WorldWideScience

Sample records for proposed wind turbine

  1. Proposed Wind Turbine Aeroelasticity Studies Using Helicopter Systems Analysis

    Ladkany, Samaan G.

    1998-01-01

    Advanced systems for the analysis of rotary wing aeroelastic structures (helicopters) are being developed at NASA Ames by the Rotorcraft Aeromechanics Branch, ARA. The research has recently been extended to the study of wind turbines, used for electric power generation Wind turbines play an important role in Europe, Japan & many other countries because they are non polluting & use a renewable source of energy. European countries such as Holland, Norway & France have been the world leaders in the design & manufacture of wind turbines due to their historical experience of several centuries, in building complex wind mill structures, which were used in water pumping, grain grinding & for lumbering. Fossil fuel cost in Japan & in Europe is two to three times higher than in the USA due to very high import taxes. High fuel cost combined with substantial governmental subsidies, allow wind generated power to be competitive with the more traditional sources of power generation. In the USA, the use of wind energy has been limited mainly because power production from wind is twice as expensive as from other traditional sources. Studies conducted at the National Renewable Energy Laboratories (NREL) indicate that the main cost in the production of wind turbines is due to the materials & the labor intensive processes used in the construction of turbine structures. Thus, for the US to assume world leadership in wind power generation, new lightweight & consequently very flexible wind turbines, that could be economically mass produced, would have to be developed [4,5]. This effort, if successful, would result in great benefit to the US & the developing nations that suffer from overpopulation & a very high cost of energy.

  2. Wind turbines

    Yeoman, J.C. Jr.

    1978-12-01

    This evaluation of wind turbines is part of a series of Technology Evaluations of possible components and subsystems of community energy systems. Wind turbines, ranging in size from 200 W to 10 MW, are discussed as candidates for prime movers in community systems. Estimates of performance characteristics and cost as a function of rated capacity and rated wind speed are presented. Data concerning material requirements, environmental effects, and operating procedures also are given and are represented empirically to aid computer simulation.

  3. Wind turbine

    Cheney, Jr., Marvin C.

    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.

  4. Proposal and Development of Radial Air-gap Coreless Generator Suitable for Small Wind Turbine using in Urban Area

    Takahashi, Toshiyuki; Yasuda, Yoh; Ohmoto, Shingo; Hara, Takehisa

    Independent distributed generations using small wind turbines are widely spread as increasing of wind power generation. Installation of small wind turbines in densely-populated urban area is not only useful from the viewpoint of digging up wind power source in weak-wind area but also for enlightenment of renewable energy due to closing power supplies to consumptions. From the point of view, the authors proposed “urban wind power generation" using collective system with a number of small vertical wind turbines and have developed a suitable generator for low-speed vertical wind turbines such as Savonius windmill. Standardized on a coreless generator, the proposed generator is designed to let direction of magnetic fluxes radial in order to install the magnets and coils on the outer end of the generator. The change of magnet composition and flux direction gives realization of maximized speed of flux change and output voltage in the limited space. With above composition, the power of the proposed one is independent on the diameter. In this report, we describe evaluated fundamental performance of a prototype of the proposed generator. As the result of the experiments, the maximum output power of 283W was obtained. The obtained starting torque is enough small to begin to rotate at weak wind condition of no more than 1m/s. Therefore, it is clear that the proposed “radial” coreless generator is suitable for self-starting and producing high power at low speed wind.

  5. Wind turbine noise diagnostics

    This presentation proposed a self-consistent model for broad-band noise emitted from modern wind turbines. The simple source model was consistent with the physics of sound generation and considered the unique features of wind turbines. Although the acoustics of wind turbines are similar to those of conventional propellers, the dimensions of wind turbines pose unique challenges in diagnosing noise emission. The general features of the sound field were deduced. Source motion and source directivity appear to be responsible for amplitude variations. The amplitude modulation is likely to make wind-turbine noise more audible, and may be partly responsible for annoyance that has been reported in the literature. Acoustic array data suggests that broad-band noise is emitted predominantly during the downward sweep of each rotor blade. Source motion and source directivity account for the observed pattern. Rotor-tower interaction effects are of lesser importance. Predicted amplitude modulation ranges from 1 dB to 6dB. 2 refs., 9 figs.

  6. Type IV Wind Turbine Model

    Hansen, Anca Daniela; Margaris, Ioannis D.

    proposed by the International Electrotechnical Commission (IEC), in the IEC61400-27-1 Committee Draft for electrical simulation models for wind power generation, which is currently under review, [1]. The Type 4 wind turbine model described in this report includes a set of adjustments of the standard Type 4...... power plant (WPP) will be considered. The aggregate WPP model, which will be based on the upscaling of the individual wind turbine model on the electrical part, will make use of an equivalent wind speed. The implemented model follows the basic structure of the generic standard Type 4 wind turbine model...... wind turbine model in order account for the dynamic features of interest to EaseWind project. The document presents a short overview of the overall structure of the wind turbine model. Descriptions of individual submodels as well as some preliminary simulation results are included to illustrate the...

  7. Controls of Hydraulic Wind Turbine

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  8. Turbulence and wind turbines

    Brand, Arno J.; Peinke, Joachim; Mann, Jakob

    2011-01-01

    The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed.......The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed....

  9. Small wind turbines

    Wood, David

    2011-01-01

    Small Wind Turbines provides a thorough grounding in analysing, designing, building, and installing a small wind turbine. Small turbines are introduced by emphasising their differences from large ones and nearly all the analysis and design examples refer to small turbines.The accompanying software includes MATLAB(R) programs for power production and starting performance, as well as programs for detailed multi-objective optimisation of blade design. A spreadsheet is also given to help readers apply the simple load model of the IEC standard for small wind turbine safety. Small Wind Turbines repr

  10. Wind Turbine Blade Design

    Crossley, Richard J.; Peter J. Schubel

    2012-01-01

    A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection ...

  11. Wind turbine state estimation

    Knudsen, Torben

    2014-01-01

    which was successful. Then the estimation of a wind turbine state including dynamic inflow was tested on a simulated NREL 5MW turbine was performed. This worked perfectly with wind speeds from low to nominal wind speed as the output prediction errors where white. In high wind where the pitch actuator...

  12. Aerodynamics of Wind Turbines

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural...... response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element...... Momentum method is also covered, as are eigenmodes and the dynamic behavior of a turbine. The new material includes a description of the effects of the dynamics and how this can be modeled in an aeroelastic code, which is widely used in the design and verification of modern wind turbines. Further, the...

  13. Aerodynamics of wind turbines

    Hansen, Martin Otto Laver

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its third edition, it has been substantially updated with respect to structural dynamics and control. The new control chapter now includes details on how to design...... Wind Turbines (VAWT). Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum...... method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. The book describes the effects of the dynamics and how this can be modelled in an aeroelastic code, which is widely used in the design and verification of modern wind turbines. Furthermore, it examines how to calculate the...

  14. Wind Turbine Blade Design

    Richard J. Crossley

    2012-09-01

    Full Text Available A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

  15. Parametric Study on a Horizontal Axis Wind Turbine Proposed for Water Pumping

    Dr. Abdullateef A. Jadallah

    2014-01-01

    Full Text Available Water pumping is considered an economically competitive sustainable process of providing water to communities, rural areas and livestock's. A parametric analysis on HAWT is carried out to explore the influence of the performance parameters on the power generated and withdrawal quantity of water. Effect of wind speed, radius of rotor, ambient condition, well depth, and efficiencies of turbine, generator and the pump were studied and reflected in important generalized performance maps. These performance graphs are valuable in best understanding of on‐design and off‐ design constraints of the horizontal axis wind turbine in water pumping. The blade geometry was also studied. Results showed the reasonable range of wind turbine performance and the corresponding water discharge within the abovementioned constraints. Rating and the effect of pitch angle on discharged water are also presented. Methodology necessary to achieve the abovementioned results is processed by a computer program written in Matlab

  16. Gust generator for wind turbines

    Wortmann, F.X.

    1979-01-01

    Construction of a gust generator is proposed which will generate gusts of variable frequency, amplitude, and spectral distribution in a reproducible manner so that the response of the model wind turbine can be investigated.

  17. Analysis of Impeller Type Wind Turbine

    Ahmed y Qasim; Ryspek Usubamatov; Zuraidah Zain

    2011-01-01

    The new global development for wind turbines obliged inventors to create new wind turbine designs that have high efficiency and better than known designs. This paper proposes the impeller wind turbine, which uses more effectively the wind energy and depends only on the acting area of the vanes. The vane wind turbine is designed to increase the drag coefficient and output of a wind turbine that uses kinetic energy of the wind. It can be used worldwide due to its high efficiency, simple constr...

  18. Wind Turbines Wake Aerodynamics

    Vermeer, L.; Sørensen, Jens Nørkær; Crespo, A.

    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 conditions. The emphasis is put on measurements in controlled conditions.For the far wake, the survey focusses on both single turbines and wind farm effects, and the experimental and numerical work are reviewed; the main interest...... is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines.The article is further restricted to horizontal axis wind turbines and excludes all other types of turbines....

  19. Wind turbine wake aerodynamics

    Vermeer, L.J. [Delft University of Technology (Netherlands). Section Wind Energy; Sorensen, J.N. [Technical University of Denmark, Lyngby (Denmark). Dept. of Mechanical Engineering; Crespo, A. [Universidad Politecnica de Madrid (Spain). Dpto. de Ingenieria Energetica y Fluidomecanica

    2003-10-01

    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 conditions. The emphasis is put on measurements in controlled conditions. For the far wake, the survey focuses on both single turbines and wind farm effects, and the experimental and numerical work are reviewed; the main interest is to study how the far wake decays downstream, in order to estimate the effect produced in downstream turbines. The article is further restricted to horizontal axis wind turbines and excludes all other types of turbines. (author)

  20. Wind Turbine Clutter

    Gallardo-Hernando, Beatriz; Pérez-Martínez, Félix; Aguado-Encabo, Fernando

    2010-01-01

    In this chapter the main effects of wind turbines on the performance of radar systems have been explained. The radar signature of wind turbine clutter is unique and then, it requires a special treatment when developing mitigation techniques. WTC clutter remains spatially static, but it fluctuates continuously in time. In surveillance radars the return from wind turbines can be completely different from one scan to the following. In addition, apart from the powerful tower return, the movement ...

  1. Wind turbine pitch optimization

    Biegel, Benjamin; Juelsgaard, Morten; Stoustrup, Jakob; Kraning, Matt; Boyd, Stephen P.

    2011-01-01

    We consider a static wind model for a three-bladed, horizontal-axis, pitch-controlled wind turbine. 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 finding blade pitch profiles for......% compared to any constant pitch profile while sacrificing at most 7% of the maximum attainable output power. Using iterative learning, we show that very similar performance can be achieved by using only load measurements, with no knowledge of the wind field or wind turbine model....

  2. Introduction to wind turbine engineering

    Wortman, A. J.

    Analytical techniques and engineering procedures concerning wind turbines are presented. Data in graphical form and methods for estimating the cost of energy derived from wind energy systems are provided. Topics considered include the applications of wind power, ideal windmill performance, geographical wind distributions, vertical wind speed gradient, propeller turbines, vertical axis lifting surface turbines, drag-type turbines, and preliminary design procedures.

  3. Noise from wind turbines

    Fegeant, Olivier [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Building Sciences

    2002-02-01

    A rapid growth of installed wind power capacity is expected in the next few years. However, the siting of wind turbines on a large scale raises concerns about their environmental impact, notably with respect to noise. To this end, variable speed wind turbines offer a promising solution for applications in densely populated areas like the European countries, as this design would enable an efficient utilisation of the masking effect due to ambient noise. In rural and recreational areas where wind turbines are sited, the ambient noise originates from the action of wind on the vegetation and about the listener's ear (pseudo-noise). It shows a wind speed dependence similar to that of the noise from a variable speed wind turbine and can therefore mask the latter for a wide range of conditions. However, a problem inherent to the design of these machines is their proclivity to pure tone generation, because of the enhanced difficulty of avoiding structural resonances in the mechanical parts. Pure tones are deemed highly annoying and are severely regulated by most noise policies. In relation to this problem, the vibration transmission of structure-borne sound to the tower of the turbine is investigated, in particular when the tower is stiffened at its upper end. Furthermore, since noise annoyance due to wind turbine is mostly a masking issue, the wind-related sources of ambient noise are studied and their masking potentials assessed. With this aim, prediction models for wind-induced vegetation noise and pseudo-noise have been developed. Finally, closely related to the effect of masking, is the difficulty, regularly encountered by local authorities and wind farm developers, to measure noise immission from wind turbines. A new measurement technique has thus been developed in the course of this work. Through improving the signal-to-noise ratio between wind turbine noise and ambient noise, the new technique yields more accurate measurement results.

  4. Parametric Study on a Horizontal Axis Wind Turbine Proposed for Water Pumping

    Dr. Abdullateef A. Jadallah; Assistant Professor

    2014-01-01

    Water pumping is considered an economically competitive sustainable process of providing water to communities, rural areas and livestock's. A parametric analysis on HAWT is carried out to explore the influence of the performance parameters on the power generated and withdrawal quantity of water. Effect of wind speed, radius of rotor, ambient condition, well depth, and efficiencies of turbine, generator and the pump were studied and reflected in important generalized ...

  5. Noise from wind turbines

    Denmark has 3200 wind turbines with an installed maximum capacity of 418MW. The most important Danish research projects into wind turbine noise and the main results are listed. These date from 1983. Two comprehensive studies are currently in progress. The first is an analytical and empirical investigation of aerodynamic noise from wind turbine rotors and has so far dealt mainly with tip noise. The measurement method, using a hard board mounted microphone on the ground near the turbine, is described. Four different tip designs have been tested. Some examples of reference sound power level spectra for three of the designs are presented. During the past two years a computerbased data acquisition system has been used for real-time determination of sound power levels. The second study, which has just commenced, is on annoyance from wind turbine noise. It will include noise measurements, masking calculations and a social survey on the perceived nuisance. (UK)

  6. Operation Design of Wind Turbines in Strong Wind Conditions

    Shen, Wen Zhong; Montes, Melissa Barroso; Odgaard, Peter Fogh; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2012-01-01

    In order to reduce the impact on the electrical grid from the shutdown of MW wind turbines at wind speeds higher than the cut-out wind speed of 25 m/s, we propose in this paper to run the turbines at high wind speeds up to 40 m/s. Two different operation designs are made for both constant speed and...

  7. WIND TURBINES FOR WIND POWER INSTALLATIONS

    Barladean A.S.

    2008-04-01

    Full Text Available The problem of wind turbine choice for wind power stations is examined in this paper. It is shown by comparison of parameters and characteristics of wind turbines, that for existing modes and speeds of wind in territory of Republic of Moldova it is necessary to use multi-blade small speed rotation wind turbines of fan class.

  8. Wind turbines and infrasound

    This paper provided the results of a study conducted to assess the impacts of wind farm-induced infrasound on nearby residences and human populations. Infrasound occurs at frequencies below those considered as detectable by human hearing. Infrasonic levels caused by wind turbines are often similar to ambient levels of 85 dBG or lower that are caused by wind in the natural environment. This study examined the levels at which infrasound poses a threat to human health or can be considered as an annoyance. The study examined levels of infrasound caused by various types of wind turbines, and evaluated acoustic phenomena and characteristics associated with wind turbines. Results of the study suggested that infrasound near modern wind turbines is typically not perceptible to humans through either auditory or non-auditory mechanisms. However, wind turbines often create an audible broadband noise whose amplitude can be modulated at low frequencies. A review of both Canadian and international studies concluded that infrasound generated by wind turbines should not significantly impact nearby residences or human populations. 17 refs., 2 tabs., 4 figs

  9. Coalescing Wind Turbine Wakes

    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.

  10. Pitchcontrol of wind turbines using model free adaptivecontrol based on wind turbine code

    Zhang, Yunqian; Chen, Zhe; Cheng, Ming; Zhang, Jianzhong

    2011-01-01

    value is only based on I/O data of the wind turbine is identified and then the wind turbine system is replaced by a dynamic linear time-varying model. In order to verify the correctness and robustness of the proposed model free adaptive pitch controller, the wind turbine code FAST which can predict the...

  11. Noise from wind turbines

    Based on a previous project concerning the calculation of the amount of noise emanating from wind turbine arrays, this one examines the subject further by investigating whether there could be significant differences in the amount of noise made by individual wind turbines in an array, and whether the noise is transmitted in varying directions - so that when it is carried in the same direction as the wind blows it would appear to be louder. The aim was also to determine whether the previously used method of calculation lacked precision. It was found that differences in noise niveaux related to individual wind turbines were insignificant and that noise was not so loud when it was not borne in the direction of the wind. It was necessary to change the method of calculation as reckoning should include the influence of the terrain, wind velocity and distance. The measuring and calculation methods are exemplified and the resulting measurements are presented in detail. (AB)

  12. Aeroservoelasticity of Wind Turbines

    Kallesøe, Bjarne Skovmose

    2007-01-01

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand...... % under ideal conditions. So, a new aeroelastic blade model has been derived, which includes important features of large wind turbines, yet simple enough to be suitable for analytical analysis and control design.......This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand...... many similarities to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations...

  13. Wind turbines. Fiction and facts

    The author gives a personal impression of factual and fictional data with respect to different aspects of wind turbines: properties, the production or capacity factor, emission of CO2, the consumption of electricity in the Netherlands, performance, cost price and exploitation costs of wind turbines, environmental effects, government policy, energy yield of 442 wind turbines at 36 sites in the Netherlands, wind turbine projects, and the value of a so-called environmental impact report for wind turbines

  14. Direct drive wind turbine

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-07-11

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  15. Direct drive wind turbine

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2007-02-27

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  16. Vertical axis wind turbines

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  17. The Dutch wind turbine industry

    An overview is given of the manufacturers of wind turbines and wind turbine blades in the Netherlands. Special attention is paid to the impact of the Dutch Integral Program Wind energy (IPW) on the developments and activities of the Dutch wind turbine industry. Implementation of wind energy is less than expected. The activities to reduce the prices for wind turbines have not yet resulted in cheaper wind turbines. The efficiency of wind energy however does not only depend on the costs for wind turbines but also on the value adjudged to the electric power from wind energy. Implementation of wind turbines must be better planned based on the condition that the developments in the wind turbine industry should be continued. Problems regarding the selection of sites and licensing procedures have to be solved. 4 tabs

  18. Annoyance rating of wind turbine noise

    This paper proposes a simple criterion for noise limitation of wind turbines: 'The LaA50 from a Wind Farm should not exceeding the LA50 of the wind generated background plus 5dB at any place of potential complaint'. This criterion is then examined and developed in the light of experience to date with turbine noise complaint and procedures. (author)

  19. European wind turbine catalogue

    The THERMIE European Community programme is designed to promote the greater use of European technology and this catalogue contributes to the fulfillment of this aim by dissemination of information on 50 wind turbines from 30 manufacturers. These turbines are produced in Europe and are commercially available. The manufacturers presented produce and sell grid-connected turbines which have been officially approved in countries where this approval is acquired, however some of the wind turbines included in the catalogue have not been regarded as fully commercially available at the time of going to print. The entries, which are illustrated by colour photographs, give company profiles, concept descriptions, measured power curves, prices, and information on design and dimension, safety systems, stage of development, special characteristics, annual energy production, and noise pollution. Lists are given of wind turbine manufacturers and agents and of consultants and developers in the wind energy sector. Exchange rates used in the conversion of the prices of wind turbines are also given. Information can be found on the OPET network (organizations recognised by the European Commission as an Organization for the Promotion of Energy Technologies (OPET)). An article describes the development of the wind power industry during the last 10-15 years and another article on certification aims to give an overview of the most well-known and acknowledged type approvals currently issued in Europe. (AB)

  20. Wind turbines and health

    This document summarized the potential health hazards associated with wind turbines, such as noise and low frequency sound, vibration and infrasound; electromagnetic fields (EMF); shadow flicker; and ice throw and structural failure. Various symptoms can be attributed to wind turbines, including dizziness, sleep disruption, and headaches. A review of available research regarding potential health affects to residents living in close proximity to wind turbines showed that the sound level associated with wind turbines at common residential setbacks is not sufficient to damage hearing, but may lead to annoyance and sleep disturbance. Research has shown that wind turbines are not a significant source of EMF exposure, and although shadows caused by the blades may be annoying, they are not likely to cause epileptic seizures at normal operational speeds. The risk of injury from ice throw can be minimized with setbacks of 200 to 400 m. Examples of Canadian wind turbine setback guidelines and regulations were also offered. It was concluded that setbacks and operational guidelines can be utilized in combination to address safety hazards, sound levels, land use issues, and impacts on people. 46 refs., 2 tabs., 2 figs.

  1. Ultimate loading of wind turbines

    Larsen, Gunner Chr.; Ronold, K.; Ejsing Jørgensen, Hans; Argyriadis, K.; Boer, J. de

    1999-01-01

    An extreme loading study has been conducted comprising a general wind climate analysis as well as a wind turbine reliability study. In the wind climate analysis, the distribution of the (horizontal) turbulence standard deviation, conditioned on the meanwind speed, has been approximated by fitting a...... design turbulence intensity for off-shore application is proposed which, in the IEC code framework, is applicable for extreme as well as for fatigue loaddetermination. In order to establish a rational method to analyse wind turbine components with respect to failure in ultimate loading, and in addition...... byapplication to the event of failure in ultimate loading in flapwise bending in the normal operating condition of a site-specific turbine....

  2. Wind turbine noise

    Due to a high density in population, wind turbine noise is a serious obstacle in the achievement of the Dutch government's aim: 1000 MW wind power in 2000. This paper presents an overview on the noise issue from the Dutch point of view. (author)

  3. Floating wind turbine system

    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.

  4. Wind Turbine Acoustics

    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.

  5. Wind turbine control and monitoring

    Luo, Ningsu; Acho, Leonardo

    2014-01-01

    Maximizing reader insights into the latest technical developments and trends involving wind turbine control and monitoring, fault diagnosis, and wind power systems, 'Wind Turbine Control and Monitoring' presents an accessible and straightforward introduction to wind turbines, but also includes an in-depth analysis incorporating illustrations, tables and examples on how to use wind turbine modeling and simulation software.   Featuring analysis from leading experts and researchers in the field, the book provides new understanding, methodologies and algorithms of control and monitoring, comput

  6. Superconducting wind turbine generators

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen; Zirngibl, Thomas; Træholt, Chresten; Nørgård, Per Bromand; Pedersen, Niels Falsig; Andersen, Niels Hessel; Østergaard, Jacob

    2010-01-01

    We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future...... offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However, the...... main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10...

  7. Wind turbine optimal control during storms

    This paper proposes a control algorithm that enables wind turbine operation in high winds. With this objective, an online optimization procedure is formulated that, based on the wind turbine state, estimates those extremal wind speed variations that would produce maximal allowable wind turbine loads. Optimization results are compared to the actual wind speed and, if there is a danger of excessive loading, the wind turbine power reference is adjusted to ensure that loads stay within allowed limits. This way, the machine can operate safely even above the cut-out wind speed, thereby realizing a soft envelope-protecting cut-out. The proposed control strategy is tested and verified using a high-fidelity aeroservoelastic simulation model

  8. Offshore Wind Turbine Design

    Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo; Tarp-Johansen, Niels Jacob; Høgedal, Michael; Jensen, Leo

    2006-01-01

    Current offshore wind turbine design methods have matured to a 1st generation state, manifested in the draft of a possible standard, IEC 61400-3 (2005). It is now time to investigate the possibilities of improving existing methods. To do so in an efficient manner a clear identification of the most...... important uncertainty drivers specific for offshore wind turbine design loads is required. Describing the initial efforts in a Danish research project, the paper points to focal points for research and development. These are mainly: soil-structure interaction, improved modelling of wave loads from deep to...

  9. Aerodynamics of wind turbines

    Hansen, Martin O L

    2015-01-01

    Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its third edition, it has been substantially updated with respect to structural dynamics and control. The new control chapter now includes details on how to design a classical pitch and torque regulator to control rotational speed and power, while the section on structural dynamics has been extended with a simplified mechanical system explaining the phenomena of forward and backward whirling modes. Readers will also benefit from a new chapter on Vertical Axis W

  10. Predicting Noise From Wind Turbines

    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.

  11. Wind turbine design

    Using wind energy to generate power has become an attractive and feasible possibility as a complement to the traditional power generation methods. This is mainly due to advances in aerodynamic analysis, development of new composite materials and the experience gained through innovative and pioneering designs. Wind energy is abundant and inexhaustible. Its use to generate power in remote areas of developing countries with less developed infrastructure could accelerate the modernisation of such regions. This paper attempts to give an overview of the technical aspects of wind turbine design and is meant for an audience new to the subject. It is not the purpose of this presentation to deal in detail with the technical aspects, but rather to highlight the salient aspects of the design. After a brief introduction, the topics covered are aerodynamics and aeroacoustics of wind turbines with a discussion of the structural dynamics and vibration engineering aspects. (author)

  12. Wind conditions for wind turbine design

    Maribo Pedersen, B.

    1999-04-01

    Delegates from Europe and USA attended the meeting and discussed general aspects of wind conditions for wind turbine design. The subjects and the presented papers covered a very broad range of aspects of wind conditions and related influence on the wind turbine. (EHS)

  13. Noise from wind turbines

    Fégeant, Olivier

    2001-01-01

    A rapid growth of installed wind power capacity is expectedin the next few years. However, the siting of wind turbines ona large scale raises concerns about their environmental impact,notably with respect to noise. To this end, variable speed windturbines offer a promising solution for applications in denselypopulated areas like the European countries, as this designwould enable an efficient utilisation of the masking effect dueto ambient noise. In rural and recreational areas where windturbi...

  14. Wind turbine spoiler

    Sullivan, W.N.

    An aerodynamic spoiler system for a vertical axis wind turbine includes spoilers on the blades initially stored near the rotor axis to minimize drag. A solenoid latch adjacent the central support tower releases the spoilers and centrifugal force causes the spoilers to move up the turbine blades away from the rotor axis, thereby producing a braking effect and actual slowing of the associated wind turbine, if desired. The spoiler system can also be used as an infinitely variable power control by regulated movement of the spoilers on the blades over the range between the undeployed and fully deployed positions. This is done by the use of a suitable powered reel and cable located at the rotor tower to move the spoilers.

  15. Wind turbine spoiler

    Sullivan, William N. (Albuquerque, NM)

    1985-01-01

    An aerodynamic spoiler system for a vertical axis wind turbine includes spoilers on the blades initially stored near the rotor axis to minimize drag. A solenoid latch adjacent the central support tower releases the spoilers and centrifugal force causes the spoilers to move up the turbine blades away from the rotor axis, thereby producing a braking effect and actual slowing of the associated wind turbine, if desired. The spoiler system can also be used as an infinitely variable power control by regulated movement of the spoilers on the blades over the range between the undeployed and fully deployed positions. This is done by the use of a suitable powered reel and cable located at the rotor tower to move the spoilers.

  16. Wind Turbine Blade

    2010-01-01

    The invention relates to a blade for a wind turbine, particularly to a blade that may be produced by an advanced manufacturing process for producing a blade with high quality structural components. Particularly, the structural components, which are preferably manufactured from fibre reinforced...

  17. Wind turbine airfoil catalogue

    Bertagnolio, F.; Sørensen, Niels N.; Johansen, Jeppe; Fuglsang, P.

    2001-01-01

    The aim of this work is two-sided. Firstly, experimental results obtained for numerous sets of airfoil measurements (mainly intended for wind turbine applications) are collected and compared with computational results from the 2D Navier-Stokes solverEllipSys2D, as well as results from the panel...

  18. Predicting Faults in Wind Turbines Using SCADA Data

    Borchersen, Anders Bech; Larsen, Jesper Abildgaard; Stoustrup, Jakob

    2013-01-01

    The cost of operation and maintenance of wind turbines is a significant part of the overall cost of wind turbines. To reduce this cost a method for enabling early fault detection is proposed and tested in this paper. The method is taking advantage of the fact that wind turbines in wind farms are ...

  19. Analysis of Impeller Type Wind Turbine

    Ahmed y Qasim

    2011-12-01

    Full Text Available The new global development for wind turbines obliged inventors to create new wind turbine designs that have high efficiency and better than known designs. This paper proposes the impeller wind turbine, which uses more effectively the wind energy and depends only on the acting area of the vanes. The vane wind turbine is designed to increase the drag coefficient and output of a wind turbine that uses kinetic energy of the wind. It can be used worldwide due to its high efficiency, simple construction, and simple technology and can be made from cheap materials. Abstrak: Pembangunan global terkini turbin angin menyebabkan pereka harus membina rekaan terbaru turbin angin yang bercekapan tinggi yang lebih baik daripada rekaan-rekaan terdahulu. Kertas ini mencadangkan pendesak turbin angin, yang menggunakan kuasa angin secara lebih efektif dan bergantung hanya terhadap permukaan bilah kipas yang terlibat. Bilah kipas turbin angin direka sebegini untuk meningkatkan pekali seret dan juga keluaran daripada turbin angin tersebut yang menggunakan tenaga kinetik angin. Cara ini boleh digunakan secara meluas di serata dunia kerana ia bercekapan tinggi, mudah dibina, menggunakan teknologi yang ringkas dan diperbuat daripada bahan-bahan yang murah.

  20. Reliability Analysis of Wind Turbines

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2008-01-01

    In order to minimise the total expected life-cycle costs of a wind turbine it is important to estimate the reliability level for all components in the wind turbine. This paper deals with reliability analysis for the tower and blades of onshore wind turbines placed in a wind farm. The limit states...... consideres are in the ultimate limit state (ULS) extreme conditions in the standstill position and extreme conditions during operating. For wind turbines, where the magnitude of the loads is influenced by the control system, the ultimate limit state can occur in both cases. In the fatigue limit state (FLS......) the reliability level for a wind turbine placed in a wind farm is considered, and wake effects from neighbouring wind turbines is taken into account. An illustrative example with calculation of the reliability for mudline bending of the tower is considered. In the example the design is determined...

