different turbine sites can have significantly different wind regimes. To aid a windfarm operator in developing appropriate control strategies, a computer code entitled ASYM has been developed at Sandia National Laboratories. ASYM is a wind turbine simulation program that can be used to evaluate different control strategies. This paper briefly describes ASYM and presents results from the code when used for evaluating control options for both variable-speed and constant-speed control. The code synthesizes dynamic wind speeds on a second-by-second basis in the time domain that conforms to a predetermined spectral content governed by the surface roughness length scale and the hourly average wind speed. The simulated wind speeds then drive a series of wind turbine (WT) control algorithms that predict key WT operational parameters such as number of annual starts and stops, annual energy production, and annual fatigue damage at a critically stressed joint on the WT. This paper also discusses future plans to improve and validate ASYM and to incorporate a comprehensive economics model and advanced control strategies such as fuzzy control, adaptive control, and expert systems. It has been shown that processes using fuzzy control algorithms operate more smoothly and more efficiently than processes that are controlled using classical methods. Fuzzy control is briefly explained and an example of its application to a wind turbine is given. The future plans include a continuing involvement with active wind plant operators who can provide feedback regarding the usefulness of the analytical tool and the validity of findings.

  12. Wind Turbine Safety and Function Test Report for the Mariah Windspire Wind Turbine

    SciTech Connect

    Huskey, A.; Bowen, A.; Jager, D.

    2010-07-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers to wind energy expansion by providing independent testing results for small wind turbines (SWT). In total, five turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests performed on the turbines, including power performance, duration, noise, and power-quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. The test equipment includes a Mariah Windspire wind turbine mounted on a monopole tower. L&E Machine manufactured the turbine in the United States. The inverter was manufactured separately by Technology Driven Products in the United States. The system was installed by the NWTC site operations group with guidance and assistance from Mariah Power.

  13. Wind Turbine Safety and Function Test Report for the Gaia-Wind 11-kW Wind Turbine

    SciTech Connect

    Huskey, A.; Bowen, A.; Jager, D.

    2010-01-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers to wind energy expansion by providing independent testing results for small wind turbines (SWT). In total, four turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests performed on the turbines, including power performance, duration, noise, and power-quality tests. The results of the testing provide the manufacturers with reports that can be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11-kW wind turbine mounted on an 18-m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark. The system was installed by the NWTC site operations group with guidance and assistance from Gaia-Wind.

  14. Development of vertical axis wind turbines

    Microsoft Academic Search

    P N Shankar

    1979-01-01

    This paper summarises the work done at the National Aeronautical Laboratory (NAL) between 1975 and 1977 on the development\\u000a of vertical axis wind turbines based on the Darrieus rotor. On the analytical side, a performance analysis was developed which\\u000a permits the estimation of the characteristics of such machines. A 5 m high wind turbine using curved wooden blades was designed,

  15. Aerodynamic performance of wind turbines. Final report

    Microsoft Academic Search

    R. E. Wilson; P. B. S. Lissaman; S. N. Walker

    1976-01-01

    The state-of-the-art of performance prediction methods for both horizontal and vertical axis wind turbines is presented. Strip theory methods for horizontal axis wind turbines are evaluated for various tip loss models. A comparison of these tip models is developed for the ERDA-NASA MOD-O rotor. The occurrence of multiple solutions in strip theory analysis is discussed and illustrated. The performance of

  16. Preliminary wind tunnel tests on the pedal wind turbine

    NASA Astrophysics Data System (ADS)

    Vinayagalingam, T.

    1980-06-01

    High solidity-low speed wind turbines are relatively simple to construct and can be used advantageously in many developing countries for such direct applications as water pumping. Established designs in this class, such as the Savonius and the American multiblade rotors, have the disadvantage that their moving surfaces require a rigid construction, thereby rendering large units uneconomical. In this respect, the pedal wind turbine recently reported by the author and which incorporates sail type rotors offers a number of advantages. This note reports preliminary results from a series of wind tunnel tests which were carried out to assess the aerodynamic torque and power characteristics of the turbine.

  17. Development of wind tunnel for laboratory wind turbine testing

    Microsoft Academic Search

    Dale S. Dolan; Danny Zepeda; Taufik Taufik

    2011-01-01

    This paper presents the development of a wind tunnel that will be used for wind turbine testing in a controlled environment. The prototype is designed to be able to provide wind speeds of up to 20 m\\/s (~43mph) depending on the cross sectional area of the tunnel chamber. A 42 inch tube axial fan is driven by a 5hp induction

  18. Tutorial of Wind Turbine Control for Supporting Grid Frequency through Active Power Control: Preprint

    SciTech Connect

    Aho, J.; Buckspan, A.; Laks, J.; Fleming, P.; Jeong, Y.; Dunne, F.; Churchfield, M.; Pao, L.; Johnson, K.

    2012-03-01

    As wind energy becomes a larger portion of the world's energy portfolio and wind turbines become larger and more expensive, wind turbine control systems play an ever more prominent role in the design and deployment of wind turbines. The goals of traditional wind turbine control systems are maximizing energy production while protecting the wind turbine components. As more wind generation is installed there is an increasing interest in wind turbines actively controlling their power output in order to meet power setpoints and to participate in frequency regulation for the utility grid. This capability will be beneficial for grid operators, as it seems possible that wind turbines can be more effective at providing some of these services than traditional power plants. Furthermore, establishing an ancillary market for such regulation can be beneficial for wind plant owner/operators and manufacturers that provide such services. In this tutorial paper we provide an overview of basic wind turbine control systems and highlight recent industry trends and research in wind turbine control systems for grid integration and frequency stability.

  19. 2/16/2014 Can You Charge Your Mobile With Wind Turbine? -TechTxr http://www.techtxr.com/can-charge-mobile-wind-turbine/ 1/7

    E-print Network

    Chiao, Jung-Chih

    2/16/2014 Can You Charge Your Mobile With Wind Turbine? - TechTxr http://www.techtxr.com/can-charge-mobile-wind-turbine Turbine? | February 9, 2014 Wind Energy Wind Mill Wind Power Wind Mobile About Wind Power Wind Generator Mobile Generator Mobile Building #12;2/16/2014 Can You Charge Your Mobile With Wind Turbine

  20. Vertical axis wind turbine designed aerodynamically at Tokai University

    Microsoft Academic Search

    Y. Kato; K. Seki; Y. Shimizu

    1981-01-01

    The advantages of the vertical axis wind turbine over conventional propeller-type wind turbines are listed, among them the fact that the turbine is free from the gyroscopic loading accompanied by wind direction tracking. Special attention is given to the straight-wing type vertical axis turbine, which is thought to be particularly advantageous. Also discussed are the characteristics of the blade. It

  1. Behavior of bats at wind turbines

    USGS Publications Warehouse

    Cryan, Paul; Gorresen, P. Marcos; Hine, Cris D.; Schirmacher, Michael; Diehl, Robert H.; Huso, Manuela M.; Hayman, David T.S.; Fricker, Paul D.; Bonaccorso, Frank J.; Johnson, Douglas H.; Heist, Kevin W.; Dalton, David C.

    2014-01-01

    Wind turbines are causing unprecedented numbers of bat fatalities. Many fatalities involve tree-roosting bats, but reasons for this higher susceptibility remain unknown. To better understand behaviors associated with risk, we monitored bats at three experimentally manipulated wind turbines in Indiana, United States, from July 29 to October 1, 2012, using thermal cameras and other methods. We observed bats on 993 occasions and saw many behaviors, including close approaches, flight loops and dives, hovering, and chases. Most bats altered course toward turbines during observation. Based on these new observations, we tested the hypotheses that wind speed and blade rotation speed influenced the way that bats interacted with turbines. We found that bats were detected more frequently at lower wind speeds and typically approached turbines on the leeward (downwind) side. The proportion of leeward approaches increased with wind speed when blades were prevented from turning, yet decreased when blades could turn. Bats were observed more frequently at turbines on moonlit nights. Taken together, these observations suggest that bats may orient toward turbines by sensing air currents and using vision, and that air turbulence caused by fast-moving blades creates conditions that are less attractive to bats passing in close proximity. Tree bats may respond to streams of air flowing downwind from trees at night while searching for roosts, conspecifics, and nocturnal insect prey that could accumulate in such flows. Fatalities of tree bats at turbines may be the consequence of behaviors that evolved to provide selective advantages when elicited by tall trees, but are now maladaptive when elicited by wind turbines.

  2. Behavior of bats at wind turbines

    PubMed Central

    Cryan, Paul. M.; Gorresen, P. Marcos; Hein, Cris D.; Schirmacher, Michael R.; Diehl, Robert H.; Huso, Manuela M.; Hayman, David T. S.; Fricker, Paul D.; Bonaccorso, Frank J.; Johnson, Douglas H.; Heist, Kevin; Dalton, David C.

    2014-01-01

    Wind turbines are causing unprecedented numbers of bat fatalities. Many fatalities involve tree-roosting bats, but reasons for this higher susceptibility remain unknown. To better understand behaviors associated with risk, we monitored bats at three experimentally manipulated wind turbines in Indiana, United States, from July 29 to October 1, 2012, using thermal cameras and other methods. We observed bats on 993 occasions and saw many behaviors, including close approaches, flight loops and dives, hovering, and chases. Most bats altered course toward turbines during observation. Based on these new observations, we tested the hypotheses that wind speed and blade rotation speed influenced the way that bats interacted with turbines. We found that bats were detected more frequently at lower wind speeds and typically approached turbines on the leeward (downwind) side. The proportion of leeward approaches increased with wind speed when blades were prevented from turning, yet decreased when blades could turn. Bats were observed more frequently at turbines on moonlit nights. Taken together, these observations suggest that bats may orient toward turbines by sensing air currents and using vision, and that air turbulence caused by fast-moving blades creates conditions that are less attractive to bats passing in close proximity. Tree bats may respond to streams of air flowing downwind from trees at night while searching for roosts, conspecifics, and nocturnal insect prey that could accumulate in such flows. Fatalities of tree bats at turbines may be the consequence of behaviors that evolved to provide selective advantages when elicited by tall trees, but are now maladaptive when elicited by wind turbines. PMID:25267628

  3. Behavior of bats at wind turbines.

    PubMed

    Cryan, Paul M; Gorresen, P Marcos; Hein, Cris D; Schirmacher, Michael R; Diehl, Robert H; Huso, Manuela M; Hayman, David T S; Fricker, Paul D; Bonaccorso, Frank J; Johnson, Douglas H; Heist, Kevin; Dalton, David C

    2014-10-21

    Wind turbines are causing unprecedented numbers of bat fatalities. Many fatalities involve tree-roosting bats, but reasons for this higher susceptibility remain unknown. To better understand behaviors associated with risk, we monitored bats at three experimentally manipulated wind turbines in Indiana, United States, from July 29 to October 1, 2012, using thermal cameras and other methods. We observed bats on 993 occasions and saw many behaviors, including close approaches, flight loops and dives, hovering, and chases. Most bats altered course toward turbines during observation. Based on these new observations, we tested the hypotheses that wind speed and blade rotation speed influenced the way that bats interacted with turbines. We found that bats were detected more frequently at lower wind speeds and typically approached turbines on the leeward (downwind) side. The proportion of leeward approaches increased with wind speed when blades were prevented from turning, yet decreased when blades could turn. Bats were observed more frequently at turbines on moonlit nights. Taken together, these observations suggest that bats may orient toward turbines by sensing air currents and using vision, and that air turbulence caused by fast-moving blades creates conditions that are less attractive to bats passing in close proximity. Tree bats may respond to streams of air flowing downwind from trees at night while searching for roosts, conspecifics, and nocturnal insect prey that could accumulate in such flows. Fatalities of tree bats at turbines may be the consequence of behaviors that evolved to provide selective advantages when elicited by tall trees, but are now maladaptive when elicited by wind turbines. PMID:25267628

  4. Tribological advancements for reliable wind turbine performance.

    PubMed

    Kotzalas, Michael N; Doll, Gary L

    2010-10-28

    Wind turbines have had various limitations to their mechanical system reliability owing to tribological problems over the past few decades. While several studies show that turbines are becoming more reliable, it is still not at an overall acceptable level to the operators based on their current business models. Data show that the electrical components are the most problematic; however, the parts are small, thus easy and inexpensive to replace in the nacelle, on top of the tower. It is the tribological issues that receive the most attention as they have higher costs associated with repair or replacement. These include the blade pitch systems, nacelle yaw systems, main shaft bearings, gearboxes and generator bearings, which are the focus of this review paper. The major tribological issues in wind turbines and the technological developments to understand and solve them are discussed within. The study starts with an overview of fretting corrosion, rolling contact fatigue, and frictional torque of the blade pitch and nacelle yaw bearings, and references to some of the recent design approaches applied to solve them. Also included is a brief overview into lubricant contamination issues in the gearbox and electric current discharge or arcing damage of the generator bearings. The primary focus of this review is the detailed examination of main shaft spherical roller bearing micropitting and gearbox bearing scuffing, micropitting and the newer phenomenon of white-etch area flaking. The main shaft and gearbox are integrally related and are the most commonly referred to items involving expensive repair costs and downtime. As such, the latest research and developments related to the cause of the wear and damage modes and the technologies used or proposed to solve them are presented. PMID:20855322

  5. Investigation of Various Wind Turbine Drivetrain Condition Monitoring Techniques

    SciTech Connect

    Sheng, S.; Oyague, F.; Butterfield, S.

    2010-08-01

    The wind industry has experienced premature turbine component failures during the past years. With the increase in turbine size, these failures, especially those found in the major drivetrain components, i.e. main shaft, gearbox, and generator, have become extremely costly. Given that the gearbox is the most costly component in the drivetrain to fix, the National Renewable Energy Laboratory (NREL) initiated the Gearbox Reliability Collaborative (GRC) to determine the causes for premature gearbox failures and subsequently, recommend improvements to gearbox design, manufacture, and operational practices. The GRC has two identical test gearboxes, which are planned for a dynamometer and a field test, respectively.

  6. Wind tunnel study on wind and turbulence intensity profiles in wind turbine wake

    Microsoft Academic Search

    Takao Maeda; Yasunari Kamada; Junsuke Murata; Sayaka Yonekura; Takafumi Ito; Atsushi Okawa; Tetsuya Kogaki

    2011-01-01

    In recent years, there has been a rapid development of the wind farms in Japan. It becomes very important to investigate the\\u000a wind turbine arrangement in wind farm, in order that the wake of one wind turbine does not to interfere with the flow in other\\u000a wind turbines. In such a case, in order to achieve the highest possible efficiency

  7. Present Status of Aeroelasticity of Wind Turbines

    NASA Astrophysics Data System (ADS)

    Rasmussen, Flemming; Hartvig Hansen, Morten; Thomsen, Kenneth; Larsen, Torben Juul; Bertagnolio, Franck; Johansen, Jeppe; Aagaard Madsen, Helge; Bak, Christian; Melchior Hansen, Anders

    2003-07-01

    Aeroelasticity is a key issue in the continuing development of wind turbines towards large, flexible, highly optimized machines. The steadily increasing technology level is reflected not necessarily by the complexity of the turbines, but by the level of knowledge and advanced principles that are taken into account during the design process and incorporated in the final optimized design. This article examines some of the main uncertainties within aeroelastic modelling of wind turbines that have been hard to resolve over the years of research, and also presents perspectives for the new aeroelastic challenges, both from the viewpoint of the researchers at Risø National Laboratory.

  8. Jet spoiler arrangement for wind turbine

    SciTech Connect

    Cyrus, J. D.; Kadlec, E. G.; Klimas, P. C.

    1985-03-12

    An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the ends thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby inducing stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

  9. How to protect a wind turbine from lightning

    NASA Technical Reports Server (NTRS)

    Dodd, C. W.; Mccalla, T., Jr.; Smith, J. G.

    1983-01-01

    Techniques for reducing the chances of lightning damage to wind turbines are discussed. The methods of providing a ground for a lightning strike are discussed. Then details are given on ways to protect electronic systems, generating and power equipment, blades, and mechanical components from direct and nearby lightning strikes.

  10. How to protect a wind turbine from lightning

    SciTech Connect

    Dodd, C.W.; McCalla, T. Jr.; Smith, J.G.

    1983-09-01

    This book discusses techniques for reducing the chances of lightning damage to wind turbines. The methods of providing a ground for a lightning strike are discussed. Then details are given on ways to protect electronic systems, generating and power equipment, blades, and mechanical components from direct and nearby lightning strikes.

  11. Stereo PIV Experiments on Horizontal Axis Wind Turbine Rotor Model

    Microsoft Academic Search

    B. Akay; D. Micallef; C. S. Ferreira; G. J. W. Van Bussel

    2011-01-01

    This paper sets out to describe the measurements and computations to construct three components of velocity field around the blade. The primary aim of the measurements was to gain insight into the physics of the flow field produced by a horizontal axis wind turbine-HAWT blade. Stereo Particle Image Velocimetry experiments were performed on a two-bladed HAWT rotor in the open

  12. Torque ripple in a Darrieus, vertical axis wind turbine

    SciTech Connect

    Reuter, R.C. Jr.

    1980-01-01

    Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon power quality. An analytical solution characterizing the phenomenon of torque ripple has been obtained which is based upon a Fourier expansion of the time dependent features of the problem. Numerical results for torque ripple, some experimental data, determination of acceptable levels and methods of controlling it, are presented and discussed.

  13. Local blockage effect for wind turbines

    NASA Astrophysics Data System (ADS)

    Nishino, Takafumi; Draper, Scott

    2015-06-01

    This paper presents a combined theoretical and CFD study on the fluid-mechanical limit of power extraction by a closely-spaced lateral array of wind turbines. The idea of this study originates in recent studies on the array optimisation of tidal/marine turbines, for which the power coefficient of each turbine is known to increase significantly if the lateral spacing between turbines, or the local blockage, is optimised. The present study, using 3D Reynolds- averaged Navier-Stokes (RANS) simulations of a boundary-layer flow over a closely-spaced lateral array of up to 9 actuator discs, suggests that a similar—albeit less significant—power increase due to the effect of local blockage can be achieved even for wind turbines. A possible theoretical approach to estimating this power increase is also discussed.

  14. Innovative wind turbines. Circulation controlled vertical axis wind turbine. Progress report, March 1December 31, 1976

    Microsoft Academic Search

    R. E. Walters; J. B. Fanucci; P. W. Hill; P. G. Migliore; W. Squire; T. L. Waltz

    1978-01-01

    Theoretical and experimental research efforts in evaluating an innovative concept for vertical axis wind turbines (VAWT) are described. The concept is that of using straight blades composed of circulation controlled airfoil sections. The theoretical analysis has been developed to determine the unsteady lift and moment characteristics of multiple-blade cross-flow wind turbines. To determine the drag data needed as input to

  15. Wind turbulence inputs for horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Holley, W. E.; Thresher, R. W.; Lin, S. R.

    1981-01-01

    Wind turbine response characteristics in the presence of atmospheric turbulence was predicted using two major modeling steps. First, the important atmospheric sources for the force excitations felt by the wind turbine system were identified and characterized. Second, a dynamic model was developed which describes how these excitations are transmitted through the structure and power train. The first modeling step, that of quantifying the important excitations due to the atmospheric turbulence was established. The dynamic modeling of the second step was undertaken separately.

  16. Research and development for shrouded wind turbines

    Microsoft Academic Search

    O. Igra

    1981-01-01

    A special shroud, designed for enclosing a wind turbine in order to exploit wind power as economically as possible, is presented. Several geometries, including the short diffuser shroud and the circular wing shroud, are discussed, and it is shown that a significant power augmentation can be achieved with a fairly compact shroud. Up to an 80% improvement in the shroud

  17. Darrieus vertical axis wind turbine program overview

    Microsoft Academic Search

    Braasch

    2008-01-01

    As a US Department of Energy (DOE) laboratory, Sandia Laboratories is developing Darrieus vertical axis wind turbine (VAWT) technology with the objective of encouraging private industry to produce economically feasible, commercially marketable wind energy systems. The first full cycle of development is essentially complete, and resulting current technology designs have been evaluated for cost-effectiveness. Aerodynamic, structural, and system analyses capabilities

  18. Practical aspects for small wind turbine applications

    Microsoft Academic Search

    Y. Tripanagnostopoulos; A. Christodoulou; S. Tselepis; M. Souliotis; J. K. Tonui

    SUMMARY Low power wind turbines (WTs) are less widely applied compared to medium and high power systems. These WTs are suitable for decentralized applications and can provide electricity to residential buildings, hotels, greenhouses, etc. These WTs can be of horizontal or vertical rotor axis, must be of low cut-in wind speed and flexible in installation and operation, considering their limits

  19. Cambridge Danehy Park Wind Turbine Preliminary Project Assessment

    E-print Network

    Cambridge Danehy Park Wind Turbine Preliminary Project Assessment Overview MIT Wind Energy Projects 4 / 25 2.5 / 25 Rated Wind Speed (m/s) 13 10 14.5 ~15 12 The above turbines were chosen to provide, several recent studies examining birds and wind turbines have observed that most birds usually avoid

  20. Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation

    E-print Network

    Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation Clemens Jauch Risø National: In this paper it is investigated how active-stall wind turbines can contribute to the stabilisation of the power. Introduction As wind power penetration reaches considerable levels, power system operators demand wind turbines

  1. Fixed pitch rotor performance of large horizontal axis wind turbines

    Microsoft Academic Search

    L. A. Viterna; R. D. Corrigan

    1982-01-01

    Experimental fixed pitch wind turbine performance data is presented for both the DOE\\/NASA Mod-0 and the Danish Gedser wind turbines. Furthermore, a method for calculating the output power from large fixed pitch wind turbines is presented. Modifications to classical blade element momentum theory are given that improve correlation with measured data. Improvement is particularly evident in high winds (low tip

  2. Dynamic Simulation of DFIG Wind Turbines on FPGA Boards

    E-print Network

    Zambreno, Joseph A.

    Dynamic Simulation of DFIG Wind Turbines on FPGA Boards Hao Chen, Student Member, IEEE, Song Sun is a friction coefficient. The wind turbine model is based on the relation between the upstream wind speed V w + 1 where p is the air density; Rw is the wind turbine radius; cp (A, (3) is the performance

  3. Influence of wind characteristics on turbine performance Ioannis Antoniou (1)

    E-print Network

    at the Danish test station for wind turbines in Hovsore, have been analyzed up to a height of 165m for a oneInfluence of wind characteristics on turbine performance Ioannis Antoniou (1) , Rozenn Wagner (1 this is that the wind speed is representative of the wind over the whole turbine rotor. While this assumption

  4. Wave Models for Offshore Wind Turbines Puneet Agarwal

    E-print Network

    Manuel, Lance

    Wave Models for Offshore Wind Turbines Puneet Agarwal§ and Lance Manuely Department of Civil practice for modeling waves on offshore wind turbines is limited to the representation of linear irregular for the turbine and for the input wind/wave conditions. While for the wind, inflow turbu- lence models are fairly

  5. Integrated monitoring of offshore wind turbines – requirements, concepts and experiences

    Microsoft Academic Search

    Rolf Günter Rohrmann; Sebastian Thöns; Werner Rücker

    2010-01-01

    Wind turbines on offshore sites (OWECs) are subjected to combined loads from wind and waves. These dynamic loads, with a frequency content within the range of the natural frequencies of the structures, cause fatigue-effective stresses in the substructures of wind turbines. Therefore, the examination of natural frequencies is an important part within the design process of wind turbines. The quality

  6. Quantifying the hurricane risk to offshore wind turbines

    E-print Network

    Jaramillo, Paulina

    Quantifying the hurricane risk to offshore wind turbines Stephen Rosea , Paulina Jaramilloa,1. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind

  7. The Research and Development Platform for Wind Energy System Used Induction Motor Replacing Wind Turbine

    Microsoft Academic Search

    Ming Qiao; Fei Lin; Ruixiang Hao; Xiaojie You; Trillion Q Zheng

    2007-01-01

    A research platform for wind energy system is developed in this paper. An inverter fed induction motor drive the wind generator replacing a real wind turbine. The power-speed characteristics of a wind turbine are physically implemented by an induction motor drive. For a given wind turbine characteristics, the shaft torque of induction motor is calculated by the given wind speed

  8. Real-time wind turbine emulator for testing wind energy conversion systems

    Microsoft Academic Search

    Santaphon Kumsup; C. Tarasantisuk

    2010-01-01

    The paper presents the development of wind turbine emulator which consists of an induction motor, torque inverter and real-time interface card. The wind turbine emulator system includes wind speed profiles, mathematical model of wind turbines, modeling of rotor blade characteristics and modeling of rotor inertia. Wind speed can be easily programmed based on white noise random model, or recorded wind

  9. Innovative wind turbines. The circulation control vertical axis wind turbine. Final report, May 1, 1978December 31, 1979

    Microsoft Academic Search

    R. E. Walters; P. G. Migliore; W. P. Wolfe

    1980-01-01

    An indoor facility was developed for use in the aerodynamic testing of Darrieus wind turbine blades. A three-component internal strain gage balance was used to deduce lift, drag and moment coefficients of blades whose angle of attack, chord to radius ratio and Reynolds number can be systematically varied. The unusual flow field of this test environment necessitates unique downwash corrections

  10. Broad band sound from wind turbine generators

    NASA Technical Reports Server (NTRS)

    Hubbard, H. H.; Shepherd, K. P.; Grosveld, F. W.