  1. Wind turbine flicker calculation using neural networks

    Papathanassiou, S.A.; Papadopoulos, M.P.; Kladas, A.G. [National Technical University of Athens (Greece). Dept. of Electrical and Computer Engineering; Kiartzis, S.J. [Aristotle University of Thessaloniki (Greece). Dept. of Electrical and Computer Engineering

    2000-07-01

    The connection of wind turbines to the distribution networks may affect the voltage quality offered to the consumers. One of the factors contributing to this effect are the rapid variations of the wind turbine output power, which cause respective fluctuations in the supply voltage, referred to as flicker. This paper presents a neural network based model for wind turbine flicker emission calculations. Neural network training patterns are developed using a simulation model of a typical 500 kW stall-controlled wind turbine, by varying wind and network parameters that might affect the expected flicker levels. The proposed neural network model predicts flicker emissions with sufficient accuracy under any normal operating conditions (wind speed mean value and turbulence intensity) and network characteristics (short circuit capacity, angle of Thevenin impedance and local load). The paper also includes an extensive discussion on the dependence of the flicker severity on the wind and network parameters considered. (Author)

  2. Wind turbine aerodynamics

    Johnson, D.A. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering, Wind Energy Group

    2010-07-01

    The need for clean, renewable electricity in remote communities of Canada and the world was discussed in this presentation. The University of Waterloo Wind Energy Laboratory (WEL) performs research in a large scale indoor environment on wind turbines, blade aerodynamics, and aeroacoustics. A key area of research involves developing turbines for remote off-grid communities where climatic conditions are challenging. This presentation outlined research that is underway on wind energy and off-grid renewable energy systems. Many communities in Canada and remote communities in the rest of the world are not connected to the grid and are dependent on other means to supply electrical energy to their community. Remote communities in northern Canada have no road access and diesel is the dominant source of electrical energy for these communities. All of the community supply of diesel comes from brief winter road access or by air. The presentation discussed existing diesel systems and the solution of developing local renewable energy sources such as wind, hydro, biomass, geothermal, and solar power. Research goals, wind energy activities, experimental equipment, and the results were also presented. Research projects have been developed in wind energy; hydrogen generation/storage/utilization; power electronics/microgrid; and community engagement. figs.

  3. Great expectations: large wind turbines

    De Vries, E.

    2001-06-01

    This article focuses on wind turbine product development, and traces the background to wind turbines from the first generation 1.5 MW machines in 1995-6, plans for the second generation 3-5 MW class turbines to meet the expected boom in offshore wind projects, to the anticipated installation of a 4.5 MW turbine, and offshore wind projects planned for 2000-2002. The switch by the market leader Vestas to variable speed operation in 2000, the new product development and marketing strategy taken by the German Pro + Pro consultancy in their design of a 1.5 MW variable speed pitch control concept, the possible limiting of the size of turbines due to logistical difficulties, opportunities offered by air ships for large turbines, and the commissioning of offshore wind farms are discussed. Details of some 2-5 MW offshore wind turbine design specifications are tabulated.

  4. Great expectations: large wind turbines

    This article focuses on wind turbine product development, and traces the background to wind turbines from the first generation 1.5 MW machines in 1995-6, plans for the second generation 3-5 MW class turbines to meet the expected boom in offshore wind projects, to the anticipated installation of a 4.5 MW turbine, and offshore wind projects planned for 2000-2002. The switch by the market leader Vestas to variable speed operation in 2000, the new product development and marketing strategy taken by the German Pro + Pro consultancy in their design of a 1.5 MW variable speed pitch control concept, the possible limiting of the size of turbines due to logistical difficulties, opportunities offered by air ships for large turbines, and the commissioning of offshore wind farms are discussed. Details of some 2-5 MW offshore wind turbine design specifications are tabulated

  5. Rotating transformers in wind turbine applications

    Hylander, J. [Chalmers Univ. of Technology, Goeteborg (Sweden); Engstroem, S. [Aegir konsult AB, Lidingoe (Sweden)

    1996-12-01

    The power consumption of rotating electrical components is often supplied via slip-rings in wind turbines. Slip-ring equipment is expensive and need maintenance and are prone to malfunction. If the slip-rings could be replaced with contact-less equipment better turbines could be designed. This paper presents the design, some FE calculations and some measurements on a prototype rotating transformer. The proposed transformer consists of a secondary rotating winding and a stationary exciting primary winding. The results indicate that this transformer could be used to replace slip-rings in wind turbines. 4 refs, 3 figs

  6. Aeroservoelasticity of wind turbines

    Skovmose Kallesoee, B.

    2007-12-14

    This thesis deals with the fundamental aeroelastic interaction between structural motion, Pitch action and control for a wind turbine blade. As wind turbines become larger, the interaction between pitch action, blade motion, aerodynamic forces, and control become even more important to understand and address. The main contribution of this thesis is the development of an aeroelastic blade model which on the one hand includes the important effects of steady state blade deformation, gravity and pitch action, and on the other it is transparent, suitable for analytical analysis and parameter studies, and furthermore linear and therefore suitable for control design. The development of the primary aeroelastic blade model is divided into four steps: 1) Nonlinear partial differential equations (PDEs) of structural blade motion are derived together with equations of pitch action and rotor speed; the individual terms in these equations are discussed and given physical interpretations; 2) Steady state blade deformation and induced velocities are computed by combining the PDEs with a steady state aerodynamic model; 3) Aeroelastic modes of motion are computed by combining the linearized PDEs with a linear unsteady aerodynamic model; this model is used to analyze how blade deformation effects the modes of motion; and 4) the linear aeroelastic blade model is derived by a modal expansion of the linearized PDEs combined with a linear unsteady aerodynamic model. The aeroelastic blade model has many similarities to a 2D blade section model, and it can be used instead of this in many applications, giving a transparent connection to a real wind turbine blade. In this work the aeroelastic blade model is used to analyze interaction between pitch action, blade motion and wind speed variations. Furthermore the model is used to develop a state estimator for estimating the wind speed and wind shear, and to suggest a load reducing controller. The state estimator estimates the wind shear very well and the load reducing controller is capable of reducing flapwise blade motion caused by wind shear with 75 % under ideal conditions. So, a new aeroelastic blade model has been derived, which includes important features of large wind turbines, yet simple enough to be suitable for analytical analysis and control design. (au)

  7. Frequency Based Fault Detection in Wind Turbines

    Odgaard, Peter Fogh; Stoustrup, Jakob

    gearbox. Only the generator speed measurement which is available in even simple wind turbine control systems is used as input. Consequently this proposed scheme does not need additional sensors and computers for monitoring the condition of the wind gearbox. The scheme is evaluated on a wide-spread wind...... parallel to the control system, using different computers and additional often expensive sensors. In this paper a simple filter based algorithm is proposed to detect changes in a resonance frequency in a system, exemplified with faults resulting in changes in the resonance frequency in the wind turbine...... turbine fault detection and fault tolerant control benchmark model, in which one of the included faults results in a change in the gear box resonance frequency. This evaluation shows the potential of the proposed scheme to monitor the condition of wind turbine gear boxes in the existing control system....

  8. Small Wind Turbine Technology Assessment

    The result of the study carried out under the scope of the ATYCA project Test Plant of Wind Systems for Isolated Applications, about the state of art of the small wind turbine technology (wind turbines with swept area smaller than 40 m2) is presented. The study analyzes the collected information on 60 models of wind turbines from 23 manufacturers in the worldwide market. Data from Chinese manufacturers, that have a large participation in the total number of small wind turbines in operation, are not included, due to the unavailability of the technical information. (Author) 15 refs

  9. Optimum propeller wind turbines

    Sanderson, R. J.; Archer, R. D.

    1983-12-01

    The Prandtl-Betz-Theodorsen theory of heavily loaded airscrews has been adapted to the design of propeller windmills which are to be optimized for maximum power coefficient. It is shown that the simpler, light-loading, constant-area wake assumption can generate significantly different 'optimum' performance and geometry, and that it is therefore not appropriate to the design of propeller wind turbines when operating in their normal range of high-tip-speed-to-wind-speed ratio. Design curves for optimum power coefficient are presented and an example of the design of a typical two-blade optimum rotor is given.

  10. Airfoils for wind turbine

    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.

  11. Harmonic Current Predictors for Wind Turbines

    Shun-Yu Chan

    2013-03-01

    Full Text Available The harmonic impact caused by wind turbines should be carefully investigated before wind turbines are interconnected. However, the harmonic currents of wind turbines are not easily predicted due to the variations of wind speed. If the harmonic current outputs can be predicted accurately, the harmonic impact of wind turbines and wind farms for power grids can be analyzed efficiently. Therefore, this paper analyzes the harmonic current characteristics of wind turbines and investigates the feasibility of developing harmonic current predictors. Field measurement, data sorting, and analysis are conducted for wind turbines. Two harmonic current predictors are proposed based on the measured harmonic data. One is the Auto-Regressive and Moving Average (ARMA-based harmonic current predictor, which can be used for real-time prediction. The other is the stochastic harmonic current predictor considering the probability density distributions of harmonic currents. It uses the measured harmonic data to establish the probability density distributions of harmonic currents at different wind speeds, and then uses them to implement a long-term harmonic current prediction. Test results use the measured data to validate the forecast ability of these two harmonic current predictors. The ARMA-based predictor obtains poor performance on some harmonic orders due to the stochastic characteristics of harmonic current caused by the variations of wind speed. Relatively, the prediction results of stochastic harmonic current predictor show that the harmonic currents of a wind turbine in long-term operation can be effectively analyzed by the established probability density distributions. Therefore, the proposed stochastic harmonic current predictor is helpful in predicting and analyzing the possible harmonic problems during the operation of wind turbines and wind farms.

  12. Wind Turbine Providing Grid Support

    A variable speed wind turbine is arranged to provide additional electrical power to counteract non-periodic disturbances in an electrical grid. A controller monitors events indicating a need to increase the electrical output power from the wind turbine to the electrical grid. The controller is...... arranged to control the wind turbine as follows: after an indicating event has been detected, the wind turbine enters an overproduction period in which the electrical output power is increased, wherein the additional electrical output power is taken from kinetic energy stored in the rotor and without...... changing the operation of the wind turbine to a more efficient working point.; When the rotational speed of the rotor reaches a minimum value, the wind turbine enters a recovery period to re-accelerate the rotor to the nominal rotational speed while further contributing to the stability of the electrical...

  13. Wind Turbine Radar Cross Section

    David Jenn; Cuong Ton

    2012-01-01

    The radar cross section (RCS) of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical...

  14. Introduction to wind turbine aerodynamics

    Schaffarczyk, Alois Peter

    2014-01-01

    Wind-Turbine Aerodynamics is a self-contained textbook which shows how to come from the basics of fluid mechanics to modern wind turbine blade design. It presents a fundamentals of fluid dynamics and inflow conditions, and gives a extensive introduction into theories describing the aerodynamics of wind turbines. After introducing experiments the book applies the knowledge to explore the impact on blade design.The book is an introduction for professionals and students of very varying levels.

  15. The VGOT Darrieus wind turbine

    Ponta, F.L.; Otero, A.D.; Lago, L. [University of Buenos Aires (Argentina). College of Engineering

    2004-07-01

    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 electrical generation system coupled to the power-wheels and the electricity is collected by a classical third rail system. The VGOT concept allows increasing the area swept by the blades, and hence the power output of the installation, without the structural problems and the low rotational speed associated with a classical Darrieus rotor of large diameter. We also propose some engineering solutions for the VGOT design and present a brief economic analysis of the feasibility of the project. (author)

  16. Methodological proposal for the design of the turbine blades of wind of horizontal axis

    A methodology is developed to estimate the chord distribution airfoil and blade twist along the radius of the blade by using axial and angular moment conservation equations, blade element theory and optimization processes. This methodology takes into account the concept related with getting wind power for different chord blade values and selecting one that facilitates to get the maximum value for wind power. This work is based on project wind energy market in Colombia: operation, risk and expansion possibilities

  17. On System Identification of Wind Turbines

    Kirkegaard, Poul Henning; Perisic, Nevena; Pedersen, B.J.

    operational model analysis (OMA) methodology can provide accurate estimates of the natural frequencies, damping ratios and mode shapes of the systems as long as the measurements have a low noise to signal ratio. However, in order to take information about the wind turbine into account a grey......Recently several methods have been proposed for the system identification of wind turbines which can be considered as a linear time-varying system due to the operating conditions. For the identification of linear wind turbine models, either black-box or grey-box identification can be used. In the...

  18. The small wind turbine field lab

    Laveyne, Joannes; Van Wyngene, Karel; Kooning, Jeroen De; Van Ackere, Samuel; Van Eetvelde, Greet; Vandevelde, Lieven

    2013-01-01

    The emerging market of small wind turbines (SWT) is characterised by a large variety of turbine types as well as turbine performance. The abundance of more ‘exotic’ types of vertical axis wind turbines (VAWT) next to the more traditional horizontal axis wind turbines (HAWT) shows that this market is still developing. However, some technologies have proven to possess the same potential typically only found in larger wind turbines. To study the (lack of) performance of current small wind turbin...

  19. Flexible systems in wind turbines. Flexibele systemen van wind turbines

    Geerdink, G.B.

    1983-01-01

    Flexible systems in wind turbines are those systems in design and construction flattening the rapidly fluctuating forces and torques, e.g., elastic suspension of rotor blades, the utilization of flexible materials and the dynamic decoupling of the electrical grid. Best materials for rotor blades are fibre reinforced plastics and (even for very large turbines) wood laminates. Flexible systems are already classic in the construction of smaller wind turbines. Wind turbines with flexible systems give less power, due to the necessary limitation of rotation speed, but construction is much cheaper.

  20. Superconducting wind turbine generators

    We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However, the main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10 MW is suggested to secure the accumulation of reliability experience. Finally, the quantities of high temperature superconducting tape needed for a 10 kW and an extreme high field 10 MW generator are found to be 7.5 km and 1500 km, respectively. A more realistic estimate is 200-300 km of tape per 10 MW generator and it is concluded that the present production capacity of coated conductors must be increased by a factor of 36 by 2020, resulting in a ten times lower price of the tape in order to reach a realistic price level for the superconducting drive train.

  1. Numerical investigation of wind turbine and wind farm aerodynamics

    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.

  2. Reliability Assessment of Wind Turbines

    Sørensen, John Dalsgaard

    2015-01-01

    Wind turbines can be considered as structures that are in between civil engineering structures and machines since they consist of structural components and many electrical and machine components together with a control system. Further, a wind turbine is not a one-of-a-kind structure but...... manufactured in series production based on many component tests, some prototype tests and zeroseries wind turbines. These characteristics influence the reliability assessment where focus in this paper is on the structural components. Levelized Cost Of Energy is very important for wind energy, especially when...... comparing to other energy sources. Therefore much focus is on cost reductions and improved reliability both for offshore and onshore wind turbines. The wind turbine components should be designed to have sufficient reliability level with respect to both extreme and fatigue loads but also not be too costly...

  3. Reliability Modeling of Wind Turbines

    Kostandyan, Erik

    Cost reductions for offshore wind turbines are a substantial requirement in order to make offshore wind energy more competitive compared to other energy supply methods. During the 20 – 25 years of wind turbines useful life, Operation & Maintenance costs are typically estimated to be a quarter to...... actions should be made and the type of actions requires knowledge on the accumulated damage or degradation state of the wind turbine components. For offshore wind turbines, the action times could be extended due to weather restrictions and result in damage or degradation increase of the remaining...... Operation & Maintenance planning. Concentrating efforts on development of such models, this research is focused on reliability modeling of Wind Turbine critical subsystems (especially the power converter system). For reliability assessment of these components, structural reliability methods are applied and...

  4. Equivalent models of wind farms by using aggregated wind turbines and equivalent winds

    As a result of the increasing wind farms penetration on power systems, the wind farms begin to influence power system, and therefore the modeling of wind farms has become an interesting research topic. In this paper, new equivalent models of wind farms equipped with wind turbines based on squirrel-cage induction generators and doubly-fed induction generators are proposed to represent the collective behavior on large power systems simulations, instead of using a complete model of wind farms where all the wind turbines are modeled. The models proposed here are based on aggregating wind turbines into an equivalent wind turbine which receives an equivalent wind of the ones incident on the aggregated wind turbines. The equivalent wind turbine presents re-scaled power capacity and the same complete model as the individual wind turbines, which supposes the main feature of the present equivalent models. Two equivalent winds are evaluated in this work: (1) the average wind from the ones incident on the aggregated wind turbines with similar winds, and (2) an equivalent incoming wind derived from the power curve and the wind incident on each wind turbine. The effectiveness of the equivalent models to represent the collective response of the wind farm at the point of common coupling to grid is demonstrated by comparison with the wind farm response obtained from the detailed model during power system dynamic simulations, such as wind fluctuations and a grid disturbance. The present models can be used for grid integration studies of large power system with an important reduction of the model order and the computation time

  5. Towers for Offshore Wind Turbines

    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.

  6. Parametric study on off-design aerodynamic performance of a horizontal axis wind turbine blade and proposed pitch control

    Highlights: • A pitch controlled 200 kW HAWT blade is designed with BEM for off-design conditions. • Parametric study conducted on power coefficient, axial and angular induction factors. • The optimal pitch angles were determined at off-design operating conditions. - Abstract: In this paper, a 200 kW horizontal axis wind turbine (HAWT) blade is designed using an efficient iterative algorithm based on the blade element momentum theory (BEM) on aerodynamic of wind turbines. The effects of off-design variations of wind speed are investigated on the blade performance parameters according to constant rotational speed of the rotor. The performance parameters considered are power coefficient, axial and angular induction factors, lift and drag coefficients on the blade, angle of attack and angle of relative wind. At higher or lower wind speeds than the designed rated speed, the power coefficient is reduced due to considerable changes in the angle of attacks. Therefore, proper pitch control angles were calculated to extract maximum possible power at various off-design speeds. The results showed a considerable improvement in power coefficient for the pitch controlled blade as compared with the baseline design in whole operating range. The present approach can be equally employed for determining pitch angles to design pitch control system of medium and large-scale wind turbines

  7. Development of Superconducting Wind Turbine Generators

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2012-01-01

    In this paper the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational speeds, because high magnetic fields can be produced by coils with very little loss. Three different superconducting wind turbine generator topologies have been proposed by three different companies. O...

  8. CFD modelling of wind turbine airfoil aerodynamics

    Campobasso, M.S.; Zanon, A.; Foerster, M.; Fraysse, F.; Bonfiglioli, A.

    2008-01-01

    This paper reports the first findings of an ongoing research programme on wind turbine computational aerodynamics at the University of Glasgow. Several modeling aspects of wind turbine airfoil aerodynamics based on the solution of the Reynoldsaveraged Navier-Stokes (RANS) equations are addressed. One of these is the effect of an a priori method for structured grid adaptation aimed at improving the wake resolution. Presented results emphasize that the proposed adaptation strategy g...

  9. Harmonic Current Predictors for Wind Turbines

    Shun-Yu Chan; Chuo-Yean Chang; Jen-Hao Teng; Rong-Ceng Leou

    2013-01-01

    The harmonic impact caused by wind turbines should be carefully investigated before wind turbines are interconnected. However, the harmonic currents of wind turbines are not easily predicted due to the variations of wind speed. If the harmonic current outputs can be predicted accurately, the harmonic impact of wind turbines and wind farms for power grids can be analyzed efficiently. Therefore, this paper analyzes the harmonic current characteristics of wind turbines and investigates the feasi...

  10. Wind Turbines and Human Health

    Knopper, Loren D; Christopher A. Ollson; 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 s...

  11. Aerodynamics of wind turbine wakes

    Sanderse, B. [ECN Wind Energy, Petten (Netherlands)

    2009-04-15

    This report reviews the available literature on the aerodynamics of wind turbines and wind farms. Firstly, two introductory chapters are devoted to the physics of the flow around a wind turbine and the existing engineering models for blade and wake aerodynamics. The focus of this work is however on the numerical modeling of wakes. The difficulties in solving the Navier-Stokes equations are discussed, and the different existing models for the description of the rotor and the wake are mentioned, along with problems associated with the choice of turbulence models and inflow conditions. The purpose of this overview is to include the latest developments in the numerical computation of wind turbine aerodynamics.

  12. Charting wind turbine performance

    Long term operating data from wind turbines up and running in various parts of the world offer a treasure chest of information. WindStats Newsletter's Danish database provides just such a source of information in the form of accumulated data form Denmark. It is useful to examine the data to see how machine performance has steadily improved over the years. The WindStats database currently includes nearly 1,800 machines of 150 kW rating and above. The performance of these were analyzed in some detail since these are the sizes that are of most interest today. However, due to the slowdown in the domestic market the majority of these machines were installed before 1990. Consequently the size distribution shows that most machines are in the range 23-31 m diameter. This analysis is restricted to power outputs of 150 kW and above, so the size distribution does not include all machines at the smaller sizes. (AB)

  13. Probabilistic Design of Wind Turbines

    Toft, Henrik Stensgaard

    turbines and the central topics considered are statistical load extrapolation of extreme loads during operation and reliability assessment of wind turbine blades. Wind turbines differ from most civil engineering structures by having a control system which highly influences the loading. In the literature...... the extreme load effects well and more consistent than the existing methods. Blades for wind turbines are normally made of composite material which consists of fiber and matrix materials. The material properties of structures made by composite materials are often subjected to a significant uncertainty...... due to variations in the constituent materials and the manufacturing process. Additionally, methods for estimating failure of composites are subjected to significant uncertainties. The reliability of wind turbine blades are assessed in both ultimate and fatigue limit states. In the ultimate limit...

  14. Megawatt wind turbines gaining momentum

    Through the short history of the modern wind turbine, electric utilities have made it amply clear that they have held a preference for large scale wind turbines over smaller ones, which is why wind turbine builders through the years have made numerous attempts develop such machines - machines that would meet the technical, aesthetic and economic demands that a customer would require. Considerable effort was put into developing such wind turbines in the early 1980s. There was the U.S. Department of Energy's MOD 1-5 program, which ranged up to 3.2 MW, Denmark's Nibe A and B, 630 kW turbine and the 2 MW Tjaereborg machine, Sweden's Naesudden, 3 MW, and Germany's Growian, 3 MW. Most of these were dismal failures, though some did show the potential of MW technology. (au)

  15. Wind Flow Analysis of Twisted Savonius Micro-Turbine Array

    Jesús Antonio Alvarez-Cedillo; Mauricio Olguín-Carbajal; Juan Carlos Herrera-Lozada; Ramón Silva-Ortigoza; Jacobo Sandoval-Gutiérrez

    2015-01-01

    This paper provides a computational analysis of wind impact on different geometric configurations of Savonius turbines proposed and previously studied in specialized literature. As a result of comparative analysis of turbines, we performed a flow analysis over a microturbine array, proposed a twisted Savonius turbine respecting its original profile, and subjected it to a comparative analysis of its performance against conventional turbines. Our new proposal of Savonius turbines stands out due...

  16. Potential health impact of wind turbines

    In response to public health concerns about wind turbines, a study was conducted to review the scientific evidence on the potential health effects of wind turbines. Several research questions were examined, including scientific evidence on the potential health impacts of wind turbines; the relationship between wind turbine noise and health; the relationship between low frequency sound, infrasound and health; assessment of exposure to wind turbines; wind turbine health and safety hazards and Ontario wind turbine setbacks; community consultation prior to wind farm construction and data gaps and research needs. The study showed that although some people living near wind turbines reported symptoms such as dizziness, headaches, and sleep disturbance, the scientific evidence available to date does not demonstrate a direct causal link between wind turbine noise and adverse health effects. The sound level from wind turbines at common residential setbacks is not sufficient to cause hearing impairment or other direct health effects, although some people may find it annoying. 41 refs., 1 appendix.

  17. Wind turbine rotor aileron

    Coleman, Clint (Warren, VT); Kurth, William T. (Warren, VT)

    1994-06-14

    A wind turbine has a rotor with at least one blade which has an aileron which is adjusted by an actuator. A hinge has two portions, one for mounting a stationary hinge arm to the blade, the other for coupling to the aileron actuator. Several types of hinges can be used, along with different actuators. The aileron is designed so that it has a constant chord with a number of identical sub-assemblies. The leading edge of the aileron has at least one curved portion so that the aileron does not vent over a certain range of angles, but vents if the position is outside the range. A cyclic actuator can be mounted to the aileron to adjust the position periodically. Generally, the aileron will be adjusted over a range related to the rotational position of the blade. A method for operating the cyclic assembly is also described.

  18. Reliability Modeling of Wind Turbines

    Kostandyan, Erik

    Cost reductions for offshore wind turbines are a substantial requirement in order to make offshore wind energy more competitive compared to other energy supply methods. During the 20 – 25 years of wind turbines useful life, Operation & Maintenance costs are typically estimated to be a quarter to...... one third of the total cost of energy. Reduction of Operation & Maintenance costs will result in significant cost savings and result in cheaper electricity production. Operation & Maintenance processes mainly involve actions related to replacements or repair. Identifying the right times when the...... actions should be made and the type of actions requires knowledge on the accumulated damage or degradation state of the wind turbine components. For offshore wind turbines, the action times could be extended due to weather restrictions and result in damage or degradation increase of the remaining...

  19. Aerodynamics of wind turbines emerging topics

    Amano, R S

    2014-01-01

    Focusing on Aerodynamics of Wind Turbines with topics ranging from Fundamental to Application of horizontal axis wind turbines, this book presents advanced topics including: Basic Theory for Wind turbine Blade Aerodynamics, Computational Methods, and Special Structural Reinforcement Technique for Wind Turbine Blades.

  20. Fault tolerant wind speed estimator used in wind turbine controllers

    Odgaard, Peter Fogh; Stoustrup, Jakob

    Advanced control schemes can be used to optimize energy production and cost of energy in modern wind turbines. These control schemes most often rely on wind speed estimations. These designs of wind speed estimators are, however, not designed to be fault tolerant towards faults in the used sensors...... applying the proposed wind speed estimator to a simulation model of a wind turbine. Notice that since the faults are accommodated in the observer scheme the actual controller do not need to be adjusted or reconfigured to accommodate the sensor faults........ In this paper a fault tolerant wind speed estimator is designed based on a set of unknown input observers, each designed to the different sets of non-faulty sensors. Faults in the rotor, generator and wind speed sensors are considered. The designed wind speed estimator is passive tolerant towards...

  1. Innovation in wind turbine design

    Jamieson, Peter

    2011-01-01

    Innovation in Wind Turbine Design addresses the fundamentals of design, the reasons behind design choices, and describes the methodology for evaluating innovative systems and components. Always referencing a state of the art system for comparison, Jamieson discusses the basics of wind turbine theory and design, as well as how to apply existing engineering knowledge to further advance the technology, enabling the reader to gain a thorough understanding of current technology before assessing where it can go in the future. Innovation in Wind Turbine Design is divided into four mai

  2. Wind turbine supply in Canada

    This study reported on wind turbine supplies to the Canadian market. The report was written to address concerns for Canada's supply outlook in the near future due to the booming wind energy market. Turbine shortages have arisen as a result of continued growth in both European and North American markets. Long lead-times on turbine orders are now increasing the pressure to lock in turbine supply during the initial phases of the development process. Future growth of the wind energy industry will be impacted if turbine supply difficulties continue to contribute to uncertainties in the development process. The report provided an overview of the North American and global wind energy markets, as well as a summary of telephone interviews conducted with turbine suppliers. The implications for the future of turbine supply to the Canadian market were also analyzed. It was concluded that policy-makers should focus on supporting the expansion of manufacturing facilities for small wind turbines and control infrastructure in Canada 7 refs., 3 figs

  3. Noise immission from wind turbines

    The project has dealt with practical ways to reduce the influence of background noise caused by wind acting on the measuring microphones. The uncertainty of measured noise emission (source strength) has been investigated. The main activity was a Round Robin Test involving measurements by five laboratories at the same wind turbine. Each laboratory brought its own instrumentation and performed the measurements and analyses according to their interpretation. The tonality of wind turbine noise is an essential component of the noise impact on the environment. In the present project the uncertainty in the newest existing methods for assessing tonality was investigated. The project included noise propagation measurements in different weather conditions around wind turbines situated in different types of terrain. The results were used to validate a noise propagation model developed in the project. Finally, the project also included a study with listeners evaluating recordings of wind turbine noise. The results are intended as guidance for wind turbine manufacturers in identifying the aspects of wind turbine noise most important to annoyance. (author)

  4. New Urban Vertical Axis Wind Turbine Design

    Alexandru-Mihai CISMILIANU

    2015-12-01

    Full Text Available This paper develops a different approach for enhancing the performance of Vertical Axis Wind Turbines for the use in the urban or rural environment and remote isolated residential areas. Recently the vertical axis wind turbines (VAWT have become more attractive due to the major advantages of this type of turbines in comparison to the horizontal axis wind turbines. We aim to enhance the overall performance of the VAWT by adding a second set of blades (3 x 2=6 blades following the rules of biplane airplanes. The model has been made to operate at a maximum power in the range of the TSR between 2 to 2.5. The performances of the VAWT were investigated numerically and experimentally and justify the new proposed design.

  5. Modeling and Control of Wind Turbine

    Luis Arturo Soriano; Wen Yu; Jose de Jesus Rubio

    2013-01-01

    In recent years, the energy production by wind turbines has been increasing, because its production is environmentally friendly; therefore, the technology developed for the production of energy through wind turbines brings great challenges in the investigation. This paper studies the characteristics of the wind turbine in the market and lab; it is focused on the recent advances of the wind turbine modeling with the aerodynamic power and the wind turbine control with the nonlinear, fuzzy, and ...