    1981-01-01

    Brief descriptions are given of the various types of large wind turbines and their sound characteristics. Candidate sources of broadband sound are identified and are rank ordered for a large upwind configuration wind turbine generator for which data are available. The rotor is noted to be the main source of broadband sound which arises from inflow turbulence and from the interactions of the turbulent boundary layer on the blade with its trailing edge. Sound is radiated about equally in all directions but the refraction effects of the wind produce an elongated contour pattern in the downwind direction.

  11. Variable diameter wind turbine rotor blades

    DOEpatents

    Jamieson, Peter McKeich; Hornzee-Jones, Chris; Moroz, Emilian M.; Blakemore, Ralph W.

    2005-12-06

    A system and method for changing wind turbine rotor diameters to meet changing wind speeds and control system loads is disclosed. The rotor blades on the wind turbine are able to adjust length by extensions nested within or containing the base blade. The blades can have more than one extension in a variety of configurations. A cable winching system, a hydraulic system, a pneumatic system, inflatable or elastic extensions, and a spring-loaded jack knife deployment are some of the methods of adjustment. The extension is also protected from lightning by a grounding system.

  12. Wind Turbine Micropitting Workshop: A Recap

    SciTech Connect

    Sheng, S.

    2010-02-01

    Micropitting is a Hertzian fatigue phenomenon that affects many wind turbine gearboxes, and it affects the reliability of the machines. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The U.S. Department of Energy has made a commitment to improving wind turbine reliability and the National Renewable Energy Laboratory (NREL) has started a gearbox reliability project. Micropitting as an issue that needed attention came to light through this effort. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of the issue by acknowledged experts, NREL hosted a wind turbine micropitting workshop, which was held at the National Wind Technology Center in Boulder, Colorado, on April 15 and 16, 2009.

  13. Active robust control of wind turbines

    NASA Astrophysics Data System (ADS)

    Rezaei, Vahid

    The research work conducted in this thesis focuses on robustness of wind energy conversion system with respect to faults in pitch actuator in order to prevent unnecessary emergency shutdown, and keep the turbine operational without significant inefficiency in its overall performance. The objective is to investigate the feasibility of using a fault estimator and a light detection and ranging (LIDAR) system as additional sensors to design a suitable control system for wind turbines. Robust control technique is used to address these issues. Three controllers are proposed in this work that try to address sources of inaccuracy in wind turbine operation: An active fault tolerant controller is first designed using a fault estimator. It is shown that a set of locally robust controllers with respect to the fault, together with a suitable smooth mixing approach, manages to overcome the problem of faults in the pitch actuator. To address the wind-dependent behavior of turbines, a second controller is designed using the LIDAR sensor. In this configuration, LIDAR provides the look ahead wind information and generates a smooth scheduling signal to provide active robustness with respect to the changes in wind speed. Lastly, utilizing both the fault estimator and LIDAR, a 2-dimensional wind-dependent active fault tolerant controller is developed to control the wind turbine in region 3 of operation. The feasibility of the proposed ideas is verified in simulation. For this purpose, the US National Renewable Energy Laboratory's FAST code is used to model the 3-balded controls advanced research turbine. A discussion on practical considerations and ideas for future work are also presented.

  14. Optimal, reliability-based turbine placement in offshore wind turbine parks

    Microsoft Academic Search

    J. D. Sørensen

    2007-01-01

    Offshore wind turbines for electricity production placed in wind farms are expected to be of one of the major future contributors for sustainable energy production. In this article, some of the problems associated with optimal planning and design of wind turbine parks are addressed. The number of wind turbines in a park is usually restricted to be placed within a

  15. Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine

    SciTech Connect

    Huskey, A.; Bowen, A.; Jager, D.

    2010-05-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is one of up to five tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. This duration test report focuses on the Mariah Power Windspire wind turbine.

  16. Wind Turbine Safety and Function Test Report for the ARE 442 Wind Turbine

    SciTech Connect

    van Dam, J.; Baker, D.; Jager, D.

    2010-02-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, four turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests that were performed on the turbines, including power performance, duration, noise, and power quality tests. Test results provide manufacturers with reports that can be used for small wind turbine certification. The test equipment includes an ARE 442 wind turbine mounted on a 100-ft free-standing lattice tower. The system was installed by the NWTC Site Operations group with guidance and assistance from Abundant Renewable Energy.

  17. Wind commercialization and Alcoa Vertical Axis Wind Turbines

    Microsoft Academic Search

    P. N. Vosburgh

    1979-01-01

    Five basic Darrieus-type Vertical Axis Wind Turbines which feature a troposkein shaped rotor blade are described along with the operation of several research machines including one of 17 m (60 kW) height and 61 cm chord blades that has demonstrated a performance coefficient of 42%. Some of the advantages of the design are the utilization of winds from all directions,

  18. The Darrieus wind turbine for electrical power generation

    NASA Astrophysics Data System (ADS)

    Robinson, M. L.

    1981-06-01

    Aspects of wind as an energy source and the momentum theory of wind turbines are briefly examined. Types of Darrieus wind turbine are described; attention is given to a turbine with airfoil blades curved in troposkein form, and a turbine with straight blades of fixed or variable pitch. The Darrieus vertical-axis wind turbine is then considered with regard to aerodynamics, annual energy output, structures, control systems, and energy storage. Brief reviews of selected Darrieus wind turbine projects are given, including those at Magdalen Islands, Canada, Sandia Laboratories, Reading University, and Australia and New Zealand.

  19. Multi-hazard Reliability Assessment of Offshore Wind Turbines 

    E-print Network

    Mardfekri Rastehkenari, Maryam 1981-

    2012-12-04

    A probabilistic framework is developed to assess the structural reliability of offshore wind turbines. Probabilistic models are developed to predict the deformation, shear force and bending moment demands on the support structure of wind turbines...

  20. Reduced Order Structural Modeling of Wind Turbine Blades 

    E-print Network

    Jonnalagadda, Yellavenkatasunil

    2011-10-21

    Conventional three dimensional structural analysis methods prove to be expensive for the preliminary design of wind turbine blades. However, wind turbine blades are large slender members with complex cross sections. They can be accurately modeled...

  1. Multi-hazard Reliability Assessment of Offshore Wind Turbines

    E-print Network

    Mardfekri Rastehkenari, Maryam 1981-

    2012-12-04

    A probabilistic framework is developed to assess the structural reliability of offshore wind turbines. Probabilistic models are developed to predict the deformation, shear force and bending moment demands on the support structure of wind turbines...

  2. Mars Technologies Spawn Durable Wind Turbines

    NASA Technical Reports Server (NTRS)

    2014-01-01

    To develop and test wind power technology for use on Mars, Ames Research Center turned to Northern Power Systems (NPS), based in Barre, Vermont. Ames awarded NPS an SBIR contract so the company could enhance their turbine’s function. Today, over 200 NASA-derived Northern Power 100s are in operation on Earth and have reduced carbon emissions by 50,000 tons annually.

  3. Methods of making wind turbine rotor blades

    DOEpatents

    Livingston, Jamie T. (Pensacola, FL); Burke, Arthur H. E. (Gulf Breeze, FL); Bakhuis, Jan Willem (Nijverdal, NL); Van Breugel, Sjef (Enschede, NL); Billen, Andrew (Daarlerveen, NL)

    2008-04-01

    A method of manufacturing a root portion of a wind turbine blade includes, in an exemplary embodiment, providing an outer layer of reinforcing fibers including at least two woven mats of reinforcing fibers, providing an inner layer of reinforcing fibers including at least two woven mats of reinforcing fibers, and positioning at least two bands of reinforcing fibers between the inner and outer layers, with each band of reinforcing fibers including at least two woven mats of reinforcing fibers. The method further includes positioning a mat of randomly arranged reinforcing fibers between each pair of adjacent bands of reinforcing fibers, introducing a polymeric resin into the root potion of the wind turbine blade, infusing the resin through the outer layer, the inner layer, each band of reinforcing fibers, and each mat of random reinforcing fibers, and curing the resin to form the root portion of the wind turbine blade.

  4. The NASA Lewis large wind turbine program

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Baldwin, D. H.

    1981-01-01

    The program is directed toward development of the technology for safe, reliable, environmentally acceptable large wind turbines that have the potential to generate a significant amount of electricity at costs competitive with conventional electric generation systems. In addition, these large wind turbines must be fully compatible with electric utility operations and interface requirements. Advances are made by gaining a better understanding of the system design drivers, improvements in the analytical design tools, verification of design methods with operating field data, and the incorporation of new technology and innovative designs. An overview of the program activities is presented and includes results from the first and second generation field machines (Mod-OA, -1, and -2), the design phase of the third generation wind turbine (Mod-5) and the advanced technology projects. Also included is the status of the Department of Interior WTS-4 machine.

  5. Innovative system for wind turbine testing

    SciTech Connect

    Camporeale, S.M.; Fortunato, B.; Marilli, G.

    1998-07-01

    An innovative system for testing small wind turbine models, is presented. The system is especially designed for Darrieus type turbines. The turbine is directly coupled to a direct current machine and a chopper, electronically controlled by means of a Pulse Width Modulator, is used to supply the circuit. The system is used for driving the turbine during the start-up procedure and for braking at various speeds during the performance test. In the paper the main characteristics of the electronic system are described and compared with a traditional system. The main goal of the electronic control is to increase the accuracy in the measurements of torque and speed for each steady state point of the turbine characteristic curve. Another useful advantage provided by the electronic control is related to the possibility of fine tuning the load in order to obtain a large number of steady state experimental points describing the characteristic curve of the turbine. Moreover the system is suitable for integration in an automatic data acquisition and control system. The experimental results, obtained in testing a small turbine in a wind tunnel by means of the electronic control system are presented and discussed at the end of the paper.

  6. Shear and Turbulence Estimates for Calculation of Wind Turbine Loads and Responses Under Hurricane Strength Winds

    NASA Astrophysics Data System (ADS)

    Kosovic, B.; Bryan, G. H.; Haupt, S. E.

    2012-12-01

    Schwartz et al. (2010) recently reported that the total gross energy-generating offshore wind resource in the United States in waters less than 30m deep is approximately 1000 GW. Estimated offshore generating capacity is thus equivalent to the current generating capacity in the United States. Offshore wind power can therefore play important role in electricity production in the United States. However, most of this resource is located along the East Coast of the United States and in the Gulf of Mexico, areas frequently affected by tropical cyclones including hurricanes. Hurricane strength winds, associated shear and turbulence can affect performance and structural integrity of wind turbines. In a recent study Rose et al. (2012) attempted to estimate the risk to offshore wind turbines from hurricane strength winds over a lifetime of a wind farm (i.e. 20 years). According to Rose et al. turbine tower buckling has been observed in typhoons. They concluded that there is "substantial risk that Category 3 and higher hurricanes can destroy half or more of the turbines at some locations." More robust designs including appropriate controls can mitigate the risk of wind turbine damage. To develop such designs good estimates of turbine loads under hurricane strength winds are essential. We use output from a large-eddy simulation of a hurricane to estimate shear and turbulence intensity over first couple of hundred meters above sea surface. We compute power spectra of three velocity components at several distances from the eye of the hurricane. Based on these spectra analytical spectral forms are developed and included in TurbSim, a stochastic inflow turbulence code developed by the National Renewable Energy Laboratory (NREL, http://wind.nrel.gov/designcodes/preprocessors/turbsim/). TurbSim provides a numerical simulation including bursts of coherent turbulence associated with organized turbulent structures. It can generate realistic flow conditions that an operating turbine would encounter under hurricane strength winds. These flow fields can be used to estimate wind turbine loads and responses with AeroDyn (http://wind.nrel.gov/designcodes/simulators/aerodyn/) and FAST (http://wind.nrel.gov/designcodes/simulators/fast/) codes also developed by NREL.

  7. The Effect of Wind Speed and Electric Rates On Wind Turbine Economics

    E-print Network

    Massachusetts at Amherst, University of

    The Effect of Wind Speed and Electric Rates On Wind Turbine Economics Economics of wind power depends mainly on the wind speeds and the turbine make and model. Definition: Simple Payback The "Simple period of a small wind power project. All the figures are per turbine, so it can be used for a one, two

  8. Aileron controls for wind turbine applications

    NASA Technical Reports Server (NTRS)

    Miller, D. R.; Putoff, R. L.

    1984-01-01

    Horizontal axis wind turbines which utilize partial or full variable blade pitch to regulate rotor speed were examined. The weight and costs of these systems indicated a need for alternate methods of rotor control. Aileron control is an alternative which has potential to meet this need. Aileron control rotors were tested on the Mod-O wind turbine to determine their power regulation and shutdown characteristics. Test results for a 20 and 38% chord aileron control rotor are presented. Test is shown that aileron control is a viable method for safety for safely controlling rotor speed, following a loss of general load.

  9. Wind turbine dynamics. NASA conference Publication 2185

    SciTech Connect

    Thresher, R.W. (ed.)

    1981-01-01

    The Second DOE/NASA Wind Turbine Dynamics Workshop was held in Cleveland, Ohio, February 24-26, 1981. Papers were presented on the dynamic behavior of large and small horizontal-axis and vertical-axis wind turbines. A total of 48 papers were contributed and are included in this proceeding. Contributors include universities, manufacturers, government laboratories, and private research organizations. The papers discuss a variety of topics including aerodynamics, structural dynamics, electrical system dynamics, control dynamics, and acoustics. Summaries of the informative discussions held at the workshop as well as the questions and answers which followed each paper are documented in the proceedings.

  10. Dynamic stall on wind turbine blades

    SciTech Connect

    Butterfield, C.P.; Simms, D.; Scott, G. (National Renewable Energy Lab., Golden, CO (United States)); Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))

    1991-12-01

    Dynamic loads must be predicted accurately in order to estimate the fatigue life of wind turbines operating in turbulent environments. Dynamic stall contributes to increased dynamic loads during normal operation of all types of horizontal-axis wind turbine (HAWTs). This report illustrates how dynamic stall varies throughout the blade span of a 10 m HAWT during yawed and unyawed operating conditions. Lift, drag, and pitching moment coefficients during dynamics stall are discussed. Resulting dynamic loads are presented, and the effects of dynamic stall on yaw loads are demonstrated using a yaw loads dynamic analysis (YAWDYN). 12 refs., 22 figs., 1 tab.

  11. Experimental characterization of vertical-axis wind turbine noise.

    PubMed

    Pearson, C E; Graham, W R

    2015-01-01

    Vertical-axis wind turbines are wind-energy generators suitable for use in urban environments. Their associated noise thus needs to be characterized and understood. As a first step, this work investigates the relative importance of harmonic and broadband contributions via model-scale wind-tunnel experiments. Cross-spectra from a pair of flush-mounted wall microphones exhibit both components, but further analysis shows that the broadband dominates at frequencies corresponding to the audible range in full-scale operation. This observation has detrimental implications for noise-prediction reliability and hence also for acoustic design optimization. PMID:25618090

  12. EFFECTS OF FIBER WAVINESS ON COMPOSITES FOR WIND TURBINE BLADES

    E-print Network

    EFFECTS OF FIBER WAVINESS ON COMPOSITES FOR WIND TURBINE BLADES J.F. Mandell D.D. Samborsky and L Composite materials of interest for wind turbine blades use relatively low cost fibers, resins and processes WORDS: Composite Materials, Fiber Waviness, Compressive Strength #12;1. INTRODUCTION Wind turbine blades

  13. Ris-R-1209(EN) European Wind Turbine Testing

    E-print Network

    Risø-R-1209(EN) European Wind Turbine Testing Procedure Developments Task 1: Measurement Method to Verify Wind Turbine Performance Character- istics Raymond Hunter RES Task coordinator Troels Friis assessment and wind turbine power performance testing. A standards maintenance team is revising the current

  14. Mechanisms of amplitude modulation in wind turbine , A. J. Bullmoreb

    E-print Network

    Paris-Sud XI, Université de

    Mechanisms of amplitude modulation in wind turbine noise M. Smitha , A. J. Bullmoreb , M. M. Candb produced by wind turbines is inherently time varying. This amplitude modulation is normally due The environmental noise impact of wind turbine generators has to be assessed when planning new installations

  15. ACOUSTIC STUDY OF THE UD / GAMESA WIND TURBINE PROJECT

    E-print Network

    Firestone, Jeremy

    ACOUSTIC STUDY OF THE UD / GAMESA WIND TURBINE PROJECT LEWES, DELAWARE January 2009 #12;ACOUSTIC STUDY OF THE UNIVERSITY OF DELAWARE / GAMESA WIND TURBINE PROJECT LEWES, DELAWARE Prepared for SUMMARY The University of Delaware (UD), Lewes proposes to locate a Gamesa G90 2.0MW wind turbine

  16. Control of Wind Turbines for Power Regulation and

    E-print Network

    Control of Wind Turbines for Power Regulation and Load Reduction Juan Jose Garcia Quirante Kongens regulation and load reduction and their ensemble in a variable-speed wind turbine. The power regulation aspects of mathematical modelling of wind turbines, and especially the control methods suited for power

  17. Fast Verification of Wind Turbine Power Summary of Project Results

    E-print Network

    Fast Verification of Wind Turbine Power Curves: Summary of Project Results by: Cameron Brown ­ s equation on high frequency wind turbine measurement data sampled at one sample per second or more. The aim's Nordtank wind turbine at the Risø site, the practical application of this new method was tested

  18. Disturbance Control of the Hydraulic Brake in a Wind Turbine

    E-print Network

    Yang, Zhenyu

    Disturbance Control of the Hydraulic Brake in a Wind Turbine Frank Jepsen, Anders Søborg brake in a wind turbine. Brake torque is determined by friction coefficient and clamp force; the latter brake is one1 of the two independent brake systems in a wind turbine. As a consequence of the gearing

  19. Offshore Series Wind Turbine Variable Hub heights & rotor diameters

    E-print Network

    Firestone, Jeremy

    3.6MW Offshore Series Wind Turbine GE Energy #12;Feature Variable Hub heights & rotor diameters harmonious function within the local grid Allows wind turbines to stay on line generating power, even during-savings feature, considering the rigors of offshore power generation. The 3.6 MW offshore wind turbine also

  20. Flicker emission of wind turbines during continuous operation

    Microsoft Academic Search

    Åke Larsson

    2002-01-01

    This paper presents an analysis and the modeling of the flicker emission of wind turbines. Measurements compared with international standards are discussed. The paper concentrates on the theoretical aspects of the flicker algorithm, wind turbine characteristics and the generation of flicker during continuous operation of wind turbines

  1. SOUND COMPLIANCE MONITORING FOR THE GAMESA WIND TURBINE

    E-print Network

    Firestone, Jeremy

    SOUND COMPLIANCE MONITORING FOR THE GAMESA WIND TURBINE UD - LEWES, DELAWARE January 2011 ` #12;SOUND COMPLIANCE MONITORING FOR THE GAMESA WIND TURBINE AT THE UNIVERSITY OF DELAWARE LEWES, DELAWARE A Gamesa G90 2.0-MW wind turbine operates at the University of Delaware (UD), Lewes campus on a parcel

  2. Initialization of wind turbine models in power system dynamics simulations

    Microsoft Academic Search

    J. G. Slootweg; H. Polinder; W. L. Kling

    2001-01-01

    As a result of increasing environmental concern, increasing amounts of electricity are generated from renewable sources. One way of generating electricity from renewable sources is to use wind turbines. A tendency to erect more wind turbines can be observed. As a result of this, in the near future wind turbines may start to influence the behavior of electrical power systems.

  3. Dynamics and Fatigue Damage of Wind Turbine Rotors

    E-print Network

    6 3 RiS0-Rr512 Dynamics and Fatigue Damage of Wind Turbine Rotors during Steady Operation Peter OF WIND TURBINE ROTORS DURING STEADY OPERATION Peter Hauge Madsen, Sten Frandsen, William E. Holley-carrying capacity of a wind turbine rotor with respect to short-term strength and material fatigue are presented

  4. Duration Test Report for the Entegrity EW50 Wind Turbine

    SciTech Connect

    Smith, J.; Huskey, A.; Jager, D.; Hur, J.

    2012-12-01

    This report summarizes the results of a duration test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

  5. innovati nWind Turbine Design Innovations Drive Industry Transformation

    E-print Network

    innovati nWind Turbine Design Innovations Drive Industry Transformation For more than 20 years. Tackling Turbine Blade Inefficiencies In 1984, NREL researchers began investigating problems with wind turbine blade designs. Inefficiency was a significant barrier to lowering the cost of wind energy

  6. Vortex Lattice Modelling of Winglets on Wind Turbine Blades

    E-print Network

    Vortex Lattice Modelling of Winglets on Wind Turbine Blades Mads Døssing Risø-R-1621(EN) Risø Title: Vortex Lattice Modelling of Winglets on Wind Turbine Blades Departments: Wind Energy Department turbines can be increased by the use of winglets without increasing the swept area. This makes them

  7. Load Alleviation on Wind Turbine Blades using Variable Airfoil Geometry

    E-print Network

    Load Alleviation on Wind Turbine Blades using Variable Airfoil Geometry Peter Bjørn Andersen, Mac to 40% when signal noise is added to the control. Keywords: Wind Turbine, Load Alleviation, Fatigue Loads, Trailing Edge Flaps, PID control, Signal Noise. 1 Introduction Wind turbine blades are subject

  8. A Simplified Morphing Blade for Horizontal Axis Wind Turbines

    E-print Network

    Recanati, Catherine

    A Simplified Morphing Blade for Horizontal Axis Wind Turbines Weijun WANG , St´ephane CARO, Fouad salinas@hotmail.com The aim of designing wind turbine blades is to improve the power capture ability by adjusting the twist of the blade's root and tip. To evaluate the performance of wind turbine blades

  9. Detection of aeroacoustic sound sources on aircraft and wind turbines

    E-print Network

    Twente, Universiteit

    Detection of aeroacoustic sound sources on aircraft and wind turbines Stefan Oerlemans #12;Detection of aeroacoustic sound sources on aircraft and wind turbines S. Oerlemans Thesis University;DETECTION OF AEROACOUSTIC SOUND SOURCES ON AIRCRAFT AND WIND TURBINES PROEFSCHRIFT ter verkrijging van de

  10. Ris-R-1352(EN) Models for Wind Turbines

    E-print Network

    Risø-R-1352(EN) Models for Wind Turbines ­ a Collection Andreas Baumgart Gunner C. Larsen, Morten H is to supply new approaches to stability investigations of wind turbines. The author's opinion #12;Contents 1 Preface 5 2 Author's Notes 7 3 Theory of Rods applied to Wind Turbine Blades 9 3

  11. Sparkr Blade Test Centre Modal Analysis of Wind Turbine Blades

    E-print Network

    Sparkær Blade Test Centre Modal Analysis of Wind Turbine Blades Modal analysis is the process for characterization of the dynamic properties of a mechanical system. The free dynamic response of the wind turbine the modes constitute a complete dynamic description of the wind turbine blade. The modes of vibration

  12. Research on floating wind turbines: a literature survey

    Microsoft Academic Search

    C. M. Wang; T. Utsunomiya; S. C. Wee; Y. S. Choo

    2010-01-01

    This article presents a literature survey of research and development on floating wind turbines. The various, proposed conceptual designs for floating platforms used for floating wind turbines are described and the working principles of these various floater concepts are outlined. This is followed by an overview of the research work that has been undertaken pertaining to floating wind turbine technology

  13. Study on Lightning Protection Methods for Wind Turbine Blades

    Microsoft Academic Search

    Takehiro Naka; Nilesh J. Vasa; Shigeru Yokoyama; Atsushi Wada; Akira Asakawa; Hideki Honda; Kazuhisa Tsutsumi; Shinji Arinaga

    2005-01-01

    Lightning protection measures for wind turbines are becoming important as the use of wind turbines is increasing rapidly along with its capacity and height. In order to understand the manner of lightning attachment to wind turbine blades, experiments with various types of blade samples were conducted. Experimental studies revealed following issues. Regarding a non-conductive blade sample, the 50% flashover voltage

  14. Taming Hurricanes With Arrays of Offshore Wind Turbines

    E-print Network

    Firestone, Jeremy

    Taming Hurricanes With Arrays of Offshore Wind Turbines Mark Z. Jacobson Cristina Archer, Willet #12;Representation of a vertically-resolved wind turbine in model Lines are model layers) or 50 m/s (destruction) speed. Can Walls of Offshore Wind Turbines Dissipate Hurricanes? #12;Katrina

  15. Design of ceramic gas turbine components

    SciTech Connect

    Stuermer, G.; Fundus, M.; Schultz, A.; Wittig, S. (Lehrstuhl und Inst. fuer Thermische, Stroemungsmaschinen, Univ. Karlsruhe, D-7500 Karlsruhe (DE))

    1991-10-01

    At the Institute for Thermal Turbomachinery (ITS), University of Karlsruhe, detailed theoretical and experimental studies concerning gas turbine components have been performed. For the analysis of the reliability of ceramic components by finite element calculations, the numerical code CERITS has been developed, which follows a strategy similar to that suggested by Gyekenyesi. CERITS determines the failure probability of ceramic components with reference to volumetric flaws. Different fracture criteria can be considered. CERITS is coupled to the finite element code ADINA, which facilitates the prediction of the required temperature and stress distributions. In this paper the procedure is demonstrated utilizing gas turbine combustor components.

  16. Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

    Microsoft Academic Search

    Pamela M. Aker; Anthony M. Jones; Andrea E. Copping

    2010-01-01

    Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at

  17. Flow separation on wind turbines blades

    Microsoft Academic Search

    G. P. Corten

    2001-01-01

    In the year 2000, 15GW of wind power was installed throughout the world, producing 100PJ\\u000aof energy annually. This contributes to the total electricity demand by only 0.2%. Both the\\u000ainstalled power and the generated energy are increasing by 30% per year world-wide. If the\\u000aairflow over wind turbine blades could be controlled fully, the generation efficiency and thus\\u000athe

  18. Built-Environment Wind Turbine Roadmap

    SciTech Connect

    Smith, J.; Forsyth, T.; Sinclair, K.; Oteri, F.

    2012-11-01

    Although only a small contributor to total electricity production needs, built-environment wind turbines (BWTs) nonetheless have the potential to influence the public's consideration of renewable energy, and wind energy in particular. Higher population concentrations in urban environments offer greater opportunities for project visibility and an opportunity to acquaint large numbers of people to the advantages of wind projects on a larger scale. However, turbine failures will be equally visible and could have a negative effect on public perception of wind technology. This roadmap provides a framework for achieving the vision set forth by the attendees of the Built-Environment Wind Turbine Workshop on August 11 - 12, 2010, at the U.S. Department of Energy's National Renewable Energy Laboratory. The BWT roadmap outlines the stakeholder actions that could be taken to overcome the barriers identified. The actions are categorized as near-term (0 - 3 years), medium-term (4 - 7 years), and both near- and medium-term (requiring immediate to medium-term effort). To accomplish these actions, a strategic approach was developed that identifies two focus areas: understanding the built-environment wind resource and developing testing and design standards. The authors summarize the expertise and resources required in these areas.

  19. Dynamic instability of small-scale wind turbine blades

    NASA Astrophysics Data System (ADS)

    Pourazarm, Pariya; Modarres-Sadeghi, Yahya; Lackner, Matthew

    2013-11-01

    Future wind turbine blades will become larger, and therefore more flexible. For more flexible blades, the ratio of the estimated critical speed for dynamic instability to the operating speed decreases, and the blades are more susceptible to such instabilities. In the current work, the dynamic instability of a rotating wind turbine blade is studied using a numerical stability analysis and supported by experimental results. For the experimental component of the work, a series of tests were conducted in a wind tunnel. The blades were designed using relatively thin, low Reynolds number airfoils and built using rapid-prototyping methods with a flexible material. As the oncoming wind speed was increased, the beam natural frequencies varied, up to a critical wind speed at which two structural modes coalesced and resulted in a coupled-mode flutter. A theoretical model based on coupled flexural-torsional beam equations subjected to aerodynamic loadings is derived to study the flow-induced instability for the designed blade. The model also predicts the onset of instability at a critical wind speed at which one of the structural modes experiences a negative damping. Future wind turbine blades will become larger, and therefore more flexible. For more flexible blades, the ratio of the estimated critical speed for dynamic instability to the operating speed decreases, and the blades are more susceptible to such instabilities. In the current work, the dynamic instability of a rotating wind turbine blade is studied using a numerical stability analysis and supported by experimental results. For the experimental component of the work, a series of tests were conducted in a wind tunnel. The blades were designed using relatively thin, low Reynolds number airfoils and built using rapid-prototyping methods with a flexible material. As the oncoming wind speed was increased, the beam natural frequencies varied, up to a critical wind speed at which two structural modes coalesced and resulted in a coupled-mode flutter. A theoretical model based on coupled flexural-torsional beam equations subjected to aerodynamic loadings is derived to study the flow-induced instability for the designed blade. The model also predicts the onset of instability at a critical wind speed at which one of the structural modes experiences a negative damping. The support provided by the Wind Technology Testing Center, a part of the Massachusetts Clean Energy Center is acknowledged.

  20. Power Performance Test Report for the SWIFT Wind Turbine

    SciTech Connect

    Mendoza, I.; Hur, J.

    2012-12-01

    This report summarizes the results of a power performance test that NREL conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the SWIFT is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  1. Overspeed spoilers for vertical axis wind turbine

    Microsoft Academic Search

    R. S. Rangi; P. South

    1978-01-01

    An overspeed spoiler is described for vertical axis wind turbines of the type having straight or curved airfoil blades attached to a vertical shaft formed by a relatively thin flat blade shaped spoiler element hinge mounted on the trailing edge, leading edge, or at a central position of a portion of the airfoil section. The element has two portions one

  2. A vertical-axis wind turbine

    Microsoft Academic Search

    S. Slavik

    1982-01-01

    Formulas are derived for the driving moment of a turbine rotor, which make it possible to determine the start-up torque for different blade profiles and arbitrary wind directions; this makes it possible to investigate the changing of angles of attack with the aim of attaining the highest start-up torque. Power, flow, and torque relationships are obtained, which can be used

  3. Root region airfoil for wind turbine

    DOEpatents

    Tangler, James L. (Boulder, CO); Somers, Dan M. (State College, PA)

    1995-01-01

    A thick airfoil for the root region of the blade of a wind turbine. The airfoil has a thickness in a range from 24%-26% and a Reynolds number in a range from 1,000,000 to 1,800,000. The airfoil has a maximum lift coefficient of 1.4-1.6 that has minimum sensitivity to roughness effects.

  4. Flutter of Darrieus wind turbine blades

    NASA Technical Reports Server (NTRS)

    Ham, N. D.

    1978-01-01

    The testing of Darrieus wind turbines has indicated that under certain conditions, serious vibrations of the blades can occur, involving flatwise bending, torsion, and chordwise bending. A theoretical method of predicting the aeroelastic stability of the coupled bending and torsional motion of such blades with a view to determining the cause of these vibrations, and a means of suppressing them was developed.

  5. Evaluation of airfoils for small wind turbines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new set of blades have been designed, fabricated, and tested at the United States Department of Agriculture-Agricultural Research Service-Conservation and Production Research Laboratory in Bushland, Texas in an attempt to improve the overall performance of small (1-10 kilowatt) wind turbines. The ...

  6. Redesign of a wind turbine hub

    E-print Network

    Hunter-Jones, Bridget I

    2014-01-01

    The current designs of wind turbine hubs contain many faults. The slew ring bearing that connects the blade to the hub takes on a large bending moment that in many cases causes the joints to fail and the blade to break ...

  7. Darrieus wind-turbine airfoil configurations

    Microsoft Academic Search

    P. G. Migliore; J. R. Fritschen

    1982-01-01

    The purpose was to determine what aerodynamic performance improvement, if any, could be achieved by judiciously choosing the airfoil sections for Darrieus wind turbine blades. Ten different airfoils, having thickness to chord ratios of twelve, fifteen and eighteen percent, were investigated. Performance calculations indicated that the NACA 6-series airfoils yield peak power coefficients at least as great as the NACA.

  8. Darrieus vertical axis wind turbine program overview

    Microsoft Academic Search

    R. H. Braasch

    1979-01-01

    Some of the more salient recent developments in the Darrieus vertical axis wind turbine technology are presented. First generation costs and future plans are discussed. Potential design improvements are presented along with their cost benefits. Aerodynamic structural, and system analyses capabilities were developed to support and evaluate the system design.

  9. Flutter of Darrieus wind turbine blades

    Microsoft Academic Search

    N. D. Ham

    1978-01-01

    The testing of Darrieus wind turbines has indicated that under certain conditions, serious vibrations of the blades can occur, involving flatwise bending, torsion, and chordwise bending. A theoretical method of predicting the aeroelastic stability of the coupled bending and torsional motion of such blades with a view to determining the cause of these vibrations, and a means of suppressing them

  10. Aerodynamic models for a Darrieus wind turbine

    Microsoft Academic Search

    P. Fraunie; C. Beguier; I. Paraschivoiu; F. Delclaux

    1982-01-01

    Various models proposed for the aerodynamics of Darrieus wind turbines are reviewed. The magnitude of the L\\/D ratio for a Darrieus rotor blade is dependent on the profile, the Re, boundary layer characteristics, and the three-dimensional flow effects. The aerodynamic efficiency is theoretically the Betz limit, and the interference of one blade with another is constrained by the drag force

  11. Wind turbine of cross-flow type

    SciTech Connect

    Ljungstrom, O.

    1982-04-20

    Wind turbine of cross-flow type with curved or in sections straight vanes (1,2,9). Two vanes or sets of blades are formed in planes parallel to the rotor axis (3) and with the blade planes disposed approximately perpendicularly to one another.

  12. Mod2 wind turbine loads test correlations

    Microsoft Academic Search

    D. K. Zimmerman; S. A. Shipley

    1986-01-01

    The Boeing Company, under contract to the Electric Power Research Institute (EPRI), has completed a test program on the Mod-2 wind turbines at Goodnoe Hills, Washington. The objectives were to update fatigue load spectra for different sites, to measure vortex generator effects, and to evaluate rotational sampling techniques. This paper presents the results of these tests and assesses the adequacy

  13. SUCTION CAISSON FOUNDATIONS FOR OFFSHORE WIND TURBINES

    Microsoft Academic Search

    Felipe A. Villalobos; Guy T. Houlsby; Byron W. Byrne

    Suction caisson foundations are being investigated for oshore wind turbine applications. The research programme includes laboratory testing, larger scale field testing and theoretical modelling. This paper concentrates on the experi- mental results obtained in combined loading tests on monopod caissons. Results obtained from monotonic and cyclic tests on caissons installed either by pushing or by suction are presented and interpreted.

  14. Fabrication and assembly of the ERDA/NASA 100 kilowatt experimental wind turbine

    NASA Technical Reports Server (NTRS)

    Puthoff, R. L.

    1976-01-01

    As part of the Energy Research and Development Administration (ERDA) wind-energy program, NASA Lewis Research Center has designed and built an experimental 100-kW wind turbine. The two-bladed turbines drives a synchronous alternator that generates its maximum output of 100 kW of electrical power in a 29-km/hr (18-mph) wind. The design and assembly of the wind turbine were performed at Lewis from components that were procured from industry. The machine was installed atop the tower on September 3, 1975.

  15. Stationary turbine component with laminated skin

    DOEpatents

    James, Allister W. (Orlando, FL)

    2012-08-14

    A stationary turbine engine component, such as a turbine vane, includes a internal spar and an external skin. The internal spar is made of a plurality of spar laminates, and the external skin is made of a plurality of skin laminates. The plurality of skin laminates interlockingly engage the plurality of spar laminates such that the external skin is located and held in place. This arrangement allows alternative high temperature materials to be used on turbine engine components in areas where their properties are needed without having to make the entire component out of such material. Thus, the manufacturing difficulties associated with making an entire component of such a material and the attendant high costs are avoided. The skin laminates can be made of advanced generation single crystal superalloys, intermetallics and refractory alloys.

  16. Development of the Risø wind turbine airfoils

    NASA Astrophysics Data System (ADS)

    Fuglsang, Peter; Bak, Christian

    2004-04-01

    This paper presents the wind turbine airfoil development at Risø. The design method is described together with our target characteristics for wind turbine airfoils. The use of the CFD code Ellipsys2D for prediction of final target characteristics is described together with the VELUX wind tunnel testing setup. Three airfoil families were developed; Risø-A1, Risø-P and Risø-B1. The Risø-A1 airfoil family was developed for rotors of 600 kW and larger. Wind tunnel testing and field testing showed that this airfoil family is well suited for stall and active stall control. However, sensitivity to roughness was higher than expected. Field tests of a 600 kW active stall wind turbine showed an estimated reduction in blade fatigue loading of up to 15% at the same annual energy yield and at the same time reduced blade weight and blade solidity. The Risø-P airfoils were developed to replace the Risø-A1 airfoils for use on pitch controlled wind turbines. Improved design objectives should reduce the sensitivity to roughness, but measurements are not yet available. The Risø-B1 airfoil family was developed for variable speed operation with pitch control of large megawatt sized rotors. Wind tunnel testing verified the high maximum lift for these airfoils, and the airfoils were found to be very insensitive to leading edge roughness. Performance with vortex generators and Gurney flaps in combination was found to be attractive for the blade root part. Field testing of a 1.5 MW rotor is in progress. Copyright

  17. Investigation of Doppler Features From Wind Turbine Scattering

    Microsoft Academic Search

    Aale Naqvi; Shang-Te Yang; Hao Ling

    2010-01-01

    We examine the Doppler features from wind turbine scattering through a series of model measurements. Both backscattered and forward-scattered data are collected in the laboratory at Ku-band from various wind turbine models undergoing rotation. The tested models include a 1:160 scale model turbine, a three-arm wire model, and a small wind turbine from Bergey Windpower with 2' blades. The findings

  18. Duration Test Report for the Viryd CS8 Wind Turbine

    SciTech Connect

    Roadman, J.; Murphy, M.; van Dam, J.

    2013-06-01

    This report summarizes the results of a duration noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with Clause 9.4 of the International Electrotechnical Commission's (IEC) standard, Wind turbines - Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed. 2.0:2006-03. NREL researchers evaluated the turbine based on structural integrity and material degradation, quality of environmental protection, and dynamic behavior.

  19. Effects of Changing Atmospheric Conditions on Wind Turbine Performance (Poster)

    SciTech Connect

    Clifton, A.

    2012-12-01

    Multi-megawatt, utility-scale wind turbines operate in turbulent and dynamic winds that impact turbine performance in ways that are gradually becoming better understood. This poster presents a study made using a turbulent flow field simulator (TurbSim) and a Turbine aeroelastic simulator (FAST) of the response of a generic 1.5 MW wind turbine to changing inflow. The turbine power output is found to be most sensitive to wind speed and turbulence intensity, but the relationship depends on the wind speed with respect to the turbine's rated wind speed. Shear is found to be poorly correlated to power. A machine learning method called 'regression trees' is used to create a simple model of turbine performance that could be used as part of the wind resource assessment process. This study has used simple flow fields and should be extended to more complex flows, and validated with field observations.

  20. Response of a Vertical Axis Wind Turbine to Time Varying Wind Conditions found within the Urban

    E-print Network

    Tullis, Stephen

    Response of a Vertical Axis Wind Turbine to Time Varying Wind Conditions found within the Urban, 2010 PP 389­401 389 ABSTRACT Experimental testing of a vertical axis wind turbine within the urban of the turbine. Temporal variation of the wind with respect to the direction and velocity fluctuations

  1. RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine

    E-print Network

    Hu, Hui

    RESEARCH ARTICLE Dynamic wind loads and wake characteristics of a wind turbine model of the unsteady vortex and turbulent flow structures in the near wake of a horizontal axis wind turbine model.e., aerodynamic forces and bending moments) acting on the wind turbine model by using a high-sensitive force

  2. WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES

    E-print Network

    Leu, Tzong-Shyng "Jeremy"

    1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1 were carried out to study the aerodynamic performance of three vertical axis wind turbines (VAWTs. On the other hand, the characteristics of unsteady flow around the helical wind turbine were studied with a hot

  3. The UAE wind turbine performance prediction using wind tunnel airfoil data

    Microsoft Academic Search

    Chenkai Zhang; Jun Hu

    2010-01-01

    It's vitally important for wind turbine aerodynamic performance predictions to design and optimize wind turbines. In view of the BEM method's fast speed and widespread use, this paper applies WT_Perf software of NREL to predict the performance on a NREL Phase VI upwind wind turbine. Measurements from the Phase VI of the NREL\\/NASA Ames wind tunnel test were used for

  4. Electrical generation using a vertical-axis wind turbine

    Microsoft Academic Search

    1982-01-01

    Traditionally, windmills have been of the propeller or multiblade types, both of which have their rotational axis parallel to the flow of the wind. A vertical-axis wind turbine has its rotational axis perpendicular to the flow of wind and requires no orientation to keep the rotor in the windstream. The vertical-axis wind turbine operates on the same principle as an

  5. Evolution and Reduction of Scour around Offshore Wind Turbines

    Microsoft Academic Search

    David McGovern; Suzana Ilic

    2010-01-01

    Evolution and Reduction of Scour around Offshore Wind Turbines In response to growing socio-economic and environmental demands, electricity generation through offshore wind turbine farms is a fast growing sector of the renewable energy market. Considerable numbers of offshore wind farms exist in the shallow continental shelf seas of the North-West Europe, with many more in the planning stages. Wind energy

  6. STRUCTURAL HEALTH MONITORING OF THE SUPPORT STRUCTURE OF WIND TURBINE USING WIRELESS SENSING SYSTEM

    E-print Network

    Boyer, Edmond

    structure to resist the complicated environmental loading, especially for the offshore wind turbine. How efficiency of wind turbine, the development of offshore wind farm is in full swing. The wind turbine heavily, especially for the offshore wind turbine. How to manage these wind turbines and monitor the structural safety

  7. The Mod-2 wind turbine development project

    NASA Technical Reports Server (NTRS)

    Linscott, B. S.; Dennett, J. T.; Gordon, L. H.

    1981-01-01

    A major phase of the Federal Wind Energy Program, the Mod-2 wind turbine, a second-generation machine developed by the Boeing Engineering and Construction Co. for the U.S. Department of Energy and the Lewis Research Center of the National Aeronautics and Space Administration, is described. The Mod-2 is a large (2.5-MW power rating) horizontal-axis wind turbine designed for the generation of electrical power on utility networks. Three machines were built and are located in a cluster at Goodnoe Hills, Washington. All technical aspects of the project are described: design approach, significant innovation features, the mechanical system, the electrical power system, the control system, and the safety system.

  8. Selected wind tunnel test results for the Darrieus wind turbine

    Microsoft Academic Search

    B. F. Blackwell; R. E. Sheldahl

    1977-01-01

    Five blade configurations of a 2-m-diam Darrieus wind turbine have been tested in the Vought Corporation 4.6- x 6.1-m (15- x 20-ft) Low-Speed Wind Tunnel. Rotor solidity, Reynolds number, and freestream velocities tested were in the following ranges: solidity, 13 to 30%; Reynolds number, 1 to 3 x 10⁵; freestream velocity, 7 to 11 m\\/s. The airfoil selection for all

  9. Selected wind tunnel test results for the Darrieus wind turbine

    Microsoft Academic Search

    B. F. Blackwell; R. E. Sheldahl

    1977-01-01

    Five blade configurations of a 2-m-diam Darrieus wind turbine have been tested in a low-speed wind tunnel. Rotor solidity, Reynolds number, and free-stream velocities tested were in the following ranges: solidity, 13-30%; Reynolds number, 100,000-300,000; free-stream velocity, 7-11 m\\/s. The airfoil selection for all configurations was NACA 0012. The parameters measured were rotor torque, rotor rotational speed, and tunnel conditions.

  10. Mod-2 wind turbine field operations experiment

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1985-01-01

    The three-machine, 7.5 MW Goodnoe Hills located near Goldendale, Washington and is now in a research/experimental operations phase that offers a unique opportunity to study the effects of single and multiple wind turbines interacting with each other, the power grid; and the environment. Following a brief description of the turbine and project history, this paper addresses major problem areas and research and development test results. Field operations, both routine and nonroutine, are discussed. Routine operation to date has produced over 13,379,000 KWh of electrical energy during 11,064 hr of rotation. Nonroutine operation includes suspended activities caused by a crack in the low speed shaft that necessitated a redesign and reinstallation of this assembly on all three turbines. With the world's largest cluster back in full operation, two of the turbines will be operated over the next years to determine their value as energy producer. The third unit will be used primarily for conducting research tests requiring configuration changes to better understand the wind turbine technology. Technical areas summarized pertain to system performance and enhancements. Specific research tests relating to acoustics, TV interference, and wake effects conclude the paper.

  11. Mod-2 wind turbine field operations experience

    SciTech Connect

    Gordon, L.H.

    1985-12-01

    The three-machine, 7.5 MW Goodnoe Hills cluster, located near Goldendale, Washington, is now in a research/experimental operations phase that offers a unique opportunity to study the effects of single and multiple wind turbines interacting with each other, the power grid; and the environment. Following a brief description of the turbine and project history, this paper addresses major problem areas and research and development test results. Field operations, both routine and nonroutine, are discussed. Routine operation to date has produced over 13,379,000 kWh of electrical energy during 11 064 h of rotation. Nonroutine operation includes suspended activities caused by a crack in the low speed shaft that necessitated a redesign and reinstallation of this assembly on all three turbines. With the world's largest cluster back in full operation, two of the turbines will be operated over the next several years to determine their value as energy producers. The third unit will be used primarily for conducting research tests requiring configuration changes to better understand the wind turbine technology. Technical areas summarized pertain to system performance and enhancements. Specific research tests relating to acoustics, TV interferences, and wake effects conclude the paper.

  12. Dynamic Models for Wind Turbines and Wind Power Plants

    SciTech Connect

    Singh, M.; Santoso, S.

    2011-10-01

    The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

  13. A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments

    NASA Astrophysics Data System (ADS)

    Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue

    2013-03-01

    The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.

  14. The application of pulsed thermography in the inspection of wind turbine blades

    NASA Astrophysics Data System (ADS)

    Tao, Ning; Zeng, Zhi; Feng, Lichun; Li, Xiaoli; Li, Yeshu; Zhang, Cunlin

    2011-08-01

    Wind power is a very promising source of environmentally safe, renewable, and the fast-growing energy source over the past several years. The blades of a wind turbine are considered to be an important component in wind turbine generator. Currently, bigger and more powerful wind blades are being built to increase the swept area of the turbine and extract more energy from the wind. Correspondingly, more capital cost is invested in manufacture and service. In order to reduce damage possibility and extend the wind turbine blades life, there are increasing demands for the inspection of wind turbine blades in the manufacturing factory and on site inspection. The regular inspections of wind turbine blades are done normally by using visual inspection and tapping test. To improve the safety of wind turbine blades, nondestructive testing technique using pulsed thermography is being investigated in this study. This technique utilized an active pulsed heating source that is applied on the outer surface of wind turbine blades, and an infrared camera to monitor the surface temperature distribution controlled by a computer. Reflective pulsed thermography was directly applied on several full scale wind blades, surface and subsurface defects, such as air bubbles, pin holes, edge bonding, etc. were clearly detected. Several specimens were intentionally manufactured to simulate the glue faults between supporting spars and glass fiber reinforced plastic (GFRP) shells with different thickness. Afterwards they were inspected by using pulsed thermography in laboratory. The current test results indicated that pulsed thermography has the potential for the detection of glue faults at least about 15mm thickness GFRP shell. It is shown that pulsed thermography maybe provide a powerful non-contacting technique for the inspection of wind turbine blades as well in the workshop just after the production or in the field that before and after installation of the wind blades and during reparation.

  15. Wind turbine structural loads resulting from wind excitation. Final report

    SciTech Connect

    Thresher, R.W.

    1985-06-01

    Two of the important unknowns concerning the economic potential of wind turbines are the fatigue life and maintenance costs, and these are directly related to the loading spectrum that the turbine experiences during its life. This report presents the results of an analysis of the Mod-2 experimental loads data that explores the relationship between the wind environment and structural loading. The report introduces and uses a new parameter for presenting mean performance and loads data that helps to reduce the data scatter. This parameter may be useful in other field evaluation activities for determining subtle differences in operating characteristics between different turbines or different sites. In addition, the role of turbulence on the resulting fatigue loads is explored, and it shows that turbulence is an important excitation source.

  16. Mod-2 wind turbine system development. Volume 2: Detailed report

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Progress in the design, fabrication, and testing of a wind turbine system is reported. The development of the MOD-2 wind turbine through acceptance testing and initial operational evaluation is documented. The MOD-2 project intends to develop early commercialization of wind energy. The first wind turbine farm (three MOD-2 units) are now being operated at the Bonneville Power Administration site near Goldendale, Washington.

  17. Dynamic behavior of variable speed wind turbines under stochastic wind

    Microsoft Academic Search

    S. A. Papathanassiou; M. P. Papadopoulos

    1999-01-01

    It is recognized that the most important advantage of the variable speed wind turbines (VS WTs) over the conventional constant speed (CS) machines are the improved dynamic characteristics, resulting in the reduction of the drive train mechanical stresses and output power fluctuations. In this paper alternative configurations of the electrical part of a VS WT are considered, using a squirrel

  18. Aerodynamic research on tipvane wind turbines

    NASA Astrophysics Data System (ADS)

    Vanbussel, G. J. W.; Vanholten, T.; Vankuik, G. A. M.

    1982-04-01

    Aerodynamic loads on small auxiliary wings that are mounted at the tips of wind turbine blades in such a way that a diffuser effect is generated, resulting in a mass flow augmentation through the turbine disk, were analyzed. For load prediction, an expansion method, or lifting line approach, was used. The complete analytical expression for the pressure field consists of two series of basic pressure fields. One series is related to the basic load distributions over the turbine blade, and the other series to the basic load distribution over the tipvane. In addition, another basic pressure field, related to a triangular load distribution over the turbine blade and the tipvane, is needed in order to take care of the lift transfer from turbine blade to tipvane. The coefficients in these pressure field expressions are a priori unknown and are determined by a boundary condition, requiring the flow to be tangential on both turbine blade and tipvane. A numerical procedure then yields the coefficients of the basic pressure fields.