  6. Reliability Assessment Of Wind Turbines

    Sørensen, John Dalsgaard

    Reduction of cost of energy for wind turbines are very important in order to make wind energy competitive compared to other energy sources. Therefore the turbine components should be designed to have sufficient reliability but also not be too costly (and safe). This paper presents models for...... uncertainty modeling and reliability assessment of especially the structural components such as tower, blades, substructure and foundation. But since the function of a wind turbine is highly dependent on many electrical and mechanical components as well as a control system also reliability aspects of these...... components are discussed and it is described how there reliability influences the reliability of the structural components. Two illustrative examples are presented considering uncertainty modeling, reliability assessment and calibration of partial safety factors for structural wind turbine components exposed...

  7. Probabilistic Design of Wind Turbines

    Sørensen, John Dalsgaard; Toft, H.S.

    2010-01-01

    Probabilistic design of wind turbines requires definition of the structural elements to be included in the probabilistic basis: e.g., blades, tower, foundation; identification of important failure modes; careful stochastic modeling of the uncertain parameters; recommendations for target reliability...... is described how uncertainties in wind turbine design related to computational models, statistical data from test specimens, results from a few full-scale tests and from prototype wind turbines can be accounted for using the Maximum Likelihood Method and a Bayesian approach. Assessment of the optimal...... reliability level by cost-benefit optimization is illustrated by an offshore wind turbine example. Uncertainty modeling is illustrated by an example where physical, statistical and model uncertainties are estimated....

  8. Online wind turbine measurement laboratory

    Hansen, K.S.; Helgesen Pedersen, K.O.; Schmidt Paulsen, U.

    2006-01-01

    As part of the International Master of Science Program in Wind Energy at DTU, a complete interactive wind turbine measurement laboratory has been developed. A 500 kW stall regulated wind turbine has been instrumented with sensors for recording 1) turbine operational parameters, 2) meteorological...... conditions, 3) electrical quantities and 4) mechanical loads in terms of strain gauge signals. The data acquisition system has been designed and implemented by Risø together with students and teachers from DTU. It is based on LabVIEW© combined with a MySQL database for data management. The system enables...... online access for real-time recordings, which are used both for demonstration purposes, in individual [student] exercises and in scientific investigations. Long-term registration of wind turbine loads results in a unique database of noncommercial time series, which are available for practicing fatigue...

  9. Probabilistic design of wind turbines

    Sorensen, J. D. [Aalborg University and Riso-DTU, Sohngaardsholmsvej 57, Aalborg (Denmark); Toft, H. S. [Aalborg University, Sohngaardsholmsvej 57, Aalborg (Denmark)

    2010-07-01

    Probabilistic design of wind turbines requires definition of the structural elements to be included in the probabilistic basis: e.g., blades, tower, foundation; identification of important failure modes; careful stochastic modeling of the uncertain parameters; recommendations for target reliability levels and recommendation for consideration of system aspects. The uncertainties are characterized as aleatoric (physical uncertainty) or epistemic (statistical, measurement and model uncertainties). Methods for uncertainty modeling consistent with methods for estimating the reliability are described. It is described how uncertainties in wind turbine design related to computational models, statistical data from test specimens, results from a few full-scale tests and from prototype wind turbines can be accounted for using the Maximum Likelihood Method and a Bayesian approach. Assessment of the optimal reliability level by cost-benefit optimization is illustrated by an offshore wind turbine example. Uncertainty modeling is illustrated by an example where physical, statistical and model uncertainties are estimated. (author)

  10. Probabilistic Design of Wind Turbines

    Henrik S. Toft

    2010-02-01

    Full Text Available Probabilistic design of wind turbines requires definition of the structural elements to be included in the probabilistic basis: e.g., blades, tower, foundation; identification of important failure modes; careful stochastic modeling of the uncertain parameters; recommendations for target reliability levels and recommendation for consideration of system aspects. The uncertainties are characterized as aleatoric (physical uncertainty or epistemic (statistical, measurement and model uncertainties. Methods for uncertainty modeling consistent with methods for estimating the reliability are described. It is described how uncertainties in wind turbine design related to computational models, statistical data from test specimens, results from a few full-scale tests and from prototype wind turbines can be accounted for using the Maximum Likelihood Method and a Bayesian approach. Assessment of the optimal reliability level by cost-benefit optimization is illustrated by an offshore wind turbine example. Uncertainty modeling is illustrated by an example where physical, statistical and model uncertainties are estimated.

  11. Meteorological Controls on Wind Turbine Wakes

    Barthelmie, Rebecca J.; Hansen, Kurt Schaldemose; Pryor, S.C.

    2013-01-01

    The primary control on the magnitude of the power losses induced by wind turbine wakes in large wind farms is the hub-height wind speed via its link to the turbine thrust coefficient. Hence, at low to moderate wind speeds (between cut-in and rated turbine wind speeds) when the thrust coefficient is...

  12. The aerodynamics of wind turbines

    Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming; Troldborg, Niels; Okulov, Valery; Shen, Wen Zhong

    In the paper we present state-of-the-art of research in wind turbine aerodynamics. We start be giving a brief historical review and a survey over aerodynamic research in wind energy. Next, we focus on some recent research results obtained by our wind energy group at Department of Mechanical...... Engineering at DTU. In particular, we show some new results on the classical problem of the ideal rotor and present a series of new results from an on-going research project dealing with the modelling and simulation of turbulent flow structures in the wake behind wind turbines....

  13. Lightning protection of wind turbines

    Soerensen, T.; Brask, M.H. [DEFU (Denmark); Jensen, F.V.; Raben, N. [SEAS (Denmark); Saxov, J. [Nordjyllandsvaerket (Denmark); Nielsen, L. [Vestkraft (Denmark); Soerensen, P.E. [Risoe National Lab. (Denmark)

    1999-03-01

    Lightning damage to wind turbines is a serious problem for Danish power companies, who have experienced some cases with very costly lightning damage and a large number of cases with minor damage. The most costly cases include one catastrophic damage to an entire wind turbine, and several cases of destruction of blades, main bearings, generators and control systems. Over the years there have been several hundreds of cases with minor damage - typically damage and interruptions of the control and communication systems, or the power systems. The Danish power companies anticipate that the lightning threat will be even bigger for the large off-shore wind turbine installations that are currently being planned in Denmark. Furthermore, it is known from the off-shore wind turbines at Vindeby in Denmark that the costs of inspection and particularly repair work must be expected to be much higher off-shore as compared to wind turbines on land. These considerations was the background for a two year project concerned with investigation of lighting damages and with the formulation of a DEFU Recommendation for lightning protection of wind turbines, which was published in January 1999. The project was funded by the Danish power companies Elsam, Eltra, Elkraft and by DEFU. (au)

  14. Development of superconducting wind turbine generators

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2013-01-01

    production volumes prohibit a large scale impact on the wind sector. The low temperature superconductors are readily available, but will need more sophisticated cooling. Eventually the Cost of Energy from superconducting wind turbines, with particular emphasis on reliability, will determine if they become......In this paper, the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational...... speeds, because high magnetic fields can be produced by coils with very little loss. Three different superconducting wind turbine generator topologies have been proposed by three different companies. One is based on low temperature superconductors; one is based on high temperature superconductors; and...

  15. Footprinting wind turbine fatigue loads

    Soeker, H. [Deutsches Windenergie-Inst., DEWI, Wilhelmshaven (Germany); Morfiadokis, E.; Kossivas, T. [Centre for Renewable Energy Sources, CRES, Pikermi Attiki (Greece); Oestman, A. [Aeronautical Research Inst. of Sweden, Bromma (Sweden)

    1999-09-01

    The effect of wind farm and complex terrain operation on wind turbine fatigue loading is of great interest but still not easily quantified. Within the EU Non Nuclear Energy R and D Programme the described project 'Measuring Footprints of Wind Turbine Fatigue Loads Using Monitoring Methods' applies a monitoring method on three wind turbines of the same type operating under flat terrain / stand alone, wind farm and complex terrain conditions. Statistics - footprints - of the load quantities are established through on-line rainflow counting of the sampled data. These footprints are evaluated to identify relevant quantities that can serve as shape, intensity and validity parameters. The paper presents the project's objectives and technical approach as well as first measurements and evaluation results.

  16. Wind turbine wakes for wind energy

    Larsen, Gunner C.; Crespo Martínez, Antonio

    2011-01-01

    During recent years, wind energy has moved from an emerging technology to a nearly competitive technology. This fact, coupled with an increasing global focus on environmental concern and a political desire of a certain level of diversification in the energy supply, ensures wind energy an important role in the future electricity market. For this challenge to be met in a cost-efficient way, a substantial part of new wind turbine installations is foreseen to be erected in big onshore or offshore...

  17. Generalized gain scheduling for deloaded wind turbine operation

    Venne, Philippe; Guillaud, X.; Teodorescu, Remus; Mahseredjian, J.

    2010-01-01

    regulate both power production and rotor speed under any wind speed conditions. In this paper, a novel controller for deloaded wind turbine operation is presented. This controller is made possible by a Cp table inversion procedure allowing generalized gain scheduling for linearization of the pitch response....... After introducing the wind turbine models, a review of classical turbine control principles and the proposed deloaded wind turbine control architecture is presented. A discussion of wind turbine non linearity and linearization principles follows. Simulation results are shown for stability, immunity to......The ability to produce less power than what is available from a wind source, a condition known as deloaded operation, is needed for a wind turbine to reproduce synchronous machine behavior in terms of inertial response and frequency droop regulation. Deloaded operation requires the ability to...

  18. Wake losses optimization of offshore wind farms with moveable floating wind turbines

    Rodrigues, S.F.; Pinto, R. T.; M. Soleimanzadeh; Bosman, Peter; Bauer, P.

    2015-01-01

    In the future, floating wind turbines could be used to harvest energy in deep offshore areas where higher wind mean speeds are observed. Currently, several floating turbine concepts are being designed and tested in small scale projects; in particular, one concept allows the turbine to move after installation. This article presents a novel layout optimization framework for wind farms composed of moveable floating turbines. The proposed framework uses an evolutionary optimization strategy in a ...

  19. Extreme Response for Wind Turbines

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    The characteristic load on wind turbines during operation are among others dependent on the mean wind speed, the turbulence intensity and type and settings of the control system. The characteristic load during operation is normally estimated by statistical extrapolation of a limited number of...... simulated 10min time series of the response according to the wind turbine standard IEC 61400-1. However, this method assumes that the individual 10min time series and the extracted peaks from the time series are independent. In the present paper is this assumption investigated based on field measurements...

  20. Asynchronous Generators for use in Gearless Wind Turbines

    Jensen, Bogi Bech; Henriksen, Matthew L.

    2011-01-01

    In this presentation the squirrel cage induction generator is proposed for a direct-drive wind turbine. The squirrel cage induction generator is proposed for direct drive wind turbines, because of its simple and rugged construction and because it does not require rare earth elements, which are a ...

  1. Control system on a wind turbine

    Varpe, Steffen Andreas

    2008-01-01

    The aim for this project is to prepare a wind turbine controller and a wind turbine computer model suitable for controller development. The wind turbine is a Vestas V27, and the wind turbine drive train is modified by ChapDrive with a specified hydraulic transmission. Both the pitch and the rotor speed can be regulated for the modified wind turbine. The model is primarily based on a set of given wind turbine rotor characteristics, transmission specifications and transmission test data. The co...

  2. Active control: Wind turbine model

    Bindner, Henrik

    1999-07-01

    This report is a part of the reporting of the work done in the project `Active Control of Wind Turbines`. This project aim is to develop a simulation model for design of control systems for turbines with pitch control and to use that model to design controllers. This report describes the model developed for controller design and analysis. Emphasis has been put on establishment of simple models describing the dynamic behavior of the wind turbine in adequate details for controller design. This has been done with extensive use of measurements as the basis for selection of model complexity and model validation as well as parameter estimation. The model includes a simple model of the structure of the turbine including tower and flapwise blade bending, a detailed model of the gear box and induction generator, a linearized aerodynamic model including modelling of induction lag and actuator and sensor models. The models are all formulated as linear differential equations. The models are validated through comparisons with measurements performed on a Vestas WD 34 400 kW wind turbine. It is shown from a control point of view simple linear models can be used to describe the dynamic behavior of a pitch controlled wind turbine. The model and the measurements corresponds well in the relevant frequency range. The developed model is therefore applicable for controller design. (au) EFP-91. 18 ills., 22 refs.

  3. Wind turbines and human health.

    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

  4. Results of a wind turbine FDI competition

    Odgaard, Peter Fogh; Stoustrup, Jakob

    In this paper some newly published methods for fault detection and isolation developed for a wind turbine benchmark model are tested, compared and evaluated. These methods have been presented as a part of an international competition. The tested methods cover different types of fault detection and...... isolation methods, which include support vector machines, observer based methods, and auto generated methods. All of these methods show interesting potentials for usage in the wind turbine application, but all with different strong and weak sides in relation to the requirements specified in the proposed...

  5. Modal Parameter Identification of New Design of Vertical Axis Wind Turbine

    Chougule, Prasad; Nielsen, Søren R.K.

    Vertical axis wind turbines have lower power efficiency than the horizontal axis wind turbines. However vertical axis wind turbines are proven to be economical and noise free on smaller scale. A new design of three bladed vertical axis wind turbine by using two airfoils in construction of each bl...... Abaqus cae software. The study is limited to evaluate lowest fundamental modal frequencies and mode shapes of proposed wind turbine....

  6. Wind energy. From small wind turbines to offshore wind farms

    This bibliographical sheet presents a book in which the authors present and discuss the present and future developments, challenges and problematic of wind energy. They notably focus on offshore wind farms, their technical solutions and current French projects, with their potentials, economic, administrative and environmental aspects, their sizing issue, and so on. They also explain in detail the potential of wind energy and its conversion, present the different subsystems of a wind turbine and their operation, and describe how to build up a wind farm project. They also address the issues related to small wind turbines

  7. Active control: Wind turbine model

    Bindner, H.

    1999-01-01

    validation as well as parameter estimation. The model includes a simple model of the structure of the turbine including tower and flapwise blade bending,a detailed model of the gear box and induction generator, a linearized aerodynamic model including modelling of induction lag and actuator and sensor models......This report is a part of the reporting of the work done in the project 'Active Control of Wind Turbines'. This project aim is to develop a simulation model for design of control systems for turbines with pitch control and to use that model to designcontrollers. This report describes the model...... developed for controller design and analysis. Emphasis has been put on establishment of simple models describing the dynamic behavior of the wind turbine in adequate details for controller design. This hasbeen done with extensive use of measurements as the basis for selection of model complexity and model...

  8. Extended Kalman Filter based State Estimation of Wind Turbine

    Kavitha N

    2013-11-01

    Full Text Available State estimation provides the best possible approximation for the state of the system by processing the available information. In the proposed work, the state estimation technique is used for the state estimation of wind turbine. Modern wind turbines operate in a wide range of wind speeds. To enable wind turbine operation in such a variety of operating conditions, sophisticated control and estimationalgorithms are needed. The theoretical basis of Extended Kalman Filter algorithm is explained in detail and performance is tested with the simulation. A nonlinear state estimator named ExtendedKalman Filter can be used for estimating the states of wind turbine. The Extended Kalman Filter is a recursive estimator that can be decomposed into two phases such as prediction and correction performed at every time instant. The states estimated by usingExtended Kalman Filter for wind turbine application includes rotor speed of turbine, tower top displacement and its velocity.

  9. Diffuser augmented wind turbine analysis code

    Carroll, Jonathan

    Wind Energy is becoming a significant source of energy throughout the world. This ever increasing field will potentially reach the limit of availability and practicality with the wind farm sites and size of the turbine itself. Therefore, it is necessary to develop innovative wind capturing devices that can produce energy in the locations where large conventional horizontal axis wind turbines (HAWTs) are too impractical to install and operate. A diffuser augmented wind turbine (DAWT) is one such innovation. DAWTs increase the power output of the rotor by increasing the wind speed into the rotor using a duct. Currently, developing these turbines is an involved process using time consuming Computational Fluid Dynamics codes. A simple and quick design tool is necessary for designers to develop efficient energy capturing devices. This work lays out the theory for a quick analysis tool for DAWTs using an axisymmetric surface vorticity method. This method allows for quick analysis of duct, hubs and rotors giving designers a general idea of the power output of the proposed hub, blade and duct geometry. The method would be similar to the way blade element momentum theory is used to design conventional HAWTs. It is determined that the presented method is viable for preliminary design of DAWTs.

  10. Structural optimization study of composite wind turbine blade

    Chen, Jin; Shen, Wen Zhong; Wang, Quan; Pang, Xiaoping; Li, Songlin; Guo, Xiaofeng

    2013-01-01

    In this paper the initial layout of a 2. MW composite wind turbine blade is designed first. The new airfoils families are selected to design a 2. MW wind turbine blade. The finite element parametric model for the blade is established. Based on the modified Blade Element Momentum theory, a new one...... the structural design and optimization of wind turbine blades. © 2012.......-way fluid-structure interaction method is introduced. A procedure combining finite element analysis and particle swarm algorithm to optimize composite structures of the wind turbine blade is developed. The procedure proposed not only allows thickness variation but also permits the spar cap location...

  11. Fault tolerant control of wind turbines using unknown input observers

    Odgaard, Peter Fogh; Stoustrup, Jakob

    This paper presents a scheme for accommodating faults in the rotor and generator speed sensors in a wind turbine. These measured values are important both for the wind turbine controller as well as the supervisory control of the wind turbine. The scheme is based on unknown input observers, which...... are also used to detect and isolate these faults. The scheme is tested on a known benchmark for FDI and FTC of wind turbines. Tests on this benchmark model show a clear potential of the proposed scheme....

  12. Vertical axis wind turbine airfoil

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  13. Wind turbine noise source characterization

    Wind turbine noise is a function of many parameters. Aerodynamics noise is a direct function of the rotor characteristics and wind speed, which can change rapidly with time. Mechanical noise is primarily a function of electrical power output, but the radiation of such noise is highly modified by vibration behaviour within the turbine. An experiment has been performed to isolate the behaviour of the major WTG noise sources with respect to electrical power output and wind speed. Twelve ground based microphones equispaced around the turbine gave detailed noise directionality information. Additional instrumentation was added to allow the separation of aerodynamic and mechanical noise components. Noise was found to be very well correlated to electrical power output. (author)

  14. DOE/SNL-TTU scaled wind farm technology facility : research opportunities for study of turbine-turbine interaction.

    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.

  15. A wind turbine hybrid simulation framework considering aeroelastic effects

    Song, Wei; Su, Weihua

    2015-04-01

    In performing an effective structural analysis for wind turbine, the simulation of turbine aerodynamic loads is of great importance. The interaction between the wake flow and the blades may impact turbine blades loading condition, energy yield and operational behavior. Direct experimental measurement of wind flow field and wind profiles around wind turbines is very helpful to support the wind turbine design. However, with the growth of the size of wind turbines for higher energy output, it is not convenient to obtain all the desired data in wind-tunnel and field tests. In this paper, firstly the modeling of dynamic responses of large-span wind turbine blades will consider nonlinear aeroelastic effects. A strain-based geometrically nonlinear beam formulation will be used for the basic structural dynamic modeling, which will be coupled with unsteady aerodynamic equations and rigid-body rotations of the rotor. Full wind turbines can be modeled by using the multi-connected beams. Then, a hybrid simulation experimental framework is proposed to potentially address this issue. The aerodynamic-dominant components, such as the turbine blades and rotor, are simulated as numerical components using the nonlinear aeroelastic model; while the turbine tower, where the collapse of failure may occur under high level of wind load, is simulated separately as the physical component. With the proposed framework, dynamic behavior of NREL's 5MW wind turbine blades will be studied and correlated with available numerical data. The current work will be the basis of the authors' further studies on flow control and hazard mitigation on wind turbine blades and towers.

  16. Low wind speed wind turbine in DIY version

    Van den Bossche, Alex

    2013-01-01

    Wind energy has still a place, as it can generate power in the winter, when less sun is available and when the wind speed is higher. This paper proposes a solution for low cost blades from a polyethylene pipe (PE) and a low cost electric bike generator, which is possible to realize by a do it yourself (DIY) person. It is intended as low wind speed wind turbine (LWWT). The design is rather optimized towards a low cost/swept area, rather than the cost/nominal power. It uses a variant on the fur...

  17. Hywind floating wind turbine project

    Crome, Tim

    2010-07-01

    The Hywind floating wind turbine concept was developed by StatoilHydro. Technip was awarded the contract for engineering, fabrication and installation of a demonstration unit in May 2008 and the completed wind turbine was installed mid June 2009 at the west coast of Norway on 220 m water depth. The demonstration unit will generate 2,3 MW and is equipped with instrumentation for monitoring mooring forces, strains and motions. The fabrication of the SPAR type steel substructure was performed at Technip Offshore Finland facilities in Pori and was towed horizontally from Finland to Norway, where it was upended to a vertical position by water filling. The completed floating wind turbine was towed vertically to the final location west of Karmoey and connected to the pre-installed three legged anchor system using an Anchor Handling Tug type vessel. The wind turbine test period is scheduled to start in September 2009. Statoil will monitor the performance of the system for two years before decision will be taken for further development. The paper will present the main challenges and lessons learned through design, fabrication and installation of this first of its kind structure. Main emphasis will be on the special challenges experienced for this floating, catenary moored, slender unit which is highly exposed for wind induced forces in addition to current and waves in hostile North Sea environments. (Author)

  18. Prediction of variability in wind turbine noise calculations

    Cotté, Benjamin; Tian, Yuan

    2015-01-01

    We propose in this work a method to predict the variability in wind turbine noise calculations due to wind speed and direction fluctuations. First, wind lidar data measurements during a 24-hour period are analyzed, and four periods with different atmospheric stability conditions are selected. Then, a wind turbine noise model based on Amiet's theory for trailing edge noise is presented and used to predict the sound pressure level at a fixed receiver during the 24-hour period. Finally, a Monte ...

  19. Innovative Design of Vertical Axis Wind Turbine

    Chougule, Prasad

    2013-01-01

    The wind turbines can be classified as: i) Horizontal axis wind turbines (HAWT), and ii) Vertical axis wind turbines (VAWT). The HAWT is fully developed and the size is growing higher. Whereas, the VAWT is not developed because of the less efficiency and vibration issues of big structure. However...

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

    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.

  1. The noise generated by wind turbines

    Sound propagation damps down with distance and varies according to different parameters like wind direction and temperature. This article begins by recalling the basic physics of sound wave propagation and gives a list of common noises and corresponding decibels. The habitual noise of wind turbines 500 m away is 35 decibels which ranks it between a quiet bedroom (30 decibels) and a calm office (40 decibels). The question about whether wind turbines are a noise nuisance is all the more difficult as the feeling of a nuisance is so objective and personal. Any project of wind turbines requires a thorough study of its estimated acoustic impact. This study is a 3 step approach: first the initial noise environment is measured, secondly the propagation of the sound generated by the wind turbine farm is modelled and adequate mitigation measures are proposed to comply the law. The law stipulates that the increase of noise must be less than 5 db during daylight and less than 3 db during night. (A.C.)

  2. Built Environment Wind Turbine Roadmap

    Smith, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Forsyth, T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sinclair, K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Oteri, F. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-11-01

    The market currently encourages BWT deployment before the technology is ready for full-scale commercialization. To address this issue, industry stakeholders convened a Rooftop and Built-Environment Wind Turbine Workshop on August 11 - 12, 2010, at the National Wind Technology Center, located at the U.S. Department of Energy’s National Renewable Energy Laboratory in Boulder, Colorado. This report summarizes the workshop.

  3. New guidelines for wind turbine gearboxes

    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.

  4. Dynamic modeling and simulation of wind turbines

    Using wind energy for generating electricity in wind turbines is a good way for using renewable energies. It can also help to protect the environment. The main objective of this paper is dynamic modeling by energy method and simulation of a wind turbine aided by computer. In this paper, the equations of motion are extracted for simulating the system of wind turbine and then the behavior of the system become obvious by solving the equations. The turbine is considered with three blade rotor in wind direction, induced generator that is connected to the network and constant revolution for simulation of wind turbine. Every part of the wind turbine should be simulated for simulation of wind turbine. The main parts are blades, gearbox, shafts and generator

  5. Wind turbine noise. Primary noise sources

    Oerlemans, S.

    2011-04-15

    Wind is a clean, cheap, and inexhaustible source of energy. However, the noise from wind turbines constitutes an important hindrance for the widespread application of wind energy. As a result, there is considerable interest in wind turbine noise, from a number of angles. As public clamour grows from those living near turbines, and misinformation and disinformation begin to take root, there is a clear need for a scientifically accurate book to give an account of the noise generated, its effects on people, and possible remedies either through technology or legislation or both. The different potential source mechanisms are described and the theoretical characteristics of flowinduced sound from wind turbine blades are explained. The noise sources on wind turbines are characterized experimentally by means of wind tunnel and field experiments. Methods to predict and reduce wind turbine noise are discussed. The dominant noise source for typical modern large wind turbines is broadband trailing edge noise from the outer part of the blades. The swishing character of the sound can be explained by trailing edge noise directivity and convective amplification. A semi-analytical, semi-empirical prediction method can accurately predict the characteristics of wind turbine noise. Wind turbine noise can be halved by means of serrations, without adverse effects on the aerodynamic performance. The book is aimed at people with a personal or professional involvement in wind turbine noise, such as environmental health or public health practitioners, wind farm developers or informed wind farm supporters and objectors.

  6. Floating wind turbines : the transport phase

    Solli, Knut Jostein

    2008-01-01

    The worldwide demand of renewable energy is increasing rapidly because of the climate problem. Wind energy appears as a clean and good solution to cope with a great part of this energy demand. Therefore, floating wind turbines have been investigated as a possible solution to increase the efficiency from the wind, as a renewable energy source. A critical phase for the floating wind turbines is the transport phase. Economically, the floating wind turbines should be transported in...

  7. Mechanical noise from wind turbines

    Community annoyance due to noise from wind turbines is often the result of noise character rather than level. Although the overall contributions from each of the two main classes of noise source, namely aerodynamic and mechanical, are often of a similar order for an untreated turbine, it is usually the mechanical sources which provide the dominant noise characteristics that may lead to annoyance. In this paper, the sources of mechanical noise are identified primarily with reference to horizontal axis wind turbines and then attention is concentrated on the rotor-shaft step-up gearbox, which is normally the top-ranking source. The major gearbox noise mechanisms and transmission paths are discussed and reference made to Noise Specifications and procedures applicable to the gearbox prior to its installation. The reduction of machinery noise is reviewed both at source and by treatment of transmission paths. (author)

  8. Probabilistic Design of Wind Turbines

    Henrik S. Toft; Sørensen, John D.

    2010-01-01

    Probabilistic design of wind turbines requires definition of the structural elements to be included in the probabilistic basis: e.g., blades, tower, foundation; identification of important failure modes; careful stochastic modeling of the uncertain parameters; recommendations for target reliability levels and recommendation for consideration of system aspects. The uncertainties are characterized as aleatoric (physical uncertainty) or epistemic (statistical, measurement and model uncertainties...

  9. Integrated installation for offshore wind turbines

    Way, J.; Bowerman, H.

    2003-07-01

    A project to investigate the feasibility of integrating the offshore installation of foundation, turbine and tower for offshore wind turbines into one operation is described. Three separate objectives are listed. They are: (1) Telescopic tower study - reversible process incorporating lift and lock mechanisms; (2) Transportation study - technical and economic feasibility of transporting and installing a wind turbine unit via a standard barge with minimal conversion and (3) Self-burial system study - to demonstrate the feasibility of self burial of a slab foundation via controlled jetting beneath the slab. The background to the study and the proposed concepts are discussed. The work carried out to date and the costs are reported together with the findings. Recommendations for future work are listed. The work was carried out by Corus UK Ltd and is managed by Future Energy Solutions for the DTI.

  10. Wind Turbine Converter Control Interaction with Complex Wind Farm Systems

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2013-01-01

    stability. The same wind turbine converter control strategy is evaluated in two different wind farms. It is emphasised that the grid-side converter controller should be characterised by sufficient harmonic/noise rejection and adjusted depending on wind farms to which it is connected. Various stability......This study presents wind turbine converter stability analysis of wind farms in frequency domain. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply investigated. Two wind farms (i.e. Horns Rev II and Karnice) are taken into consideration in...... this study. It is shown that wind farm components, such as long high-voltage alternating current cables and park transformers, can introduce significant low-frequency series resonances seen from the wind turbine terminals that can affect wind turbine control system operation and overall wind farm...

  11. Wake losses optimization of offshore wind farms with moveable floating wind turbines

    Highlights: • We present a layout optimization framework for wind farms with moveable turbines. • Using moveable wind turbines in optimized layouts maximizes energy production. • Turbine and wind farm designers should cooperate to optimize offshore wind projects. - Abstract: In the future, floating wind turbines could be used to harvest energy in deep offshore areas where higher wind mean speeds are observed. Currently, several floating turbine concepts are being designed and tested in small scale projects; in particular, one concept allows the turbine to move after installation. This article presents a novel layout optimization framework for wind farms composed of moveable floating turbines. The proposed framework uses an evolutionary optimization strategy in a nested configuration which simultaneously optimizes the anchoring locations and the wind turbine position within the mooring lines for each individual wind direction. The results show that maximum energy production is obtained when moveable wind turbines are deployed in an optimized layout. In conclusion, the framework represents a new design optimization tool for future offshore wind farms composed of moveable floating turbines

  12. Design of Wind Turbine Vibration Monitoring System

    Shoubin Wang

    2013-04-01

    Full Text Available In order to ensure safety of wind turbine operation and to reduce the occurrence of faults as well as to improve the reliability of wind turbine operation, a vibration monitoring for wind turbine is developed. In this paper, it analyses the enlargement of all the parts of the structure and the working mechanism, the research method of wind turbine operation vibration is introduced, with the focus being the use of the sensor principle. Finally the hardware design and software of this system is introduced and the main function of this system is described, which realizes condition monitoring of the work state of wind turbines.