  19. Ris R1024EN Design of the Wind Turbine

    E-print Network

    Ris R1024EN Design of the Wind Turbine Airfoil Family RIS AXX Kristian S. Dahl, Peter Fuglsang Ris National Laboratory, Roskilde, Denmark December 1998 #12;Abstract A method for design of wind turbine turbine. The airfoils are designed to have maximum lift-drag ratio until just below stall, a design lift

  20. Design Loads for Wind Turbines using the Environmental Contour Method

    E-print Network

    Manuel, Lance

    Design Loads for Wind Turbines using the Environmental Contour Method Korn Saranyasoontorn, TX 78712 When interest is in establishing ultimate design loads for wind turbines such that a service). The parametric conditional load distri- butions require extensive turbine response simulations over the entire

  1. RELIABILITY COMPARISON MODELS FOR OFFSHORE WIND TURBINES (OWT)

    E-print Network

    Bernstein, Joseph B.

    RELIABILITY COMPARISON MODELS FOR OFFSHORE WIND TURBINES (OWT) Yizhou Lu, T. M. Delorm, A. Christou of survivor functions R(t) of drive-trains, after 1 year of operation, between Offshore Wind Turbine (OWT) vs (Types1-4a) - horizontal axis turbines (3-6 MW) were selected for reliability modelling & technology

  2. Innovative wind turbines. The circulation control vertical axis wind turbine. Final report, May 1, 1978-December 31, 1979

    SciTech Connect

    Walters, R.E.; Migliore, P.G.; Wolfe, W.P.

    1980-01-01

    An indoor facility was developed for use in the aerodynamic testing of Darrieus wind turbine blades. A three-component internal strain gage balance was used to deduce lift, drag and moment coefficients of blades whose angle of attack, chord to radius ratio and Reynolds number can be systematically varied. The unusual flow field of this test environment necessitates unique downwash corrections for angle of attack and induced drag.

  3. The fault diagnosis of large-scale wind turbine based on expert system

    NASA Astrophysics Data System (ADS)

    Chen, Changzheng; Li, Yun

    2011-10-01

    The wind turbine is the critical equipment for wind power, due to the poor working environment and the long running, the wind turbine components will have a variety of failures. Planned maintenance which has long been used is unable to understand the operational status of equipment comprehensively and timely in a way, especially for large wind machine, the repair work took too long time and cause serious damage. Therefore, fault diagnosis and predictive maintenance becomes more imminent. In this paper, the fault symptoms and corresponding reason of the large-scale wind turbine parts are analyzed and summarized ,such as gear box, generator, yaw system, and so on . And on this basis, the large-scale wind turbine fault diagnosis expert system was constructed by using expert system tool CLIPS and Visual C + +.

  4. Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

    SciTech Connect

    Aker, Pamela M.; Jones, Anthony M.; Copping, Andrea E.

    2010-11-23

    Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.

  5. Atmospheric turbulence parameters for modeling wind turbine dynamics

    NASA Technical Reports Server (NTRS)

    Holley, W. E.; Thresher, R. W.

    1982-01-01

    A model which can be used to predict the response of wind turbines to atmospheric turbulence is given. The model was developed using linearized aerodynamics for a three-bladed rotor and accounts for three turbulent velocity components as well as velocity gradients across the rotor disk. Typical response power spectral densities are shown. The system response depends critically on three wind and turbulence parameters, and models are presented to predict desired response statistics. An equation error method, which can be used to estimate the required parameters from field data, is also presented.

  6. 66 APRIL | 2010 The FuTure oF Wind Turbine

    E-print Network

    Kusiak, Andrew

    66 APRIL | 2010 The FuTure oF Wind Turbine diagnosTics Wind energy is undergoing expansion in the form of large-scale wind farms, wind energy cooperatives, wind turbines owned by indi- vidual investors of wind turbines, operation and maintenance (O&M) costs remain high due to failures of wind turbine

  7. Lifetime prediction for ceramic gas turbine components

    SciTech Connect

    Stuermer, G.; Schulz, A.; Wittig, S. (Univ. Karlsruhe, Karlsruhe (Germany))

    1993-01-01

    At the Institute for Thermal Turbomachinery, University of Karlsruhe (ITS), theoretical and experimental investigations of ceramic gas turbine components are performed. For the reliability analysis by finite element calculations the computer code CERITS has been developed. This code is used to determine the fast fracture reliability of ceramic components subjected to polyaxial stress states with reference to volumetric flaws and was presented at the 1990 IGTI Gas Turbine Conference. CERITS-L now includes subcritical crack growth. With the new code CERITS-L, failure probabilities of ceramic components can be calculated under given load situations versus time. In comparing these time-dependent failure probabilities with a given permissible failure probability, the maximum operation time of a component can be determined. The considerable influence of the subcritical crack growth upon the lifetime of ceramic components is demonstrated at the flame tube segments of the ITS ceramic combustor.

  8. Vertical axis wind turbine drive train transient dynamics

    SciTech Connect

    Clauss, D.B.; Carne, T.G.

    1981-01-01

    Start-up of a vertical axis wind turbine causes transient torque oscillations in the drive train with peak torques which may be over two and one-half times the rated torque of the turbine. These peak torques are of sufficient magnitude to possibly damage the drive train; safe and reliable operation requires that mechanical components be overdesigned to carry the peak torques caused by transient events. A computer code, based on a lumped parameter model of the drive train, has been developed and tested for the Low Cost 17-Meter turbine; the results show excellent agreement with field data. The code has subsequently been used to predict the effect of a slip clutch on transient torque oscillations.

  9. Braking System for Wind Turbines

    NASA Technical Reports Server (NTRS)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  10. Wind ripple in vertical-axis wind turbines

    SciTech Connect

    Akins, R.E.

    1981-01-01

    The aerodynamically induced fluctuations in the output of a VAWT have often been considered a disadvantage of such systems. The fluctuations observed in the output of a VAWT are composed of contributions due to aerodynamic effects, incident turbulence, and in some cases, mechanical resonances. In order to quantitatively assess these effects, experimental techniques have been developed which allow analysis of full-scale performance of wind turbines with particular emphasis on the effects caused by turbulence in the incident wind. These methods have been used to monitor the performance of the DOE/Sandia 17-m VAWT. Results are presented which provide an indication of the effects of incident turbulence intensity on the fluctuations in output of the turbine. Trends which relate the fluctuations in output to the fluctuations in incident wind are identified and discussed.

  11. CFD-based design load analysis of 5MW offshore wind turbine

    NASA Astrophysics Data System (ADS)

    Tran, T. T.; Ryu, G. J.; Kim, Y. H.; Kim, D. H.

    2012-11-01

    The structure and aerodynamic loads acting on NREL 5MW reference wind turbine blade are calculated and analyzed based on advanced Computational Fluid Dynamics (CFD) and unsteady Blade Element Momentum (BEM). A detailed examination of the six force components has been carried out (three force components and three moment components). Structure load (gravity and inertia load) and aerodynamic load have been obtained by additional structural calculations (CFD or BEM, respectively,). In CFD method, the Reynolds Average Navier-Stokes approach was applied to solve the continuity equation of mass conservation and momentum balance so that the complex flow around wind turbines was modeled. Written in C programming language, a User Defined Function (UDF) code which defines transient velocity profile according to the Extreme Operating Gust condition was compiled into commercial FLUENT package. Furthermore, the unsteady BEM with 3D stall model has also adopted to investigate load components on wind turbine rotor. The present study introduces a comparison between advanced CFD and unsteady BEM for determining load on wind turbine rotor. Results indicate that there are good agreements between both present methods. It is importantly shown that six load components on wind turbine rotor is significant effect under Extreme Operating Gust (EOG) condition. Using advanced CFD and additional structural calculations, this study has succeeded to construct accuracy numerical methodology to estimate total load of wind turbine that compose of aerodynamic load and structure load.

  12. WindPACT Turbine Rotor Design Study: June 2000--June 2002 (Revised)

    SciTech Connect

    Malcolm, D. J.; Hansen, A. C.

    2006-04-01

    This report presents the results of the turbine rotor study completed by Global Energy Concepts (GEC) as part of the U.S. Department of Energy's WindPACT (Wind Partnership for Advanced Component Technologies) project. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy from wind turbines to fall to a target of 3.0 cents/kilowatt-hour in low wind speed sites. The study focused on different rotor configurations and the effect of scale on those rotors.

  13. Wind turbine wake detection with a single Doppler wind lidar

    NASA Astrophysics Data System (ADS)

    Wang, H.; Barthelmie, R. J.

    2015-06-01

    Using scanning lidar wind turbine wakes can be probed in three dimensions to produce a wealth of temporally and spatially irregular data that can be used to characterize the wakes. Unlike data from a meteorological mast or upward pointing lidar, the spatial coordinates of the measurements are not fixed and the location of the wake also varies in three dimensions. Therefore the challenge is to provide automated detection algorithms to identify wakes and quantify wake characteristics from this type of dataset. Here an algorithm is developed and evaluated on data from a large wind farm in the Midwest. A scanning coherent Doppler wind lidar was configured to measure wind speed in the wake of a continuously yawing wind turbine for two days during the experiment and wake profiles were retrieved with input of wind direction information from the nearby meteorological mast. Additional challenges to the analysis include incomplete coverage of the entire wake due to the limited scanning domain, and large wind shear that can contaminate the wake estimate because of the height variation along the line-of-sight. However, the algorithm developed in this paper is able to automatically capture wakes in lidar data from Plan Position Indicator (PPI) scans and the resultant wake statistics are consistent with previous experiment's results.

  14. Fatigue life variability and reliability analysis of a wind turbine blade

    NASA Astrophysics Data System (ADS)

    Veers, P. S.; Sutherland, H. J.; Ashwill, T. D.

    Wind turbines must withstand harsh environments that induce many stress cycles into their components. A numerical analysis package is used to illustrate the sobering variability in predicted fatigue life with relatively small changes in inputs. The variability of the input parameters is modeled to obtain estimates of the fatigue reliability of the turbine blades.

  15. 36 SEPTEMBER | 2012 WiNd TURbiNE CAPACiTY

    E-print Network

    Kusiak, Andrew

    36 SEPTEMBER | 2012 WiNd TURbiNE CAPACiTY FRONTiER FROM SCAdA ThE WORld hAS SEEN A significant contributor to this growth. The wind turbine generated energy depends on the wind potential and the turbine of wind turbines. Supervi- sory control and data acquisition (SCADA) systems record wind turbine

  16. A vertical-axis wind turbine

    NASA Astrophysics Data System (ADS)

    Slavik, S.

    Formulas are derived for the driving moment of a turbine rotor, which make it possible to determine the start-up torque for different blade profiles and arbitrary wind directions; this makes it possible to investigate the changing of angles of attack with the aim of attaining the highest start-up torque. Power, flow, and torque relationships are obtained, which can be used to determine required generator power curves. The solution of the equation of motion of the rotor makes it possible to investigate the time dependence of the kinematic variables and power. A design diagram is discussed, which can be used to determine the mean turbine-shaft horsepower as a function of shaft geometry and velocity, and wind velocity.

  17. Aileron controls for wind turbine applications

    SciTech Connect

    Miller, D.R.; Putoff, R.L.

    1984-01-01

    Horizontal-axis wind turbines utilize partial or full variable blade pitch to regulate rotor speed. The weight and costs of these systems indicated a need for alternate methods of rotor control. Aileron-control is an alternative which has potential to meet this need. The NASA Lewis Research Center has been experimentally testing aileron-control rotors on the Mod-O wind turbine to determine their power regulation and shutdown characteristics. This paper presents experimental test results for a 20 and 38% chord aileron-control rotor. The test results to date show that aileron-control is a viable method for safely controlling rotor speed, following a loss of generator load.

  18. Wind Turbine Generator System Duration Test Report for the Gaia-Wind 11 kW Wind Turbine

    SciTech Connect

    Huskey, A.; Bowen, A.; Jager, D.

    2010-09-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Renewable Energy Laboratory's (NRELs) National Wind Technology Center (NWTC) as a part of this project. Duration testing is one of up to five tests that may be performed on the turbines, including power performance, safety and function, noise, and power quality tests. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification. The test equipment includes a Gaia-Wind 11 kW wind turbine mounted on an 18 m monopole tower. Gaia-Wind Ltd. manufactured the turbine in Denmark, although the company is based in Scotland. The system was installed by the NWTC Site Operations group with guidance and assistance from Gaia-Wind.

  19. Disturbance Accommodating Adaptive Control with Application to Wind Turbines

    NASA Technical Reports Server (NTRS)

    Frost, Susan

    2012-01-01

    Adaptive control techniques are well suited to applications that have unknown modeling parameters and poorly known operating conditions. Many physical systems experience external disturbances that are persistent or continually recurring. Flexible structures and systems with compliance between components often form a class of systems that fail to meet standard requirements for adaptive control. For these classes of systems, a residual mode filter can restore the ability of the adaptive controller to perform in a stable manner. New theory will be presented that enables adaptive control with accommodation of persistent disturbances using residual mode filters. After a short introduction to some of the control challenges of large utility-scale wind turbines, this theory will be applied to a high-fidelity simulation of a wind turbine.

  20. Wear Analysis of Wind Turbine Gearbox Bearings

    SciTech Connect

    Blau, Peter Julian [ORNL; Walker, Larry R [ORNL; Xu, Hanbing [ORNL; Parten, Randy J [ORNL; Qu, Jun [ORNL; Geer, Tom [ORNL

    2010-04-01

    The objective of this effort was to investigate and characterize the nature of surface damage and wear to wind turbine gearbox bearings returned from service in the field. Bearings were supplied for examination by S. Butterfield and J. Johnson of the National Wind Technology Center (NREL), Boulder, Colorado. Studies consisted of visual examination, optical and electron microscopy, dimensional measurements of wear-induced macro-scale and micro-scale features, measurements of macro- and micro-scale hardness, 3D imaging of surface damage, studies of elemental distributions on fracture surfaces, and examinations of polished cross-sections of surfaces under various etched and non-etched conditions.

  1. The Netherlands experimental vertical axis wind turbine

    Microsoft Academic Search

    J. B. D. H. Bolt

    1978-01-01

    The paper gives a general description of an experimental 5.3-m-diam vertical axis wind turbine and its associated power conversion system and other subsystems. The two glass-fiber reinforced plastic blades are strengthened by bonded light-metal plates. As design-criteria for the static strength of the blades, a maximum blade rotation speed of 450 rpm in calm weather conditions and a reducing speed

  2. Numerical prediction of wind turbine noise

    Microsoft Academic Search

    A. Tadamasa; M. Zangeneh

    2011-01-01

    This paper develops and validates the first principle based numerical method for predicting the noise radiated from the rotating Horizontal-Axis Wind Turbine (HAWT) blades. The noise radiated to the far-field was predicted by the code based on Ffowcs Williams–Hawkings (FW–H) equation, using both original non-permeable formulation and permeable formulation. A commercially available CFD solver, ANSYS CFX 11.0, was used to

  3. Aeroelastic analysis of the Darrieus wind turbine

    Microsoft Academic Search

    1982-01-01

    The stability of small oscillations of the troposkein-shaped blade used on Darrieus wind turbines is investigated. The blade is assumed to be attached to a perfectly rigid rotor shaft and spinning in still air. Linear equations of motion are derived which include the effects of inplane, out-of-plane, and torsional stiffness, mass and aerodynamic center offsets, and the aerodynamic wake. Results

  4. Composite rotor blades for wind turbine generators

    Microsoft Academic Search

    W. D. Weigel

    1981-01-01

    The materials, techniques, and methods used to construct a 150 ft test blade, two 31 ft blades for a 40 kW WECS, and rotor blades for the Mod-1 wind turbine are described. Considerations of strength, stiffness, and mass distributions, as well as cost, led to the choice of filament wound fiberglass\\/epoxy material using transverse filament tape which has structural fibers

  5. Mod 2 Wind Turbine Development Project

    SciTech Connect

    None

    1980-10-01

    The primary objective in the development of Mod 2 was to design a wind turbine to produce energy for less than 5 cents/kWh based on 1980 cost forecasts. The pricing method used to project the Mod 2 energy costs is the levelized fixed charge rate approach, generally accepted in the electric utility industry as a basis for relative ranking of energy alternatives. This method derives a levelized energy price necessary to recover utility's purchasing, installing, owning, operating, and maintenance costs.

  6. The Federal Advanced Wind Turbine Program

    SciTech Connect

    Hock, S M; Thresher, R W [National Renewable Energy Lab., Golden, CO (United States); Goldman, P R [USDOE, Washington, DC (United States)

    1991-12-01

    The development of technologically advanced, higher efficiency wind turbines has been identified as a high priority activity by the US wind industry. The Department of Energy's Wind Energy Program has begun a multi-year development program aimed at assisting the wind industry with the design, development, and testing of advanced wind turbine systems that can compete with conventional electric generation for $0.05/kWh at 13 mph sites by the mid-1990s and with fossil-fuel-based generators for $0.04/kWh at 13 mph sites by the year 2000. The development plan consists of four phases: (1) Conceptual Design Studies; (2) Near-Term Product Development; (3) Next Generation Technology Integration and Design, and (4) Next- Generation Technology Development and Testing. The Conceptual Design Studies were begun in late 1990, and are scheduled for completion in the Spring of 1992. Preliminary results from these analyses are very promising and indicate that the goals stated above are technically feasible. This paper includes a brief summary of the Conceptual Design Studies and presents initial plans for the follow-on activities. 3 refs., 4 figs.

  7. The Federal Advanced Wind Turbine Program

    SciTech Connect

    Hock, S.M.; Thresher, R.W. [National Renewable Energy Lab., Golden, CO (United States); Goldman, P.R. [USDOE, Washington, DC (United States)

    1991-12-01

    The development of technologically advanced, higher efficiency wind turbines has been identified as a high priority activity by the US wind industry. The Department of Energy`s Wind Energy Program has begun a multi-year development program aimed at assisting the wind industry with the design, development, and testing of advanced wind turbine systems that can compete with conventional electric generation for $0.05/kWh at 13 mph sites by the mid-1990s and with fossil-fuel-based generators for $0.04/kWh at 13 mph sites by the year 2000. The development plan consists of four phases: (1) Conceptual Design Studies; (2) Near-Term Product Development; (3) Next Generation Technology Integration and Design, and (4) Next- Generation Technology Development and Testing. The Conceptual Design Studies were begun in late 1990, and are scheduled for completion in the Spring of 1992. Preliminary results from these analyses are very promising and indicate that the goals stated above are technically feasible. This paper includes a brief summary of the Conceptual Design Studies and presents initial plans for the follow-on activities. 3 refs., 4 figs.

  8. Recent results from data analysis of dynamic stall on wind turbine blades

    SciTech Connect

    Butterfield, C P; Simms, D [National Renewable Energy Lab., Golden, CO (United States); Huyer, S [Colorado Univ., Boulder, CO (United States)

    1992-01-01

    Wind turbines are subjected to dynamic loading from a variety of different sources. Wind shear and turbulence cause time-varying inflow that results in unsteady airloads. Tower shadow, upwind turbine wakes, and yaw angles also introduce unsteady inflow to wind turbine rotors. Wind turbine designers must predict these loads accurately in order to adequately design blades, hubs, and the remaining support structure to achieve a 30-year life. Structural analysts have not been able to predict mean or dynamic loads accurately enough to predict the fatigue life of major wind turbine components with confidence. Part of the problem is due to uncertainty in the stochastic wind environments as mentioned earlier. Another important part of the problem is the lack of basic knowledge of rotary wing airfoil stall performance. There is mounting evidence that dynamic stall may be related to dynamic loads that are greater than predictions. This paper describes some results of investigations of unsteady aerodynamic loads measured on a wind turbine blade. The objective of the investigation is to understand the steady and unsteady stall behavior of wind turbine blades. 13 refs.

  9. Flow separation on wind turbines blades

    NASA Astrophysics Data System (ADS)

    Corten, G. P.

    2001-01-01

    In the year 2000, 15GW of wind power was installed throughout the world, producing 100PJ of energy annually. This contributes to the total electricity demand by only 0.2%. Both the installed power and the generated energy are increasing by 30% per year world-wide. If the airflow over wind turbine blades could be controlled fully, the generation efficiency and thus the energy production would increase by 9%. Power Control To avoid damage to wind turbines, they are cut out above 10 Beaufort (25 m/s) on the wind speed scale. A turbine could be designed in such a way that it converts as much power as possible in all wind speeds, but then it would have to be to heavy. The high costs of such a design would not be compensated by the extra production in high winds, since such winds are rare. Therefore turbines usually reach maximum power at a much lower wind speed: the rated wind speed, which occurs at about 6 Beaufort (12.5 m/s). Above this rated speed, the power intake is kept constant by a control mechanism. Two different mechanisms are commonly used. Active pitch control, where the blades pitch to vane if the turbine maximum is exceeded or, passive stall control, where the power control is an implicit property of the rotor. Stall Control The flow over airfoils is called "attached" when it flows over the surface from the leading edge to the trailing edge. However, when the angle of attack of the flow exceeds a certain critical angle, the flow does not reach the trailing edge, but leaves the surface at the separation line. Beyond this line the flow direction is reversed, i.e. it flows from the trailing edge backward to the separation line. A blade section extracts much less energy from the flow when it separates. This property is used for stall control. Stall controlled rotors always operate at a constant rotation speed. The angle of attack of the flow incident to the blades is determined by the blade speed and the wind speed. Since the latter is variable, it determines the angle of attack. The art of designing stall rotors is to make the separated area on the blades extend in such a way, that the extracted power remains precisely constant, independent of the wind speed, while the power in the wind at cut-out exceeds the maximum power of the turbine by a factor of 8. Since the stall behaviour is influenced by many parameters, this demand cannot be easily met. However, if it can be met, the advantage of stall control is its passive operation, which is reliable and cheap. Problem Definition In practical application, stall control is not very accurate and many stall-controlled turbines do not meet their specifications. Deviations of the design-power in the order of tens of percent are regular. In the nineties, the aerodynamic research on these deviations focussed on: profile aerodynamics, computational fluid dynamics, rotational effects on separation and pressure measurements on test turbines. However, this did not adequately solve the actual problems with stall turbines. In this thesis, we therefore formulated the following as the essential question: "Does the separated blade area really extend with the wind speed, as we predict?" To find the answer a measurement technique was required, which 1) was applicable on large commercial wind turbines, 2) could follow the dynamic changes of the stall pattern, 3) was not influenced by the centrifugal force and 4) did not disturb the flow. Such a technique was not available, therefore we decided to develop it. Stall Flag Method For this method, a few hundred indicators are fixed to the rotor blades in a special pattern. These indicators, called "stall flags" are patented by the Netherlands Energy Research Foundation (ECN). They have a retro-reflective area which, depending on the flow direction, is or is not covered. A powerful light source in the field up to 500m behind the turbine illuminates the swept rotor area. The uncovered reflectors reflect the light to the source, where a digital video camera records the dynamic stall patterns. The images are analyse

  10. Simulation model of wind turbine 3p torque oscillations due to wind shear and tower shadow

    Microsoft Academic Search

    Dale S. L. Dolan; Peter W. Lehn

    2006-01-01

    To determine the control structures and possible power quality issues, the dynamic torque generated by the blades of a wind turbine must be represented. This paper presents an analytical formulation of the generated aerodynamic torque of a three-bladed wind turbine including the effects of wind shear and tower shadow. The comprehensive model includes turbine-specific parameters such as radius, height, and

  11. Simulation Model of Wind Turbine 3p Torque Oscillations due to Wind Shear and Tower Shadow

    Microsoft Academic Search

    Dale S. L. Dolan; P. W. Lehn

    2006-01-01

    To determine control structures and possible power quality issues, the dynamic torque generated by the blades of a wind turbine must be represented. This paper presents an analytical formulation of the generated aerodynamic torque of a three bladed wind turbine including effects of wind shear and tower shadow. The comprehensive model includes turbine specific parameters such as radius, height, and

  12. Life cycle assessment of a floating offshore wind turbine

    Microsoft Academic Search

    Jan Weinzettel; Marte Reenaas; Christian Solli; Edgar G. Hertwich

    2009-01-01

    A development in wind energy technology towards higher nominal power of the wind turbines is related to the shift of the turbines to better wind conditions. After the shift from onshore to offshore areas, there has been an effort to move further from the sea coast to the deep water areas, which requires floating windmills. Such a concept brings additional

  13. DOE/NASA Mod-0A wind turbine performance

    NASA Technical Reports Server (NTRS)

    Richards, T. R.; Neustadter, H. E.

    1978-01-01

    Design and operation of a large wind turbine at Clayton, New Mexico is reported. This is the first of three identical 200 kW wind turbines to be operated on electric utility networks. A comparison between its predicted and measured power versus wind speed performance is presented.

  14. Large-eddy simulation of flow past wind turbine rotors

    Microsoft Academic Search

    Iman Borazjani; Fotis Sotiropoulos

    2010-01-01

    Understanding the effects of atmospheric turbulence and terrain- specific flow phenomena on the aerodynamic performance of wind turbine rotors is critical perquisite for improving blade designs, developing effective flow control strategies and improving wind farm layouts. We develop a high resolution numerical method capable of carrying out large-eddy simulation of wind turbine flows in arbitrarily complex terrains. The method employs

  15. Integrated Dynamic Analysis of Floating Offshore Wind Turbines

    Microsoft Academic Search

    Bjørn Skaare; Tor David Hanson; Finn Gunnar Nielsen; Rune Yttervik; Anders Melchior Hansen; Kenneth Thomsen; Torben Juul Larsen

    Summary A computer tool for simulation of the dynamic response of floating wind turbines exposed to forces from wind, waves and current has been developed for Hydro Oil & Energy's floating wind turbine concept, HYWIND. Two existing, independent, computer program systems are used as basis for the new tool. The HAWC2 computer program from Risø National Laboratory is a state-of-the-art

  16. Coordinate Control of Wind Turbine and Battery in Wind Turbine Generator System

    NASA Astrophysics Data System (ADS)

    Senjyu, Tomonobu; Kikunaga, Yasuaki; Tokudome, Motoki; Uehara, Akie; Yona, Atsushi; Funabashi, Toshihisa

    Battery is installed for with wind power generator to level the output power fluctuations, since output power fluctuations of wind power generator are large. However, if large battery is installed in wind turbine generator, the capital cost for wind power system will increase. Hence, the smallest size of battery should be preferable to save the capital cost. In this paper, we propose a methodology for controlling combined system output power and storage energy capacity of battery system. The system consists of wind turbine generator and battery energy storage system. The generated power fluctuation in low and high frequency range are smoothed by pitch angle control and battery charge or discharge. This coordinated control reduces the rated battery capacity and windmill blade stress. In our proposed method, we apply H? control theory to achieve good response and robustness. The effectiveness of the proposed control system is simulated.

  17. Development of Fully Coupled Aeroelastic and Hydrodynamic Models for Offshore Wind Turbines: Preprint

    SciTech Connect

    Jonkman, J. M.; Sclavounos, P. D.

    2006-01-01

    Aeroelastic simulation tools are routinely used to design and analyze onshore wind turbines, in order to obtain cost effective machines that achieve favorable performance while maintaining structural integrity. These tools employ sophisticated models of wind-inflow; aerodynamic, gravitational, and inertial loading of the rotor, nacelle, and tower; elastic effects within and between components; and mechanical actuation and electrical responses of the generator and of control and protection systems. For offshore wind turbines, additional models of the hydrodynamic loading in regular and irregular seas, the dynamic coupling between the support platform motions and wind turbine motions, and the dynamic characterization of mooring systems for compliant floating platforms are also important. Hydrodynamic loading includes contributions from hydrostatics, wave radiation, and wave scattering, including free surface memory effects. The integration of all of these models into comprehensive simulation tools, capable of modeling the fully coupled aeroelastic and hydrodynamic responses of floating offshore wind turbines, is presented.

  18. Darrieus wind turbine: construction and testing

    Microsoft Academic Search

    K. Abbott; L. L. Christianson; M. A. Hellickson

    1982-01-01

    A Darrieus was designed and constructed to be mechanically coupled to a heat pump for agricultural applications. This design minimized the cost of a cantilevered Darrieus and was suitable for testing purposes. All turbine components operated satisfactorily during testing, but the upper bearing and torque tube may fail after extended use. Performance characteristics of a variable-speed Darrieus were found by

  19. State of the art in wind turbine aerodynamics and aeroelasticity

    NASA Astrophysics Data System (ADS)

    Hansen, M. O. L.; Sørensen, J. N.; Voutsinas, S.; Sørensen, N.; Madsen, H. Aa.

    2006-06-01

    A comprehensive review of wind turbine aeroelasticity is given. The aerodynamic part starts with the simple aerodynamic Blade Element Momentum Method and ends with giving a review of the work done applying CFD on wind turbine rotors. In between is explained some methods of intermediate complexity such as vortex and panel methods. Also the different approaches to structural modelling of wind turbines are addressed. Finally, the coupling between the aerodynamic and structural modelling is shown in terms of possible instabilities and some examples.

  20. A hybrid cyclogiro-Darrieus-rotor wind turbine

    Microsoft Academic Search

    J. A. C. Kentfield

    1979-01-01

    A vertical-axis wind turbine combining features of cyclogiro and Darrieus rotor designs has been developed. The wind turbine has less mechanical complexity than a conventional cyclogiro and shows better performance at low velocity ratios than a Darrieus rotor. Model tests of two- and three-bladed prototypes of the wind turbine prove that both designs are self-starting. Cyclically variable blade angles of

  1. A Status of Study on Icing of Wind Turbine Blades

    Microsoft Academic Search

    Xuxiang Lu; Haibo Li; Xiaohu Deng

    2011-01-01

    During recent years, more and more wind turbines are planned and erected in cold and hostile climate sites, there may be more higher icing probability during the year.The problem of icing accretion on wind turbine blades brings many adverse effects. The purpose of this paper is aim to discuss some methods about icing-detect and anti-icing for wind turbine blades.

  2. Wind flow characteristics in the wakes of large wind turbines. Volume 1: Analytical model development

    NASA Technical Reports Server (NTRS)

    Eberle, W. R.

    1981-01-01

    A computer program to calculate the wake downwind of a wind turbine was developed. Turbine wake characteristics are useful for determining optimum arrays for wind turbine farms. The analytical model is based on the characteristics of a turbulent coflowing jet with modification for the effects of atmospheric turbulence. The program calculates overall wake characteristics, wind profiles, and power recovery for a wind turbine directly in the wake of another turbine, as functions of distance downwind of the turbine. The calculation procedure is described in detail, and sample results are presented to illustrate the general behavior of the wake and the effects of principal input parameters.

  3. Wind Turbine Pitch Optimization Benjamin Biegel Morten Juelsgaard Matt Kraning Stephen Boyd Jakob Stoustrup

    E-print Network

    Wind Turbine Pitch Optimization Benjamin Biegel Morten Juelsgaard Matt Kraning Stephen Boyd Jakob-controlled wind tur- bine. When placed in a wind field, the turbine experiences several mechanical loads, which measurements, with no knowledge of the wind field or wind turbine model. I. INTRODUCTION Wind turbines

  4. Wind turbine inspection tests at UCSD

    NASA Astrophysics Data System (ADS)

    Tippmann, Jeffery D.; Manohar, Arun; Lanza di Scalea, Francesco

    2012-04-01

    The wind energy industry is rapidly growing in order to meet the increasing world energy demands as well as the need for clean and renewable energy sources. With the goal to explore new technologies and innovations which could help potentially improve the efficiency and effectiveness of wind energy, the NDE/SHM laboratory at UCSD acquired a unique wind turbine blade that will be used for performing several research projects related to wind turbine blade technology and non-destructive inspection techniques. The blade was built using the CX-100 design developed by TPI Composites, Inc. and Sandia National Laboratory (SNL). The 9-m blade was constructed with several embedded defects that represent the most common manufacturing defects typically found, such as out-of-plane waviness, composite delamination, and adhesive disbond. The defects were embedded during the manufacturing process by using similar methods developed by both TPI and SNL for simulating actual defect characteristics. Though the blade is small in comparison to the average utility sized blade of around 40 meters, the blade features similar materials and manufacturing methods, allowing for several inspections techniques to be studied on a representative platform. The inspection techniques include advanced infrared thermography and other guided wave techniques.

  5. Wind turbine rotor speed control system

    SciTech Connect

    Kisovec, A.V.

    1982-10-26

    A wind turbine rotor speed control for ensuring a constant rotational speed within tight tolerances includes a self-sufficient rotor incorporating aerodynamic and mechanical devices to provide the control. There is a fixed turbine blade adapted to be mounted on a shaft for rotation therewith, the fixed blade having pivotal blade tips at its respective ends. The pitch control of the blade tips regulates the rotor speed. Aerodynamic tabs are pivotally secured adjacent each of the ends of the respective trailing edges of the fixed blade. The relative wind acts on each tab which is connected to a series of links and pitch cams to regulate the pitch of the blade tips from a feathered position, to a cut-in position, to a rated wind position, and vice-versa. There are torque cams actuated by torsional strain on the shaft bearing which is connected to the shaft and to the pitch cams by a series of links so that as the wind approaches its rated velocity value the pitch cams become ineffective and the torque cams take over the speed control. There are also overspeed centrifugal devices connected to the pitch cams to cause the blade tips to feather in emergency overspeed conditions so as to stop the rotor.

  6. Development of methodology for horizontal axis wind turbine dynamic analysis

    NASA Technical Reports Server (NTRS)

    Dugundji, J.

    1982-01-01

    Horizontal axis wind turbine dynamics were studied. The following findings are summarized: (1) review of the MOSTAS computer programs for dynamic analysis of horizontal axis wind turbines; (2) review of various analysis methods for rotating systems with periodic coefficients; (3) review of structural dynamics analysis tools for large wind turbine; (4) experiments for yaw characteristics of a rotating rotor; (5) development of a finite element model for rotors; (6) development of simple models for aeroelastics; and (7) development of simple models for stability and response of wind turbines on flexible towers.

  7. Dynamic modeling of doubly fed induction generator wind turbines

    Microsoft Academic Search

    Janaka B. Ekanayake; Lee Holdsworth; XueGuang Wu; Nicholas Jenkins

    2003-01-01

    It is now recognized that many large wind farms will employ doubly fed induction generator (DFIG) variable speed wind turbines. A number of such wind farms are already in operation and more are planned or under construction. With the rising penetration of wind power into electricity networks, increasingly comprehensive studies are required to identify the interaction between the wind farm(s)

  8. Wind Resource Estimation: From Trades to Turbines

    NASA Astrophysics Data System (ADS)

    Hahmann, A. N.; Badger, J.; Mortensen, N. G.; Jørgensen, H. E.

    2008-12-01

    Risø DTU has been involved in wind resource estimation for many years. Initially, we used observed winds and microscale modeling within the WAsP (the Wind Atlas Analysis and Application Program) software. This method has proven very accurate in places such as Denmark where the landscape is relatively flat, the wind climatology is mainly driven by synoptic-scale weather patterns, and where a dense observational network is available. For regions with a sparse observation network or with more complex terrain, large-scale geostrophic winds derived from global reanalysis are brought down to the mesoscale by using a statistical- dynamical downscaling method. The method uses a classification of the large-scale wind patterns which is then adjusted to the higher resolutions by the use of idealized mesoscale model simulations. Once mesoscale-corrected winds classes are calculated, they are linked to microscale models to take into account the true characteristics of the landscape. In both methods the common goal is to create generalized wind climates, from which location-specific wind climates can be calculated. The generalized (or regional) wind climate gives the frequency distributions of wind speed and direction for standardized and idealized terrain conditions. It serves to link mesoscale to microscale and vice-verse. Without this link, it is not possible to make a proper verification of wind climates derived from modeling against measured winds or apply the mesoscale results for wind farm studies. The results of the statistical-dynamical approach are not as accurate in regions where topographically forced and thermally induced effects dominate the boundary layer wind climatology. For this reason, we are currently developing enhancements to the system by exploring the use of stronger dynamical components to the statistical-dynamical method including comparison to a purely dynamical downscaling simulation for the area of interest. In this presentation we will discuss the range of methods and give examples of recent applications to wind atlas generation.

  9. DAMAGE DETECTION METHODS ON WIND TURBINE BLADE TESTING WITH WIRED AND WIRELESS ACCELEROMETER SENSORS

    E-print Network

    Paris-Sud XI, Université de

    DAMAGE DETECTION METHODS ON WIND TURBINE BLADE TESTING WITH WIRED AND WIRELESS ACCELEROMETER for nonstationary blade excitations. KEYWORDS : Structural Health Monitoring, Damage Detection, Wind Turbine, Wireless sensing, Wavelets. INTRODUCTION Detecting damage in wind turbine blades is a very

  10. Actuator control of edgewise vibrations in wind turbine blades

    NASA Astrophysics Data System (ADS)

    Staino, A.; Basu, B.; Nielsen, S. R. K.

    2012-03-01

    Edgewise vibrations with low aerodynamic damping are of particular concern in modern multi-megawatt wind turbines, as large amplitude cyclic oscillations may significantly shorten the life-time of wind turbine components, and even lead to structural damages or failures. In this paper, a new blade design with active controllers is proposed for controlling edgewise vibrations. The control is based on a pair of actuators/active tendons mounted inside each blade, allowing a variable control force to be applied in the edgewise direction. The control forces are appropriately manipulated according to a prescribed control law. A mathematical model of the wind turbine equipped with active controllers has been formulated using an Euler-Lagrangian approach. The model describes the dynamics of edgewise vibrations considering the aerodynamic properties of the blade, variable mass and stiffness per unit length and taking into account the effect of centrifugal stiffening, gravity and the interaction between the blades and the tower. Aerodynamic loads corresponding to a combination of steady wind including the wind shear and the effect of turbulence are computed by applying the modified Blade Element Momentum (BEM) theory. Multi-Blade Coordinate (MBC) transformation is applied to an edgewise reduced order model, leading to a linear time-invariant (LTI) representation of the dynamic model. The LTI description obtained is used for the design of the active control algorithm. Linear Quadratic (LQ) regulator designed for the MBC transformed system is compared with the control synthesis performed directly on an assumed nominal representation of the time-varying system. The LQ regulator is also compared against vibration control performance using Direct Velocity Feedback (DVF). Numerical simulations have been carried out using data from a 5-MW three-bladed Horizontal-Axis Wind Turbine (HAWT) model in order to study the effectiveness of the proposed active controlled blade design in reducing edgewise vibrations. Results show that the use of the proposed control scheme significantly improves the response of the blade and promising performances can be achieved. Furthermore, under the conditions considered in this study quantitative comparisons of the LQ-based control strategies reveal that there is a marginal improvement in the performances obtained by applying the MBC transformation on the time-varying edgewise vibration model of the wind turbine.

  11. Spatial mapping and attribution of Wyoming wind turbines, 2012

    USGS Publications Warehouse

    O'Donnell, Michael S.; Fancher, Tammy S.

    2014-01-01

    These data represent locations of wind turbines found within Wyoming as of August 2012. We assigned each wind turbine to a wind farm and, in these data, provide information about each turbine’s potential megawatt output, rotor diameter, hub height, rotor height, the status of the land ownership where the turbine exists, the county each turbine is located in, wind farm power capacity, the number of units currently associated with each wind farm, the wind turbine manufacturer and model, the wind farm developer, the owner of the wind farm, the current purchaser of power from the wind farm, the year the wind farm went online, and the status of its operation. Some of the attributes are estimates based on the information we found via the American Wind Energy Association and other on-line reports. The locations are derived from National Agriculture Imagery Program (2009 and 2012) true color aerial photographs and have a positional accuracy of approximately +/-5 meters. These data will provide a planning tool for wildlife- and habitat-related projects underway at the U.S. Geological Survey’s Fort Collins Science Center and other government and non-government organizations. Specifically, we will use these data to support quantifying disturbances of the landscape as related to wind energy as well as to quantify indirect disturbances to flora and fauna. This data set represents an update to a previous version by O’Donnell and Fancher (2010).

  12. How hard can it be to pitch a wind turbine blade? Moment of inertia approximately

    E-print Network

    a wind turbine blade? Motivation · How to model a hydraulic pitch actuator? · Second order system it be to pitch a wind turbine blade? Hydraulic system #12;How hard can it be to pitch a wind turbine blade? Flows a wind turbine blade? Hydraulic pitch actuator for the virtual NREL 5 MW turbine · Motivation · Actuator

  13. Analysis of wind turbines on offshore support structures excited by random wind and random waves

    Microsoft Academic Search

    D. S. Oscar; T. L. Paez

    1988-01-01

    A numerical approach has been developed to predict the dynamic response of structures excited by random wind and random waves, such as wind turbines at offshore locations. The software developed by this effort, called OFFSHORE HAWTDYN, calculates the displacement time response of horizontal axis wind turbines (HAWTs) attached to offshore support structures subjected to steady and random wind and wave

  14. Rotationally sampled wind characteristics and correlations with MOD-OA wind turbine response

    SciTech Connect

    George, R.L.; Connell, J.R.

    1984-09-01

    This report presents results of a comprehensive wind and wind turbine measurement program: the Clayton, New Mexico, vertical plane array/MOD-OA project. In this experiment, the turbulent wind was measured for a large array of fixed anemometers located two blade diameters upwind of a 200-kW horizontal-axis wind turbine (HAWT). Simultaneously, key wind turbine response parameters were also measured. The first of two major objectives of this experiment was to determine the turbulent wind, rotationally sampled to emulate the motion of the wind turbine blade, for the range of different wind speeds and stability classes actually experienced by the wind turbine. The second major objective was to correlate this rotationally sampled wind with the wind turbine blade stress and power, in order to assess the usefulness of the wind measurements for wind turbine loads testing a prediction. Time series of rotationally sampled winds and wind turbine blade bending moments and power were converted to frequency spectra using Fourier transform techniques. These spectra were used as the basis for both qualitative and quantitative comparisons among the various cases. A quantitative comparison between the rotationally sampled wind input and blade bending response was made, using the Fourier spectra to estimate the blade transfer function. These transfer functions were then used to calculate an approximate damping coefficient for the MOD-OA fiberglass blade.

  15. Wind Turbine Generator System Power Performance Test Report for the Gaia-Wind 11-kW Wind Turbine

    SciTech Connect

    Huskey, A.; Bowen, A.; Jager, D.

    2009-12-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. It is a power performance test that the National Renewable Energy Laboratory (NREL) conducted on the Gaia-Wind 11-kW small wind turbine.

  16. In-field use of laser Doppler vibrometer on a wind turbine blade

    SciTech Connect

    Rumsey, M.; Hurtado, J.; Hansche, B. [and others

    1998-12-31

    One of our primary goals was to determine how well a laser Doppler vibrometer (LDV) could measure the structural dynamic response of a wind turbine that was parked in the field. We performed a series of preliminary tests in the lab to determine the basic limitations of the LDV for this application. We then instrumented an installed parked horizontal axis wind turbine with accelerometers to determine the natural frequencies, damping, and mode shapes of the wind turbine and rotor as a baseline for the LDV and our other tests. We also wanted to determine if LDV modal information could be obtained from a naturally (wind) excited wind turbine. We compared concurrently obtained accelerometer and LDV data in an attempt to assess the quality of the LDV data. Our test results indicate the LDV can be successfully used in the field environment of an installed wind turbine, but with a few restrictions. We were successful in obtaining modal information from a naturally (wind) excited wind turbine in the field, but the data analysis requires a large number of averaged data sets to obtain reasonable results. An ultimate goal of this continuing project is to develop a technique that will monitor the health of a structure, detect damage, and hopefully predict an impending component failure.

  17. NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)

    SciTech Connect

    Not Available

    2013-10-01

    NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.

  18. Wind turbine speed control by automatic yawing

    SciTech Connect

    Hohenemser, K.H.; Swift, A.H.P.

    1983-05-01

    A yaw dynamics analysis was developed for a two-bladed horizontal axis wind turbine with passive cyclic pitch variation achieved by letting the blade pair freely oscillate about a common axis with which the blades formed a small prelag angle. This type of rotor was found capable of high yaw rates without imposing vibratory hub moments and without producing noticeable flapping amplitudes. Experiments were conducted with a tail vane stabilized 7.6-m-diam wind rotor driving a three-phase alternator tuned and loaded to produce a rotor torque proportional to the square of the rotor speed. Two yaw control systems which replaced the usual blade feathering controls were investigated: an active yaw control system using a hydraulic rotor speed governor, and a passive system responding to a combination of rotor thrust and torque. During strong gusts both systems limited rotor speed quite accurately. The passive system appeared to be more promising because of its greater reliability and because of the greater ease of adapting it to larger size wind turbines.

  19. Wind Turbines Make Waves: Why Some Residents near Wind Turbines Become Ill

    ERIC Educational Resources Information Center

    Havas, Magda; Colling, David

    2011-01-01

    People who live near wind turbines complain of symptoms that include some combination of the following: difficulty sleeping, fatigue, depression, irritability, aggressiveness, cognitive dysfunction, chest pain/pressure, headaches, joint pain, skin irritations, nausea, dizziness, tinnitus, and stress. These symptoms have been attributed to the…

  20. Development of Fully Coupled Aeroelastic and Hydrodynamic Models for Offshore Wind Turbines: Preprint

    Microsoft Academic Search

    J. M. Jonkman; P. D. Sclavounos

    2006-01-01

    Aeroelastic simulation tools are routinely used to design and analyze onshore wind turbines, in order to obtain cost effective machines that achieve favorable performance while maintaining structural integrity. These tools employ sophisticated models of wind-inflow; aerodynamic, gravitational, and inertial loading of the rotor, nacelle, and tower; elastic effects within and between components; and mechanical actuation and electrical responses of the

  1. Aeroelastic stability analysis of a Darrieus wind turbine

    Microsoft Academic Search

    D. Popelka

    1982-01-01

    An aeroelastic stability analysis was developed for predicting flutter instabilities on vertical axis wind turbines. The analytical model and mathematical formulation of the problem are described as well as the physical mechanism that creates flutter in Darrieus turbines. Theoretical results are compared with measured experimental data from flutter tests of the Sandia 2 Meter turbine. Based on this comparison, the

  2. Dynamic simulation of dual-speed wind turbine generation

    SciTech Connect

    Muljadi, E.; Butterfield, C.P.

    1996-10-01

    Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using two induction generators with two different rated speeds. With single- speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. The operation at maximum Cp can occur only at a single wind speed. However, if the wind speed varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind-speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative to capture more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine will be investigated. One type of control algorithm for dual- speed operation is proposed. Results from a dynamic simulation will be presented to show how the control algorithm works and how power, current and torque of the system vary as the wind turbine is exposed to varying wind speeds.

  3. Structural design and fabrication of the Sandia 34-meter Vertical Axis Wind Turbine

    NASA Astrophysics Data System (ADS)

    Ashwill, T. D.

    1987-01-01

    The Wind Energy Research Division of Sandia National Laboratories has been funded by the Wind/Ocean Technology Division of the Department of Energy (DOE) to design and build a 34-meter diameter Vertical Axis Wind Turbine (VAWT). The turbine design incorporates the results of recent VAWT research in aerodynamics and structural dynamics. Initial system concept studies identified several blade options that met the required power rating of 500 kW. The final blade and rotor configurations were chosen based on finite element calculations that determined the turbine modes of response, their frequency of vibration, and stress levels. Parked survival turbine components were designed to withstand the loading of a 150 mph (67.0 m/s) wind coupled with maximum cable tensions. Specific areas of design discussed include the rotor, cables, bearings, brakes, and foundations.

  4. Characterization of micro-Doppler radar signature of commercial wind turbines

    NASA Astrophysics Data System (ADS)

    Kong, Fanxing; Zhang, Yan; Palmer, Robert

    2014-05-01

    The large utility-scale wind turbines are reported to have negative impact on nearby radars due to complex scattering mechanisms, which is usually referred to as the radar Wind Turbine Clutter (WTC). Extremely complicated time-varying Doppler spectrum have been observed. Conventional ground clutter filter techniques thus have failed in mitigating the non-stationary components in the frequency domain. Rotation of the blades is a micro-motion as the wind turbine always stays at the same location. The time-evolving spectrum associated with the blade rotation is therefore a Micro-Doppler signature, which is important in characterizing radar WTC. This paper will disclose some latest findings from our recent studies in characterizing the Micro-Doppler radar signatures of wind turbine through electromagnetic modeling.

  5. Wind turbine ring/shroud drive system

    DOEpatents

    Blakemore, Ralph W.

    2005-10-04

    A wind turbine capable of driving multiple electric generators having a ring or shroud structure for reducing blade root bending moments, hub loads, blade fastener loads and pitch bearing loads. The shroud may further incorporate a ring gear for driving an electric generator. In one embodiment, the electric generator may be cantilevered from the nacelle such that the gear on the generator drive shaft is contacted by the ring gear of the shroud. The shroud also provides protection for the gearing and aids in preventing gear lubricant contamination.

  6. MOD-0 wind turbine dynamics test correlations

    NASA Technical Reports Server (NTRS)

    Brooks, B. M.

    1981-01-01

    The behavior of the teetered, downwind, free yaw, MOD-0 wind turbine, as represented by NASA dynamic test data, was used to support confidence in the Hamilton Standard computer code simulations. Trim position, performance at trim, and teeter response as predicted by the computer codes were compared to test results. Using the computer codes, other possible configurations for MOD-0 were investigated. Several new test configurations are recommended for exploring free yaw behavior. It is shown that eliminating rotor tilt and optimizing cooling and blade twist can contribute to good free yaw behavior and stability. The effects of rotor teeter, teeter gravity balance, inflow and other physical and operating parameters were also investigated.