  13. Sound wave contours around wind turbine arrays

    Noise pollution is an important factor in selecting suitable sites for wind turbines in order to realize 1000 MW of wind power as planned by the Dutch government for the year 2000. Therefore an accurate assessment of wind turbine noise is important. The amount of noise pollution from a wind turbine depends on the wind conditions. An existing standard method to assess wind turbine noise is supplemented and adjusted. In the first part of the investigation the method was developed and applied for a solitary sound source. In the second part attention is paid to the use of the method for wind turbine arrays. It appears that the adjusted method results in a shift of the contours of the permitted noise level. In general the contours are 15-25% closer to the wind farm, which means that the minimal permitted distance between houses and wind turbine arrays can be reduced. 14 figs., 1 tab., 4 appendices, 7 refs

  14. Risk of collision between service vessels and offshore wind turbines

    Offshore wind farms are growing in size and are situated farther and farther away from shore. The demand for service visits to transfer personnel and equipment to the wind turbines is increasing, and safe operation of the vessels is essential. Currently, collisions between service vessels and offshore wind turbines are paid little attention to in the offshore wind energy industry. This paper proposes a risk assessment framework for such collisions and investigates the magnitude of the collision risk and important risk-influencing factors. The paper concludes that collisions between turbines and service vessels even at low speed may cause structural damage to the turbines. There is a need for improved consideration of this kind of collision risk when designing offshore wind turbines and wind farms.

  15. A Method for Modeling of Floating Vertical Axis Wind Turbine

    Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir

    2013-01-01

    It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper....... In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind...... turbine. This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction...

  16. Modelling and control of large wind turbine

    zafar, syed hammad

    2013-01-01

    In order to make the wind energy an economical alternative for energy production, upscaling of turbine to 10 - 15MW may be necessary to reduce the overall cost of energy production. This production target requires a considerable increase in the turbine size and placing the turbines at high wind speed locations. But increase in turbine size also increases the uneven load distribution across the turbine structure. Therefore an efficient load reduction technique is necessary to increase the turb...

  17. Dynamic stall model for wind turbine airfoils

    Larsen, J.W.; Nielsen, S.R.K.; Krenk, Steen

    2007-01-01

    A model is presented for aerodynamic lift of wind turbine profiles under dynamic stall. The model combines memory delay effects under attached flow with reduced lift due to flow separation under dynamic stall conditions. The model is based on a backbone curve in the form of the static lift as a...... first-order filter. The latter is likely to occur during active pitch control of vibrations. It is shown that all included effects can be important when considering wind turbine blades. The proposed model is validated against test data from two load cases, one at fully attached flow conditions and one...... during dynamic stall conditions. The proposed model is compared with five other dynamic stall models including, among others, the Beddoes-Leishman model and the ONERA model. It is demonstrated that the proposed model performs equally well or even better than more complicated models and that the included...

  18. Structured Control of LPV Systems with Application to Wind Turbines

    Adegas, Fabiano Daher; Stoustrup, Jakob

    closed-loop system. Algorithms for the computation of feasible as well as optimal controllers are presented. The general case where no restrictions are imposed on the parameter dependence is treated here due to its suitability for modeling wind turbines. A comprehensive numerical example of a gain......-scheduled LPV controller design with prescribed pattern for wind turbines illustrate the utilization of the proposed algorithm.......This paper deals with structured control of linear parameter varying systems (LPV) with application to wind turbines. Instead of attempting to reduce the problem to linear matrix inequalities (LMI), we propose to design the controllers via an LMI-based iterative algorithm. The proposed algorithm...

  19. High-Power Wind Turbine: Performance Calculation

    Goldaev Sergey V.

    2015-01-01

    Full Text Available The paper is devoted to high-power wind turbine performance calculation using Pearson’s chi-squared test the statistical hypothesis on distribution of general totality of air velocities by Weibull-Gnedenko. The distribution parameters are found by numerical solution of transcendental equation with the definition of the gamma function interpolation formula. Values of the operating characteristic of the incomplete gamma function are defined by numerical integration using Weddle’s rule. The comparison of the calculated results using the proposed methodology with those obtained by other authors found significant differences in the values of the sample variance and empirical Pearson. The analysis of the initial and maximum wind speed influence on performance of the high-power wind turbine is done

  20. Wind Flow Analysis of Twisted Savonius Micro-Turbine Array

    Jesús Antonio Alvarez-Cedillo

    2015-01-01

    Full Text Available This paper provides a computational analysis of wind impact on different geometric configurations of Savonius turbines proposed and previously studied in specialized literature. As a result of comparative analysis of turbines, we performed a flow analysis over a microturbine array, proposed a twisted Savonius turbine respecting its original profile, and subjected it to a comparative analysis of its performance against conventional turbines. Our new proposal of Savonius turbines stands out due to its lower residual turbulence. The turbine dimensions are suited to the geometric relationships previously analyzed, and they are suggested in a way to respect the original profile of each turbine. The size of each turbine is small since its application is proposed for power generation in a low power array which can be placed on any building as part of its outer walls.

  1. Large superconducting wind turbine generators

    Abrahamsen, Asger Bech; Magnusson, Niklas; Jensen, Bogi Bech; Runde, M.

    2012-01-01

    To realize large (>10 MW) direct-driven off-shore wind turbines, a number of steps are needed to reduce weight and cost compared to on-shore technologies. One of the major challenges is to provide drive trains which can comply with the large torque as the turbine rotor diameter is scaled up and the...... rotation speed is lowered in order to limit the tip speed of the blades. The ability of superconducting materials to carry high current densities with very small losses might facilitate a new class of generators operating with an air gap flux density considerably higher than conventional generators and...

  2. Airfoil characteristics for wind turbines

    Bak, C.; Fuglsang, P.; Sørensen, Niels N.; Aagaard Madsen, Helge; Shen, W.Z.; Sørensen, Jens Nørkær

    1999-01-01

    Airfoil characteristics for use in the Blade Element Momentum (BEM) method calculating the forces on Horizontal Axis Wind Turbines (HAWT) are derived by use of systematic methods. The investigation and derivation of the airfoil characteristics are basedon four different methods: 1) Inverse momentum...... to a commonly used set of airfoil characteristics. The numerical optimisation is based on both the 3D CFDcomputations and measurements on a 41-m rotor with LM 19.1 and LM 19.0 blades, respectively. The method requires power and loads from a turbine and is promising since a set of lift and drag curves...

  3. Large, horizontal-axis wind turbines

    Linscott, B. S.; Perkins, P.; Dennett, J. T.

    1984-01-01

    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 generating systems are presented. In addition, these large wind turbines must be fully compatible with electric utility operations and interface requirements. There are several ongoing large wind system development projects and applied research efforts directed toward meeting the technology requirements for utility applications. Detailed information on these projects is provided. The Mod-O research facility and current applied research effort in aerodynamics, structural dynamics and aeroelasticity, composite and hybrid composite materials, and multiple system interaction are described. A chronology of component research and technology development for large, horizontal axis wind turbines is presented. Wind characteristics, wind turbine economics, and the impact of wind turbines on the environment are reported. The need for continued wind turbine research and technology development is explored. Over 40 references are sited and a bibliography is included.

  4. Wind resource assessment method for floating deep offshore wind turbines

    Estanqueiro, Ana; Couto, A.; Rodrigues, L.; Marujo, R.

    2014-01-01

    This study presents a new methodology for the assessment of the wind energy resource at deep offshore locations where the use of floating wind turbines is foreseen. The wind resource assessment methodology developed follows the principles used by IEC 61400-12-1 standard in general and proposes the use of experimental data from a floating light detection and ranging (LIDAR) system on a deep offshore region – that assumes the role of the ‘temporary mast’ – and a coastal meteorological mast inst...

  5. Method and apparatus for wind turbine braking

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    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.

  6. Market for wind turbines in italy

    Wind power utilization in Italy has not been very popular until the privatization of the ENEL and introduction of subsidies for private electricity producers. The greatest interest is concentrated around large wind turbines. Therefore the Danish manufacturers with know-how within large wind turbines can establish themselves on the Italian market. Cooperation with one of the four local wind turbine manufacturers is advisable. (EG)

  7. Signal analysis of wind turbine acoustic noise

    Lehto, Panu

    2014-01-01

    In Finland wind turbines are becoming more common. Wind farms are built outside residential concentrations where wind conditions are strong enough for power production. Even though the locations are remote, turbines are sometimes erected near dwellings and therefore the generated noise emissions have to meet certain threshold levels. In order to ensure that the required noise levels do not exceed the limits, measurements have to be done. The most recent standard for wind turbine noise anal...

  8. Superconducting wind turbine generators

    Mijatovic, Nenad

    A HTS machine could be a way to address some of the technical barriers offshore wind energy is about to face. Due to the superior power density of HTS machines, this technology could become a milestone on which many, including the wind industry, will rely on in the future. The work presented in...... this thesis is a part of a larger endeavor, the Superwind project that focused on identifying the potentials that HTS machines could offer to the wind industry and addressing some of the challenges in the process. In order to identify these challenges, I have designed and constructed an HTS machine...... towards more competitive alternative to conventional machines. Additionally, by constructing the HTS machine setup we went through most of the issues related to the HTS machine design which we managed to address in rather simple manner using everyday materials and therefore proving that HTS machines are...

  9. Superconducting Wind Turbine Generators

    Mijatovic, Nenad

    A HTS machine could be a way to address some of the technical barriers offshore wind energy is about to face. Due to the superior power density of HTS machines, this technology could become a milestone on which many, including the wind industry, will rely in the future. The work presented in this...... thesis is a part of a larger endeavor, the Superwind project that focused on identifying the potentials that HTS machines could offer to the wind industry and addressing some of the challenges in the process. In order to identify these challenges, I have design and constructed a HTS machine experimental...... can still be optimized towards more competitive alternative to conventional machines. Additionally, by constructing the HTS machine setup we went through most of the issues related to the HTS machine design which we managed to address in rather simple manner using everyday materials and therefore...

  10. Dynamic Models for Wind Turbines and Wind Power Plants

    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.

  11. A novel floating offshore wind turbine concept

    Vita, Luca; Schmidt Paulsen, Uwe; Friis Pedersen, Troels; Aagaard Madsen , Helge; Rasmussen, Flemming

    2009-01-01

    This paper will present a novel concept of afloating offshore wind turbine. The new concept isintended for vertical-axis wind turbine technology.The main purpose is to increase simplicity and toreduce total costs of an installed offshore windfarm. The concept is intended for deep water andlarge size turbines.

  12. Adaptive Backstepping Control of Lightweight Tower Wind Turbine

    Galeazzi, Roberto; Borup, Kasper Trolle; Niemann, Hans Henrik; Poulsen, Niels Kjølstad; Caponetti, Fabio

    This paper investigates the feasibility of operating a wind turbine with lightweight tower in the full load region exploiting an adaptive nonlinear controller that allows the turbine to dynamically lean against the wind while maintaining nominal power output. The use of lightweight structures for...... towers and foundations would greatly reduce the construction cost of the wind turbine, however extra features ought be included in the control system architecture to avoid tower collapse. An adaptive backstepping collective pitch controller is proposed for tower point tracking control, i.e. to modify the...... extreme wind gust event, and the feasibility of stabilizing the tower position while maintaining the rated power output is shown....

  13. Fluid-Structure Interaction Analysis of Wind Turbines

    Hsu, Ming-Chen

    Countries around the world are putting substantial effort into the development of wind energy technologies. The urgent need of renewable energy puts pressure on the wind energy industry research and development to enhance the current wind generation capabilities and decrease the associated costs. Currently most wind turbine aerodynamics and aeroelasticity simulations are performed using low-fidelity methods. These methods are simple to implement and fast to execute; however, the cases involving important features, such as unsteady flow, turbulence, and details of the wind turbine geometry, are beyond their range of applicability. In this dissertation, we introduce a paradigm shift in wind turbine analysis by developing 3D, complex geometry, time-dependent, multi-physics modeling procedures for wind turbine fluid-structure interaction (FSI). The proposed framework consists of a collection of numerical methods combined into a single framework for FSI modeling and simulation of wind turbines at full scale. The use of the Navier-Stokes equations of incompressible flows for wind turbine aerodynamics is validated against experimental data. The structural modeling of the composite blades is based on the Kirchhoff-Love thin shell theory discretized using isogeometric analysis. The coupled FSI formulation is derived using the augmented Lagrangian approach and accommodates non-matching fluid-structure interface discretizations. The challenges of fluid-structural coupling and the handling of computational domains in relative motion are discussed, and the FSI computations of a 5 MW offshore baseline wind turbine are shown.

  14. Damping Wind and Wave Loads on a Floating Wind Turbine

    Christiansen, Søren; Bak, Thomas; Knudsen, Torben

    Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due to...

  15. Power Electronics for the Next Generation Wind Turbine System

    Ma, Ke

    The wind power generation has been steadily growing both for the total installed capacity and for the individual turbine size. Due to much more significant impacts to the power grid, the power electronics, which can change the behavior of wind turbines from an unregulated power source to an active...... generation unit, are becoming crucial in the wind turbine system. The objective of this project is to study the power electronics technology used for the next generation wind turbines. Some emerging challenges as well as potentials like the cost of energy and reliability are going to be addressed. First......, converter controls and grid conditions are taken into account. In order to relieve the electrical and thermal stress of the converter in wind turbine system, some new control methods and concepts are thereby proposed. In Chapter 4 a thermal control concept which utilizes the reactive power is used to...

  16. On the Fatigue Analysis of Wind Turbines

    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.

  17. RBI Optimization of Offshore Wind Turbines

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coming years. Offshore wind turbines with an electricity production of 5-10 MW are planned. Typically, the wind turbine...... methods for oil & gas installations, a framework for optimal inspection and maintenance planning of offshore wind turbines is presented. Special aspects for offshore wind turbines considered are the fatigue loading characteristics where usually the wind loading are dominating the wave loading, wake...... support structure is a steel structure consisting of a tower and a monopile, tripod or jacket type foundation. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod type of wind turbine support structures. Based on risk-based inspection planning...

  18. Wind turbine sound power measurements.

    Keith, Stephen E; Feder, Katya; Voicescu, Sonia A; Soukhovtsev, Victor; Denning, Allison; Tsang, Jason; Broner, Norm; Richarz, Werner; van den Berg, Frits

    2016-03-01

    This paper provides experimental validation of the sound power level data obtained from manufacturers for the ten wind turbine models examined in Health Canada's Community Noise and Health Study (CNHS). Within measurement uncertainty, the wind turbine sound power levels measured using IEC 61400-11 [(2002). (International Electrotechnical Commission, Geneva)] were consistent with the sound power level data provided by manufacturers. Based on measurements, the sound power level data were also extended to 16 Hz for calculation of C-weighted levels. The C-weighted levels were 11.5 dB higher than the A-weighted levels (standard deviation 1.7 dB). The simple relationship between A- and C- weighted levels suggests that there is unlikely to be any statistically significant difference between analysis based on either C- or A-weighted data. PMID:27036281

  19. Wind Turbine Manufacturing Process Monitoring

    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. Wind turbine technology principles and design

    Adaramola, Muyiwa

    2014-01-01

    IntroductionPart I: AerodynamicsWind Turbine Blade Design; Peter J. Schubel and Richard J. CrossleyA Shrouded Wind Turbine Generating High Output Power with Wind-Lens Technology; Yuji Ohya and Takashi KarasudaniEcomoulding of Composite Wind Turbine Blades Using Green Manufacturing RTM Process; Brahim AttafAerodynamic Shape Optimization of a Vertical-Axis Wind Turbine Using Differential Evolution; Travis J. Carrigan, Brian H. Dennis, Zhen X. Han, and Bo P. WangPart II: Generators and Gear Systems

  1. New wind turbines of high profitability

    To generate more quantities of electric energy from wind it is necessary to use the new type of wind turbine built in regulable mantle's nozzle, which the free air stream of wind replaces in programmed i.e. regulated and partially concentrated. In this way their efficiency is multiplied. New turbines are getting more power (P = f(v3)) from cube of higher speeds from weaker and medium winds. Short economic analysis evidently indicates that profit achieved by new wind turbines is 5 (five) times higher than that by conventional turbines. (author)

  2. Load Extrapolation During Operation for Wind Turbines

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    In the recent years load extrapolation for wind turbines has been widely considered in the wind turbine industry. Loads on wind turbines during operations are normally dependent on the mean wind speed, the turbulence intensity and the type and settings of the control system. All these parameters...... must be taken into account when characteristic load effects during operation are determined. In the wind turbine standard IEC 61400-1 a method for load extrapolation using the peak over threshold method is recommended. In this paper this method is considered and some of the assumptions are examined...

  3. Motion of floating wind turbines

    Linde, Børge

    2010-01-01

    Motion of floating wind turbines has been studied. A literature study on different concepts and what tools are available for simulating them is presented. Marintek’s simulation software SIMO is used for time simulations. In the calculations, the hydrodynamic forces, mooring line forces and aerodynamic forces from the tower and rotor are taken into account. In addition a pitch control algorithm is used for the rotor blades. Results are compared to available experimental results from model test...

  4. Fault ride through and voltage regulation for grid connected wind turbine

    Kyaw, Min Min; Ramachandaramurthy, V.K. [Power Quality Research Group, Department of Electrical Power Engineering, Universiti Tenaga Nasional, Putrajaya Campus, 43009 Selangor (Malaysia)

    2011-01-15

    High penetration of wind generation challenges wind turbine operators to supply reliable power and extract optimum power from the wind. Hence, the fault ride through (FRT) capability of wind turbine together with the optimum power tracking and regulation of wind turbine output voltage due to fluctuating nature of the wind becomes essential. In this paper, a method is proposed to ensure that the double fed induction generator (DFIG) wind turbine continues to operate during severe grid faults and maintains a constant output voltage, irrespective of the fluctuating wind. The proposed controller also allows the DFIG wind turbine to track optimum power from the wind. Extensive simulation is performed using PSCAD/EMTDC software and results obtained show that the DFIG output voltage fulfills the grid code requirements. The results also show that the proposed method is able to track the optimum power, regulate the DFIG output voltage and perform fault ride through of wind turbine. (author)

  5. Numerical Simulations of Wakes of Wind Turbines in Wind Farms

    Troldborg, Niels; Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming

    2006-01-01

    Wakes of both a stand-alone wind turbine and 3 wind turbines placed in a row is analysed using a numerical method where a three-dimensional Navier Stokes solver is combined with an actuator line technique. The computations on the single turbine indicate the appearance of low frequency fluctuations...... of the wake similar to what is observed behind a disc. Furthermore, the computations on a row of turbines demonstrate that downstream turbines might experience the distinct tip vortices formed in the wake of upstream turbines. Results also show that placing the turbines too closely can significantly...

  6. A novel floating offshore wind turbine concept

    Vita, Luca; Schmidt Paulsen, Uwe; Friis Pedersen, Troels; Aagaard Madsen, Helge; Rasmussen, Flemming

    2009-01-01

    This paper will present a novel concept of a floating offshore wind turbine. The new concept is intended for vertical-axis wind turbine technology. The main purpose is to increase simplicity and to reduce total costs of an installed offshore wind farm. The concept is intended for deep water and...

  7. Standards for measurements and testing of wind turbine power quality

    Soerensen, P. [Risoe National Lab., Roskilde (Denmark); Gerdes, G.; Klosse, R.; Santjer, F. [DEWI, Wilhelmshaven (Germany); Robertson, N.; Davy, W. [NEL, Glasgow (United Kingdom); Koulouvari, M.; Morfiadakis, E. [CRES, Pikermi (Greece); Larsson, Aa. [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1999-03-01

    The present paper describes the work done in power quality sub-task of the project `European Wind Turbine Testing Procedure Developments` funded by the EU SMT program. The objective of the power quality sub-task has been to make analyses and new recommendation(s) for the standardisation of measurement and verification of wind turbine power quality. The work has been organised in three major activities. The first activity has been to propose measurement procedures and to verify existing and new measurement procedures. This activity has also involved a comparison of the measurements and data processing of the participating partners. The second activity has been to investigate the influence of terrain, grid properties and wind farm summation on the power quality of wind turbines with constant rotor speed. The third activity has been to investigate the influence of terrain, grid properties and wind farm summation on the power quality of wind turbines with variable rotor speed. (au)

  8. Optimization of wind turbine rotors

    Nygaard, Tor Anders

    1999-07-01

    The Constrained Steepest Descent method has been applied to the optimization of wind turbine rotors through the development of a numerical model. The model consists of an optimization kernel, an aerodynamic model, a structural dynamic model of a rotating beam, and a cost model for the wind turbine. The cost of energy is minimized directly by varying the blade design, the rotational speed and the resulting design of the drive-train and tower. The aerodynamic model is a combination of a fast engineering model based on strip-theory and two and three-dimensional Euler solvers. The two-dimensional Euler solver is used for generation of pre-stall airfoil data. Comparisons with experimental data verify that the engineering model effectively approximates non-stalled flow, except at the blade tip. The three-dimensional Euler solver is in good agreement with the experimental data at the tip, and is therefore a useful supplement for corrections of the tip-loss model, and evaluation of an optimized design. The structural dynamic model evaluates stresses and deformations for the blade. It is based on constitutive relations for a slender beam that are solved with the equations of motions using a finite-difference method. The cost model evaluates the design change of the wind turbine and the resulting costs that occur when a change in blade design modifies the blade mass and the overall forces. The cost model is based on engineering design rules for the drive-train and tower. The model was applied using a Danish 600 kW wind turbine as a reference. Two rotors were optimized using traditional NACA airfoils and a new low-lift airfoil family developed specifically for wind turbine purposes. The cost of energy decreased four percent for the NACA rotor, and seven percent for the low-lift rotor. Optimizations with a high number of degrees of freedom show that a designer has considerable flexibility in choosing some primary parameters such as rated power and rotor diameter, if the rest of the parameters are optimized. The model requires modest computer resources, and seems to be well suited for use as an industrial design tool. (author)

  9. Wind Turbine Noise Modelling Based on Amiet's Theory

    Tian, Yuan; Cotté, Benjamin; Chaigne, Antoine

    2013-01-01

    Broadband noise generated aerodynamically is the dominant noise source for a modern wind turbine(Brooks et al, 1989; Oerlemans et al, 2007). In this paper, two main broadband noise mechanisms, namely trailing edge noise and turbulent inflow noise, are examined in detail using frequency domain noise prediction models based on Amiet's analytical theory. Improvements are proposed to adapt the original model to wind turbines . First, a wall pressure spectral model proposed recently by Rozenberg, ...

  10. Constant Power Control Of 15 DFIG Wind Turbines With Superconducting Magnetic Energy Storage System

    V.Krishnamurthy 1 , Ch.Rajesh Kumar

    2013-01-01

    With the increasing penetration of wind power into electric power grids, energy storage devices will be required to dynamically match the intermittency of wind energy. This paper proposes a novel two-layer constant power control scheme for a wind farm equipped with doubly fed induction generator (DFIG) wind turbines. Each DFIG wind turbine is equipped with a superconducting magnetic energy storage system (ESS) and is controlled by the low-layer wind turbine generator (WTG) controllers and coo...

  11. Cost optimization of wind turbines for large-scale offshore wind farms

    This report contains a preliminary investigation of site specific design of off-shore wind turbines for a large off-shore wind farm project at Roedsand that is currently being proposed by ELKRAFT/SEAS. The results were found using a design tool for wind turbines that involve numerical optimization and aeroelastic calculations of response. The wind climate was modeled in detail and a cost function was used to estimate costs from manufacture and installation. Cost of energy is higher for off-shore installations. A comparison of an off-shore wind farm site with a typical stand alone on-shore site showed an increase of the annual production of 28% due to the difference in wind climate. Extreme loads and blade fatigue loads were nearly identical, however,fatigue loads on other main components increased significantly. Optimizations were carried out to find the optimum overall off-shore wind turbine design. A wind turbine for the off-shore wind farm should be different compared with a stand-alone on-shore wind turbine. The overall design changed were increased swept area and rated power combined with reduced rotor speed and tower height. Cost was reduced by 12% for the final 5D/14D off-shore wind turbine from 0.306 DKr/kWh to 0.270 DKr/kWh. These figures include capital costs from manufacture and installation but not on-going costs from maintenance. These results make off-shore wind farms more competitive and comparable to the reference on-shore stand-alone wind turbine. A corresponding reduction of cost of energy could not be found for the stand alone on-shore wind turbine. Furthermore the fatigue loads on wind turbines in on-shore wind farms will increase and cost of energy will increase in favor of off-shore wind farms. (au) EFP-95; EU-JOULE-3; 21 tabs., 7 ills., 8 refs

  12. Market experiences with small wind turbines

    An overview is given of the marketing experiences of Lagerwey Windturbines with the exploitation of small wind turbines. Attention is paid to the market mechanisms which effect the sale and implementation of small wind turbines: payback of surplus power, provincial and regional subsidies, grid connection costs, energy prices, and flexible solutions for grid connections. Also problems with municipalities with regard to regulations or construction licenses are discussed. Some recommendations are given to stimulate the market for small wind turbines. 1 fig., 1 ref

  13. Small Wind Research Turbine: Final Report

    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.

  14. Integrated optimization of floating wind turbine systems

    Sandner, Frank; Schlipf, David; Matha, Denis; Cheng, Po Wen

    2014-01-01

    An exemplary methodology is shown for the integrated conceptioning of a floating wind turbine system with focus on the spar-type hull and the wind turbine blade-pitch-to-feather controller. It is a special interest to use a standard controller, which is easily implementable, even at early design stages. The optimization of the system is done with adapted static and dynamic models through a stepwise narrowing of the design space according to the requirements of floating wind turbines. After se...

  15. Influence of refraction on wind turbine noise

    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 sou...

  16. Hybrid Optimization for Wind Turbine Thick Airfoils

    Grasso, F. [ECN Wind Energy, Petten (Netherlands)

    2012-06-15

    One important element in aerodynamic design of wind turbines is the use of specially tailored airfoils to increase the ratio of energy capture and reduce cost of energy. This work is focused on the design of thick airfoils for wind turbines by using numerical optimization. A hybrid scheme is proposed in which genetic and gradient based algorithms are combined together to improve the accuracy and the reliability of the design. Firstly, the requirements and the constraints for this class of airfoils are described; then, the hybrid approach is presented. The final part of this work is dedicated to illustrate a numerical example regarding the design of a new thick airfoil. The results are discussed and compared to existing airfoils.

  17. Report on the safety of wind turbines installations; Rapport sur la securite des installations eoliennes

    Guillet, R.; Leteurtrois, J.P.

    2004-07-01

    This report aims to study the regulatory framework governing the safety of wind turbines and proposes improvement actions. It concerns the wind turbines risk assessment, the technical bases of the wind turbines safety, the regulation relative to the safety and possible evolutions. (A.L.B.)

  18. Wind Turbine Control: Robust Model Based Approach

    Mirzaei, Mahmood

    is because, on the one hand, control methods can decrease the cost of energy by keeping the turbine close to its maximum efficiency. On the other hand, they can reduce structural fatigue and therefore increase the lifetime of the wind turbine. The power produced by a wind turbine is proportional to....... Wind turbines are the most common wind energy conversion systems and are hoped to be able to compete economically with fossil fuel power plants in near future. However this demands better technology to reduce the price of electricity production. Control can play an essential part in this context. This...... structure reasonable, the ratio of mass to size should be reduced. This trend results in more flexible structures. Control of the flexible structure of a wind turbine in a wind field with stochastic nature is very challenging. In this thesis we are examining a number of robust model based methods for wind...

  19. Condition monitoring system of wind turbine generators

    Abdusamad, Khaled B.

    The development and implementation of the condition monitoring systems (CMS) play a significant role in overcoming the number of failures in the wind turbine generators that result from the harsh operation conditions, such as over temperature, particularly when turbines are deployed offshore. In order to increase the reliability of the wind energy industry, monitoring the operation conditions of wind generators is essential to detect the immediate faults rapidly and perform appropriate preventative maintenance. CMS helps to avoid failures, decrease the potential shutdowns while running, reduce the maintenance and operation costs and maintain wind turbines protected. The knowledge of wind turbine generators' faults, such as stator and rotor inter-turn faults, is indispensable to perform the condition monitoring accurately, and assist with maintenance decision making. Many techniques are utilized to avoid the occurrence of failures in wind turbine generators. The majority of the previous techniques that are applied to monitor the wind generator conditions are based on electrical and mechanical concepts and theories. An advanced CMS can be implemented by using a variety of different techniques and methods to confirm the validity of the obtained electrical and mechanical condition monitoring algorithms. This thesis is focused on applying CMS on wind generators due to high temperature by contributing the statistical, thermal, mathematical, and reliability analyses, and mechanical concepts with the electrical methodology, instead of analyzing the electrical signal and frequencies trends only. The newly developed algorithms can be compared with previous condition monitoring methods, which use the electrical approach in order to establish their advantages and limitations. For example, the hazard reliability techniques of wind generators based on CMS are applied to develop a proper maintenance strategy, which aims to extend the system life-time and reduce the potential failures during operation due to high generator temperatures. In addition, the use of some advanced statistical techniques, such as regression models, is proposed to perform a CMS on wind generators. Further, the mechanical and thermal characteristics are employed to diagnose the faults that can occur in wind generators. The rate of change in the generator temperature with respect to the induced electrical torque; for instance is considered as an indicator to the occurrence of faults in the generators. The behavior of the driving torque of the rotating permanent magnet with respect to the permanent magnet temperature can also utilize to indicate the operation condition. The permanent magnet model describes the rotating permanent magnet condition during operation in the normal and abnormal situations. In this context, a set of partial differential equations is devolved for the characterization of the rotations of the permanent. Finally, heat transfer analysis and fluid mechanics methods are employed to develop a suitable CMS on the wind generators by analyzing the operation conditions of the generator's heat exchanger. The proposed methods applied based on real data of different wind turbines, and the obtained results were very convincing.