  7. innovati nNREL Innovations Contribute to an Award-Winning Small Wind Turbine

    E-print Network

    innovati nNREL Innovations Contribute to an Award-Winning Small Wind Turbine The Skystream 3.7 wind (NREL) and Southwest Windpower, a commercially successful small wind turbine manufacturer. NREL drew blade design that makes the wind turbine more efficient and quieter than most. Small wind turbines

  8. Representing wind turbine electrical generating systems in fundamental frequency simulations

    Microsoft Academic Search

    J. G. Slootweg; H. Polinder; W. L. Kling

    2003-01-01

    Increasing numbers of wind turbines are being erected. In the near future, they may start to influence the dynamics of electrical power systems by interacting with conventional generation equipment and with loads. The impact of wind turbines on the dynamics of electrical power systems therefore becomes an important subject, studied by means of power system dynamics simulations. Various types of

  9. Fault ride-through capability of DFIG wind turbines

    Microsoft Academic Search

    Anca D. Hansen; Gabriele Michalke

    2007-01-01

    This paper concentrates on the fault ride-through capability of doubly fed induction generator (DFIG) wind turbines. The main attention in the paper is, therefore, drawn to the control of the DFIG wind turbine and of its power converter and to the ability to protect itself without disconnection during grid faults. The paper provides also an overview on the interaction between

  10. Wind turbines emulating inertia and supporting primary frequency control

    Microsoft Academic Search

    Johan Morren; Sjoerd W. H. de Haan; Wil L. Kling; J. A. Ferreira

    2006-01-01

    The increasing penetration of variable-speed wind turbines in the electricity grid will result in a reduction of the number of connected conventional power plants. This will require changes in the way the grid frequency is controlled. In this letter, a method is proposed to let variable-speed wind turbines emulate inertia and support primary frequency control. The required power is obtained

  11. Understanding the unbalanced-voltage problem in wind turbine generation

    Microsoft Academic Search

    E. Muljadi; D. Yildirim; T. Batan; C. P. Butterfield

    1999-01-01

    Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness, and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operates with a small range of slips with respect to synchronous speed.

  12. New wind turbine grounding system to reduce step & touch voltage

    Microsoft Academic Search

    H. Kazemi Karegar; M. Arabi

    2010-01-01

    Step and touch voltage are two main parameters of a grounding system. Common way to reduce these two factors is using distributed mesh network under ground of substation, but wind turbines grounding system are different and limited area. In this paper, the wind turbine grounding system will be analyzed and step and touch voltage will be obtained. For this purpose,

  13. A 200kW wind turbine power chain

    Microsoft Academic Search

    Yan Tai Chang; K. W. E. Cheng; Jiongkang Lin

    2009-01-01

    This paper presents a modern configuration of the power chain for a high power wind turbine machine using permanent magnet generator. A test setup is shown and device specifications are described. Advantages of using direct drive generators are also shown. The discussion on the use of SRG is proposed. It provides a low speed solution of the wind turbine power

  14. Variable Speed Wind Turbines for Power System Stability Enhancement

    Microsoft Academic Search

    Nayeem Rahmat Ullah; Torbjrn Thiringer

    2007-01-01

    This paper investigates possible improvements in grid voltage stability and transient stability with wind energy converter units using modified P\\/Q control. The voltage source converter (VSC) in modern variable speed wind turbines is utilized to achieve this enhancement. The findings show that using only available hardware for variable-speed turbines improvements could be obtained in all cases. Moreover, it was found

  15. Monopile as Part of Aeroelastic Wind Turbine Simulation Code

    Microsoft Academic Search

    Rune Rubak; Jørgen Thirstrup Petersen

    2005-01-01

    The influence on wind turbine design loads of variations in stiffness and damping of a monopile foundation with soil interaction is demonstrated through a case study, which takes non-linearities into account. The study illustrates the importance of a detailed foundation model, and demonstrates the framework, which is an important part of a successful optimization of wind turbines. In particular for

  16. Method for predicting impulsive noise generated by wind turbine rotors

    Microsoft Academic Search

    L. A. Viterna

    1982-01-01

    Large wind turbines can generate both broad band and impulsive noises. These noises can be controlled by proper choice of rotor design parameters such as rotor location with respect to the supporting tower, tower geometry and tip speed. A method was developed to calculate the impulsive noise generated when the wind turbine blade experiences air forces that are periodic functions

  17. The NASA-LeRC wind turbine sound prediction code

    Microsoft Academic Search

    L. A. Viterna

    1981-01-01

    Development of the wind turbine sound prediction code began as part of an effort understand and reduce the noise generated by Mod-1. Tone sound levels predicted with this code are in good agreement with measured data taken in the vicinity Mod-1 wind turbine (less than 2 rotor diameters). Comparison in the far field indicates that propagation effects due to terrain

  18. How I Home-Built an Electricity Producing Wind Turbine

    NSDL National Science Digital Library

    Davis, Michael

    This site has step-by-step instructions on how to build a wind turbine with parts you can purchase from the hardware store and e-bay. The website includes photographs and text which illustrate how to build the wind turbine.

  19. Flow Past the Sail Blade of a Wind Turbine

    NASA Astrophysics Data System (ADS)

    Kusaiynov, K.; Kambarova, Zh. T.; Tanasheva, N. K.; Shaimerdenova, K. M.; Alibekova, A. R.

    2015-04-01

    An experiment to determine the aerodynamic characteristics of a wind turbine with sail blades was conducted on a model. The dependence of the drag and lift coefficients on the dimensionless angle of attack and the number of wind-turbine blades has been determined experimentally.

  20. Control Design Toolbox for Large-Scale PRVS Wind Turbines

    Microsoft Academic Search

    Sergio Dominguez; W. E. Leithead

    The trend towards large multi-MW wind turbines has given new impetus to the development of wind turbine con- trollers. Additional objectives are being placed on the controller making the specification of the control system more complex. A new toolbox, which assists with most of the control design cycle, has been developed. Its purpose is to assist and guide the control

  1. Observations of dynamic stall on Darrieus wind turbine blades

    Microsoft Academic Search

    Nobuyuki Fujisawa; Satoshi Shibuya

    2001-01-01

    Flow field around a Darrieus wind turbine blade in dynamic stall is studied by flow visualization and particle image velocimetry (PIV) measurement in stationary and rotating frames of reference. The experiment is carried out using the small-scale Darrieus wind turbine in a water tunnel. The unsteady nature of the dynamic stall observed by the flow visualization is quantitatively reproduced in

  2. Engineering development status of the Darrieus wind turbine

    Microsoft Academic Search

    B. F. Blackwell; W. N. Sullivan; R. C. Reuter; J. F. Banas

    1977-01-01

    The aerodynamics, structural stability, and system adaptability of Darrieus wind turbines (DWT) are examined and reviewed. The basic workings, aerodynamic performance, and wind tunnel data on DWT are presented. Structural studies are reviewed, covering blade statics, blade dynamics, blade flutter, the turbine support structure, and materials selection. Functioning of the DWT in a utility power grid is probed, with comparisons

  3. Flow Past the Sail Blade of a Wind Turbine

    NASA Astrophysics Data System (ADS)

    Kusaiynov, K.; Kambarova, Zh. T.; Tanasheva, N. K.; Shaimerdenova, K. M.; Alibekova, A. R.

    2015-03-01

    An experiment to determine the aerodynamic characteristics of a wind turbine with sail blades was conducted on a model. The dependence of the drag and lift coefficients on the dimensionless angle of attack and the number of wind-turbine blades has been determined experimentally.

  4. Wind turbine control using a gearless epicyclic transmission

    Microsoft Academic Search

    Xiao Qing Ma; Vikram Chopra; S. H. H. Zargarbashi; Jorge Angeles

    2010-01-01

    A recurrent problem in energy production by means of wind turbines is how to keep a constant angular velocity at the shaft driving the alternator in the presence of a randomly varying turbine angular velocity. The latter is caused by the random nature of the wind velocity. Proposed in this paper is an innovative two-degree-of-freedom mechanism, with the morphology of

  5. DOE/NREL Advanced Wind Turbine Development Program

    SciTech Connect

    Butterfield, C.P.; Smith, B.; Laxson, A.; Thresher, B. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Goldman, P. [USDOE Assistant Secretary for Conservation and Renewable Energy, Washington, DC (United States). Wind/Hydro/Ocean Technologies Div.] [USDOE Assistant Secretary for Conservation and Renewable Energy, Washington, DC (United States). Wind/Hydro/Ocean Technologies Div.

    1993-05-01

    The development of technologically advanced, high-efficiency wind turbines continues to be a high-priority activity of the US wind industry. The National Renewable Energy Laboratory (formerly the Solar Energy Research Institute), sponsored by the US Department of Energy (DOE), has initiated the Advanced Wind Turbine Program to assist the wind industry in the development of a new class of advanced wind turbines. The initial phase of the program focused on developing conceptual designs for near-term and advanced turbines. The goal of the second phase of this program is to use the experience gained over the last decade of turbine design and operation combined with the latest existing design tools to develop a turbine that will produce energy at $0.05 per kilowatt-hour (kWh) in a 5.8-m/s (13-mph) wind site. Three contracts have been awarded, and two more are under negotiation in the second phase. The third phase of the program will use new innovations and state-of-the-art wind turbine design technology to produce a turbine that will generate energy at $0.04/kWh in a 5.8-m/s wind site. Details of the third phase will be announced in early 1993.

  6. Grid interface for a wind turbine-fuel cell system

    Microsoft Academic Search

    E. Ribeiro; A. J. M. Cardoso; C. Boccaletti

    2010-01-01

    Environmental and sustainability concerns are increasing the importance of distributed generation based on renewable energy sources and its grid integration. This paper proposes a grid interface for a hybrid system composed by fuel cells, a wind turbine and supercapacitors. Such grid interface permits to control the wind turbine energy using a diode rectifier and an intermediate DC boost converter and

  7. Lightning protection for wind turbine blades and bearings

    Microsoft Academic Search

    Ian Cotton; Nick Jenkins; Krishnan Pandiaraj

    2001-01-01

    The protection of wind turbines from lightning damage is increasingly important as they increase in size and are placed in locations where access to carry out repairs may be difficult. As blades are the most common attachment point of lightning, they must be adequately protected. In addition, the passage of lightning current through wind turbine bearings introduces a risk of

  8. Performance-optimized horizontal-axis wind turbines

    Microsoft Academic Search

    R. E. Wilson; S. N. Walker

    1977-01-01

    Design procedures for optimum wind turbines is shown to be different from that used for propellers. An optimum design generation approach for wind turbines is developed from a modified strip theory that includes tip-loss. The approach entails a local optimization of blade element parameters to maximize power output. Examples are presented that illustrate the optimum design generation procedure and off-design

  9. High Tip Speed Operation for Offshore Wind Turbines

    Microsoft Academic Search

    Andreas Knauer; Tor David Hanson

    Summary The operation of large offshore wind turbines at high rotational speeds is investigated with focus on rotor aerodynamics, performance for the extended operational range and the potential for tower top mass reductions. 2D aerodynamic investigations were carried out with the program XFOIL on the NACA 63415 airfoil. Several 5 MW wind turbine rotors were designed to operate at tip

  10. Foundation modelling to assess dynamic behaviour of offshore wind turbines

    Microsoft Academic Search

    M. B. Zaaijer

    2006-01-01

    The dynamic behaviour of wind turbines at offshore locations is more complex than that of both onshore wind turbines and offshore platforms used in the oil and gas industry. In order to reduce the computational burden, the work presented in this paper aims at simplification of the dynamic model of the foundation, while maintaining sufficient accuracy. A stiffness matrix at

  11. Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint

    SciTech Connect

    Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

    2011-12-01

    Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

  12. Locations and attributes of wind turbines in New Mexico, 2011

    USGS Publications Warehouse

    Carr, Natasha B.; Diffendorfer, James B.; Fancher, Tammy; Hawkins, Sarah J.; Latysh, Natalie; Leib, Kenneth J.; Matherne, Anne Marie

    2013-01-01

    This dataset represents an update to U.S. Geological Survey Data Series 596. Locations and attributes of wind turbines in New Mexico, 2009 (available at http://pubs.usgs.gov/ds/596/).This updated New Mexico wind turbine Data Series provides geospatial data for all 562 wind turbines established within the State of New Mexico as of June 2011, an increase of 155 wind turbines from 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, county, and development status of wind turbine. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, and year the facility went online. The locations of turbines are derived from 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program (NAIP); the photographs have a positional accuracy of about ±5 meters. The locations of turbines constructed during or prior to August 2009 are based on August 2009 NAIP imagery and turbine locations constructed after August 2009 were based June 2011 NAIP imagery. The location of turbines under construction during June 2011 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas developed by the U.S. Geological Survey (http://my.usgs.gov/eerma/). The Energy Atlas synthesizes data on existing and potential energy development in Colorado and New Mexico and includes additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools also are included in the Energy Atlas. The format of the Energy Atlas is designed to facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

  13. Locations and attributes of wind turbines in Colorado, 2011

    USGS Publications Warehouse

    Carr, Natasha B.; Diffendorfer, James E.; Fancher, Tammy; Hawkins, Sarah J.; Latysh, Natalie; Leib, Kenneth J.; Matherne, Anne Marie

    2013-01-01

    This dataset represents an update to U.S. Geological Survey Data Series 597. Locations and attributes of wind turbines in Colorado, 2009 (available at http://pubs.usgs.gov/ds/597/). This updated Colorado wind turbine Data Series provides geospatial data for all 1,204 wind turbines established within the State of Colorado as of September 2011, an increase of 297 wind turbines from 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, county, and development status of the wind turbine. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, and year the facility went online. The locations of turbines are derived from 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program (NAIP); the photographs have a positional accuracy of about ±5 meters. Locations of turbines constructed during or prior to August 2009 are based on August 2009 NAIP imagery and turbine locations constructed after August 2009 were based on September 2011 NAIP imagery. The location of turbines under construction during September 2011 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas developed by the U.S. Geological Survey (http://my.usgs.gov/eerma/). The Energy Atlas synthesizes data on existing and potential energy development in Colorado and New Mexico and includes additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools also are included in the Energy Atlas. The format of the Energy Atlas is designed to facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

  14. Kinetic Energy Transport in a Vertical-Axis Wind Turbine Array

    NASA Astrophysics Data System (ADS)

    Kinzel, Matthias; Araya, Daniel; Dabiri, John

    2013-11-01

    We present experimental results from a full scale array of vertical-axis wind turbines (VAWTs) under natural wind conditions. The wind velocities throughout the turbine array are measured using a portable meteorological tower with seven, vertically-staggered, three-component ultrasonic anemometers. These measurements yield detailed insight into the turbine wakes and the recovery of the flow velocity behind the turbines. Quadrant hole analysis is employed to gain a better understanding of the energy transport at the top and the bottom of the VAWT array. The results are compared to the flow in horizontal-axis wind farms as well as urban and plant canopies. Emphasis is given to the flow physics in the adjustment region of the canopy, i.e. the region where the flow transitions from an atmospheric boundary layer to a canopy flow. We present experimental results from a full scale array of vertical-axis wind turbines (VAWTs) under natural wind conditions. The wind velocities throughout the turbine array are measured using a portable meteorological tower with seven, vertically-staggered, three-component ultrasonic anemometers. These measurements yield detailed insight into the turbine wakes and the recovery of the flow velocity behind the turbines. Quadrant hole analysis is employed to gain a better understanding of the energy transport at the top and the bottom of the VAWT array. The results are compared to the flow in horizontal-axis wind farms as well as urban and plant canopies. Emphasis is given to the flow physics in the adjustment region of the canopy, i.e. the region where the flow transitions from an atmospheric boundary layer to a canopy flow. The authors gratefully acknowledge funding from the Gordon and Betty Moore Foundation through Grant 2645, the National Science Foundation Energy for Sustainability program (Grant No. CBET-0725164) and the Office of Naval Research (Grant No. N000141211047).

  15. Wind turbine generator with improved operating subassemblies

    SciTech Connect

    Cheney Jr., M. C.

    1985-10-08

    A wind turbine includes a yaw spring return assembly to return the nacelle from a position to which it has been rotated by yawing forces, thus preventing excessive twisting of the power cables and control cables. It also includes negative coning restrainers to limit the bending of the flexible arms of the rotor towards the tower, and stop means on the rotor shaft to orient the blades in a vertical position during periods when the unit is upwind when the wind commences. A pendulum pitch control mechanism is improved by orienting the pivot axis for the pendulum arm at an angle to the longitudinal axis of its support arm, and excessive creep is of the synthetic resin flexible beam support for the blades is prevented by a restraining cable which limits the extent of pivoting of the pendulum during normal operation but which will permit further pivoting under abnormal conditions to cause the rotor to stall.

  16. Passive load control for large wind turbines.

    SciTech Connect

    Ashwill, Thomas D.

    2010-05-01

    Wind energy research activities at Sandia National Laboratories focus on developing large rotors that are lighter and more cost-effective than those designed with current technologies. Because gravity scales as the cube of the blade length, gravity loads become a constraining design factor for very large blades. Efforts to passively reduce turbulent loading has shown significant potential to reduce blade weight and capture more energy. Research in passive load reduction for wind turbines began at Sandia in the late 1990's and has moved from analytical studies to blade applications. This paper discusses the test results of two Sandia prototype research blades that incorporate load reduction techniques. The TX-100 is a 9-m long blade that induces bend-twist coupling with the use of off-axis carbon in the skin. The STAR blade is a 27-m long blade that induces bend-twist coupling by sweeping the blade in a geometric fashion.

  17. Wind turbine trailing edge aerodynamic brakes

    SciTech Connect

    Migliore, P G [National Renewable Energy Lab., Golden, CO (United States); Miller, L S [Wichita State Univ., KS (United States). Dept. of Aerospace Engineering; Quandt, G A

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  18. Nonlinear Control of a Wind Turbine Sven Creutz Thomsen

    E-print Network

    ratio [kg/m3] - Air density r [rad/s] - Angular speed of rotor g [rad/s] - Angular speed of generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.4 Wind augmented variable speed model . . . . . . . . . . . . . . . . . . 19 2.5 Linear wind describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind

  19. Nonlinear Control of a Wind Turbine Sven Creutz Thomsen

    E-print Network

    # [­] ­ Tip speed ratio # [kg/m 3 ] ­ Air density # r [rad/s] ­ Angular speed of rotor # g [rad/s] ­ Angular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.4 Wind augmented variable speed model . . . . . . . . . . . . . . . . . . 19 2.5 Linear wind describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind

  20. Wind turbines: is there a human health risk?

    PubMed

    Roberts, Jennifer D; Roberts, Mark A

    2013-04-01

    The term "Wind Turbine Syndrome" was coined in a recently self-published book, which hypothesized that a multitude of symptoms such as headache and dizziness resulted from wind turbines generating low frequency sound (LFS). The objective of this article is to provide a summary of the peer-reviewed literature on the research that has examined the relationship between human health effects and exposure to LFS and sound generated from the operation of wind turbines. At present, a specific health condition has not been documented in the peer-reviewed literature that has been classified as a disease caused by exposure to sound levels and frequencies generated by the operation of wind turbines. Communities are experiencing a heightened sense of annoyance and fear from the development and siting of wind turbine farms. High-quality research and effective risk communication can advance this course from one of panic to one of understanding and exemplification for other environmental advancements. PMID:23621051

  1. Spatial mapping and attribution of Wyoming wind turbines

    USGS Publications Warehouse

    O'Donnell, Michael S.; Fancher, Tammy S.

    2010-01-01

    This Wyoming wind-turbine data set represents locations of wind turbines found within Wyoming as of August 1, 2009. Each wind turbine is assigned to a wind farm. For each turbine, this report contains information about the following: potential megawatt output, rotor diameter, hub height, rotor height, land ownership, county, wind farm power capacity, the number of units currently associated with its wind farm, the wind turbine manufacturer and model, the wind farm developer, the owner of the wind farm, the current purchaser of power from the wind farm, the year the wind farm went online, and the status of its operation. Some attributes are estimates based on information that was obtained through the American Wind Energy Association and miscellaneous online reports. The locations are derived from August 2009 true-color aerial photographs made by the National Agriculture Imagery Program; the photographs have a positional accuracy of approximately ?5 meters. The location of wind turbines under construction during the development of this data set will likely be less accurate than the location of turbines already completed. The original purpose for developing the data presented here was to evaluate the effect of wind energy development on seasonal habitat used by greater sage-grouse. Additionally, these data will provide a planning tool for the Wyoming Landscape Conservation Initiative Science Team and for other wildlife- and habitat-related projects underway at the U.S. Geological Survey's Fort Collins Science Center. Specifically, these data will be used to quantify disturbance of the landscape related to wind energy as well as quantifying indirect disturbances to flora and fauna. This data set was developed for the 2010 project 'Seasonal predictive habitat models for greater sage-grouse in Wyoming.' This project's spatially explicit seasonal distribution models of sage-grouse in Wyoming will provide resource managers with tools for conservation planning. These specific data are being used for assessing the effect of disturbance resulting from wind energy development within Wyoming on sage-grouse populations.

  2. Darrieus wind-turbine airfoil configurations

    SciTech Connect

    Migliore, P.G.; Fritschen, J.R.

    1982-06-01

    The purpose of this study was to determine what aerodynamic performance improvement, if any, could be achieved by judiciously choosing the airfoil sections for Darrieus wind turbine blades. Analysis was limited to machines using two blades of infinite aspect ratio, having rotor solidites from seven to twenty-one percent, and operating at maximum Reynolds numbers of approximately three million. Ten different airfoils, having thickness to chord ratios of twelve, fifteen and eighteen percent, were investigated. Performance calculations indicated that the NACA 6-series airfoils yield peak power coefficients at least as great as the NACA four-digit airfoils which have historically been chosen for Darrieus turbines. Furthermore, the power coefficient-tip speed ratio curves were broader and flatter for the 6-series airfoils. Sample calculations for an NACA 63/sub 2/-015 airfoil showed an annual energy output increase of 17 to 27% depending upon rotor solidity, compared to an NACA 0015 airfoil. An attempt was made to account for the flow curvature effects associated with Darrieus turbines by transforming the NACA 63/sub 2/-015 airfoil to an appropriate shape.

  3. Annoyance, detection and recognition of wind turbine noise.

    PubMed

    Van Renterghem, Timothy; Bockstael, Annelies; De Weirt, Valentine; Botteldooren, Dick

    2013-07-01

    Annoyance, recognition and detection of noise from a single wind turbine were studied by means of a two-stage listening experiment with 50 participants with normal hearing abilities. In-situ recordings made at close distance from a 1.8-MW wind turbine operating at 22 rpm were mixed with road traffic noise, and processed to simulate indoor sound pressure levels at LAeq 40 dBA. In a first part, where people were unaware of the true purpose of the experiment, samples were played during a quiet leisure activity. Under these conditions, pure wind turbine noise gave very similar annoyance ratings as unmixed highway noise at the same equivalent level, while annoyance by local road traffic noise was significantly higher. In a second experiment, listeners were asked to identify the sample containing wind turbine noise in a paired comparison test. The detection limit of wind turbine noise in presence of highway noise was estimated to be as low as a signal-to-noise ratio of -23 dBA. When mixed with local road traffic, such a detection limit could not be determined. These findings support that noticing the sound could be an important aspect of wind turbine noise annoyance at the low equivalent levels typically observed indoors in practice. Participants that easily recognized wind-turbine(-like) sounds could detect wind turbine noise better when submersed in road traffic noise. Recognition of wind turbine sounds is also linked to higher annoyance. Awareness of the source is therefore a relevant aspect of wind turbine noise perception which is consistent with previous research. PMID:23624007

  4. Smoothing effects of distributed wind turbines. Part 1. Coherence and smoothing effects at a wind farm

    NASA Astrophysics Data System (ADS)

    Nanahara, Toshiya; Asari, Masahiro; Sato, Takamitsu; Yamaguchi, Koji; Shibata, Masaaki; Maejima, Tsutomu

    2004-04-01

    Recently there has been a marked increase in wind power generation. From a power system point of view, because a wind turbine is an intermittent generator with large output fluctuation, any increase in the number of wind turbines gives rise to concerns about the adverse effects of wind turbines on power quality. The smoothing effects of wind turbine output fluctuation are of great importance in assessing the impacts of a large number of wind turbines. This article examines smoothing effects at a wind farm. First it presents a summary of wind measurements taken at two locations with six masts over a period of 1 year on both flat and complex terrain. Then the spatial coherence of wind speed is analysed, paying special attention to its dependence on the distance between observation points, wind direction, wind velocity and fluctuation frequency. Approximation equations for coherence of frequency and distance are obtained by applying Davenport's expression to the observed data. Second, coherence between turbine output at a wind farm is investigated; the results indicate that coherence for wind speed and turbine output shows a considerable resemblance. The article also examines smoothing effects at a wind farm using power spectral density through a theoretical approach. The study proves that smoothing effects can be approximated with a lowpass filter and that the effects at a wind farm should not be taken into account for periods of more than 10 min in case of assessing them on the safe side. Copyright

  5. ERCOT's Dynamic Model of Wind Turbine Generators: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.

    2005-08-01

    By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.

  6. CgWind: A high-order accurate simulation tool for wind turbines and wind farms

    SciTech Connect

    Chand, K K; Henshaw, W D; Lundquist, K A; Singer, M A

    2010-02-22

    CgWind is a high-fidelity large eddy simulation (LES) tool designed to meet the modeling needs of wind turbine and wind park engineers. This tool combines several advanced computational technologies in order to model accurately the complex and dynamic nature of wind energy applications. The composite grid approach provides high-quality structured grids for the efficient implementation of high-order accurate discretizations of the incompressible Navier-Stokes equations. Composite grids also provide a natural mechanism for modeling bodies in relative motion and complex geometry. Advanced algorithms such as matrix-free multigrid, compact discretizations and approximate factorization will allow CgWind to perform highly resolved calculations efficiently on a wide class of computing resources. Also in development are nonlinear LES subgrid-scale models required to simulate the many interacting scales present in large wind turbine applications. This paper outlines our approach, the current status of CgWind and future development plans.

  7. Aspects of structural health and condition monitoring of offshore wind turbines

    PubMed Central

    Antoniadou, I.; Dervilis, N.; Papatheou, E.; Maguire, A. E.; Worden, K.