  20. Adaptive Fuzzy Logic Control of Wind Turbine Emulator

    BOUZID Mohamed Amine

    2014-03-01

    Full Text Available In this paper, a Wind Turbine Emulator (WTE based on a separately excited direct current (DC motor is studied. The wind turbine was emulated by controlling the torque of the DC motor. The WTE is used as a prime mover for Permanent Magnet Synchronous Machine (PMSM. In order to extract maximum power from the wind, PI and Fuzzy controllers were tested. Simulation results are given to show performance of proposed fuzzy control system in maximum power points tracking in a wind energy conversion system under various wind conditions. The strategy control was implemented in simulation using MATLAB/Simulink.

  1. Wind Turbine Generator System Safety and Function Test Report for the Ventera VT10 Wind Turbine

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

    2012-11-01

    This report summarizes the results of a safety and function test that NREL conducted on the Ventera VT10 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.

  2. Wind Turbine Generator System Safety and Function Test Report for the Entegrity EW50 Wind Turbine

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

    2012-11-01

    This report summarizes the results of a safety and function 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.

  3. Wind tunnel tests of a free yawing downwind wind turbine

    Verelst, David Robert; Larsen, Torben J.; van Wingerden, Jan-Willem

    2014-01-01

    This research paper presents preliminary results on a behavioural study of a free yawing downwind wind turbine. A series of wind tunnel tests was performed at the TU Delft Open Jet Facility with a three bladed downwind wind turbine and a rotor radius of 0.8 meters. The setup includes an off the...

  4. Background sound levels and wind turbine noise

    This paper reviewed the regulators' approach to the challenge of establishing sound level limits in wind turbine arrays that allow for variations in background sound level with wind speed. Wind speed influences the amount of noise produced by wind turbines and also the noise associated with wind passing over terrain and through foliage. New guidelines by Ontario's Ministry of the Environment were discussed along with wind noise as a function of speed in remote locations having a variety of terrain and foliage types. It was concluded that wind induced noise can effectively mask the steady noise of wind turbine generators, especially during high wind conditions. The extent of wind induced noise depends on the local terrain, foliage and wind speed through vegetation. Masking wind turbine noise by wind induced noise in vegetation can be reduced during stable atmospheric conditions which are common at night. The extent of masking by wind induced noise depends on the level and characteristics of wind turbine noise and wind induced noise. 9 refs., 2 tabs., 2 figs

  5. Defect distribution and reliability assessment of wind turbine blades

    Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter; Sørensen, John Dalsgaard

    2011-01-01

    In this paper, two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size, based on the...... assumption that one error in the production process tends to trigger several defects. For both models, additional information, such as number, type, and size of the defects, is included as stochastic variables. In a numerical example, the reliability is estimated for a generic wind turbine blade model both...... the reliability for the wind turbine blade using Bayesian statistics....

  6. Noise annoyance from wind turbines a review

    This study summarises present knowledge on noise perception and annoyances from wind turbines in areas were people live or spend recreation time. There are two main types of noise from a wind turbine: mechanical noise and aerodynamic noise. The aerodynamic noise emits from the rotor blades passing the air. It has a swishing character with a modulation that makes it noticeable from the background noise. This part of the wind turbine noise was found to be the most annoying. Field studies performed among people living in the vicinity of wind turbines showed that there was a correlation between sound pressure level and noise annoyance, but annoyance was also influenced by visual factors such as the attitude to wind turbines' impact on the landscape. Noise annoyance was found at lower sound pressure levels than in studies of annoyance from traffic noise. There is no scientific evidence that noise at levels created by wind turbines could cause health problems other than annoyance. No studies on noise from wind turbines in wilderness areas have been found, but the reaction to other noise sources such as aircraft have been studied. In recreational areas, the expectation of quietness is high among visitors, but wind turbines are, in contrary to aircraft, stationary and could be avoided by recreationists. The visual impact of wind turbines might though be the dominant source of annoyance. Regulations on noise from wind turbines are based on different principles. Some states, e.g. Denmark, have a special legislation concerning wind turbines, while others, like Sweden, have used recommendations originally developed for a different noise source. The noise level could either be absolute, as in Germany, or related to the background noise level as in France. This background noise level could be standardised, measured or related to wind speed

  7. Mechanical noise from wind turbines

    Community annoyance due to noise from wind turbines is often the result of noise character rather than level. Although the overall contributions from each of the two main classes of noise source, namely aerodynamic and mechanical, are often of a similar order for an untreated turbine, it is usually the mechanical sources which provide the dominant noise characteristics that may lead to annoyance. In this paper, the sources of mechanical noise are identified primarily with reference to HAWTs and then attention is concentrated on the rotor-shaft step-up gearbox, which is normally the top-ranking source. The major gearbox noise mechanisms and transmission paths are discussed and reference made to Noise Specifications and procedures applicable to the gearbox prior to its installation. The reduction of machinery noise is reviewed both at source and by treatment of transmission paths. (author)

  8. Operation and control of large wind turbines and wind farms

    Soerensen, Poul; Hansen, Anca D.; Thomsen, Kenneth (and others)

    2005-09-01

    This report is the final report of a Danish research project 'Operation and control of large wind turbines and wind farms'. The objective of the project has been to analyse and assess operational strategies and possibilities for control of different types of wind turbines and different wind farm concepts. The potentials of optimising the lifetime/energy production ratio by means of using revised operational strategies for the individual wind turbines are investigated. Different strategies have been simulated, where the power production is decreased to an optimum when taking loads and actual price of produced electricity into account. Dynamic models and control strategies for the wind farms have also been developed, with the aim to optimise the operation of the wind farms considering participation in power system control of power (frequency) and reactive power (voltage), maximise power production, keep good power quality and limit mechanical loads and life time consumption. The project developed models for 3 different concepts for wind farms. Two of the concepts use active stall controlled wind turbines, one with AC connection and one with modern HVDC/VSC connection of the wind farm. The third concept is based on pitch controlled wind turbines using doubly fed induction generators. The models were applied to simulate the behaviour of the wind farm control when they were connected to a strong grid, and some initial simulations were performed to study the behaviour of the wind farms when it was isolated from the main grid on a local grid. Also the possibility to use the available information from the wind turbine controllers to predict the wind speed has been investigated. The main idea has been to predict the wind speed at a wind turbine using up-wind measurements of the wind speed in another wind turbine. (au)

  9. Spatial planning of wind turbines

    NONE

    2004-01-01

    This paper proposes guidelines for spatial planning for wind power, based on experience with spatial planning in Belgium, Denmark, France and the Netherlands. In addition experiences from Germany and Ireland have been used. This guidelines quotes all decisive criteria for successful implementation of wind energy: landscape integration, stakeholders involvement, noise and distance from buildings. (author)

  10. Unified Model of Multiple Wind Turbines

    Mutule, A.; Kochukov, O.

    2014-08-01

    An approach is proposed to the modelling of wind farms in the electric power system long-term planning. It allows a specialist to perform calculations based on scanty information and offers a set of ready-to-use data for easy, fast, and precise modelling. The authors exemplify the calculations of wind speed probability density and power curves and give an idea for relevant corrections. They also show how to pass from a single wind turbine model to the unified model of multiple wind turbines which would meet the requirements of long-term planning tasks. The paper presents the data on wind farms that are operating in UK and Oceania Rakst? ir apskat?ta v?ja elektrostaciju model?šana ilgtermi?a att?st?bas pl?nošanas uzdevumos. Model?šana tika veikta, izmantojot ierobežotu datu apjomu, kuri bija piejami lietot?jam. Gatavie dati deva iesp?ju veikt ?tru un prec?zu model?šanu. Raksts pied?va metodi k? p?riet no viena v?ja ?eneratora modeli uz v?ja elektrostaciju (vair?ki v?ja ?eneratori) modeli, kas atbilst ilgtermi?a att?st?bas pl?nošanas pras?b?m. Rakst? atspogu?oti dati no Oke?nijas un Lielbrit?nijas eksist?još?m v?ja elektrostacij?m

  11. Structured Linear Parameter Varying Control of Wind Turbines

    Adegas, Fabiano Daher; Sloth, Christoffer; Stoustrup, Jakob

    presented. We specifically consider variable-speed, variable-pitch wind turbines with faults on actuators and sensors. Linear parameter-varying (LPV) controllers can be designed by a proposed method that allows the inclusion of faults in the LPV controller design. Moreover, the controller structure can be...... arbitrarily chosen: static output feedback, dynamic (reduced order) output feedback, decentralized, among others. The controllers are scheduled on an estimated wind speed to manage the parametervarying nature of the model and on information from a fault diagnosis system. The optimization problems involved in......High performance and reliability are required for wind turbines to be competitive within the energy market. To capture their nonlinear behavior, wind turbines are often modeled using parameter-varying models. In this chapter, a framework for modelling and controller design of wind turbines is...

  12. Implementation of Pitch Control Of wind Turbine Using Simulink (Matlab

    Sachin Khajuria, Jaspreet Kaur

    2012-06-01

    Full Text Available In this paper, it is shown that how the variable speed wind turbine can be used to generate a fixed value of voltage at the output with the help of a pi controller and it is done by varying the pitch angle of the blades Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind speed is above rated speed and various controlling variables may be chosen, such as wind speed, generator speed and generator power. As conventional pitch control usually use PI controller, the mathematical model of the system should be known well. The block diagram of the proposed speed control system which consists of speed controller, actuator model and the turbine linearized model is simulated by Matlab-Simulink software package. the simulation results show that the controller accurately adjusts the blade pitch angle to set the wind turbine power output to its reference value.

  13. Grid fault and design-basis for wind turbines - Final report

    Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Markou, Helen; Sørensen, Poul Ejnar; Iov, Florin

    models and different fault ride-through control strategies have been developed and assessed in this project for three different wind turbine concepts (active stall wind turbine, variable speed doublyfed induction generator wind turbine, variable speed multipole permanent magnet wind turbine). A computer...... fulfillment of the grid connection requirements poses challenges for the design of both the electrical system and the mechanical structure of wind turbines. The development of wind turbine models and novel control strategies to fulfill the TSO’s requirements are of vital importance in this design. Dynamic...... approach for the quantification of the wind turbines structural loads caused by the fault ride-through grid requirement, has been proposed and exemplified for the case of an active stall wind turbine. This approach relies on the combination of knowledge from complimentary simulation tools, which have...

  14. Seaside, mountain and... wind turbines

    Several courts have given a ruling considering that the law 'Montagne' (January 9., 1985) and the law 'Littoral' (January 3., 1986) are opposable to the building license of wind turbines. The law 'Littoral' imposes that any new construction in seaside areas has to be built in continuity of existing villages or hamlets. The law 'Montagne' imposes similar constraints to avoid the construction of isolated buildings in mountain areas but, contrary to the law 'Littoral', it allows some impairment for instance for the construction of certain public equipment. (A.C.)

  15. Flexible wind turbines. Flexibele molens

    van der Veld, P.J.

    1983-01-01

    Wind turbines are subject to strong and suddenly fluctuating forces, on special parts of the construction (blade root, axis, hub, mast). This requires sophisticated concepts and special, preferable fibrous, materials. Flexible materials and hingeing constructions and vibration-breaking systems are used widely. Some remarkable concepts are to be mentioned. In some cases the mast as a whole is movable and even turnable around a vertical axis, thus absorbing dangerous forces and also permitting the nacelle to be fixed to the mast. Rotors are designed where the blades are hingeing not at or very near the hub, but at a certain distance from it.

  16. Actuator Control of Edgewise Vibrations in Wind Turbine Blades

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

    2012-01-01

    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......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...... 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...

  17. Anisotropy of turbulence in wind turbine wakes

    Gomez-Elvira, Rafael [Comision Nacional de Energia (Spain); Crespo, Antonio; Migoya, Emilio; Manuel, Fernando [Departamento de Ingenieria Energetica y Fluidomecanica, Escuela Tecnica Superior de Ingenieros Industriales, Universidad Politecnica de Madrid, Jose Gutierrez Abascal, 2. 28006 Madrid (Spain); Hernandez, Julio [Departamento de Mecanica, ETSII, Universidad Nacional de Educacion a Distancia, Ciudad Universitaria, 28040 Madrid (Spain)

    2005-10-01

    This work is mainly dedicated to the study of non-isotropic characteristics of turbulence in wind turbine wakes, specifically the shear layer of the near wake. A calculation method based on an explicit algebraic model for the components of the turbulent stress tensor is proposed, and the results are found to be in acceptable agreement with experimental results. Analytical expressions for the estimation of an upper limit of the global turbulence kinetic energy, k, and the individual contributions of each diagonal term in the turbulent stress tensor are proposed. Their predictions are compared with experimental results.

  18. Mitigation of Wind Power Fluctuation by Active Current Control of Variable Speed Wind Turbines

    Zhang, Yunqian; Chen, Zhe; Hu, Weihao; Cheng, Ming

    2013-01-01

    Wind shear and tower shadow are the sources of power fluctuation of grid connected wind turbines during continuous operation. This paper presents a simulation model of a MW-level doubly fed induction generator (DFIG) based variable speed wind turbine with a partial-scale back-to-back power...... converter in Simulink. A simple and effective method of wind power fluctuations mitigation by active current control of DFIG is proposed. It smoothes the generator output active power oscillations by adjusting the active current of the DFIG, such that the power oscillation is stored as the kinetic energy of...... the wind turbine. The simulations are performed on the NREL 1.5MW upwind reference wind turbine model. The simulation results are presented and discussed to demonstrate the validity of the proposed control method....

  19. Fuzzy regulator design for wind turbine yaw control.

    Theodoropoulos, Stefanos; Kandris, Dionisis; Samarakou, Maria; Koulouras, Grigorios

    2014-01-01

    This paper proposes the development of an advanced fuzzy logic controller which aims to perform intelligent automatic control of the yaw movement of wind turbines. The specific fuzzy controller takes into account both the wind velocity and the acceptable yaw error correlation in order to achieve maximum performance efficacy. In this way, the proposed yaw control system is remarkably adaptive to the existing conditions. In this way, the wind turbine is enabled to retain its power output close to its nominal value and at the same time preserve its yaw system from pointless movement. Thorough simulation tests evaluate the proposed system effectiveness. PMID:24693237

  20. Design Mining Interacting Wind Turbines.

    Preen, Richard J; Bull, Larry

    2016-01-01

    An initial study has recently been presented of surrogate-assisted evolutionary algorithms used to design vertical-axis wind turbines wherein candidate prototypes are evaluated under fan-generated wind conditions after being physically instantiated by a 3D printer. Unlike other approaches, such as computational fluid dynamics simulations, no mathematical formulations were used and no model assumptions were made. This paper extends that work by exploring alternative surrogate modelling and evolutionary techniques. The accuracy of various modelling algorithms used to estimate the fitness of evaluated individuals from the initial experiments is compared. The effect of temporally windowing surrogate model training samples is explored. A surrogate-assisted approach based on an enhanced local search is introduced; and alternative coevolution collaboration schemes are examined. PMID:25635699

  1. Preliminary modelling study of ice accretion on wind turbines

    Pedersen, Marie Cecilie; Yin, Chungen

    2014-01-01

    icing events. In this paper, a new methodology for prediction of icing-induced production loss is proposed, from which the fundamentals of ice accretion on wind turbines can be better understood and the operational production losses can be more reliably predicted. Computational fluid dynamics (CFD......) modelling of ice accretion on wind turbines is also performed for different ice events, resulting in a reliable framework for CFD-based ice accretion modelling which is one of the key elements in the new methodology....

  2. Aerodynamic interference between two Darrieus wind turbines

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

    1981-04-01

    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 tipspeed ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.

  3. Wind turbines fundamentals, technologies, application, economics

    Hau, Erich

    2013-01-01

    "Wind Turbines" addresses all those professionally involved in research, development, manufacture and operation of wind turbines. It provides a cross-disciplinary overview of modern wind turbine technology and an orientation in the associated technical, economic and environmental fields.  In its revised third edition, special emphasis has been given to the latest trends in wind turbine technology and design, such as gearless drive train concepts, as well as on new fields of application, in particular the offshore utilisation of wind energy. The author has gained experience over decades designing wind energy converters with a major industrial manufacturer and, more recently, in technical consulting and in the planning of large wind park installations, with special attention to economics.

  4. Tjæreborg Wind Turbine (Esbjerg)

    Øye, Stig

    1991-01-01

    This paper presents the first measured timeseries for the Tjæreborg (Tjaereborg) Wind Turbine during operation with stepwise pitch angle changes.......This paper presents the first measured timeseries for the Tjæreborg (Tjaereborg) Wind Turbine during operation with stepwise pitch angle changes....

  5. Dynamic Phase Compensation of wind turbines

    Soerensen, P.; Skaarup, J.; Iov, Florin

    2004-01-01

    This paper describes a dynamic phase compensation unit for a wind turbine with directly connected induction generators. The compensation unit is based on thyristor switched capacitors, where conventional wind turbine compensations use mechanical contactors to switch the capacitors. The unit modules...

  6. Voltage Quality of Grid Connected Wind Turbines

    Chen, Zhe; Blaabjerg, Frede; Sun, Tao

    Grid connected wind turbines may cause quality problems, such as voltage variation and flicker. This paper discusses the voltage variation and flicker emission of grid connected wind turbines with doubly-fed induction generators. A method to compensate flicker by using a voltage source converter...

  7. Advanced Wind Turbine Drivetrain Concepts. Workshop Report

    none,

    2010-12-01

    This report presents key findings from the Department of Energy’s Advanced Drivetrain Workshop, held on June 29-30, 2010, to assess different advanced drivetrain technologies, their relative potential to improve the state-of-the-art in wind turbine drivetrains, and the scope of research and development needed for their commercialization in wind turbine applications.

  8. Lightning protection system for a wind turbine

    Costin, Daniel P.; Petter, Jeffrey K.

    2008-05-27

    In a wind turbine (104, 500, 704) having a plurality of blades (132, 404, 516, 744) and a blade rotor hub (120, 712), a lightning protection system (100, 504, 700) for conducting lightning strikes to any one of the blades and the region surrounding the blade hub along a path around the blade hub and critical components of the wind turbine, such as the generator (112, 716), gearbox (708) and main turbine bearings (176, 724).

  9. Small power wind turbine (Type DARRIEUS

    Marcel STERE

    2012-03-01

    Full Text Available This presentation focuses on the calculation for small vertical axis wind turbines (VAWT for an urban application. The fixed-pitch straight – bladed vertical axis wind turbine (SB-VAWT is one of the simplest types of wind turbine and accepts wind from any angle (no yaw system. This turbine is useful for moderate wind speeds (3 - 6 m/s. A case study is presented based upon the use of well documented symmetrical NACA 0012 turbine blade profile. We describe a solution for VAWT. To perform a linear static analysis in the structure, the commercial finite element analysis code ANSYS is used because of its flexibility for handling information in files written in a more or less free format.

  10. Superconductivity for Large Scale Wind Turbines

    R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth

    2012-10-12

    A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.

  11. Damping Wind and Wave Loads on a Floating Wind Turbine

    Torben Knudsen; Søren Christiansen; Thomas Bak

    2013-01-01

    Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due to the partly unconstrained movement of the platform and ocean wave excitation. If this additional complexity is not dealt with properly, this may lead to a significant increase in the structural loads ...

  12. Site matching study of pitch-controlled wind turbine generator

    Highlights: • The suitability between wind turbine and site is studied based on Weibull function. • A given pitch-controlled wind turbine is selected as an example. • Wire-frame graphs for capacity factor and performance index are illustrated. • There exist some critical points on both kinds of curves. - Abstract: In wind energy utilization the capacity factor and turbine performance index are commonly applied to evaluate a turbine generator’s efficiency. In this paper, a modified turbine performance index is presented to study the suitability problem between wind site and wind turbine based on the Weibull probability function. Firstly four sets of wind speeds randomly generated by computer with given Weibull shape and scale parameters are illustrated to show the effects of the Weibull parameters on wind speed distributions. Further considering a pitch-controlled turbine generator with given operation speeds, the wire-frame graphs for both the capacity factor and performance index are shown for various shape parameters from 1 to 5, and scale parameters from 1 to 25 m/s. For a common case of shape parameter 2, the maximum capacity factor is about 0.56 while the maximum performance index is 0.38 at scale parameter near 17 m/s. There exist some critical points on both kinds of curves at different scale parameters. Wind characteristics collected from 23 sites are considered as examples to show the basic idea of the paper. Through the manner proposed, the engineer could make the best match for wind site and turbine in wind energy application

  13. Wind turbines - generating noise or electricity?

    Wind turbine technology has made great strides in the past few years. Annual energy output is up by two orders of magnitude and nacelle weight and noise has been halved. Computational fluid dynamics has paid a part in advancing knowledge of air flow and turbulence around wind generators. Current research is focused on how to increase turbine size and improve efficiency. A problem is that while larger wind turbines will produce cheaper electricity, the noise problem will mean that the number of acceptable sites will decrease. The biggest wind generators will need about 800 m clearance from the nearest house. (UK)

  14. Performance assessment of a small wind turbine with crossflow runner by numerical simulations

    Dragomirescu, A. [University Politehnica of Bucharest, Department of Hydraulics, Hydraulic Machinery and Environmental Engineering, Splaiul Independentei 313, 060042 Bucharest (Romania)

    2011-03-15

    Most of the classical wind turbines are not able to start at wind speeds as low as 2-3 m/s. Other turbines, like Savonius, have a low maximum efficiency, which renders them useless in poor wind conditions. Therefore, new turbine designs are required to harvest wind power even when the wind speed is low. A wind turbine having a crossflow runner, similar to the Banki water turbine, is studied numerically in this work in order to estimate its performance. The results obtained suggest that this turbine has a considerable high starting torque and its maximum power coefficient is comparable to those of horizontal axis wind turbines. Based on the results obtained, some improvements of the design are proposed in order to further increase turbine performance. (author)

  15. Urban wind turbines. Guidelines for small wind turbines in the built environment

    The objective of the WINEUR project (Wind Energy Integration in the Urban Environment) is to determine the deployability of small wind turbines in built environments while identifying the current significant constraints and possible solutions. The purpose of this document is to Inform the stakeholders about the state of the development of small wind turbines for the built environment; Provide practical guidelines to actors dealing with installation of small wind turbines in urban areas; and Provide recommendations for future products and for market development

  16. The small wind turbine field lab extensive field tests for small wind turbines

    Van Wyngene, Karel; Laveyne, Joannes; Kooning, Jeroen De; Stockman, Kurt; Sergeant, Peter; Van Paepegem, Wim; Botteldooren, Dick; De Maeyer, Jeroen; Van Eetvelde, Greet; Vandevelde, Lieven

    2013-01-01

    This paper describes the research possibilities at the Small Wind Turbine Field Lab and the involved research groups of Ghent University, covering different aspects of a small wind energy system. In contrast to large and medium-sized wind turbines, small wind turbines are still plagued by relatively high production and purchase costs, and low reliability and energy yield. Furthermore, most of them have not been subjected to a field test program. Power-Link, the energy knowledge platform of Gh...

  17. Adaptive Extremum Control and Wind Turbine Control

    Ma, Xin

    1997-01-01

    This thesis is divided into two parts, i.e., adaptive extremum control and modelling and control of a wind turbine. The rst part of the thesis deals with the design of adaptive extremum controllers for some processes which have the behaviour that process should have as high e ciency as possible...... parameters, and thus directly lends itself to parameter estimation and adaptive control. The extremum control law is derived based on static optimization of a performance function. For a process with nonlinearity at output the intermediate signal between the linear part and nonlinear part plays an important...... role. If it can be emphasis on control design. The models have beenvalidated by experimental data obtained from an existing wind turbine. The e ective wind speed experienced by the rotor of a wind turbine, which is often required by some control methods, is estimated by using a wind turbine as a wind...

  18. Illustration of Modern Wind Turbine Ancillary Services

    Margaris, Ioannis D.; Hansen, Anca Daniela; Sørensen, Poul Ejnar; Hatziargyriou, Nikolaos D.

    2010-01-01

    turbines replace conventional units on the production side. This article includes a review of the basic control issues regarding the capability of the Doubly Fed Induction Generator (DFIG) wind turbine configuration to fulfill the basic technical requirements set by the system operators and contribute to......Increasing levels of wind power penetration in modern power systems has set intensively high standards with respect to wind turbine technology during the last years. Security issues have become rather critical and operation of wind farms as conventional power plants is becoming a necessity as wind...... power system security. An overview of ancillary services provided by wind turbine technology nowadays is provided, i.e., fault ride-through capability, reactive power supply and frequency-active power control....

  19. Illustration of Modern Wind Turbine Ancillary Services

    Ioannis D. Margaris

    2010-06-01

    Full Text Available Increasing levels of wind power penetration in modern power systems has set intensively high standards with respect to wind turbine technology during the last years. Security issues have become rather critical and operation of wind farms as conventional power plants is becoming a necessity as wind turbines replace conventional units on the production side. This article includes a review of the basic control issues regarding the capability of the Doubly Fed Induction Generator (DFIG wind turbine configuration to fulfill the basic technical requirements set by the system operators and contribute to power system security. An overview of ancillary services provided by wind turbine technology nowadays is provided, i.e., fault ride-through capability, reactive power supply and frequency-active power control.

  20. Meteorological aspects of siting large wind turbines

    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.

  1. Turbulence in vertical axis wind turbine canopies

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  2. Adaptive Robust Control of Variable Speed Wind Turbine Generator

    Ahmad Zare

    2015-09-01

    Full Text Available In this work we want to propose a control strategy to maximize the wind energy captured in a variable speed wind turbines, for this goal the speed of turbine should keep in optimum speed when the wind speed is changing. Many control approach has been suggested that is base on approximate models that it causes unsuitable behavior of system because of Uncertainty parameters of the system. Hence at this work we use adaptive robust control approach that it can to compensate Uncertain of the parameters and present a smooth system with maximum energy production. Numerical simulations are given to illustrate the effectiveness and validity of the proposed approach.

  3. Offshore wind turbines reliability, availability and maintenance

    Tavner, Peter

    2012-01-01

    The first book to specifically focus on offshore wind turbine technology and which addresses practically wind turbine reliability and availability. The book draws on the author's experience of power generation reliability and availability and the condition monitoring of that plant to describe the problems facing the developers of offshore wind farms and the solutions available to them to raise availability, reduce cost of energy and improve through life cost.

  4. A Wind-Turbine Power Curve Approach

    Noergaard, Per [Risoe National Laboratory, Roskilde (Denmark); Holttinen, Hannele [VTT (Finland)

    2004-07-01

    A simple methodology is described - the multi-turbine power curve approach - a methodology to generate a qualified estimate of the time series of the aggregated power generation from planned wind turbine units distributed in an area where limited wind time series are available. This is often the situation in a planning phase where you want to simulate planned expansions in a power system with wind power. The methodology is described in a step-by- step guideline.

  5. Low frequency noise and wind turbines

    Concerns have been raised in the UK that noise radiated from wind Turbines contains sufficiently high levels of low frequency energy that may pose a threat to human health. It was suggested that symptoms included nausea, headaches and anxiety. This document, issued by the British Wind Energy Association (BWEA), provides information on the issue of low frequency noise and wind turbines, based on current knowledge. (author)

  6. Analysis and estimation of transient stability for a grid-connected wind turbine with induction generator

    Li, H.; Zhao, B.; Yang, C.; Chen, H. W.; Chen, Z.

    2011-01-01

    grid-connected wind turbine with squirrel cage induction generator (SCIG). Firstly, by using an equivalent lump mass method, a three-mass wind turbine equivalent model is proposed considering both the blades and the shaft flexibility of the wind turbine drive train system. Combined with the detailed...... electromagnetic transient models of a SCIG, the transient behaviors of the wind turbine generation system during a three-phase fault are simulated and compared with the traditional models. Secondly, in order to quickly estimate the transient stability limit of the wind turbine generation system, a direct method...

  7. Wind Turbine Wake-Redirection Control at the Fishermen's Atlantic City Windfarm: Preprint

    Churchfield, M.; Fleming, P.; Bulder, B.; White, S.

    2015-05-06

    In this paper, we will present our work towards designing a control strategy to mitigate wind turbine wake effects by redirecting the wakes, specifically applied to the Fishermen’s Atlantic City Windfarm (FACW), proposed for deployment off the shore of Atlantic City, New Jersey. As wind turbines extract energy from the air, they create low-speed wakes that extend behind them. Full wake recovery Full wake recovery to the undisturbed wind speed takes a significant distance. In a wind energy plant the wakes of upstream turbines may travel downstream to the next row of turbines, effectively subjecting them to lower wind speeds, meaning these waked turbines will produce less power.

  8. Analysis of the Environmental Impact on Remanufacturing Wind Turbines

    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.

  9. A Two-Bladed Concept Wind Turbine

    Kim, Taeseong

    This article shows the potential for reducing extreme loads with an innovative design of wind turbine, a partial pitch two-bladed concept turbine. The most extreme conditions to test a turbine are considered to be stand-still combined with a grid failure in which the wind comes from all directions...... from 0 to 360 degrees. All aeroelastic load simulations are done by using the aeroelastic code HAWC2. From the load comparisons between the partial pitch two-bladed turbine and a conventional three-bladed turbine it is observed that the partial pitch two-bladed turbine can reduce the extreme tower...... bottom bending moment by approximately 33% compared to the three-bladed turbine....

  10. Structural Reliability Aspects in Design of Wind Turbines

    Sørensen, John Dalsgaard

    2007-01-01

    Reliability assessment, optimal design and optimal operation and maintenance of wind turbines are an area of significant interest for the fast growing wind turbine industry for sustainable production of energy. Offshore wind turbines in wind farms give special problems due to wake effects inside the farm. Reliability analysis and optimization of wind turbines require that the special conditions for wind turbine operation are taken into account. Control of the blades implies load reductions fo...