    2015-01-01

    Wind power has expanded significantly over the past years, although reliability of wind turbine systems, especially of offshore wind turbines, has been many times unsatisfactory in the past. Wind turbine failures are equivalent to crucial financial losses. Therefore, creating and applying strategies that improve the reliability of their components is important for a successful implementation of such systems. Structural health monitoring (SHM) addresses these problems through the monitoring of parameters indicative of the state of the structure examined. Condition monitoring (CM), on the other hand, can be seen as a specialized area of the SHM community that aims at damage detection of, particularly, rotating machinery. The paper is divided into two parts: in the first part, advanced signal processing and machine learning methods are discussed for SHM and CM on wind turbine gearbox and blade damage detection examples. In the second part, an initial exploration of supervisor control and data acquisition systems data of an offshore wind farm is presented, and data-driven approaches are proposed for detecting abnormal behaviour of wind turbines. It is shown that the advanced signal processing methods discussed are effective and that it is important to adopt these SHM strategies in the wind energy sector. PMID:25583864

  8. Wind turbine power tracking using an improved multimodel quadratic approach.

    PubMed

    Khezami, Nadhira; Benhadj Braiek, Naceur; Guillaud, Xavier

    2010-07-01

    In this paper, an improved multimodel optimal quadratic control structure for variable speed, pitch regulated wind turbines (operating at high wind speeds) is proposed in order to integrate high levels of wind power to actively provide a primary reserve for frequency control. On the basis of the nonlinear model of the studied plant, and taking into account the wind speed fluctuations, and the electrical power variation, a multimodel linear description is derived for the wind turbine, and is used for the synthesis of an optimal control law involving a state feedback, an integral action and an output reference model. This new control structure allows a rapid transition of the wind turbine generated power between different desired set values. This electrical power tracking is ensured with a high-performance behavior for all other state variables: turbine and generator rotational speeds and mechanical shaft torque; and smooth and adequate evolution of the control variables. PMID:20434153

  9. Turbine Inflow Characterization at the National Wind Technology Center

    SciTech Connect

    Clifton, A.; Schreck, S.; Scott, G.; Kelley, N.; Lundquist, J. K.

    2012-01-01

    Utility-scale wind turbines operate in dynamic flows that can vary significantly over timescales from less than a second to several years. To better understand the inflow to utility-scale turbines, two inflow towers were installed and commissioned at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center near Boulder, Colorado, in 2011. These towers are 135 m tall and instrumented with a combination of sonic anemometers, cup anemometers, wind vanes, and temperature measurements to characterize the inflow wind speed and direction, turbulence, stability and thermal stratification to two utility-scale turbines. Herein, we present variations in mean and turbulent wind parameters with height, atmospheric stability, and as a function of wind direction that could be important for turbine operation as well as persistence of turbine wakes. Wind speed, turbulence intensity, and dissipation are all factors that affect turbine performance. Our results show that these all vary with height across the rotor disk, demonstrating the importance of measuring atmospheric conditions that influence wind turbine performance at multiple heights in the rotor disk, rather than relying on extrapolation from lower levels.

  10. Tests of an overrunning clutch in a wind turbine

    SciTech Connect

    Seidel, R.C.; Pfanner, H.G.

    1981-07-01

    The report describes the tests that were run on an overrunning clutch, a concept being considered for use on advanced wind turbine designs. The overrunning clutch has potential to simplify operations and improve wind turbine performance in low and variable winds. The energy capture can be increased because, as the wind decreases, the wind turbine does not motor but is permitted to coast below synchronous speed. Also, as the wind speed increases, the rotor rpm increases to synchronous and produces power without requiring time for wind speed averaging or synchronization. The overrunning clutch was installed between the gearbox and the alternator. Overrunning clutches are mature mechanical devices made by a number of manufacturers and have rated life cycles consistent with a thirty year wind turine life.

  11. The EPRI/DOE Utility Wind Turbine Performance Verification Program

    SciTech Connect

    Calvert, S.; Goldman, P. [Department of Energy, Washington, DC (United States); DeMeo, E.; McGowin, C. [Electric Power Research Inst., Palo Alto, CA (United States); Smith, B.; Tromly, K. [National Renewable Energy Lab., Golden, CO (United States)

    1997-01-01

    In 1992, the Electric Power Research Institute (EPRI) and the US Department of Energy (DOE) initiated the Utility Wind Turbine Performance Verification Program (TVP). This paper provides an overview of the TVP, its purpose and goals, and the participating utility projects. Improved technology has significantly reduced the cost of energy from wind turbines since the early 1980s. In 1992, turbines were producing electricity for about $0.07--$0.09/kilowatt-hour (kWh) (at 7 m/s [16 mph sites]), compared with more than $0.30/kWh in 1980. Further technology improvements were expected to lower the cost of energy from wind turbines to $0.05/kWh. More than 17,000 wind turbines, totaling more than 1,500 MW capacity, were installed in the US, primarily in California and Hawaii. The better wind plants had availabilities above 95%, capacity factors exceeding 30%, and operation and maintenance costs of $0.01/kWh. However, despite improving technology, EPRI and DOE recognized that utility use of wind turbines was still largely limited to turbines installed in California and Hawaii during the 1980s. Wind resource assessments showed that other regions of the US, particularly the Midwest, had abundant wind resources. EPRI and DOE sought to provide a bridge from utility-grade turbine development programs under way to commercial purchases of the wind turbines. The TVP was developed to allow utilities to build and operate enough candidate turbines to gain statistically significant operating and maintenance data.

  12. Wind tunnel and numerical study of a small vertical axis wind turbine

    Microsoft Academic Search

    Robert Howell; Ning Qin; Jonathan Edwards; Naveed Durrani

    2010-01-01

    This paper presents a combined experimental and computational study into the aerodynamics and performance of a small scale vertical axis wind turbine (VAWT). Wind tunnel tests were carried out to ascertain overall performance of the turbine and two- and three-dimensional unsteady computational fluid dynamics (CFD) models were generated to help understand the aerodynamics of this performance.Wind tunnel performance results are

  13. Modelling of Offshore Wind Turbine Wakes with the Wind Farm Program FLaP

    Microsoft Academic Search

    Bernhard Lange; Hans-Peter Waldl; Algert Gil Guerrero; Detlev Heinemann; Rebecca J. Barthelmie

    2003-01-01

    The wind farm layout program FLaP estimates the wind speed at any point in a wind farm and the power output of the turbines. The ambient flow conditions and the properties of the turbines and the farm are used as input. The core of the program is an axisymmetric wake model describing the wake behind one rotor. Here an approach

  14. Operational experience with a 5m Darrieus wind turbine

    Microsoft Academic Search

    V. A. L. Chasteau

    1977-01-01

    A demonstration Darrieus wind turbine with a rotor diameter of 4.72 m was found to provide a power output much different from the output predicted by theory. Whereas a peak power of about 6 kW in a 14 m\\/sec wind was expected, the turbine in fact developed ever-increasing power with wind speed increments, registering a maximum output of 23 kW

  15. PHYSICAL REVIEW E 88, 042146 (2013) Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics

    E-print Network

    Peinke, Joachim

    2013-01-01

    PHYSICAL REVIEW E 88, 042146 (2013) Uncovering wind turbine properties through two, such as the rated speed of the wind turbine or the descriptive wind speed statistics, can be related to the equations describing the evolution of power production and wind speed at single wind turbines. DOI: 10

  16. Grid code requirements concerning connection and operation of wind turbines in Germany

    Microsoft Academic Search

    I. Erlich; U. Bachmann

    2005-01-01

    This paper discusses issues of German grid codes relating to wind turbines. With the high utilization of wind power a simultaneous loss of several thousand MW wind generation became a realistic scenario in the German power system. Therefore, the main requirements concern the fault ride through capability of wind turbines. Accordingly, disconnection of wind turbines and wind farms above 15

  17. Wind turbine wake interactions; results from blind tests

    NASA Astrophysics Data System (ADS)

    Krogstad, Per-Åge; Sætran, Lars

    2015-06-01

    Results from three "Blind test" Workshops on wind turbine wake modeling are presented. While the first "Blind test" (BT1, 2011) consisted of a single model turbine located in a large wind tunnel, the complexity was increased for each new test in order to see how various models performed. Thus the next "Blind test" (BT2, 2012) had two turbines mounted in-line. This is a crucial test for models intended to predict turbine performances in a wind farm. In the last "Blind test" (BT3, 2013) the two turbines were again mounted in-line, but offset sideways so that the rotor of the downstream turbine only intersected half the wake from the upstream turbine. This case produces high dynamic loads and strong asymmetry in the wake. For each "Blind test" the turbine geometry and wind tunnel environment was specified and the participants were asked to predict the turbine performances, as well as the wake development to five diameters downstream of the second turbine. For the first two tests axisymmetry could be assumed if the influence of the towers was neglected. This was not possible in BT3 and therefore only fully 3D methods could be applied. In all tests the prediction scatter was surprisingly high.

  18. Development tests for the 2.5 megawatt Mod-2 wind turbine generator

    NASA Technical Reports Server (NTRS)

    Andrews, J. S.; Baskin, J. M.

    1982-01-01

    The 2.5 megawatt MOD-2 wind turbine generator test program is discussed. The development of the 2.5 megawatt MOD-2 wind turbine generator included an extensive program of testing which encompassed verification of analytical procedures, component development, and integrated system verification. The test program was to assure achievement of the thirty year design operational life of the wind turbine system as well as to minimize costly design modifications which would otherwise have been required during on site system testing. Computer codes were modified, fatigue life of structure and dynamic components were verified, mechanical and electrical component and subsystems were functionally checked and modified where necessary to meet system specifications, and measured dynamic responses of coupled systems confirmed analytical predictions.

  19. A preliminary analysis of the audible noise of constant speed, horizontal axis wind turbine generators

    Microsoft Academic Search

    D. N. Keast; R. C. Potter

    1980-01-01

    A preliminary analytical procedure developed for calculating certain aerodynamic sound levels produced by large, horizontal axis wind turbine generators (WTG's) such as the DOE\\/NASA Mods- O, OA, 1, and 22. It postulates a noise component due to the (constant) rotation of the blades of the WTG, plus a wake-noise component that increases with the square of the power produced by

  20. Duration Test Report for the SWIFT Wind Turbine

    SciTech Connect

    Mendoza, I.; Hur, J.

    2013-01-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. Three turbines where selected for testing at the National Wind Technology Center (NWTC) as a part of round two of the Small Wind Turbine Independent Testing project. Duration testing is one of up to 5 tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality. The results of the testing will provide the manufacturers with reports that may be used for small wind turbine certification.

  1. Lifting system and apparatus for constructing wind turbine towers

    DOEpatents

    Livingston, Tracy; Schrader, Terry; Goldhardt, James; Lott, James

    2011-02-01

    The disclosed invention is utilized for mounting a wind turbine and blade assembly on the upper end of a wind turbine tower. The invention generally includes a frame or truss that is pivotally secured to the top bay assembly of the tower. A transverse beam is connected to the frame or truss and extends fore of the tower when the frame or truss is in a first position and generally above the tower when in a second position. When in the first position, a wind turbine or blade assembly can be hoisted to the top of the tower. The wind turbine or blade assembly is then moved into position for mounting to the tower as the frame or truss is pivoted to a second position. When the turbine and blade assembly are secured to the tower, the frame or truss is disconnected from the tower and lowered to the ground.

  2. Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines

    E-print Network

    Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind measurements of the wind fields engulfing today's huge wind turbines. Our aim is to measure in real- time 3D have named "The Remote Sensing Full Scale Laser Wind Scanner Facility", viz.: The recent advent

  3. Design, Analysis, and Learning Control of a Fully Actuated Micro Wind Turbine

    E-print Network

    Tedrake, Russ

    Design, Analysis, and Learning Control of a Fully Actuated Micro Wind Turbine J. Zico Kolter of renewable energy, and improvements to wind turbine design and control can have a significant impact a actuated micro wind turbine intended for research purposes. While most academic work on wind turbine

  4. The Potential Health Impact of Wind Turbines Chief Medical Officer of Health (CMOH) Report

    E-print Network

    Firestone, Jeremy

    The Potential Health Impact of Wind Turbines Chief Medical Officer of Health (CMOH) Report May 2010) of Ontario in response to public health concerns about wind turbines, particularly related to noise. Assisted by wind turbines. The review concludes that while some people living near wind turbines report symptoms

  5. LPTV SUBSPACE ANALYSIS OF WIND TURBINES DATA Laurent Mevel1, Ivan Gueguen2, Dmitri Tcherniak3

    E-print Network

    Paris-Sud XI, Université de

    integrity of wind turbines. With the recent development of large and very large offshore wind turbines have been proposed. These algorithms are applied to both a numerical model of an operating wind turbineLPTV SUBSPACE ANALYSIS OF WIND TURBINES DATA Laurent Mevel1, Ivan Gueguen2, Dmitri Tcherniak3 1

  6. www.cesos.ntnu.no Author Centre for Ships and Ocean Structures Offshore Wind Turbine Operation

    E-print Network

    Nørvåg, Kjetil

    1 www.cesos.ntnu.no Author ­ Centre for Ships and Ocean Structures Offshore Wind Turbine Operation icing for offshore Wind Turbines ? · Wherever there is sea icing ! · Temperature bellow zero degree Structures Outline · Introduction · Wind Turbine Operational Conditions · Wind Turbine Operation under

  7. Composite rotor blades for wind turbine generators

    NASA Astrophysics Data System (ADS)

    Weigel, W. D.

    The materials, techniques, and methods used to construct a 150 ft test blade, two 31 ft blades for a 40 kW WECS, and rotor blades for the Mod-1 wind turbine are described. Considerations of strength, stiffness, and mass distributions, as well as cost, led to the choice of filament wound fiberglass/epoxy material using transverse filament tape which has structural fibers running across the width of the tape. A number of 90 deg windings were added to the rotor after tape winding to provide compaction and hoop strength. Curing comprised five hours at 180 F. The Mod-1 blades were required to match the steel blades in weight, stiffness, deflection, and frequencies. The finished product weighed 20,000 lb and featured a metal tip cap and braided wire trailing edge strap for lightning protection. The 40 kW was a NACA 23018 in the center and 23012 at the tip, while the Mod-1 blade was a NACA 23025 in the center and 23015 at the tip.

  8. Vibration Based Structural Health Monitoring for Utility Scale Wind Turbines

    NASA Astrophysics Data System (ADS)

    Bassett, Kyle

    Structural health monitoring (SHM) is a process of implementing a damage detection strategy for a mechanical system. Wind turbine machinery stands to benefit from SHM significantly as the ability to detect early stages of damage before serious malfunction or collapse reduces the overall operating costs of wind power projects. Vibration analysis of dynamic structural response is an approach to SHM that has been successfully applied to mechanical and civil systems and shows promise for wind turbine application due to availability of instruments, ease of installation, and overall affordability. This study presents the development of vibration based wind turbine structural health monitoring through experimental analysis of an operating wind turbine. A database of acquired vibration response signals detailing over 3 hours of turbine operation was assembled and a Daubachies 6th order wavelet was used to perform a 12 level discrete wavelet decomposition such that general trends and patterns within the signals could be identified. After determining response behavior of a healthy turbine, a novel vibration based SHM scheme is developed based on findings from experimental work. Specific interest has been paid to monitoring yaw and braking systems as they have been identified as problematic. With further development this vibration scheme can be applied by wind farm operators to reduce downtime and failure frequency of utility scale wind turbines.

  9. Wind Energy and Climate: Modeling the Atmospheric Impacts of Wind Energy Turbines

    Microsoft Academic Search

    A. S. Adams; D. W. Keith

    2007-01-01

    The size and number of wind farms is growing across the globe. Wind energy provides the climatic benefit of producing energy without emitting CO2, however wind energy also produces unintended impacts. Large wind farms directly influence the atmospheric boundary layer by (1.) reducing wind speeds, (2.) generating blade scale turbulence in the wake of the turbines, and (3.) generating shear

  10. Response of the Mod-OA wind-turbine rotor to turbulent atmospheric wind

    SciTech Connect

    Thresher, R.W.; Holley, W.E.; Hershberg, E.L.; Lin, S.R.

    1982-12-01

    The major focus of this paper will be the description of the fluctuating loads caused by the atmospheric turbulence. The wind turbulence inputs used in this study are determined in three basic modeling steps. First, the turbulent velocity field is characterized by a model which provides the correlation between velocity components at different spatial positions and at different times. Second, the velocity field is approximated in the rotor disk plane using a series expansion which includes terms that are uniform across the rotor disk, gradient terms which vary linearly across the disk, and terms which vary quadratically across the disk. All of these terms are time dependent. In the third step, simple rational spectral representations are determined which approximate the derived correlation model for these turbulence components. The Von Karman model is used to characteize the correlation between velocities at spatially separated points. Quasi-steady linear aerodynamic theory is used to compute the forces on the rotor blades of the Mod-OA wind turbine operating in a turbulent flow. The blade used for these computations is the fiberglass blade in place on the Mod-OA turbine as of November 1981. Using the combined turbulence and aerodynamic model the following rotor responses are computed: thrust, torque, pitch and yaw moments, and blade root bending moments. These computations were made for the case of fixed pitch operation and incorporate the influence of a linear mean wind shear. Results presented include power spectral density plots of the wind and turbine outputs described above for three different mean wind conditions. There is a comparison of the various responses to determine the relative importance of the turbulence inputs on rotor blade loads.

  11. Quantifying the hurricane risk to offshore wind turbines

    PubMed Central

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J.; Grossmann, Iris; Apt, Jay

    2012-01-01

    The U.S. Department of Energy has estimated that if the United States is to generate 20% of its electricity from wind, over 50 GW will be required from shallow offshore turbines. Hurricanes are a potential risk to these turbines. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built in the United States. We present a probabilistic model to estimate the number of turbines that would be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind farms in four representative locations in the Atlantic and Gulf Coastal waters of the United States. In the most vulnerable areas now being actively considered by developers, nearly half the turbines in a farm are likely to be destroyed in a 20-y period. Reasonable mitigation measures—increasing the design reference wind load, ensuring that the nacelle can be turned into rapidly changing winds, and building most wind plants in the areas with lower risk—can greatly enhance the probability that offshore wind can help to meet the United States’ electricity needs. PMID:22331894

  12. Structural health monitoring of wind turbines

    SciTech Connect

    Simmermacher, T.; James, G.H. III.; Hurtado, J.E.

    1997-09-01

    To properly determine what is needed in a structural health monitoring system, actual operational structures need to be studied. We have found that to effectively monitor the structural condition of an operational structure four areas must be addressed: determination of damage-sensitive parameters, test planning, information condensation, and damage identification techniques. In this work, each of the four areas has been exercised on an operational structure. The structures studied were all be wind turbines of various designs. The experiments are described and lessons learned will be presented. The results of these studies include a broadening of experience in the problems of monitoring actual structures as well as developing a process for implementing such monitoring systems.

  13. Aeroelastic analysis of the Darrieus wind turbine

    SciTech Connect

    Meyer, E.E.

    1982-01-01

    The stability of small oscillations of the troposkein-shaped blade used on Darrieus wind turbines is investigated. The blade is assumed to be attached to a perfectly rigid rotor shaft and spinning in still air. Linear equations of motion are derived which include the effects of inplane, out-of-plane, and torsional stiffness, mass and aerodynamic center offsets, and the aerodynamic wake. Results presented include the free-vibration characteristics of the rotating blade, stability of the blade rotating in air, and the effects of mass density, mass center offset, and stiffness parameters on the flutter rotation rates. All results are presented in dimensionless form, hence apply to a family of blades.

  14. Locations and attributes of wind turbines in New Mexico, 2009

    USGS Publications Warehouse

    Carr, Natasha B.; Diffendorfer, Jay E.; Fancher, Tammy S.; Latysh, Natalie E.; Leib, Kenneth J.; Matherne, Anne-Marie; Turner, Christine

    2011-01-01

    The New Mexico wind-turbine data series provides geospatial data for all wind turbines established within the State as of August 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, and county. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, year the facility went online, and development status of wind facility. Turbine locations were derived from 1-meter August 2009 true-color aerial photographs produced by the National Agriculture Imagery Program; the photographs have a positional accuracy of about + or - 5 meters. The location of turbines under construction during August 2009 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas currently (2011) in development by the U.S. Geological Survey. The Energy Atlas will synthesize data on existing and potential energy development in Colorado and New Mexico and will include additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools will be included in the Energy Atlas. The format of the Energy Atlas will facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

  15. Locations and attributes of wind turbines in Colorado, 2009

    USGS Publications Warehouse

    Carr, Natasha B.; Diffendorfer, Jay E.; Fancher, Tammy S.; Latysh, Natalie E.; Leib, Kenneth J.; Matherne, Anne-Marie; Turner, Christine

    2011-01-01

    The Colorado wind-turbine data series provides geospatial data for all wind turbines established within the State as of August 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, and county. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, year the facility went online, and development status of wind facility. Turbine locations were derived from August 2009 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program; the photographs have a positional accuracy of about + or - 5 meters. The location of turbines under construction during August 2009 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas currently (2011) in development by the U.S. Geological Survey. The Energy Atlas will synthesize data on existing and potential energy development in Colorado and New Mexico and will include additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools will be included in the Energy Atlas. The format of the Energy Atlas will facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

  16. Selection of Wind Turbine Blade Materials for Fatigue Resistance

    E-print Network

    Selection of Wind Turbine Blade Materials for Fatigue Resistance John Mandell Montana StateE glass and similar compositions · High Performance Glass (WindStrand) C b· Carbon #12;Tensile Fatigue E Gl (2 f b i )E-Glass (2 fabrics), WindStrand, Carbon ; Epoxy Resins; Stress Based (top) and Stress

  17. DOE/NASA wind turbine data acquisition. Part 1: Equipment

    NASA Technical Reports Server (NTRS)

    Strock, O. J.

    1980-01-01

    Large quantities of data were collected, stored, and analyzed in connection with research and development programs on wind turbines. The hardware configuration of the wind energy remote data acquisition system is described along with its use on the NASA/DOE Wind Energy Program.

  18. Riso-M-2546 g Wind Turbine Test

    E-print Network

    Riso-M-2546 g Wind Turbine Test Wind Matic WM 17S Troels Friis Pedersen The Test Station TEST WIND MATIC WM 17S Troels Friis Pedersen The Test Station for Windmills, Ris0 Abstract* The report; DYNAMIC LOADS; HORIZONTAL AXIS TUR- BINES; MECHANICAL TESTS; NOISE; PERFORMANCE TESTING; POWER GENERATION

  19. Seabed instability simplified model and application in offshore wind turbine

    Microsoft Academic Search

    Zhang Yong-li; Li Jie

    2009-01-01

    The offshore wind power is increasingly developed, it is essential to study the design technology of the offshore wind turbine foundation, which is crucial to reduce the construction cost of the offshore wind farm. In the design of marine pile foundations, the evaluation of wave-induced seabed stability is quite significant. Based on the mechanical properties of seabed, this article firstly

  20. Wind turbine/generator set and method of making same

    DOEpatents

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2013-06-04

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  1. Midwest Consortium for Wind Turbine Reliability and Optimization

    SciTech Connect

    Scott R. Dana; Douglas E. Adams; Noah J. Myrent

    2012-05-11

    This report provides an overview of the efforts aimed to establish a student focused laboratory apparatus that will enhance Purdue's ability to recruit and train students in topics related to the dynamics, operations and economics of wind turbines. The project also aims to facilitate outreach to students at Purdue and in grades K-12 in the State of Indiana by sharing wind turbine operational data. For this project, a portable wind turbine test apparatus was developed and fabricated utilizing an AirX 400W wind energy converter. This turbine and test apparatus was outfitted with an array of sensors used to monitor wind speed, turbine rotor speed, power output and the tower structural dynamics. A major portion of this project included the development of a data logging program used to display real-time sensor data and the recording and creation of output files for data post-processing. The apparatus was tested in an open field to subject the turbine to typical operating conditions and the data acquisition system was adjusted to obtain desired functionality to facilitate use for student projects in existing courses offered at Purdue University and Indiana University. Data collected using the data logging program is analyzed and presented to demonstrate the usefulness of the test apparatus related to wind turbine dynamics and operations.

  2. Response sensitivity of wind turbines to atmospheric turbulence

    SciTech Connect

    Thresher, R.W.; Holley, W.E.

    1981-05-01

    The dynamic response of wind turbines to atmospheric turbulence is examined. The modeling handles both the wind inputs and the resulting loads using the analysis techniques of random vibration theory and spectral analysis. Presented are typical response results for a small, 8kW wind turbine and a large, 2.5 MW turbine. The turbine system mechanical model employs 5 degrees-of-freedom to represent the lower frequency motions of the system. The rotor is assumed to be rigid and is three bladed for simplicity. The aerodynamic forces are modeled using a simple quasi-static strip theory. The emphasis is placed on this model to identify the key turbulence inputs which are important in wind turbine design. On the basis of results computed for the two turbines modeled, it is determined that the most important turbulence inputs are the longitudinal fluctuations in the direction of the mean wind which act uniformly across the rotor disk (engulfs the rotor disk), and the across the disk gradients of the longitudinal wind fluctuations. Although each of these invokes a different machine response, they are judged to be of equal importance, because they each contribute significantly to the vibration energy of the lower system frequencies. The report presents numerous spectral density plots for the various turbine system responses, and discusses the results in some detail.