  11. Structural Reliability of Wind Turbine Blades

    Dimitrov, Nikolay Krasimirov

    turbine blades. The main purpose is to draw a clear picture of how reliability-based design of wind turbines can be done in practice. The objectives of the thesis are to create methodologies for efficient reliability assessment of composite materials and composite wind turbine blades, and to map the...... detailed demonstration of the process of estimating the reliability of a wind turbine blade and blade components, a number of probabilistic load and strength models are formulated, and the following scientific and practical questions are answered: a) What material, load and uncertainty models need to be...... partial safety factors against a target reliability level. The main conclusions from the thesis are that a) the problem of estimating the reliability of wind turbine blades has been addressed in detail, and suitable methodologies for carrying efficient and robust reliability analysis have been identified...

  12. Influence of refraction on wind turbine noise

    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.

  13. Resonances and Aerodynamic Damping of a Vertical Axis Wind Turbine

    Ottermo, Fredric; Bernhoff, Hans

    2012-01-01

    The dynamics of a straight-bladed vertical axis wind turbine is investigated with respect to oscillations due to the elasticity of struts and shaft connecting to the hub. In particular, for the three-bladed turbine, a concept is proposed for dimensioning the turbine to maximize the size of the resonance free rpm range for operation. The effect of aerodynamic damping on the struts is also considered. The damping of these types of oscillations for a typical turbine is found to be good.

  14. Condition Monitoring of Offshore Wind Turbines

    Wisznia, Roman

    2013-01-01

    The growing interest around offshore wind power, providing at the same time better wind conditions and fewer visual or environmental impacts, has lead many energy suppliers to consider the installation of offshore wind farms. However, the marine environment makes the installation and maintenance of wind turbines much more complicated, raising the capital and operation costs to an undesirable level and preventing the fast progression of this technology worldwide. Availability of offshore wind ...

  15. European wind turbine standards 2 (EWTS-2)

    Pierik, J.T.G.; Dekker, J.W.M.; Braam, H. [and others

    1999-03-01

    A summary is given of the main results of the European Wind Turbine Standards II project. EWTS-II was completed in 1998 and included investigations on: 1) wind farms-wind field and turbine loading; 2) complex terrain and fatigue loading; 3) extreme wind conditions; 4) quantification of failure probabilities; 5) integration of blade tests in design; 6) power performance in complex terrain; 7) site evaluation. In addition to these scientific evaluations, the EWTS-II participants established an organization of qualified measuring institute in the field of wind energy, the MEASNET organization. MEASNET unified measurement procedures of the participating institutes and guarantees qualified measurements and mutual acceptance among its members. (LN)

  16. Composite materials for wind power turbine blades

    Brøndsted, P.; Lilholt, H.; Lystrup, Aa.

    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...... procedures for documentation of properties are reviewed, and fatigue loading histories are discussed, together with methods for data handling and statistical analysis of (large) amounts of test data. Future challenges for materials in the field of wind turbines are presented, with a focus on thermoplastic...... composites, new structural materials concepts, new structural design aspects, structural health monitoring, and the coming trends and markets for wind energy....

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

    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.

  18. Wind Turbine Noise and Natural Sounds: Masking, Propagation and Modeling

    Bolin, Karl

    2009-05-15

    Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. Ambient sounds influence the audibility of wind turbine noise. Models for assessing two commonly occurring natural ambient sounds namely vegetation sound and sound from breaking waves are presented in paper A and B. A sound propagation algorithm has been compared to long range measurements of sound propagation in paper C. Psycho-acoustic tests evaluating the threshold and partial loudness of wind turbine noise when mixed with natural ambient sounds have been performed. These are accounted for in paper D. The main scientific contributions are the following.Paper A: A semi-empiric prediction model for vegetation sound is proposed. This model uses up-to-date simulations of wind profiles and turbulent wind fields to estimate sound from vegetation. The fluctuations due to turbulence are satisfactory estimated by the model. Predictions of vegetation sound also show good agreement to measured spectra. Paper B: A set of measurements of air-borne sound from breaking waves are reported. From these measurements a prediction method of sound from breaking waves is proposed. Third octave spectra from breaking waves are shown to depend on breaker type. Satisfactory agreement between predictions and measurements has been achieved. Paper C: Long range sound propagation over a sea surface was investigated. Measurements of sound transmission were coordinated with local meteorological measurements. A sound propagation algorithm has been compared to the measured sound transmission. Satisfactory agreement between measurements and predictions were achieved when turbulence were taken into consideration in the computations. Paper D: The paper investigates the interaction between wind turbine noise and natural ambient noise. Two loudness models overestimate the masking from two psychoacoustic tests. The wind turbine noise is completely concealed when the ambient sound level (A-weighed) is around 10 dB higher than the wind turbine noise level. Wind turbine noise and ambient noise were presented simultaneously at the same A-weighed sound level. The subjects then perceived the loudness of the wind turbine noise as 5 dB lower than if heard alone

  19. Active load control techniques for wind turbines.

    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.

  20. An investigation on wind turbine resonant vibrations

    Tibaldi, Carlo; Kim, Taeseong; Larsen, Torben J.; Rasmussen, Flemming; Rocca Serra, R. de; Sanz, F.

    2016-01-01

    frequencies at which minimal excitation should be present during operations. The study shows that significant edgewise blade vibrations can occur on modern wind turbines even if the aeroelastic damping of the edgewise modes is positive. When operating close to resonant conditions, small differences in the...... aeroelastic modes can be excited. The investigation is performed using aeroelastic models corresponding to a 1.5 MW class wind turbine with slight variations in blade properties. Copyright © 2015 John Wiley & Sons, Ltd.......Wind turbine resonant vibrations are investigated based on aeroelastic simulations both in frequency and time domain. The investigation focuses on three different aspects: the need of a precise modeling when a wind turbine is operating close to resonant conditions; the importance of estimating wind...

  1. Model of wind shear conditional on turbulence and its impact on wind turbine loads

    Dimitrov, Nikolay Krasimirov; Natarajan, Anand; Kelly, Mark C.

    2015-01-01

    is most pronounced on the blade flap loads. It is further shown that under moderate wind turbulence, the wind shear exponents may be over-specified in the design standards, and a reduction of wind shear exponent based on the present measurements can contribute to reduced fatigue damage equivalent......We analyse high-frequency wind velocity measurements from two test stations over a period of several years and at heights ranging from 60 to 200 m, with the objective to validate wind shear predictions as used in load simulations for wind turbine design. A validated wind shear model is thereby...... proposed for flat terrain and that can significantly decrease the uncertainty associated with fatigue load predictions for wind turbines with large rotors. An essential contribution is the conditioning of wind shear on the 90% quantile of wind turbulence, such that the appropriate magnitude of the design...

  2. Grid support capabilities of wind turbines

    Michalke, Gabriele; Hansen, Anca Daniela

    Wind power has gained a significant penetration level in several power systems all over the world. Due to this reason modern wind turbines are requested to contribute to power system support. Power system operators have thus introduced grid codes, which specify a set of requirements for wind turb...

  3. Basic rotor aerodynamics applied to wind turbines

    Hansen, M.O.L.

    1998-01-01

    It is the hope of the author that the notes will impart a basic understanding of the mechanisms behind the production of forces on a wind turbine. Even though aero-elastic codes, including a standard Blade Element Momentum method, can be bought, it is considered important that the theory behind this method and its limitations is understood. The aerodynamics of a wind turbine is important, but building a wind turbine is a multi disciplinary task since it requires knowledge of meteorology, atmospheric turbulence, fluid mechanics, structural dynamics, generators, electrical grid connections, gear boxes, hydraulics, foundations, economics and so on. (au) 14 refs.

  4. Applied modal analysis of wind turbine blades

    Pedersen, H.B.; Kristensen, O.J.D.

    2003-01-01

    In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Differentequipment for mounting the accelerometers are...... unloaded wind turbine blade. During this campaign the modal analysis are performed on ablade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Øyes blade_EV1...

  5. Site specific optimization of wind turbines energy cost: Iterative approach

    Highlights: • Optimization model of wind turbine parameters plus rectangular farm layout is developed. • Results show that levelized cost for single turbine fluctuates between 46.6 and 54.5 $/MW h. • Modeling results for two specific farms reported optimal sizing and farm layout. • Results show that levelized cost of the wind farms fluctuates between 45.8 and 67.2 $/MW h. - Abstract: The present study was aimed at developing a model to optimize the sizing parameters and farm layout of wind turbines according to the wind resource and economic aspects. The proposed model, including aerodynamic, economic and optimization sub-models, is used to achieve minimum levelized cost of electricity. The blade element momentum theory is utilized for aerodynamic modeling of pitch-regulated horizontal axis wind turbines. Also, a comprehensive cost model including capital costs of all turbine components is considered. An iterative approach is used to develop the optimization model. The modeling results are presented for three potential regions in Iran: Khaf, Ahar and Manjil. The optimum configurations and sizing for a single turbine with minimum levelized cost of electricity are presented. The optimal cost of energy for one turbine is calculated about 46.7, 54.5 and 46.6 dollars per MW h in the studied sites, respectively. In addition, optimal size of turbines, annual electricity production, capital cost, and wind farm layout for two different rectangular and square shaped farms in the proposed areas have been recognized. According to the results, optimal system configuration corresponds to minimum levelized cost of electricity about 45.8 to 67.2 dollars per MW h in the studied wind farms

  6. Optimization and Control of a Variable Speed Wind Turbine with a Permanent Magnet Synchronous Generator

    Satyam Kumar Upadhyay#[1] , Sudhanshu Tripathi#[2] , Neeraj singh#[3] , Gaurav Srivastava

    2013-01-01

    The aim of this paper is to propose a control strategy and also analyse a fairly typical configuration of a wind turbine generating system connected with permanent magnet synchronous generator under varying speed. To reduce output power variations in wind turbine generating system, pitch angle controller of wind turbine has been used broadly. When the wind speed crosses the rated speed pitch angle controller become s active and control the power and speed to their rated values. To obtain this...

  7. Wave Disturbance Reduction of a Floating Wind Turbine Using a Reference Model-based Predictive Control

    Christiansen, Søren; Tabatabaeipour, Seyed Mojtaba; Bak, Thomas; Knudsen, Torben

    2013-01-01

    Floating wind turbines are considered as a new and promising solution for reaching higher wind resources beyond the water depth restriction of monopile wind turbines. But on a floating structure, the wave-induced loads significantly increase the oscillations of the structure. Furthermore, using a controller designed for an onshore wind turbine yields instability in the fore-aft rotation. In this paper, we propose a general framework, where a reference model models the desired closed-loop beha...

  8. Improving the Power Quality of Six Parallel Operated Onshore Wind Turbines using UPFC

    N. Archana; R. Vidhyapriya

    2015-01-01

    This study is aimed at improving the power quality of an onshore wind turbine connected to the grid, using a Unified Power Factor Controller. A six parallel operated onshore wind turbine is used as a model to demonstrate the effectiveness of the proposed system. The wind generating system consists of doubly fed induction generator connected to the wind turbine. An average model of the doubly fed induction generator is used and the control signals are generated using closed loop control. The u...

  9. Multimodel Modeling and Predictive Control for Direct-Drive Wind Turbine with Permanent Magnet Synchronous Generator

    Wang, Lei; Shen, Tao; Chen, Chen

    2014-01-01

    The safety and reliability of the wind turbines wholly depend on the completeness and reliability of the control system which is an important problem for the validity of the wind energy conversion systems (WECSs). A method based on multimodel modeling and predictive control is proposed for the optimal operation of direct-drive wind turbine with permanent magnet synchronous generator in this paper. In this strategy, wind turbine with direct-drive permanent magnet synchronous generator is model...

  10. Integrated analysis of wind turbines - The impact of power systems on wind turbine design

    Barahona Garzón, Braulio; Sørensen, Poul Ejnar; Hansen, Anders Melchior; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio

    2012-01-01

    Megawatt-size wind turbines nowadays operate in very complex environmental conditions, and increasingly demanding power system requirements. Pursuing a cost-effective and reliable wind turbine design is a multidisciplinary task. However nowadays, wind turbine design and research areas such as aeroelastic and mechanical, electrical and control, and grid integration, make use of simulation tools dedicated to specific areas. Practical experience shows there is a need to bridge the expertise from...

  11. Power Electronics for the Next Generation Wind Turbine System

    Ma, Ke

    This book presents recent studies on the power electronics used for the next generation wind turbine system. Some criteria and tools for evaluating and improving the critical performances of the wind power converters have been proposed and established. The book addresses some emerging problems as...... well as possibilities for the wind power conversion, and may be useful as an inspiring reference for the researchers in this field....

  12. Damage tolerance and structural monitoring for wind turbine blades.

    McGugan, M; Pereira, G; Sørensen, B F; Toftegaard, H; Branner, K

    2015-02-28

    The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective exploitation of offshore wind. PMID:25583858

  13. Damage tolerance and structural monitoring for wind turbine blades

    McGugan, Malcolm; Pereira, Gilmar Ferreira; Sørensen, Bent F.; Toftegaard, Helmuth Langmaack; Branner, Kim

    2015-01-01

    The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be...... possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective...... exploitation of offshore wind....

  14. Forecast and Performance of Wind Turbines

    T. Ahilan

    2012-01-01

    Full Text Available Problem statement: Wind energy industry is a nonprofit organization that works hands-on with local and community based wind projects, providing technical support to create an understanding of wind energy opportunities for rural economic benefit. This study provides a detailed vision of the global wind power market and the Indian wind market in particular. It also helps in analyzing and forecasting key metrics relating to the installed capacities, market size and growth. Approach: It helps lay the foundation to build markets for locally owned wind projects in the southeast of Tamil Nadu as well as to help rural landowners and communities benefit more from corporate owned wind projects. As part of this effort, this study organizes state, regional and national wind energy for aimed at moving the wind energy policy and project development dialogue forward, especially regarding community wind projects. Results: This study is designed to give an overview of the wind energy industry and the many benefits and challenges to wind power development in India today. Yet most research in the wind industry remains focused on near term issues, while energy system models that focus on century-long time horizons undervalue wind by imposing exogenous limits on growth. This study fills a critical gap in the literature by taking a closer look at the importance, growth and tariff of large-scale wind. The report helps to comprehend the wind turbine industry and the regulatory framework regarding the wind market in India. It offers interesting results on the market share of the top manufacturers in the India wind turbine industry. Additionally, it also provides the profiles of ten major wind turbine companies in India. Conclusion/Recommendations: This has been an ongoing process to discover the best combination for a given environment in which the wind turbine has to operate and with various challenges met, India would be in a better position to develop and carry forward its own determined initiatives to better the prospects of the wind turbine technology in the coming years. This sectoral innovation systems framework is especially useful tool for analyzing the growth of wind turbine industry and in its essence to preserve the environment with reduction in carbon dioxide emissions.

  15. Evaluation of different turbine concepts for wind power

    Eriksson, Sandra; Bernhoff, Hans; Leijon, Mats [Swedish Centre for Renewable Electric Energy Conversion, Division for Electricity and Lightning Research, Box 534, 751 21 Uppsala (Sweden)

    2008-06-15

    Every year the number of installed wind power plants in the world increases. The horizontal axis wind turbine is the most common type of turbine but there exist other types. Here, three different wind turbines are considered; the horizontal axis wind turbine and two different concepts of vertical axis wind turbines; the Darrieus turbine and the H-rotor. This paper aims at making a comparative study of these three different wind turbines from the most important aspects including structural dynamics, control systems, maintenance, manufacturing and electrical equipment. A case study is presented where three different turbines are compared to each other. Furthermore, a study of blade areas for different turbines is presented. The vertical axis wind turbine appears to be advantageous to the horizontal axis wind turbine in several aspects. (author)

  16. Diffuser for augmenting a wind turbine

    Foreman, Kenneth M. (North Bellmore, NY); Gilbert, Barry L. (Westbury, NY)

    1984-01-01

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  17. Dynamic Properties of Offshore Wind Turbine Foundations

    Damgaard, Mads

    ages structurally over its service life. Well-covered in the field of earthquake engineering, the dynamic response of civil engineering structures is highly dependent on the impedance of the soil–foundation system. For offshore wind turbine applications, however, the hysteretical and geometrical...... thesis that examines the soil–foundation interaction and its influence on the natural and dynamic vibration characteristics of offshore wind turbines, and presents a novel, time-efficient coupled aero-hydro-elastic model of the wind turbine system accounting for the dissipation effects through wave...... with the coupled boundary element and finite element methods, these approaches are not applicable for coupled wind turbine simulations from a computational point of view. As a consequence, lumped-parameter models with frequency-independent real coefficients are applied in the thesis and successfully...

  18. Mobile measurement system for wind turbines

    Kildemoes Moeller, T.

    1997-06-01

    The aim of this project `Udviklingsafproevning af smaa moellevinger` has been to develop a mobile measurement system for wind turbines. The following report describes the measurement system. The project has been financed by the Danish Ministry of Energy. (au)

  19. Vertical Axis Wind Turbine Foundation parameter study

    Lodde, P.F.

    1980-07-01

    The dynamic failure criterion governing the dimensions of prototype Vertical Axis Wind Turbine Foundations is treated as a variable parameter. The resulting change in foundation dimensions and costs is examined.

  20. Structural analysis considerations for wind turbine blades

    Spera, D. A.

    1979-01-01

    Approaches to the structural analysis of wind turbine blade designs are reviewed. Specifications and materials data are discussed along with the analysis of vibrations, loads, stresses, and failure modes.

  1. Wind Turbine Drivetrain Condition Monitoring - An Overview

    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.

  2. Assessment of tonal noise from wind turbines

    The significance of tonal components in noise emissions from wind turbines is discussed. The application of standard tonal assessment methods is reviewed together with the principle differences between methods and some potential areas of difficulty. (Author)

  3. Investigation of Wind Turbine Rotor Concepts for Offshore Wind Farms

    Current plans in offshore wind energy developments call for further reduction of cost of energy. In order to contribute to this goal, several wind turbine rotor concepts have been investigated. Assuming the future offshore wind turbines will operate only in the offshore wind farms, the rotor concepts are not only evaluated for their stand-alone performances and their potential in reducing the loads, but also for their performance in an offshore wind farm. In order to do that, the 10MW reference wind turbine designed in Innwind.EU project is chosen as baseline. Several rotor parameters have been modified and their influences are investigated for offshore wind turbine design purposes. This investigation is carried out as a conceptual parametrical study. All concepts are evaluated numerically with BOT (Blade optimisation tool) software in wind turbine level and with Farmflow software in wind farm level for two wind farm layouts. At the end, all these concepts are compared with each other in terms of their advantages and disadvantages

  4. LES investigation of infinite staggered wind-turbine arrays

    The layouts of turbines affect the turbine wake interactions and thus the wind farm performance. The wake interactions in infinite staggered wind-turbine arrays are investigated and compared with infinite aligned turbine arrays in this paper. From the numerical results we identify three types of wake behaviours, which are significantly different from wakes in aligned wind-turbine arrays. For the first type, each turbine wake interferes with the pair of staggered downstream turbine wakes and the aligned downstream turbine. For the second type, each turbine wake interacts with the first two downstream turbine wakes but does not show significant interference with the second aligned downstream turbine. For the third type, each turbine wake recovers immediately after passing through the gap of the first two downstream turbines and has little interaction with the second downstream turbine wakes The extracted power density and power efficiency are also studied and compared with aligned wind-turbine arrays

  5. Tjæreborg Wind Turbine

    Øye, Stig

    1991-01-01

    This paper presents results from the fourth measurement camapign at the Tjæreborg (Tjaereborg) WInd Turbine during operation with stepwise pitch angle changes. The measurements cover one hour of operation at wind speeds between 7 and 10 m/s aceraging approximately 8.7 m/s.......This paper presents results from the fourth measurement camapign at the Tjæreborg (Tjaereborg) WInd Turbine during operation with stepwise pitch angle changes. The measurements cover one hour of operation at wind speeds between 7 and 10 m/s aceraging approximately 8.7 m/s....

  6. Available and announced offshore wind turbines

    At the end of 2011, about 4000 MW of offshore wind capacity had been installed in Europe. With market shares of respectively 50% and 40%, Siemens and Vestas are the dominant manufacturers on this market. In the field of offshore wind, Siemens is primarily successful with its wind turbine type SET3,6 (3.6 MW) and Vestas with the V90 of 3.0 MW. The offshore wind turbines of other manufacturers that have a higher capacity do not play a significant role with their market share.

  7. Study on wind turbine arrangement for offshore wind farms

    Shen, Wen Zhong; Mikkelsen, Robert Flemming

    2011-01-01

    In this paper, the separation distance between two neighboring offshore wind turbines has been carried out by using the Actuator Line/Navier-Stokes technique developed at the Technical University of Denmark (DTU). Under offshore atmospheric conditions, Large Eddy Simulation has been performed for two Tjæreborg 2 MW wind turbines in tandem with separation distances of 4D, 5D, 6D, 7D, 8D and 10D at the design wind speed of 10 m/s. The power performance of the wake turbine showed to be about 23%...

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

    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.

  9. Aerodynamical noise from wind turbine generators

    Two extensive measurement series of noise from wind turbines have been made during different modifications of their rotors. One series focused on the influence from the tip shape on the noise, while the other series dealt with the influence from the trailing edge. The experimental layout for the two investigations was identical. The total A-weighted noise from the wind turbine was measured in 1/3 octave bands from 50 Hz to 10 kHz in 1-minute periods simultaneously with wind speed measurements. The microphone was mounted on a hard board on the ground about 40 m directly downwind of the wind turbine, and the wind speed meter was placed at the same distance upwind of the wind turbine 10 m above ground. Regression analysis was made between noise and wind speed in each 1/3 octave band to determine the spectrum at 8 m/s. During the measurements care was taken to avoid influence from background noise, and the influence from machinery noise was minimized and corrected for. Thus the results display the aerodynamic rotor noise from the wind turbines. By use of this measurement technique, the uncertainty has been reduced to 1.5 - 2 dB per 1/3 octave band in the relevant frequency range and to about 1 dB on the total A-weighted levels. (au) (10 refs.)

  10. 11kW Stand Alone Wind Turbine Based on Proven Wind Turbine

    Bindner, Henrik; Wodstrup, Jens; Andersen, Jesper; Blaabjerg, Frede; Teodorescu, Remus

    enable control of frequency and voltage independently on both the grid side and the generator side. The prototype has been installed at Risø. The paper will present results from test runs of the system both operating stand-alone supplying a single load and in parallel operation with a diesel genset....... measurement programme. The positive operational experience with the turbine has motivated the development of a stand-alone version. The stand-alone version uses the standard version of the wind turbine combined with a back-to-back converter arrangement in order to decouple the wind turbine from the grid and......The paper will present the rationale behind the design of a stand-alone version of a existing 11kW wind turbine that has been installed at 100 sites mainly in Denmark. The wind turbine has been developed as a part of the Danish household wind turbine programme that included certification, and a...

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

    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.

  12. Passively cooled direct drive wind turbine

    Costin, Daniel P. (Chelsea, VT)

    2008-03-18

    A wind turbine is provided that passively cools an electrical generator. The wind turbine includes a plurality of fins arranged peripherally around a generator house. Each of the fins being oriented at an angle greater than zero degrees to allow parallel flow of air over the fin. The fin is further tapered to allow a constant portion of the fin to extend beyond the air stream boundary layer. Turbulence initiators on the nose cone further enhance heat transfer at the fins.

  13. A Reinforced Blade for a Wind Turbine

    2010-01-01

    The present invention relates to a reinforced blade for a wind turbine having elongated reinforcing members in the blade extending substantially in the plane of the profile chord in order to strengthen the blade against edgewise and flapwise forces.......The present invention relates to a reinforced blade for a wind turbine having elongated reinforcing members in the blade extending substantially in the plane of the profile chord in order to strengthen the blade against edgewise and flapwise forces....

  14. Assessment of wind turbine load measurement instrumentation

    Morfiadakis, E.; Papadopoulos, K. [CRES (Greece); Borg, N. van der [ECN, Petten (Netherlands); Petersen, S.M. [Risoe, Roskilde (Denmark); Seifert, H. [DEWI, Wilhelmshaven (Germany)

    1999-03-01

    In the framework of Sub-Task3 `Wind turbine load measurement instrumentation` of EU-project `European Wind Turbine Testing Procedure Development`, the load measurement techniques have been assessed by laboratory, full scale and numerical tests. The existing methods have been reviewed with emphasis on the strain gage application techniques on composite materials and recommendations are provided for the optimisation of load measurement techniques. (au) EU. 14 refs.

  15. Reliability-Based Optimization of Wind Turbines

    Sørensen, John Dalsgaard; Tarp-Johansen, N.J.

    Reliability-based optimization of the main tower and monopile foundation of an offshore wind turbine is considered. Different formulations are considered of the objective function including benefits and building and failure costs of the wind turbine. Also different reconstruction policies in case...... of failure are considered, including systematic reconstruction and failure of the control system. An example is presented, and as a part of the result the optimal reliability level is obtained....

  16. Wind turbine measurements for noise source indentification

    This report summarises the results of a study developing a method of measuring and analysing noise from a wind turbine that provides repeatability and can be used to obtain data on noise, vibration, weather conditions and wind turbine operation. The experimental setup is described, and the overall level analysis, and the analyses of mechanical and aerodynamic noise are examined. The effects of turbulence on noise, and investigation of blade swish are discussed

  17. The social acceptability of wind turbines: some resident are ready to pay to keep their wind turbines

    The author proposes a synthesis of a survey performed on four wind farms located in different French regions. It appears that only 5 % of residents feel that wind turbines are disturbing, that a dismantling would be detrimental to the resident well-being, that site expansions are well perceived in terms of social well-being, that residents do not really prefer small wind farms. The author outlines that the obtained results cannot be applied to other sites

  18. A new geometrical construction using rounded surfaces proposed for the transverse flux machine for direct drive wind turbine

    Argeseanu, Alin; Nica, Florin Valentin Traian; Ritchie, Ewen; Leban, Krisztina

    improved by FEM modelling and analysis. Using the new concept, a significant reduction of the active materials is obtained. The innovative geometry also provides a uniform magnetic field in the core structure. According to the comparison of both the TFM with prismatic and rounded core geometries the new......This paper proposes a new construction for transverse flux machines (TFM) using a rounded surfaces core geometry. The new concept has been developed for TFM with U core geometry. In this case a new analytic design procedure was proposed. The analytic design of the new TFM construction is further...

  19. Site-optimization of wind turbine generators

    Wolff, T.J. de; Thillerup, J. [Nordtank Energy Group, Richmond, VA (United States)

    1997-12-31

    The Danish Company Nordtank is one of the pioneers within the wind turbine industry. Since 1981 Nordtank has installed worldwide more than 2500 wind turbine generators with a total name plate capacity that is exceeding 450 MW. The opening up of new and widely divergent markets has demanded an extremely flexible approach towards wind turbine construction. The Nordtank product range has expanded considerable in recent years, with the main objective to develop wind energy conversion machines that can run profitable in any given case. This paper will describe site optimization of Nordtank wind turbines. Nordtank has developed a flexible design concept for its WTGs in the 500/750 kW range, in order to offer the optimal WTG solution for any given site and wind regime. Through this flexible design, the 500/750 turbine line can adjust the rotor diameter, tower height and many other components to optimally fit the turbine to each specific project. This design philosophy will be illustrated with some case histories of recently completed projects.

  20. Vertical-axial component wind turbine with a high coefficient using for wind energy

    The report presents the results of research and development on of promising wind units carousel type with a high ratio utilization of wind energy. This devices use a well-known invention – the wind turbine Darrieus. The rotation of the turbine is due to the action of ascensional power to aerodynamic well-streamlined symmetrical about the chord wing profiles of NASA, which are working wind turbine blades. The shaft rotation can be connected with the working blades of one of two ways: using the “swings” or the way “troposkino”. Darrieus turbine has a ratio utilization of wind energy xmax=045. Despite the fact that this is a good indicator of the efficiency of the turbine working, the proposed option allows us to significantly increase the value of this coefficient. The bases methodology of this research is a method of technical and technological research and development design of prospective wind energy construction (WES). Key words: wind turbine, the blade, coefficient utilization of wind energy

  1. Computational aerodynamics and aeroacoustics for wind turbines

    Shen, W.Z.

    2009-10-15

    The present thesis consists of 19 selected papers dealing with the development and use of CFD methods for studying the aerodynamics and aero-acoustics of wind turbines. The papers are written in the period from 1997 to 2008 and numbered according to the list in page v. The work consists of two parts: an aerodynamic part based on Computational Fluid Dynamics and an aero-acoustic part based on Computational Aero Acoustics for wind turbines. The main objective of the research was to develop new computational tools and techniques for analysing flows about wind turbines. A few papers deal with applications of Blade Element Momentum (BEM) theory to wind turbines. In most cases the incompressible Navier-Stokes equations in primitive variables (velocity-pressure formulation) are employed as the basic governing equations. However, since fluid mechanical problems essentially are governed by vortex dynamics, it is sometimes advantageous to use the concept of vorticity (defined as the curl of velocity). In vorticity form the Navier-Stokes equations may be formulated in different ways, using a vorticity-stream function formulation, a vorticity-velocity formulation or a vorticity-potential-stream function formulation. In [1] - [3] two different vorticity formulations were developed for 2D and 3D wind turbine flows. In [4] and [5] numerical techniques for avoiding pressure oscillations were developed when solving the velocity-pressure coupling system in the in-house EllipSys2D/3D code. In [6] - [8] different actuator disc techniques combined with CFD are presented. This includes actuator disc, actuator line and actuator surface techniques, which were developed to simulate flows past one or more wind turbines. In [9] and [10] a tip loss correction method that improves the conventional models was developed for use in combination with BEM or actuator/Navier-Stokes computations. A simple and efficient technique for determining the angle of attack for flow past a wind turbine rotor was developed in [11], and in [12] tunnel wall corrections for wind tunnels with closed or open test sections were developed. The second part of the thesis deals with Computational Aero-Acoustics (CAA). With the spread of wind turbines near urban areas, there is an increasing need for accurate predictions of aerodynamically generated noise. Indeed, noise has become one of the most important issues for further development of wind power, and the iv Wen Zhong Shen ability of controlling and minimising noise emission may be advantageous when competing on the world energy market. To predict generation and propagation of aerodynamic noise, it is required to solve the compressible Navier-Stokes equations. As the scales of the flow and the acoustic waves are quite different (about 1/M, M=Mach number=Uinfinity/c), it is difficult to resolve them together at the same time. Hardin and Pope proposed a non-linear two-step (viscous incompressible flow and inviscid acoustic perturbation) splitting procedure for computational aero-acoustics that is suitable for both generation and propagation. The advantage of the splitting approach, as compared to the acoustic analogies, is that the source strength is obtained directly and that it accounts for sound radiation as well as scattering. In [13] and [14] an inconsistency in the original formulation of Hardin and Pope 1994 was analysed and a consistent formulation was proposed and applied to laminar flows. An aero-acoustic formulation for turbulent flows was in [15] developed for Large Eddy Simulation (LES), Unsteady Reynolds Averaged Navier-Stokes Simulation (URANS) and Detached Eddy Simulation (DES). In [16] a collocated grid / finite volume method for aero-acoustic computations was developed and implemented in the EllipSys2D/3D code. In [17] and [18] three dimensional flowacoustic computations were carried out. Finally, the aero-acoustic formulation using high order Finite Difference schemes (Dispersion Relation Preserving (DRP) / Optimized Compact schemes) was developed in [19] and implemented in the EllipSys2D/3D code. (LN)

  2. Dynamic response of a floating offshore wind turbine

    Stølsmark, Rasmus

    2010-01-01

    The ever increasing demand for renewable energy, combined with limited areas suitable for large wind farms, has put focus on the development of floating wind turbines. In this thesis the dynamic response of a floating wind turbine, subjected to forces from wind and waves, is analyzed. The wind turbine is of a spar buoy design, similar to Statoil's Hywind project. Simulations with two main type of load cases were run, based on the international offshore wind turbine standard IEC...

  3. Wind turbine pitch control using ICPSO-PID algorithm

    Xu, Chang; Tian, Qiangqiang; Shen, Wen Zhong; Zhen, Yuan; Liu, Deyou; Zhang, Ming

    2013-01-01

    controller parameters quickly; and the feed-forward controller for wind speed can improve dynamics of a pitch-control system; additionally the power controller can allow a wind turbine to have a constant power output as a wind speed is over the rated one. Compared with a conventional PID, the controller with......For the traditional simplified first-order pitch-control system model, it is difficult to describe a real dynamic characteristic of a variable pitch action system, thus a complete high order mathematical model has to be developed for the pitch control of wind turbine generation (WTG). In the paper......, a pitch controller was designed based on power and wind speed and by considering the inertia and delay characteristics of a pitch-control system to achieve a constant power output when a wind speed was beyond the rated one. A novel ICPSO-PID control algorithm was proposed based on a combination of...

  4. Behavior of bats at wind turbines.

    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

  5. Behavior of bats at wind turbines

    Cryan, Paul M.; 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.

  6. Frequency based Wind Turbine Gearbox Fault Detection applied to a 750 kW Wind Turbine

    Odgaard, Peter Fogh; Nejad, Amir R.

    operating in parallel with the control system, and also uses additional sensors measuring different accelerations and noises, etc. In this paper gearbox data from high fidelity gearbox model of a 750 kW wind turbine gearbox, simulated with and without faults are used to shown the potential of frequency......Reliability and availability of modern wind turbines are of increasing importance, for two reasons. The first is due to the fact that power grids around in the world depends at a higher and higher degree on wind energy, and the second is the importance of lowering Cost of Energy of the wind...... turbines. One of the critical components in modern wind turbines is the gearbox. Failures in the gearbox are costly both due to the cost of the gearbox itself, but also due to lost power generation during repair of it. Wind turbine gearboxes are consequently monitored by condition monitoring systems...

  7. Birds and wind turbines: can they co-exist?

    The wind farm is situated along an exposed pier at Blyth Harbour and has now been designated as part of a SSI and part of a proposed RAMSAR site. The bird activity within the harbour is high and is also the wintering home of the Purple Sandpiper. An offshore wind farm is proposed for the area, one kilometre from the pier. Two turbines will be erected with the support of the European Commission THERMIE Programme. The bird study at Blyth has been funded by Border Wind, Blyth Harbour Wind Farm Company and the DTI as part of an ETSU funded study. (UK)

  8. Wind Turbine Generator Modeling and Simulation Where Rotational Speed is the Controlled Variable

    Mihet-Popa, Lucian; Blaabjerg, Frede; Boldea, Ion

    2004-01-01

    the interaction between a wind turbine and the power system. The model is intended to simulate the behaviour of the wind turbine using induction generators both during normal operation. Sample simulation results for two induction generators (2/0.5 MW) validate the fundamental issues.......To optimise the power produced in a wind turbine, the speed of the turbine should vary with the wind speed. A simple control method is proposed that will allow an induction machine to run a turbine at its maximum power coefficient. Various types of power control strategies have been suggested for...... application in variable speed wind turbines. The usual strategy is to control the power or the torque acting on the wind turbine shafts. This paper presents an alternative control strategy, where the rotational speed is the controlled variable. The paper describes a model, which is being developed to simulate...

  9. Innovative multi rotor wind turbine designs

    Kale, S.A.; Sapali, S.N. [College of Engineering. Mechanical Engineering Dept, Pune (India)

    2012-07-01

    Among the renewable energy sources, today wind energy is the most recognized and cost effective. Developers and researchers in this sector are optimistic and continuously working innovatively to improve the technology. The wind power obtained is proportional to the swept area of wind turbine. The swept area is increased by using a single rotor of large diameter or multi rotors in array. The rotor size is growing continuously with mature technology. Multi rotor technology has a long history and the multi rotor concept persists in a variety of modern innovative systems but the concept has fallen out of consideration in mainstream design from the perception that is complex and unnecessary as very large single rotor units are now technically feasible. This work addresses the evaluation of different multi rotor wind turbine systems. These innovative wind turbines are evaluated on the basis of feasibility, technological advantages, security of expected power performance, cost, reliability, impact of innovative system, comparison with existing wind turbine design. The findings of this work will provide guidelines for the practical and economical ways for further research on the multi rotor wind turbines. (Author)

  10. Load prediction of stall regulated wind turbines

    Bjoerck, A.; Dahlberg, J.Aa. [Aeronautical Research Inst. of Sweden, Bromma (Sweden); Carlen, I. [Chalmers Univ. of Technology, Goeteborg (Sweden). Div. of Marine Structural Engineering; Ganander, H. [Teknikgruppen AB, Sollentua (Sweden)

    1996-12-01

    Measurements of blade loads on a turbine situated in a small wind farm shows that the highest blade loads occur during operation close to the peak power i.e. when the turbine operates in the stall region. In this study the extensive experimental data base has been utilised to compare loads in selected campaigns with corresponding load predictions. The predictions are based on time domain simulations of the wind turbine structure, performed by the aeroelastic code VIDYN. In the calculations a model were adopted in order to include the effects of dynamic stall. This paper describes the work carried out so far within the project and key results. 5 refs, 10 figs

  11. Analysis of counter-rotating wind turbines

    Shen, Wen Zhong; Zakkam, Vinod Arun Kumar; Sørensen, Jens Nørkær; Appa, Kari

    2007-01-01

    This paper presents a study on the performance of a wind turbine with two counter-rotating (CRWT) rotors. The characteristics of the two counter-rotating rotors are on a 3-bladed Nordtank 500 kW rotor. The analysis has been carried out by using an Actuator Line technique implemented in the Navier......-Stokes code EllipSys3D. The analysis shows that the Annual Energy Production can be increased to about 43.5 %, as compared to a wind turbine with a single rotor. In order to determine the optimal settings of the CRWT turbine, parameters such as distance between two rotors and rotational speed have been...

  12. Wind Turbines on CO2 Neutral Luminaries in Urban Areas

    In the present work, an overview of three different wind turbines used in hybrid luminaries is presented. The turbines are: vertical-axis twisted Savonius, three-blade horizontal-axis, and vertical-axis three-blade helical H-rotor. The considered luminaries are also equipped with photovoltaic...... buildings. A new vertical-axis twisted Savonius rotor is proposed for a luminary being designed for such a district within the “Development of CO2 neutral urban luminary” project....

  13. Orthogonal Bases used for Feed Forward Control of Wind Turbines

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2011-01-01

    In optimizing wind turbines it can be of a large help to use information of wind speeds at upwind turbine for the control of downwind turbines, it is, however, problematic to use these measurements directly since they are highly influenced by turbulence behind the wind turbine rotor plane. In this...

  14. Power electronics for modern wind turbines

    Blaabjerg, Frede

    2006-01-01

    Wind energy is now the world's fastest growing energy source. In the past 10 years, the global wind energy capacity has increased rapidly. The installed global wind power capacity has grown to 47.317 GW from about 3.5 GW in 1994. The global wind power industry installed 7976 MW in 2004, an increase in total installed generating capacity of 20%. The phenomenal growth in the wind energy industry can be attributed to the concerns to the environmental issues, and research and development of innovative cost-reducing technologies.Denmark is a leading producer of wind turbines in the world, with an a

  15. Jet spoiler arrangement for wind turbine

    Cyrus, Jack D. (Corrales, NM); Kadlec, Emil G. (Albuquerque, NM); Klimas, Paul C. (Albuquerque, NM)

    1985-01-01

    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.

  16. Design Oriented Aerodynamic Modelling of Wind Turbine Performance

    The development of a wind turbine aerodynamics model using a Boundary Integral Equation model (BIEM) is presented. The methodology is valid to study inviscid unsteady flows around three dimensional bodies of arbitrary shape and arbitrarily moving with respect to the incoming flow. The extension of this methodology to study viscosity effects in turbine blade flow at high angle of attack is addressed and an approach to determine aerodynamic loads over a wide range of turbine operating conditions is proposed. Numerical applications considering a selected test cases from the NREL experimental dataset are presented. Finally, the application of the proposed turbine aerodynamics model into a multi-disciplinary study including aeroelasticity of pylon-turbine assembly and aeroacoustics modelling of induced noise is briefly described

  17. Infrasound emission generated by wind turbines

    Ceranna, Lars; Pilger, Christoph

    2014-05-01

    Aerodynamic noise emissions from the continuously growing number of wind turbines in Germany are creating increasing problems for infrasound recording systems. Such systems are equipped with highly sensitive micro pressure sensors, which are accurately measuring acoustic signals in a frequency range inaudible to humans. At infrasound station IGADE, north of Bremen, a constantly increasing background noise has been observed throughout the years since its installation in 2005. The spectral peaks are reflecting well the blade passing harmonics, which vary with prevailing wind speeds. Overall, a decrease is noted for the infrasound array's detection capability. This aspect is particularly important for the other two sites of the German infrasound stations I26DE in the Bavarian Forest and I27DE in Antarctica, because plans for installing wind turbines near these locations are being under discussion. These stations are part of the International Monitoring System (IMS) verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), and have to meet stringent specifications with respect to infrasonic background noise. Therefore data obtained during a field experiment with mobile micro-barometer stations for measuring the infrasonic pressure level of a single horizontal-axis wind turbine have been revisited. The results of this experiment successfully validate a theoretical model which estimates the generated sound pressure level of wind turbines and makes it possible to specify the minimum allowable distance between wind turbines and infrasound stations for undisturbed recording. Since the theoretical model also takes wind turbine design parameters into account, suitable locations for planned infrasound stations outside the determined disturbance range can be found, which will be presented; and vice versa, the model calculations' results for fixing the minimum distance for wind turbines planned for installation in the vicinity of an existing infrasound array.

  18. Local blockage effect for wind turbines

    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.

  19. Wind power integration: from individual wind turbine to wind park as a power plant:

    Zhou, Y.

    2009-01-01

    As power capacities of single wind turbine, single wind park and total wind power installation are continuously increasing, the wind power begins to challenge the safety operation of the power system. This thesis focuses on the grid integration aspects such as the dynamic behaviours of wind power during disturbances, and dynamic behaviours of power system with large wind power integration. The work in this thesis is in a down-up approach, starting with concepts for individual wind turbines, i...

  20. Tribological advancements for reliable wind turbine performance.

    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

  1. Vertical axis wind turbine control strategy

    McNerney, G.M.

    1981-08-01

    Early expensive in automatic operation of the Sandia 17-m vertical axis research wind turbine (VAWT) has demonstrated the need for a systematic study of control algorithms. To this end, a computer model has been developed that uses actual wind time series and turbine performance data to calculate the power produced by the Sandia 17-m VAWT operating in automatic control. The model has been used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long-term energy production. An attempt has been made to generalize these results from local site and turbine characteristics to obtain general guidelines for control algorithm design.

  2. RELIABILITY OF MACHINE ELEMENTS IN WIND TURBINES

    Willi GRUENDER

    2010-06-01

    Full Text Available Worldwide electrical energy production generated by wind turbines grows at a rate of 30 percent. This doubles the total production every three years. At the same time the power of individual stations goes up by 20 percent annually. Whereas today the towers, rotors and drive trains have to handle 5 MW, in about six to eight years they might produce up to fifteen MW. As a consequence, enormous pressure is put on the wind turbine manufacturers, the component suppliers and the operators. And because prototype and field testing is limited by its expense, the design of new turbines demands thorough analysis and simulation. Looking at the critical components of a wind turbine this paper describes advanced design tools which help to anticipate failures, but also assists in optimizing reliability and service life. Development of the software tools has been supported by research activities in many universities.

  3. Environmental life cycle analyses of wind turbines

    The aim of this investigation is to determine environmental aspects of (1) upscaling of both onshore and offshore turbines and (2) offshore versus onshore placement of turbines. Attention has also been paid to a couple of waste processing options in order to obtain a responsible disposal of dismissed wing blades of wind turbines. Shortcomings of the followed procedure for life cycle assessments are pinpointed in the field of the software package, the inventory and the normalization of effect scores both for classification and evaluation. Upscaling from a 300 kW wind turbine to a 500 kW wind turbine results in a decrease (20-50%) of all environmental impacts considered in this study both for an onshore and an offshore situation. This is caused by the fact that the increase of materials use turns out to be lower than the increase in energy production. However, smaller differences than assumed in this study in electricity production between the two types of wind turbines - depending on wind climate and design - will result in a lower decrease or even an increase in environmental impacts. Offshore placement leads to considerably higher environmental impacts compared to onshore placement (5-180%). However, offshore placement offers important advantages in the field of noise pollution, adverse effect on landscape and level of electricity production. 11 figs., 25 tabs., 41 refs

  4. Anechoic wind tunnel study of turbulence effects on wind turbine broadband noise

    Loyd, B.; Harris, W. L.

    1995-01-01

    This paper describes recent results obtained at MIT on the experimental and theoretical modelling of aerodynamic broadband noise generated by a downwind rotor horizontal axis wind turbine. The aerodynamic broadband noise generated by the wind turbine rotor is attributed to the interaction of ingested turbulence with the rotor blades. The turbulence was generated in the MIT anechoic wind tunnel facility with the aid of biplanar grids of various sizes. The spectra and the intensity of the aerodynamic broadband noise have been studied as a function of parameters which characterize the turbulence and of wind turbine performance parameters. Specifically, the longitudinal integral scale of turbulence, the size scale of turbulence, the number of turbine blades, and free stream velocity were varied. Simultaneous measurements of acoustic and turbulence signals were made. The sound pressure level was found to vary directly with the integral scale of the ingested turbulence but not with its intensity level. A theoretical model based on unsteady aerodynamics is proposed.

  5. Observer Based Detection of Sensor Faults in Wind Turbines

    Odgaard, Peter Fogh; Stoustrup, Jakob; Nielsen, R.; Damgaard, Chris

    2009-01-01

    An observer based scheme is proposed to detect sensor faults in wind  turbines. In the example used for the proposed scheme the wind turbine  drive train is considered. A model of the drive train is used to  design the observer, and in this model the wind speed is an important  input, however, if...... an unknown input observer the fault detection  scheme can be non dependent on the actual wind speed. The scheme  is validated on data from a more advanced and detailed simulation  model. The proposed scheme detects the sensor faults a few samples  after the beginning of the faults....

  6. Study on wind turbine arrangement for offshore wind farms

    Shen, Wen Zhong; Mikkelsen, Robert Flemming

    2011-01-01

    In this paper, the separation distance between two neighboring offshore wind turbines has been carried out by using the Actuator Line/Navier-Stokes technique developed at the Technical University of Denmark (DTU). Under offshore atmospheric conditions, Large Eddy Simulation has been performed for...... to the turbulence mixing. This study hints that the optimal separation distance between neighboring turbines for offshore wind farms should be 7 rotor diameters....

  7. Wind Turbine Test Wind Matic WM 15S

    Friis Pedersen, Troels

    1986-01-01

    The report describes standard measurements performed on a Wind-Matic WM 15S, 55 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, dynamical behaviour of the turbine, loads at cut-in and braking, rotor torque at stopped condition, and noise emission.

  8. Wind Turbine Test Wind Matic WM 15S

    Friis Pedersen, Troels

    The report describes standard measurements performed on a Wind-Matic WM 15S, 55 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, dynamical...... behaviour of the turbine, loads at cut-in and braking, rotor torque at stopped condition, and noise emission....

  9. European wind turbine testing procedure developments. Task 1: Measurement method to verify wind turbine performance characteristics

    Hunter, R.; Friis Pedersen, Troels; Dunbabin, P.; Antoniou, Ioannis; Frandsen, Sten Tronæs; Klug, H.; Albers, A.; Lee, W.K.

    2001-01-01

    There is currently significant standardisation work ongoing in the context of wind farm energy yield warranty assessment and wind turbine power performance testing. A standards maintenance team is revising the current IEC (EN) 61400-12 Ed 1 standard forwind turbine power performance testing. The ...... anemometry, multi-variate regression analysis and density normalisation....

  10. An integrated structural strength analysis method for Spar type floating wind turbine

    Hu, Zhi-qiang; Liu, Yi; Wang, Jin

    2016-04-01

    An integrated structural strength analysis method for a Spar type floating wind turbine is proposed in this paper, and technical issues related to turbine structure modeling and stress combination are also addressed. The NREL-5MW "Hywind" Spar type wind turbine is adopted as study object. Time-domain dynamic coupled simulations are performed by a fully-coupled aero-hydro-servo-elastic tool, FAST, on the purpose of obtaining the dynamic characteristics of the floating wind turbine, and determining parameters for design load cases of finite element calculation. Then design load cases are identified, and finite element analyses are performed for these design load cases. The structural stresses due to wave-induced loads and wind-induced loads are calculated, and then combined to assess the structural strength of the floating wind turbine. The feasibility of the proposed structural strength analysis method for floating wind turbines is then validated.

  11. Transient stability of DFIG wind turbines at an external short-circuit fault

    Sun, Tao; Chen, Zhe; Blaabjerg, Frede

    2005-01-01

    The fast development of wind power generation brings new requirements for wind turbine integration into the network. After clearance of an external short-circuit fault, gridconnected wind turbines should restore their normal operation without power loss caused by disconnections. This article...... concentrates on the transient stability of variable speed wind turbines with doubly fed induction generators (DFIGs) at an external short-circuit fault. A simulation model of a MW-level variable speed wind turbine with a DFIG developed in PSCAD/EMTDC is presented and the control and protection schemes are...... uncritical post-fault situations the control schemes are able to restore the wind turbine's normal operation without disconnections.lt is also proved that the proposed measure is effective in re-establishing the voltage at the wind turbine terminal in critical post-fault situations....

  12. Wind turbines - localisation strategy in Denmark

    Sites for 1500 MW wind power in Denmark by 2005 will be found through a decentralized planning process with public participation. The wind turbines will be sited in parks and clusters in order to secure good economy and satisfactory locations in the landscape. (author)

  13. Compressible Flow About Wind Turbine Blades

    Dulikravich, D. S.

    1983-01-01

    WIND program numerically solves exact full-potential equation for three dimensional, stead inviscid flow through isolated wind-turbine rotor. Proram automatically generates three dimensional, boundary-conforming grid and iteratively solves full-potential equation while fully accounting for rotating and Coriolis effects. Program written in FORTRAN IV.

  14. Virtual inertia for variable speed wind turbines

    Zeni, Lorenzo; Rudolph, Andreas Jakob; Münster-Swendsen, Janus; Margaris, Ioannis; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2013-01-01

    Inertia provision for frequency control is among the ancillary services that different national grid codes will likely require to be provided by future wind turbines. The aim of this paper is analysing how the inertia response support from a variable speed wind turbine (VSWT) to the primary frequ...... conventional generation. The range of wind speeds near the power limitation zone seems to be the most critical from a primary response point of view. The theoretical reasons behind this are elucidated in the paper. Copyright © 2012 John Wiley & Sons, Ltd.......Inertia provision for frequency control is among the ancillary services that different national grid codes will likely require to be provided by future wind turbines. The aim of this paper is analysing how the inertia response support from a variable speed wind turbine (VSWT) to the primary...... frequency control of a power system can be enhanced. Unlike fixed speed wind turbines, VSWTs do not inherently contribute to system inertia, as they are decoupled from the power system through electronic converters. Emphasis in this paper is on how to emulate VSWTs inertia using control of the power...

  15. Advances in wind turbine blade design and materials

    Wind energy is gaining critical ground in the area of renewable energy, with wind energy being predicted to provide up to 8% of the world’s consumption of electricity by 2021. Advances in wind turbine blade design and materials reviews the design and functionality of wind turbine rotor blades as...... well as the requirements and challenges for composite materials used in both current and future designs of wind turbine blades. Part one outlines the challenges and developments in wind turbine blade design, including aerodynamic and aeroelastic design features, fatigue loads on wind turbine blades...... fatigue resistance of wind turbine blades. The final part of the book describes advances in wind turbine blade materials, development and testing, including biobased composites, surface protection and coatings, structural performance testing and the design, manufacture and testing of small wind turbine...

  16. Flow separation on wind turbines blades

    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...

  17. Large Horizontal-Axis Wind Turbines

    Thresher, R. W. (Editor)

    1982-01-01

    The proceedings of a workshop held in Cleveland, July 28-30, 1981 are described. The workshop emphasized recent experience in building and testing large propeller-type wind turbines, expanding upon the proceedings of three previous DOE/NASA workshops at which design and analysis topics were considered. A total of 41 papers were presented on the following subjects: current and advanced large wind turbine systems, rotor blade design and manufacture, electric utility activities, research and supporting technology, meteorological characteristics for design and operation, and wind resources assessments for siting.

  18. Large, low cost composite wind turbine blades

    Gewehr, H. W.

    1979-01-01

    A woven roving E-glass tape, having all of its structural fibers oriented across the tape width was used in the manufacture of the spar for a wind turbine blade. Tests of a 150 ft composite blade show that the transverse filament tape is capable of meeting structural design requirements for wind turbine blades. Composite blades can be designed for interchangeability with steel blades in the MOD-1 wind generator system. The design, analysis, fabrication, and testing of the 150 ft blade are discussed.

  19. Fatigue Reliability of Offshore Wind Turbine Systems

    Marquez-Dominguez, Sergio; Sørensen, John Dalsgaard

    Optimization of the design of offshore wind turbine substructures with respect to fatigue loads is an important issue in offshore wind energy. A stochastic model is developed for assessing the fatigue failure reliability. This model can be used for direct probabilistic design and for calibration of...... appropriate partial safety factors / fatigue design factors (FDF) for steel substructures of offshore wind turbines (OWTs). The fatigue life is modeled by the SN approach. Design and limit state equations are established based on the accumulated fatigue damage. The acceptable reliability level for optimal...... fatigue design of OWTs is discussed and results for reliability assessment of typical fatigue critical design of offshore steel support structures are presented....

  20. Report made on behalf of the commission of economic affairs and of the development plan about the proposal of law from M. Jean-Francois Le Grand relative to the layout of wind turbines and to the protection of environment; Rapport fait au nom de la commission des affaires economiques et du plan (1) sur la proposition de loi de M. Jean-Francois Le Grand relative a l'implantation des eoliennes et a la protection de l'environnement

    Le Grand, J.F.

    2002-07-01

    This proposal of law aims at clarifying and uniformizing the law relative to the layout of wind turbines. Wind turbines can have a bad aesthetical impact on landscapes, and thus the development of wind energy requires a normative framework for the selection of the best projects. Each project will have to fulfill both an impact study and a public inquiry if the wind turbine exceeds 12 m of height. (J.S.)

  1. The social acceptability of wind turbines: some resident are ready to pay to keep their wind turbines. Survey on four French wind farms

    The authors report a study which aimed at exploiting and deepening the results of a 2001 survey on visual and sound disturbances caused by wind turbines in Sigean (Aude), at identifying all the attitudes and opinions with respect with wind energy, and at assessing the different characteristics of a wind farm (height, localization, and so on). A survey has been performed on four sites located in different French regions. The authors discuss the social-demographic characteristics of the population samples, the global opinion on wind energy, and the opinion of the people on wind turbines located in their neighbourhood. They propose an estimation of benefits and damages related to the vicinity of wind turbines. By applying a method of choice experiments, they reveal the preferences of residents

  2. Wind Turbine Micropitting Workshop: A Recap

    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.

  3. Computer control for remote wind turbine operation

    Manwell, J.F.; Rogers, A.L.; Abdulwahid, U.; Driscoll, J. [Univ. of Massachusetts, Amherst, MA (United States)

    1997-12-31

    Light weight wind turbines located in harsh, remote sites require particularly capable controllers. Based on extensive operation of the original ESI-807 moved to such a location, a much more sophisticated controller than the original one has been developed. This paper describes the design, development and testing of that new controller. The complete control and monitoring system consists of sensor and control inputs, the control computer, control outputs, and additional equipment. The control code was written in Microsoft Visual Basic on a PC type computer. The control code monitors potential faults and allows the turbine to operate in one of eight states: off, start, run, freewheel, low wind shut down, normal wind shutdown, emergency shutdown, and blade parking. The controller also incorporates two {open_quotes}virtual wind turbines,{close_quotes} including a dynamic model of the machine, for code testing. The controller can handle numerous situations for which the original controller was unequipped.

  4. Load attenuating passively adaptive wind turbine blade

    Veers, Paul S. (Albuquerque, NM); Lobitz, Donald W. (Albuquerque, NM)

    2003-01-01

    A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

  5. Structural Reliability Aspects in Design of Wind Turbines

    Sørensen, John Dalsgaard

    Reliability assessment, optimal design and optimal operation and maintenance of wind turbines are an area of significant interest for the fast growing wind turbine industry for sustainable production of energy. Offshore wind turbines in wind farms give special problems due to wake effects inside ...

  6. An Optimal Number-Dependent Preventive Maintenance Strategy for Offshore Wind Turbine Blades Considering Logistics

    Ann-Brith Strömberg; Michael Patriksson; Mahmood Shafiee

    2013-01-01

    In offshore wind turbines, the blades are among the most critical and expensive components that suffer from different types of damage due to the harsh maritime environment and high load. The blade damages can be categorized into two types: the minor damage, which only causes a loss in wind capture without resulting in any turbine stoppage, and the major (catastrophic) damage, which stops the wind turbine and can only be corrected by replacement. In this paper, we propose an optimal number-dep...

  7. Unsteady flow simulation of a vertical axis augmented wind turbine: a two-dimensional study

    Nobile, Rosario; Vahdati, Maria; Barlow, Janet F.; Mewburn-Crook , Anthony

    2014-01-01

    As the integration of vertical axis wind turbines in the built environment is a promising alternative to horizontal axis wind turbines, a 2D computational investigation of an augmented wind turbine is proposed and analysed. In the initial CFD analysis, three parameters are carefully investigated: mesh resolution; turbulence model; and time step size. It appears that the mesh resolution and the turbulence model affect result accuracy; while the time step size examined, for the unsteady nature ...

  8. Investigations of a building-integrated ducted wind turbine module

    Dannecker, Robert K. W.; Grant, Andrew D.

    2002-01-01

    So far, wind energy has not played a major role in the group of technologies for embedded generation in the built environment. However, the wind flow around conventional tall buildings generates differential pressures, which may cause an enhanced mass flow through a building-integrated turbine. As a first step, a prototype of a small-scale ducted wind turbine has been developed and tested, which seems to be feasible for integration into the leading roof edge of such a building. Here an experimental and numerical investigation of the flow through building-integrated ducting is presented. Pressure and wind speed measurements have been carried out on a wind tunnel model at different angles of incident wind, and different duct configurations have been tested. It was confirmed that wind speeds up to 30% higher than in the approaching freestream may be induced in the duct, and good performance was obtained for angles of incident wind up to ±60°. The experimental work proceeded in parallel with computational fluid dynamics (CFD) modelling. The geometry of the system was difficult to represent to the required level of accuracy, and modelling was restricted to a few simple cases, for which the flow field in the building-integrated duct was compared with experimental results. Generally good agreement was obtained, indicating that CFD techniques could play a major role in the design process. Predicted power of the proposed device suggests that it will compare favourably with conventional small wind turbines and photovoltaics in an urban environment.

  9. Robust Utilization of Wind Turbine Flexibility for Grid Stabilization

    Juelsgaard, Morten; Bendtsen, Jan Dimon; Wisniewski, Rafal

    This work considers the use of wind turbines for stabilizing an electrical grid, by employing temporary overproduction with respect to available power. We present a simple model describing a turbine, and show how the possible period of overproduction, can be maximized through a series of convex...... problems, where the load is distributed among several turbines in a farm. We then present an optimization scheme that guarantees a lower limit for the overproduction period and subsequently propose an adaptive implementation that is robust against parameter uncertainties....