  3. Mars Technologies Spawn Durable Wind Turbines

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.

    2013-01-01

    Sometimes referred to as regenerative life support systems, the concept includes an enclosed self-sufficient habitat that can independently support life for years on end. Such a system aims not only to produce its own food and water but to purify air and convert waste into useful byproducts. In the early 1990s, NASA was planning for an extended stay on Mars, and Bubenheim and his Ames colleagues were concentrating efforts on creating a complete ecological system to sustain human crewmembers during their time on the Red Planet. The main barrier to developing such a system, he says, is energy. Mars has no power plants, and a regenerative system requires equipment that runs on electricity to do everything from regulating humidity in the atmosphere to monitoring the quality of recycled water. The Ames group started looking at how to best make power on a planet that is millions of miles away from Earth and turned to a hybrid concept combining wind and solar power technologies. The reason was that Mars experiences frequent dust storms that can block nearly all sunlight. When theres a dust storm and the wind is blowing, the wind system could be the dominant power source. When the wind is not blowing and the sun is out, photovoltaics could be the dominant source, says Bubenheim.To develop and test the wind power technology, Ames turned to a remote, harsh environment here on Earth: the South Pole. The South Pole was a really good analog for Mars, says Bubenheim. The technology features for going to Mars were the same technology features needed to make something work at the South Pole.Around the same time that NASA started investigating energy technologies for the Red Planet, the National Science Foundation (NSF) was working on a redesign of their station at the South Pole. To power its operations, NSF used fuel that it flew to the remote location, but the Foundation recognized the benefits of also using onsite renewable energy technologies. In the winter they have small crews and their power requirements are less, says Bubenheim. In the summers, they bring in larger groups and photovoltaics could supply a lot of power. Using renewable energy technology could be a way of reducing the amount of fuel they have to fly in.Technology TransferTo advance wind turbine technology to meet the requirements of extremely harsh environments like that on Mars, Ames partnered with NSF and the Department of Energy. It was clear that a lot of the same features were also desirable for the cold regions of the Earth, says Bubenheim. NASA took the leadership on the team because we had the longest-term technology a Mars turbine. Years before, NSF had worked with a company called Northern Power Systems (NPS), based in Barre, Vermont, to deploy a 3-kilowatt wind turbine on Black Island off the coast of Antarctica.Sometimes referred to as regenerative life support systems, the concept includes an enclosed self-sufficient habitat that can independently support life for years on end. Such a system aims not only to produce its own food and water but to purify air and convert waste into useful byproducts. In the early 1990s, NASA was planning for an extended stay on Mars, and Bubenheim and his Ames colleagues were concentrating efforts on creating a complete ecological system to sustain human crewmembers during their time on the Red Planet. The main barrier to developing such a system, he says, is energy. Mars has no power plants, and a regenerative system requires equipment that runs on electricity to do everything from regulating humidity in the atmosphere to monitoring the quality of recycled water. The Ames group started looking at how to best make power on a planet that is millions of miles away from Earth and turned to a hybrid concept combining wind and solar power technologies. The reason was that Mars experiences frequent dust storms that can block nearly all sunlight. When there's a dust storm and the wind is blowing, the wind system could be the dominant power source. When the wind is not blowing and the sun is out, photovoltaics could be the domina

  4. Assessment Parameters and Matching between the Sites and Wind Turbines

    NASA Astrophysics Data System (ADS)

    Chermitti, A.; Bencherif, M.; Nakoul, Z.; Bibitriki, N.; Benyoucef, B.

    The objective of this paper is to introduce the assessment parameters of the wind energy production of sites and pairing between the sites and wind turbines. The exploration is made with the wind data gathered at 10 m high is based on the atlas of the wind of Algeria established by the National office of the Meteorology runs 37 stations of measures. The data is used for a feasibility analysis of optimum future utilization of Wind generator potentiality in five promising sites covering a part of landscape types and regions in Algeria. Detailed technical assessment for the ten most promising potential wind sites was made using the capacity factor and the site effectiveness approach. The investigation was performed assuming several models of small, medium and big size wind machines representing different ranges of characteristic speeds and rated power suitable for water pumping and electric supply. The results show that small wind turbines could be installed in some coast region and medium wind turbines could be installed in the high plateau and some desert regions and utilized for water supply and electrical power generation, the sites having an important wind deposit, in high plateau we find Tiaret site's but in the desert there is some sites for example Adrar, Timimoun and In Amenas, in these sites could be installed a medium and big size wind turbines.

  5. Comparison of three methods for wind turbine capacity factor estimation.

    PubMed

    Ditkovich, Y; Kuperman, A

    2014-01-01

    Three approaches to calculating capacity factor of fixed speed wind turbines are reviewed and compared using a case study. The first "quasiexact" approach utilizes discrete wind raw data (in the histogram form) and manufacturer-provided turbine power curve (also in discrete form) to numerically calculate the capacity factor. On the other hand, the second "analytic" approach employs a continuous probability distribution function, fitted to the wind data as well as continuous turbine power curve, resulting from double polynomial fitting of manufacturer-provided power curve data. The latter approach, while being an approximation, can be solved analytically thus providing a valuable insight into aspects, affecting the capacity factor. Moreover, several other merits of wind turbine performance may be derived based on the analytical approach. The third "approximate" approach, valid in case of Rayleigh winds only, employs a nonlinear approximation of the capacity factor versus average wind speed curve, only requiring rated power and rotor diameter of the turbine. It is shown that the results obtained by employing the three approaches are very close, enforcing the validity of the analytically derived approximations, which may be used for wind turbine performance evaluation. PMID:24587755

  6. Demonstration of the Ability of RCAS to Model Wind Turbines

    SciTech Connect

    Jonkman, J.; Cotrell, J.

    2003-08-01

    In recent years, the wind industry has sponsored the development, verification, and validation of comprehensive aeroelastic simulators, which are used for wind turbine design, certification, and research. Unfortunately, as wind turbines continue to grow in size and sometimes exhibit unconventional design characteristics, the existing codes do not always support the additional analysis features required for proper design. The development history, functionality, and advanced nature of RCAS (Rotorcraft Comprehensive Analysis System) make this code a sensible option. RCAS is an aeroelastic simulator developed over a 4-year cooperative effort amongst the U.S. Army's Aeroflightdynamics Directorate, Advanced Rotorcraft Technology (ART), Inc., and the helicopter industry. As its name suggests, RCAS was created for the rotorcraft industry but developed as a general purpose code for modeling the aerodynamic and structural response of any system with rotating and nonrotating subsystems (such as wind turbines). To demonstrate that RCAS can analyze wind turbines, models of a conventional, 1.5-MW, 3-bladed, upwind, horizontal axis wind turbine (HAWT) are created in RCAS and wind turbine analysis codes FAST (Fatigue, Aerodynamics, Structures, and Turbulence) and ADAMS (Automatic Dynamic Analysis of Mechanical Systems). Using these models, a side-by-side comparison of structural response predictions is performed under several test scenarios.

  7. Comparison of Three Methods for Wind Turbine Capacity Factor Estimation

    PubMed Central

    Ditkovich, Y.; Kuperman, A.

    2014-01-01

    Three approaches to calculating capacity factor of fixed speed wind turbines are reviewed and compared using a case study. The first “quasiexact” approach utilizes discrete wind raw data (in the histogram form) and manufacturer-provided turbine power curve (also in discrete form) to numerically calculate the capacity factor. On the other hand, the second “analytic” approach employs a continuous probability distribution function, fitted to the wind data as well as continuous turbine power curve, resulting from double polynomial fitting of manufacturer-provided power curve data. The latter approach, while being an approximation, can be solved analytically thus providing a valuable insight into aspects, affecting the capacity factor. Moreover, several other merits of wind turbine performance may be derived based on the analytical approach. The third “approximate” approach, valid in case of Rayleigh winds only, employs a nonlinear approximation of the capacity factor versus average wind speed curve, only requiring rated power and rotor diameter of the turbine. It is shown that the results obtained by employing the three approaches are very close, enforcing the validity of the analytically derived approximations, which may be used for wind turbine performance evaluation. PMID:24587755

  8. Impact of wind turbine noise in the Netherlands.

    PubMed

    Verheijen, Edwin; Jabben, Jan; Schreurs, Eric; Smith, Kevin B

    2011-01-01

    The Dutch government aims at an increase of wind energy up to 6 000 MW in 2020 by placing new wind turbines on land or offshore. At the same time, the existing noise legislation for wind turbines is being reconsidered. For the purpose of establishing a new noise reception limit value expressed in L den , the impact of wind turbine noise under the given policy targets needs to be explored. For this purpose, the consequences of different reception limit values for the new Dutch noise legislation have been studied, both in terms of effects on the population and regarding sustainable energy policy targets. On the basis of a nation-wide noise map containing all wind turbines in The Netherlands, it is calculated that 3% of the inhabitants of The Netherlands are currently exposed to noise from wind turbines above 28 dB(A) at the fa?ade. Newly established dose-response relationships indicate that about 1500 of these inhabitants are likely to be severely annoyed inside their dwellings. The available space for new wind turbines strongly depends on the noise limit value that will be chosen. This study suggests an outdoor A-weighted reception limit of L den = 45 dB as a trade-off between the need for protection against noise annoyance and the feasibility of national targets for renewable energy. PMID:22122963

  9. Development of a New Procedure for Reliability Modeling of Wind Turbine Generators

    Microsoft Academic Search

    Paul Giorsetto; Kent F. Utsurogi

    1983-01-01

    A method for determining the impact of wind generation on system reliability is developed. This method combines the effects of wind turbine forced outage rates and varying power output due to wind speed variations. Since individual wind turbines on a windfarm all have an output related to wind speed, each turbine's output cannot be assumed to be independent random variables.

  10. Impact of DFIG wind turbines on transient stability of power systems a review

    E-print Network

    Pota, Himanshu Roy

    Impact of DFIG wind turbines on transient stability of power systems ­ a review Authors Na Abstract of wind farms are using variable speed wind turbines equipped with doubly-fed induction generators (DFIG) due to their advantages over other wind turbine generators. Therefore, the analysis of wind power

  11. Analysis and Comparison of Test Results from the Small Wind Research Turbine Test Project: Preprint

    Microsoft Academic Search

    D. Corbus; D. Prascher

    2004-01-01

    Most small wind turbines furl (yaw or tilt out of the wind) as a means of limiting power and rotor speeds in high winds. The Small Wind Research Turbine (SWRT) testing project was initiated in 2003 with the goal of better characterizing both small wind turbine loads (including thrust) and dynamic behavior, specifically as they relate to furling. The main

  12. Dynamics modeling and loads analysis of an offshore floating wind turbine

    Microsoft Academic Search

    Jason Mark Jonkman

    2007-01-01

    The vast deepwater wind resource represents a potential to use offshore floating wind turbines to power much of the world with renewable energy. Many floating wind turbine concepts have been proposed, but dynamics models, which account for the wind inflow, aerodynamics, elasticity, and controls of the wind turbine, along with the incident waves, sea current, hydrodynamics, and platform and mooring

  13. Dynamics of offshore floating wind turbines-model development and verification

    Microsoft Academic Search

    Jason M. Jonkman

    2009-01-01

    The vast deepwater wind resource represents a potential to use offshore floating wind turbines to power much of the world with renewable energy. Many floating wind turbine concepts have been proposed, but dynamics models, which account for the wind inflow, aerodynamics, elasticity and controls of the wind turbine, along with the incident waves, sea current, hydrodynamics, and platform and mooring

  14. Reliability Estimation of Parameters of Helical Wind Turbine with Vertical Axis.

    PubMed

    Dumitrascu, Adela-Eliza; Lepadatescu, Badea; Dumitrascu, Dorin-Ion; Nedelcu, Anisor; Ciobanu, Doina Valentina

    2015-01-01

    Due to the prolonged use of wind turbines they must be characterized by high reliability. This can be achieved through a rigorous design, appropriate simulation and testing, and proper construction. The reliability prediction and analysis of these systems will lead to identifying the critical components, increasing the operating time, minimizing failure rate, and minimizing maintenance costs. To estimate the produced energy by the wind turbine, an evaluation approach based on the Monte Carlo simulation model is developed which enables us to estimate the probability of minimum and maximum parameters. In our simulation process we used triangular distributions. The analysis of simulation results has been focused on the interpretation of the relative frequency histograms and cumulative distribution curve (ogive diagram), which indicates the probability of obtaining the daily or annual energy output depending on wind speed. The experimental researches consist in estimation of the reliability and unreliability functions and hazard rate of the helical vertical axis wind turbine designed and patented to climatic conditions for Romanian regions. Also, the variation of power produced for different wind speeds, the Weibull distribution of wind probability, and the power generated were determined. The analysis of experimental results indicates that this type of wind turbine is efficient at low wind speed. PMID:26167524

  15. Reliability Estimation of Parameters of Helical Wind Turbine with Vertical Axis

    PubMed Central

    Dumitrascu, Adela-Eliza; Lepadatescu, Badea; Dumitrascu, Dorin-Ion; Nedelcu, Anisor; Ciobanu, Doina Valentina

    2015-01-01

    Due to the prolonged use of wind turbines they must be characterized by high reliability. This can be achieved through a rigorous design, appropriate simulation and testing, and proper construction. The reliability prediction and analysis of these systems will lead to identifying the critical components, increasing the operating time, minimizing failure rate, and minimizing maintenance costs. To estimate the produced energy by the wind turbine, an evaluation approach based on the Monte Carlo simulation model is developed which enables us to estimate the probability of minimum and maximum parameters. In our simulation process we used triangular distributions. The analysis of simulation results has been focused on the interpretation of the relative frequency histograms and cumulative distribution curve (ogive diagram), which indicates the probability of obtaining the daily or annual energy output depending on wind speed. The experimental researches consist in estimation of the reliability and unreliability functions and hazard rate of the helical vertical axis wind turbine designed and patented to climatic conditions for Romanian regions. Also, the variation of power produced for different wind speeds, the Weibull distribution of wind probability, and the power generated were determined. The analysis of experimental results indicates that this type of wind turbine is efficient at low wind speed. PMID:26167524

  16. Yaw dynamics of horizontal axis wind turbines

    SciTech Connect

    Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))

    1992-05-01

    Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.

  17. Vertical axis wind turbine turbulent response model:

    SciTech Connect

    Not Available

    1990-01-01

    The dynamic response of Sandia National Laboratories' 34-m Darrieus rotor wind turbine at Bushland, Texas, is presented. The formulation used a double-multiple streamtube aerodynamic model with a turbulent airflow and included the effects of linear aeroelastic forces. The structural analysis used established procedures with the program MSC/NASTRAN. The effects of aeroelastic forces on the damping of natural modes agree well with previous results at operating rotor speeds, but show some discrepancies at very high rotor speeds. A number of alternative expressions for the spectrum of turbulent wind were investigated. The model loading represented by each does not differ significantly; a more significant difference is caused by imposing a full lateral coherence of the turbulent flow. Spectra of the predicted stresses at various locations show that without aeroelastic forces, very severe resonance is likely to occur at certain natural frequencies. Inclusion of aeroelastic effects greatly attenuates this stochastic response, especially in modes involving in-plane blade bending. 15 refs., 8 figs., 7 tabs.

  18. Investigation of Various Wind Turbine Drivetrain Condition Monitoring Techniques (Presentation)

    SciTech Connect

    Sheng, S.

    2011-08-01

    This presentation was given at the 2011 Wind Turbine Reliability Workshop sponsored by Sandia National Laboratories in Albuquerque, NM on August 2-3, 2011. It discusses work for the Gearbox Reliability Collaborative including downtime caused by turbine subsystems, annual failure frequency of turbine subsystems, cost benefits of condition monitoring (CM), the Gearbox Reliability Collaborative's condition monitoring approach and rationale, test setup, and results and observations.

  19. Aeroelastic stability analysis of a Darrieus wind turbine

    SciTech Connect

    Popelka, D.

    1982-02-01

    An aeroelastic stability analysis has been developed for predicting flutter instabilities on vertical axis wind turbines. The analytical model and mathematical formulation of the problem are described as well as the physical mechanism that creates flutter in Darrieus turbines. Theoretical results are compared with measured experimental data from flutter tests of the Sandia 2 Meter turbine. Based on this comparison, the analysis appears to be an adequate design evaluation tool.

  20. Effect of operating methods of wind turbine generator system on net power extraction under wind velocity fluctuations in fields

    Microsoft Academic Search

    Tetsuya Wakui; Kazuya Yamaguchi; Takumi Hashizume; Eisuke Outa; Yoshiaki Tanzawa

    1999-01-01

    The effect of how a wind turbine generator system is operated is discussed from the viewpoint of net power extraction with wind velocity fluctuations in relation to the scale and the dynamic behavior of the system. On a wind turbine generator system consisting of a Darrieus-Savonius hybrid wind turbine, a load generator and a battery, we took up two operating

  1. Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines

    E-print Network

    Victoria, University of

    Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Mooring Line Modelling and Design Optimization of Floating Offshore Wind Turbines by Matthew Thomas Jair. Curran Crawford, Supervisor (Department of Mechanical Engineering) ABSTRACT Floating offshore wind

  2. Performance Study and Optimization of the Zephergy Wind Turbine 

    E-print Network

    Soodavi, Moein

    2013-12-04

    There are many problems associated with small wind turbines, such as small Reynolds number and poor starting performance, that make them much more expensive than the large ones per unit power. New technologies are needed to improve the quality...

  3. Basic Integrative Models for Offshore Wind Turbine Systems 

    E-print Network

    Aljeeran, Fares

    2012-07-16

    This research study developed basic dynamic models that can be used to accurately predict the response behavior of a near-shore wind turbine structure with monopile, suction caisson, or gravity-based foundation systems. The marine soil conditions...

  4. Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine 

    E-print Network

    Bae, Yoon Hyeok

    2013-04-23

    In the present study, a numerical simulation tool has been developed for the rotor-floater-tether coupled dynamic analysis of Multiple Unit Floating Offshore Wind Turbine (MUFOWT) in the time domain including aero-blade-tower dynamics and control...

  5. Variable speed generator technology options for wind turbine generators

    NASA Technical Reports Server (NTRS)

    Lipo, T. A.

    1995-01-01

    The electrical system options for variable speed operation of a wind turbine generator are treated in this paper. The key operating characteristics of each system are discussed and the major advantages and disadvantages of each are identified

  6. Performance Study and Optimization of the Zephergy Wind Turbine

    E-print Network

    Soodavi, Moein

    2013-12-04

    There are many problems associated with small wind turbines, such as small Reynolds number and poor starting performance, that make them much more expensive than the large ones per unit power. New technologies are needed to improve the quality...

  7. Mod-2 wind turbine system development. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The development of the MOD-2 wind turbine through acceptance testing and initial operational evaluation is documented. Pitch control hydraulic system, yaw control system, drive train, electrical power station, control system, operations and maintenance experience, and availability are discussed.

  8. Darrieus Vertical-Axis Wind Turbine program at Sandia Laboratories

    Microsoft Academic Search

    E. G. Kadlec

    1976-01-01

    The Darrieus Vertical Axis Wind Turbine (VAWT) technology development program is described. The application receiving emphasis utilizes the VAWT operating at constant speed to generate electricity which is fed directly into a utility grid.

  9. Large Wind Turbine Design Characteristics and R and D Requirements

    NASA Technical Reports Server (NTRS)

    Lieblein, S. (editor)

    1979-01-01

    Detailed technical presentations on large wind turbine research and development activities sponsored by public and private organizations are presented. Both horizontal and vertical axis machines are considered with emphasis on their structural design.

  10. Vertical axis wind turbine with continuous blade angle adjustment

    E-print Network

    Weiss, Samuel Bruce

    2010-01-01

    The author presents a concept for a vertical axis wind turbine that utilizes each blade's entire rotational cycle for power generation. Each blade has its own vertical axis of rotation and is constrained to rotate at the ...

  11. DOE/SNL-TTU scaled wind farm technology facility : research opportunities for study of turbine-turbine interaction.

    SciTech Connect

    Barone, Matthew Franklin; White, Jonathan

    2011-09-01

    The proposed DOE/Sandia Scaled Wind Farm Technology Facility (SWiFT) hosted by Texas Tech University at Reese Technology Center in Lubbock, TX, will provide a facility for experimental study of turbine-turbine interaction and complex wind farm aerodynamics. This document surveys the current status of wind turbine wake and turbine-turbine interaction research, identifying knowledge and data gaps that the proposed test site can potentially fill. A number of turbine layouts is proposed, allowing for up to ten turbines at the site.

  12. Wind Turbine Lightning Protection Project: 1999-2001

    SciTech Connect

    McNiff, B.

    2002-05-01

    A lightning protection research and support program was instituted by NREL to help minimize lightning damage to wind turbines in the United States. This paper provides the results of a field test program, an evaluation of protection on selected turbines, and a literature search as well as the dissemination of the accumulated information.

  13. An aerodynamic performance theory for the Darrieus wind turbine

    Microsoft Academic Search

    D. J. Sharp

    1977-01-01

    Blade element and momentum theories are used to predict the induced velocity distribution over the vertical height of the Darrieus wind turbine. The effect of local Reynolds number values on airfoil data is also taken into account. The airfoil for the turbine blades is the NACA 0012 profile; a blade shape of the troposkien type is adopted for the analysis.

  14. Low cost Darrieus vertical-axis wind turbine design

    Microsoft Academic Search

    D. K. Ai

    1979-01-01

    The main objective of a low cost Darrieus type wind turbine design effort carried out for the U.S. Department of Energy is to obtain realistic fabrication cost data based on current technology. An existing 17 m Sandia research turbine served as a background machine for development of the Low Cost design. Different design aspects of the 17 m Low Cost

  15. Wind turbine development for rural electrification in Nicaragua

    Microsoft Academic Search

    Kyle Bassett; Lucas Semple

    2012-01-01

    This paper presents the development of a wind turbine designed for rural electrification efforts throughout Nicaragua. The turbine was designed to use locally available and recycled materials in order to reduce production costs and thus make them more feasible for developing countries. A vertical axis configuration was chosen in order to have minimal impact on local ecology and terrain aesthetics.

  16. Sea ice and icing risk for offshore wind turbines

    Microsoft Academic Search

    L. Battisti; R. Fedrizzi; A. Brighenti; T. Laakso

    There are two important issues related to wind turbines performances in offshore sites that locate in cold cli- mates: sea ice (flows, driving ice, land-fast ice) and the presence of atmospheric icing (due to water in the air as in-cloud operation, rainfall and sea sprays) which may potentially lead to ice formation on turbines' struc- tures. Icing of rotor blades

  17. Analysis of internal drive train dynamics in a wind turbine

    NASA Astrophysics Data System (ADS)

    Peeters, Joris L. M.; Vandepitte, Dirk; Sas, Paul

    2006-01-01

    Three types of multibody models are presented for the investigation of the internal dynamics of a drive train in a wind turbine. The first approach is limited to the analysis of torsional vibrations only. Then a rigid multibody model is presented with special focus on the representation of the bearings and gears in the drive train. The generic model implementation can be used for parallel as well as planetary gear stages with both helical and spur gears. Examples for different gear stages describe the use of the presented formulations. Furthermore, the influence of the helix angle and the flexibility of the bearings on the results of eigenmode calculations are discussed. The eigenmodes of a planetary stage are classified as rotational, translational or out-of-plane modes. Thirdly, the extension to a flexible multibody model is presented as a method to include directly the drive train components' flexibilities. Finally, a comparison of two different modelling techniques is discussed for a wind turbine's drive train with a helical parallel gear stage and two planetary gear stages. In addition, the response calculation for a torque input at the generator demonstrates which eigenmodes can be excited through this path. Copyright

  18. FAROW: A tool for fatigue and reliability of wind turbines

    SciTech Connect

    Veers, P.S. [Sandia National Labs., Albuquerque, NM (US); Lange, C.H.; Winterstein, S.R. [Stanford Univ., CA (US). Civil Engineering Dept.

    1993-07-01

    FAROW is a computer program that evaluates the fatigue and reliability of wind turbine components using structural reliability methods. A deterministic fatigue life formulation is based on functional forms of three basic parts of wind turbine fatigue calculation: (1) the loading environment, (2) the gross level of structural response given the load environment, and (3) the local failure criterion given both load environment and gross stress response. The calculated lifetime is compared with a user specific target lifetime to assess probabilities of premature failure. The parameters of the functional forms can be defined as either constants or random variables. The reliability analysis uses the deterministic lifetime calculation as the limit state function of a FORM/SORM (first and second order reliability methods) calculation based on techniques developed by Rackwitz. Besides probability of premature failure, FAROW calculates the mean lifetime, the relative importance of each of the random variables, and the sensitivity of the results to all of the input parameters, both constant inputs and the parameters that define the random variable inputs. The ability to check the probability of failure with Monte Carlo simulation is included as an option.

  19. Wind turbines for electric utilities: Development status and economics

    NASA Technical Reports Server (NTRS)

    Ramler, J. R.; Donovan, R. M.

    1979-01-01

    The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a fuel saver is discussed and the COE range that would be generally attractive to utilities is indicated.

  20. Wind turbines for electric utilities - Development status and economics

    NASA Technical Reports Server (NTRS)

    Ramler, J. R.; Donovan, R. M.

    1979-01-01

    The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a 'fuel saver' is discussed and the COE range that would be generally attractive to utilities is indicated.