  10. Dynamic Analysis of Wind Turbine Blades Using Radial Basis Functions

    Ming-Hung Hsu

    2011-01-01

    Wind turbine blades play important roles in wind energy generation. The dynamic problems associated with wind turbine blades are formulated using radial basis functions. The radial basis function procedure is used to transform partial differential equations, which represent the dynamic behavior of wind turbine blades, into a discrete eigenvalue problem. Numerical results demonstrate that rotational speed significantly impacts the first frequency of a wind turbine blade. Moreover, the pitch an...

  11. Efficiency and Functionality of a Contra-Rotating Wind Turbine

    Kullmann, Felix

    2015-01-01

    Goal of this study was to evaluate in terms of efficiency and functionality a newly modelled contra-rotating wind turbine. This new wind turbine was examined in order to find more ecological and econmical technologies in the wind energy sector. Betz Limit will be proofed for single rotor wind turbines and the higher possible energy extraction coefficient for double rotor wind turbines will be explained. Main source for the experimental set-up and validation of the found results is P. Santhana...

  12. Wind Turbines and Coastal Recreation Demand

    Landry, Craig E.; Tom Allen; Todd Cherry; John C. Whitehead

    2010-01-01

    We examine the impact of coastal wind turbines on coastal tourism and recreation for residents of the northern CAMA counties in North Carolina. A combination of telephone and web survey data are used to assess the impact of coastal wind farms on trip behavior and site choice. Most of the respondents to our telephone survey claim to support offshore wind energy development, and independent survey data suggest that the observed levels of support may be indicative of the broader population in th...

  13. The design of wind turbine for electrical power generation in Malaysian wind characteristics

    The paper describes the study of a wind turbine for electrical power generation in Malaysia wind characteristics. In this research, the wind turbine is designs based on the local wind characteristics and tries to avoid the problems faced in the past (turbine design, access, manpower and technical). The new wind turbine rotor design for a medium speed wind speed turbine utilises the concept of open-close type of horizontal axis (up-wind) wind turbine is intended to widen the optimum performance range for electrical generation in Malaysia wind characteristics. The wind turbine has been designed to cut-in at a lower speed, and to provide the rotation speed that high enough to run a generator. The analysis and design of new low speed wind turbine blades and open-close turbine rotor and prediction of turbine performance are being detailed in this paper. (Author)

  14. A neuro-fuzzy controlling algorithm for wind turbine

    Li Lin [Tampere Univ. of Technology (Finland); Eriksson, J.T. [Tampere Univ. of Technology (Finland)

    1995-12-31

    The wind turbine control system is stochastic and nonlinear, offering a demanding field for different control methods. An improved and efficient controller will have great impact on the cost-effectiveness of the technology. In this article, a design method for a self-organizing fuzzy controller is discussed, which combines two popular computational intelligence techniques, neural networks and fuzzy logic. Based on acquisited dynamic parameters of the wind, it can effectively predict wind changes in speed and direction. Maximum power can always be extracted from the kinetic energy of the wind. Based on the stimulating experiments applying nonlinear dynamics to a `Variable Speed Fixed Angle` wind turbine, it is demonstrated that the proposed control model 3rd learning algorithm provide a predictable, stable and accurate performance. The robustness of the controller to system parameter variations and measurement disturbances is also discussed. (author)

  15. Fault Detection of Wind Turbines with Uncertain Parameters

    Tabatabaeipour, Seyed Mojtaba; Odgaard, Peter Fogh; Bak, Thomas; Stoustrup, Jakob

    2012-01-01

    used generate a set that contains all states consistent with the past measurements and the given model of the wind turbine including uncertainties and noise. This set represents all possible states the system can be in if not faulty. If the current measurement is not consistent with this set, a fault......In this paper a set-membership approach for fault detection of a benchmark wind turbine is proposed. The benchmark represents relevant fault scenarios in the control system, including sensor, actuator and system faults. In addition we also consider parameter uncertainties and uncertainties on the...... torque coefficient. High noise on the wind speed measurement, nonlinearities in the aerodynamic torque and uncertainties on the parameters make fault detection a challenging problem. We use an effective wind speed estimator to reduce the noise on the wind speed measurements. A set-membership approach is...

  16. A wind turbine evaluation model under a multi-criteria decision making environment

    Highlights: ► This paper proposes an evaluation model to select suitable turbines in a wind farm. ► Interpretive structural modeling is used to know the relationship among factors. ► Fuzzy analytic network process is used to calculate the priorities of turbines. ► The results can be references for selecting the most appropriate wind turbines. - Abstract: Due to the impacts of fossil and nuclear energy on the security, economics, and environment in the world, the demand of alternative energy resources is expanding consistently and tremendously in recent years. Wind energy production, with its safe and environmental characteristics, has become the fastest growing renewable energy source in the world. The construction of new wind farms and the installation of new wind turbines are important processes in order to provide a long-term energy production. In this research, a comprehensive evaluation model, which incorporates interpretive structural modeling (ISM) and fuzzy analytic network process (FANP), is constructed to select suitable turbines when developing a wind farm. A case study is carried out in Taiwan in evaluating the expected performance of several potential types of wind turbines, and experts in a wind farm are invited to contribute their expertise in determining the importance of the factors of the wind turbine evaluation and in rating the performance of the turbines with respect to each factor. The most suitable turbines for installation can finally be generated after the calculations. The results can be references for decision makers in selecting the most appropriate wind turbines.

  17. Distribution of extreme gust loads of wind turbines

    Cheng, P.W.; Bierbooms, W.A.A.M. [Institute for Wind Energy, TU Delft, Stevinweg 1, 2628 CN Delft (Netherlands)

    2001-03-01

    Extreme gust loading of wind turbines has been treated deterministically as prescribed in the design codes, without taking into account the stochastic property of the wind turbulence. In this paper a rational approach to quantify the variability of the gust loading of a wind turbine is presented and a new approach on the simulation of the extreme gusts with constrained simulations is proposed. The results from simulations with deterministic gusts and stochastic gusts are compared. The distribution of the extreme response due to extreme gust is derived using the constrained gust approach. The influence on response of a spatial gust and a point gust is studied. The effect of the gust centre on the turbine response has also been taken into account. The response distribution at a certain mean wind speed is determined with full-scale time domain simulation and compared to the distribution derived with constrained gusts. The method is demonstrated using the turbine model of a prototype wind turbine; for this reason the result is preliminary and generalization should be made with care.

  18. H∞ Based Control for Load Mitigation in Wind Turbines

    Aron Pujana-Arrese

    2012-04-01

    Full Text Available This article demonstrates a strategy to design multivariable and multi-objective controllers based on the H∞ norm reduction applied to a wind turbine. The wind turbine model has been developed in the GH Bladed software and it is based on a 5 MW wind turbine defined in the Upwind European project. The designed control strategy works in the above rated power production zone and performs generator speed control and load reduction on the drive train and tower. In order to do this, two robust H∞ MISO (Multi-Input Single-Output controllers have been developed. These controllers generate collective pitch angle and generator torque set-point values to achieve the imposed control objectives. Linear models obtained in GH Bladed 4.0 are used, but the control design methodology can be used with linear models obtained from any other modelling package. Controllers are designed by setting out a mixed sensitivity problem, where some notch filters are also included in the controller dynamics. The obtained H∞ controllers have been validated in GH Bladed and an exhaustive analysis has been carried out to calculate fatigue load reduction on wind turbine components, as well as to analyze load mitigation in some extreme cases. The analysis compares the proposed control strategy based on H∞ controllers to a baseline control strategy designed using the classical control methods implemented on the present wind turbines.

  19. Grid impact of variable-speed wind turbines

    Larsson, Aa. [Chalmers Univ. of Technology, Dept. of Electric Power Engineering, Goeteborg (Sweden); Soerensen, P. [Risoe National Lab., Roskilde (Denmark); Santjer, F. [German Wind Energy Inst., DEWI, Wilhelmshaven (Germany)

    1999-03-01

    In this paper the power quality of variable-speed wind turbines equipped with forced-commutated inverters is investigated. Measurements have been taken on the same type of variable-speed wind turbines in Germany and Sweden. The measurements have been analysed according to existing IEC standards. Special attention has been paid to the aggregation of several wind turbines on flicker emission and harmonics. The aggregation has been compared with the summation laws used in the draft IEC 61400-21 `Power Quality Requirements for Grid Connected wind turbines`. The methods for calculating and summing flicker proposed by IEC Standards are reliable. Harmonics and inter-harmonics are treated in IEC 61000-4-7 and IEC 61000-3-6. The methods for summing harmonics and inter-harmonics in IEC 61000-3-6 are applicable to wind turbines. In order to obtain a correct magnitude of the frequency components, the use of a well-defined window width, according to IEC 61000-4-7 Amendment 1 is of a great importance. (au)

  20. Study on optimal design of wind turbine blade airfoil and its application

    This study was carried out with two goals. One was the development of a model of a wind turbine blade airfoil and the other was the application of the folding blade. In general, in large sized (MW) wind turbines, damage is prevented in small wind turbines since equipment costs and maintenance costs are high, and therefore, the blade will cause serious damage. The wind turbine proposed in this study does not require maintenance, and the blades do not break during high winds because they are folded in accordance with changes in the wind speed. But generators are not cut out, while maintaining a constant angle will continue to produce. The focus of this study, the wind turbine is continued by folding blade system in strong winds and gusts without stopping production

  1. Wavelet Transformation for Damage Identication in Wind Turbine Blades

    Ulriksen, Martin Dalgaard; Skov, Jonas falk; Kirkegaard, Poul Henning; Damkilde, Lars

    The present paper documents a proposed modal and wavelet analysis-based structural health monitoring (SHM) method for damage identification in wind turbine blades. A finite element (FE) model of a full-scale wind turbine blade is developed and introduced to a transverse surface crack. Hereby, post......-damage mode shapes are derived through modal analysis and subsequently analyzed with continuous two-dimensional wavelet transformation for damage identification, namely detection, localization and assessment. It is found that valid damage identification is obtained even when utilizing the mode shape of the...

  2. Aspects in Formulating Mathematical Model of Wind Turbine

    Waleed Khalil Ahmed

    2013-06-01

    Full Text Available The present paper explores the mathematical molding of the wind turbine and its influence on the subsequent stages. Specifically, the paper investigate the modeling of gear train of the wind turbine and distinguishes the difference in the approaches usually used to establish the mathematical model which is later has a significant impact on the design, characteristic and performance of the modeled system. Mainly two commonly used approached for the gear train systems are analyzed and discussed.  The main well know mechanisms are investigated in term of the most proposed assumptions to deal with the damping, shaft stiffness and inertia effect of the gear. This paper elucidates these concerns??????: ???, ????, ?????, ?? ?????, ?? ????, ????, ????, ????

  3. Assessment and prediction of wind turbine noise

    The significance of basic aerodynamic noise sources for wind turbine noise are assessed, using information on the aero-acoustic mechanisms of other rotors, which have been studied in depth for many years. From the analysis, areas of potential improvement in wind turbine noise prediction are defined. Suggestions are made for approaches to wind turbine noise control which separate the noise problems at cut-in from those at rated power. Some of these offer the possibility of noise reduction without unfavourable effects on performance. Based on this analysis, a new model for prediction of wind turbine noise is presented and comparisons made between prediction and experiment. The model is based on well established aeroacoustic theory and published laboratory data for the two principal sources, inflow turbulence and boundary layer trailing edge interaction. The new method gives good agreement with experiment with the case studied so far. Parametric trends and sensitivities for the model are presented. Comparisons with previous prediction methods are also given. A consequence of the new model is to put more emphasis on boundary layer trailing edge interaction as a noise source. There are prospects for reducing noise from this source detail changes to the wind turbine design. (author)

  4. Impact of wind turbines on birds

    The paper is a review of the present knowledge on impacts of wind turbines on birds, requested by the Danish Ministry of the Environment and Energy. The main conclusions of the review are, that in nearly all the studies so far the numbers of birds recorded colliding with wind turbines have been limited. Some studies indicate that stationary (breeding) birds inside the wind turbine area in the short run habituate to wind turbines, especially the noise and visual impacts, and that the risk for collision becomes low. However, some of the few more long term studies indicate that a negative impact may occur in later generations of breeding birds. In some studies a disturbance effect on bird species, which temporarily stay inside a wind turbine area in order to forage or rest, is observed. The degree of impact is species-specific. An effect is typically recorded inside a zone of up to 250-800 m, with geese and waders as the most sensitive groups of birds. (author)

  5. Grid integration impacts on wind turbine design and development

    Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Sørensen, Poul Ejnar; Iov, F.

    This paper presents an overall perspective on contemporary issues like wind power plants and grid integration. The purpose is to present and discuss the impacts of emerging new grid connection requirements on modern wind turbines. The grid integration issue has caused several new challenges to the...... wind turbine design and development. The survival of different wind turbine concepts and controls is strongly conditioned by their ability to comply with stringent grid connection requirements, imposed by utility companies. Beside its impact on the mechanical design and control of wind turbines, the...... grid integration aspect has also an effect on wind turbines' role in the power system, on wind turbine technologies' survival on the market, as well as on the wind turbines' loads. Over the last years, it became obviously, that there it is an increasing need for design and research of wind turbines...

  6. Simplified formulae for the estimation of offshore wind turbines clutter on marine radars.

    Grande, Olatz; Cañizo, Josune; Angulo, Itziar; Jenn, David; Danoon, Laith R; Guerra, David; de la Vega, David

    2014-01-01

    The potential impact that offshore wind farms may cause on nearby marine radars should be considered before the wind farm is installed. Strong radar echoes from the turbines may degrade radars' detection capability in the area around the wind farm. Although conventional computational methods provide accurate results of scattering by wind turbines, they are not directly implementable in software tools that can be used to conduct the impact studies. This paper proposes a simple model to assess the clutter that wind turbines may generate on marine radars. This method can be easily implemented in the system modeling software tools for the impact analysis of a wind farm in a real scenario. PMID:24782682

  7. Methods and apparatus for reducing peak wind turbine loads

    Moroz, Emilian Mieczyslaw

    2007-02-13

    A method for reducing peak loads of wind turbines in a changing wind environment includes measuring or estimating an instantaneous wind speed and direction at the wind turbine and determining a yaw error of the wind turbine relative to the measured instantaneous wind direction. The method further includes comparing the yaw error to a yaw error trigger that has different values at different wind speeds and shutting down the wind turbine when the yaw error exceeds the yaw error trigger corresponding to the measured or estimated instantaneous wind speed.

  8. Wind energy cooperatives and private wind turbines in the Netherlands

    Experience of wind energy cooperatives in establishing and running wind turbines in the Netherlands is reported. The Dutch government provides subsidies of about 35% of the investment cost. Despite that, there are still problems and the paper outlines possible solutions. (UK)

  9. Wind tunnel tests of a free yawing downwind wind turbine

    Verelst, David Robert; Larsen, Torben J.; van Wingerden, J.W.

    During February and April 2012 a series of wind tunnel tests were performed at the TU Delft Open Jet Facility (OJF) with a three bladed downwind wind turbine and a rotor radius of 0.8 meters. The setup includes an off the shelf three bladed hub, nacelle and generator on which relatively flexible...

  10. Wind Turbine Test. Wind Matic WM 17S

    Friis Pedersen, Troels

    1986-01-01

    The report describes standard measurements performed on a Wind-Matic WM 17S, 75 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, structural dynamics, loads at cut-in and braking, rotor torque at stopped condition, and noise emission.

  11. Wind Turbine Test. Wind Matic WM 17S

    Friis Pedersen, Troels

    The report describes standard measurements performed on a Wind-Matic WM 17S, 75 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, structural...... dynamics, loads at cut-in and braking, rotor torque at stopped condition, and noise emission....

  12. Bend-twist coupling potential of wind turbine blades

    Fedorov, Vladimir; Berggreen, Christian

    2014-01-01

    and tested on small-scale coupled composite beams. In the proposed method the coupling coefficient for a generic beam is introduced based on the Euler-Bernoulli beam formulation. By applying the developed method for analysis of a commercial wind turbine blade structure it is demonstrated that a bend...

  13. Aeroelastic analysis of a troposkien-type wind turbine blade

    Nitzsche, F.

    1981-01-01

    The linear aeroelastic equations for one curved blade of a vertical axis wind turbine in state vector form are presented. The method is based on a simple integrating matrix scheme together with the transfer matrix idea. The method is proposed as a convenient way of solving the associated eigenvalue problem for general support conditions.

  14. Actuator Line Modeling of Wind Turbine Wakes

    Troldborg, Niels

    2009-01-01

    This thesis contains a comprehensive 3D Navier-Stokes computational study of the characteristics of wakes of wind turbines operating in various flow conditions including interacting wakes between a row of turbines. The computations were carried out using the actuator line technique combined with...... neglected. Furthermore, it is shown that the main effect governing the large scale meandering of wakes is the large scale structures of the ambient turbulence field. Finally studies are conducted on rows of respectively two and three turbines. The investigation includes evaluation of the loading on the...... rotors and it is shown that the turbines are subject to rather severe yaw moments, even in situations where the mean wind is oriented along the row. This observation is indicative of large scale dynamics of the wakes....

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

    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.

  16. Overview of power converter designs feasible for high voltage transformer-less wind turbine

    Sztykiel, Michal

    Many leading wind turbine manufacturers are pushing forward in variable-speed wind turbines, often exceeding 5 MW. Therefore, novel designs and concepts for optimal high power wind turbines appeared. One of the most promising concepts is the high voltage (10-35 kV) transformer-less topology. High...... voltage design enables low power losses and elimination of bulky step-up transformer from the wind turbine system. However, new challenges appear for such topology, which have to be properly identified and successfully overcome. This paper presents possible concept for transformer-less wind turbine...... topology along with an overview of most promising candidates for optimal full-scale power converter design. Study is carried with proposed and justified high voltage wind turbine application along with selection of existing and most promising multilevel power converter topologies, which could be...

  17. Performance of spanish wind turbines

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1994, going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author)

  18. Wind tunnel tests of a free yawing downwind wind turbine

    This research paper presents preliminary results on a behavioural study of a free yawing downwind wind turbine. A series of wind tunnel tests was performed at the TU Delft Open Jet Facility with a three bladed downwind wind turbine and a rotor radius of 0.8 meters. The setup includes an off the shelf three bladed hub, nacelle and generator on which relatively flexible blades are mounted. The tower support structure has free yawing capabilities provided at the base. A short overview on the technical details of the experiment is given as well as a brief summary of the design process. The discussed test cases show that the turbine is stable while operating in free yawing conditions. Further, the effect of the tower shadow passage on the blade flapwise strain measurement is evaluated. Finally, data from the experiment is compared with preliminary simulations using DTU Wind Energy's aeroelastic simulation program HAWC2

  19. Mars Technologies Spawn Durable Wind Turbines

    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.

  20. Reliability-Based Design of Wind Turbine Foundations – Computational Modelling

    Vahdatirad, Mohammad Javad

    increased cost-effectiveness in wind turbines, and an optimized design must be implemented on the expensive structural components. The traditional wind turbine foundation typically expends 25-30% of the total wind turbine budget; thus it is one of the most costly fabrication components. Therefore, a...... parameters, and calibrate the current deterministic methods. The overall objective of the present Ph.D. research is to propose a reliability-based design for the traditional wind turbine foundation. For this reason, probabilistic computational models have been established to characterize the uncertainties...

  1. Methods of making wind turbine rotor blades

    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.

  2. Aerodynamic and aeroacoustic for wind turbine

    Mohamed, Maizi [Centre de Développement des Energies Renouvelables (cder). Alger (Algeria); Rabah, Dizene [Université des Sciences et de Technologie Haouari Boumdienne (USTHB). Alger (Algeria)

    2015-03-10

    This paper describes a hybrid approach forpredicting noise radiated from the rotating Wind Turbine (HAWT) blades, where the sources are extracted from an unsteady Reynolds-Averaged-Navier Stocks (URANS) simulation, ANSYS CFX 11.0, was used to calculate The near-field flow parameters around the blade surface that are necessary for FW-H codes. Comparisons with NREL Phase II experimental results are presented with respect to the pressure distributions for validating a capacity of the solver to calculate the near-field flow on and around the wind turbine blades, The results show that numerical data have a good agreement with experimental. The acoustic pressure, presented as a sum of thickness and loading noise components, is analyzed by means of a discrete fast Fourier transformation for the presentation of the time acoustic time histories in the frequency domain. The results convincingly show that dipole source noise is the dominant noise source for this wind turbine.

  3. Shoosing the appropriate size wind turbine

    Lynette, R. [FloWind Corp., San Rafael, CA (United States)

    1996-12-31

    Within the past several years, wind turbines rated at 400 kW and higher have been introduced into the market, and some manufacturers are developing machines rated at 750 - 1,000+ kW. This raises the question: What is the appropriate size for utility-grade wind turbines today? The answer depends upon the site where the machines will be used and the local conditions. The issues discussed in the paper are: (1) Site-Related (a) Visual, noise, erosion, television interference, interference with aviation (b) Siting efficiency (2) Logistics (a) Adequacy of roads and bridges to accept large vehicles (b) Availability and cost of cranes for erection and maintenance (c) Capability of local repair/overhauls (3) Cost Effectiveness (a) Capital costs (1) Wind Turbine (2) Infrastructure costs (b) Maintenance costs (4) Technical/Financial Risk. 1 fig., 1 tab.

  4. Shape Optimization of Wind Turbine Blades

    Wang, Xudong; Shen, Wen Zhong; Zhu, Wei Jun; Sørensen, Jens Nørkær; Chen, Jin

    2009-01-01

    This paper presents a design tool for optimizing wind turbine blades. The design model is based on an aerodynamic/aero-elastic code that includes the structural dynamics of the blades and the Blade Element Momentum (BEM) theory. To model the main aero-elastic behaviour of a real wind turbine, the...... rotor. The design variables used in the current study are the blade shape parameters, including chord, twist and relative thickness. To validate the implementation of the aerodynamic/aero-elastic model, the computed aerodynamic results are compared to experimental data for the experimental rotor used in...... the European Commision-sponsored project Model Experiments in Controlled Conditions, (MEXICO) and the computed aero-elastic results are examined against the FLEX code for flow post the Tjereborg 2 MW rotor. To illustrate the optimization technique, three wind turbine rotors of different sizes (the...

  5. Nonlinear Multibody Dynamics of Wind Turbines

    Holm-Jørgensen, Kristian

    The continuing development of wind turbines aim at higher effect production and reducing the purchase and maintenance costs for the customers. This demands that the components in the wind turbine are optimized closer to the limit than previously. In order to determine the design loads it is...... the assembling point. This method is more general and can also be used to model the blade in e.g. two substructures or to model other components in the wind turbine. To determine the structural properties of a blade for use in beam element models, a FEmodel is implemented which besides the more common...... each substructure e.g. a part of the blade is modelled by use of Bernoulli-Euler beam elements with St. Venant torsion. For each substructure a belonging moving frame is present, where to the displacements of the substructure must be relative small, in order for the linear displacement assumption to be...

  6. Aerodynamic and aeroacoustic for wind turbine

    This paper describes a hybrid approach forpredicting noise radiated from the rotating Wind Turbine (HAWT) blades, where the sources are extracted from an unsteady Reynolds-Averaged-Navier Stocks (URANS) simulation, ANSYS CFX 11.0, was used to calculate The near-field flow parameters around the blade surface that are necessary for FW-H codes. Comparisons with NREL Phase II experimental results are presented with respect to the pressure distributions for validating a capacity of the solver to calculate the near-field flow on and around the wind turbine blades, The results show that numerical data have a good agreement with experimental. The acoustic pressure, presented as a sum of thickness and loading noise components, is analyzed by means of a discrete fast Fourier transformation for the presentation of the time acoustic time histories in the frequency domain. The results convincingly show that dipole source noise is the dominant noise source for this wind turbine

  7. Operational-Condition-Independent Criteria Dedicated to Monitoring Wind Turbine Generators: Preprint

    Yang, W.; Sheng, S.; Court, R.

    2012-08-01

    To date the existing wind turbine condition monitoring technologies and commercially available systems have not been fully accepted for improving wind turbine availability and reducing their operation and maintenance costs. One of the main reasons is that wind turbines are subject to constantly varying loads and operate at variable rotational speeds. As a consequence, the influences of turbine faults and the effects of varying load and speed are coupled together in wind turbine condition monitoring signals. So, there is an urgent need to either introduce some operational condition de-coupling procedures into the current wind turbine condition monitoring techniques or develop a new operational condition independent wind turbine condition monitoring technique to maintain high turbine availability and achieve the expected economic benefits from wind. The purpose of this paper is to develop such a technique. In the paper, three operational condition independent criteria are developed dedicated for monitoring the operation and health condition of wind turbine generators. All proposed criteria have been tested through both simulated and practical experiments. The experiments have shown that these criteria provide a solution for detecting both mechanical and electrical faults occurring in wind turbine generators.

  8. Evaluating the impact of electrical grid connection on the wind turbine performance for Hofa wind farm scheme in Jordan

    The growth of wind energy is attributed to the development of turbine size and the increase in number of units in each wind farm. The current modern design of large wind turbines (WT) is directed towards producing efficient, sensitive and reliable units. To achieve this goal, modern turbines are equipped with several devices which are operated with highly advanced electronic circuits. Sensing instruments, measuring devices and control processes of major systems and subsystems are based on various types of electronic apparatus and boards. These boards are very sensitive to the voltage variations caused by abnormal conditions in both the turbine itself and the electric grid to which the wind farm is connected. This paper evaluates wind farm records and proposes a number of methods to overcome such obstacles associated with the design of large wind turbines. Several cases of grid abnormality such as sudden feeder interruption due to the short circuit, network disconnection, voltage variation and circuit breaker opening affecting wind turbines operation and availability are classified and presented. The weight of such impact is determined for each type of disturbances associated with electronic problems in the wind turbine. Wind turbine performance at Hofa wind farm scheme in Jordan is taken as a case study

  9. Wind energy; CFD simulation of wakes and wind turbine forces

    Fredriksen,Tommy

    2015-01-01

    Wind power is a clean and renewable energy source, which plays an important role in the world’s energy landscape. When developing a wind farm it is beneficial to analyze the flow pattern in order to maximize the total performance of the wind farm, it is also important to predict wake patterns to prevent structural damage on downstream turbines. Traditional fully detailed CFD models will be very computational heavy to utilize for such analysis. In order to perform an analysis with ...

  10. Micro-wind turbine system in urban environment

    Leung, MKH; Gambarota, L; Y. Deng; Leung, YC

    2011-01-01

    Wind power is identified to be of great potential for extensive development in many countries to reduce the fossil fuel based power generation. Conventional three blades wind turbines are commonly used in locations with high wind energy density, while small wind turbines are developed for less windy locations such as urban areas and flat lands. An innovative micro wind turbine was developed to generate power in urban environment where wind speed is usually low. Differing from the ...

  11. Aerodynamic study of a small horizontal-axis wind turbine

    Nita, Cornelia; Marius Gabriel COJOCARU; Mihai Leonida NICULESCU

    2012-01-01

    The wind energy is deemed as one of the most durable energetic variants of the future because the wind resources are immense. Furthermore, one predicts that the small wind turbine will play a vital role in the urban environment. Unfortunately, nowadays, the noise emissions from wind turbines represent one of the main obstacles to widespread the use in populated zones. Moreover, the energetic efficiency of these wind turbines has to be high even at low and medium wind velocities because, usual...

  12. Modeling of wind turbines for power system studies

    Petru, T.

    2001-05-01

    When wind turbines are installed into the electric grid, the power quality is affected. Today, strict installation recommendations often prevail due to a lack of knowledge on this subject. Consequently, it is important to predict the impact of wind turbines on the electric grid before the turbines are installed. The thesis describes relevant power quality issues, discusses different configurations of wind turbines with respect to power quality and draw requirements regarding wind turbine modeling. A model of a stall-regulated, fixed-speed wind turbine system is introduced and its power quality impact on the electric grid is evaluated. The model is verified with field measurements.

  13. Aeroelastic instability problems for wind turbines

    Hansen, Morten Hartvig

    2007-01-01

    This paper deals with the aeroelostic instabilities that have occurred and may still occur for modem commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines. A review of previous works is combined with derivations of analytical...... stability limits for typical blade sections that show the fundamental mechanisms of these instabilities. The risk of stall-induced vibrations is mainly related to blade airfoil characteristics, effective direction of blade vibrations and structural damping, whereas the blade tip speed, torsional blade...

  14. Offshore Wind Turbines Situated in Areas with Strong Currents

    Jensen, Morten S.; Larsen, Brian Juul; Frigaard, Peter; DeVos, Leen; D. Christensen, Erik; Asp Hansen, Erik; Solberg, Tron; H. Hjertager, Bjørn; Bove, Stefano

    Prediction of local scour caused by offshore wind turbine foundations using empirical formulae or numerical models.......Prediction of local scour caused by offshore wind turbine foundations using empirical formulae or numerical models....

  15. Magnus wind turbines as an alternative to the blade ones

    Experimental and calculated data on a wind turbine equipped with rotating cylinders instead of traditional blades are reported. Optimal parameters and the corresponding operational characteristics of the windwheel are given in comparison with those of the blade wind turbines

  16. Innovative system for wind turbine testing

    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.

  17. Resonant vibration control of wind turbine blades

    Svendsen, Martin Nymann; Krenk, Steen; Høgsberg, Jan Becker

    The paper deals with introduction of damping to specific vibration modes of wind turbine blades, using a resonant controller with acceleration feedback. The wind turbine blade is represented by three-dimensional, two-node finite elements in a local, rotating frame of reference. The element...... formulation accounts for arbitrary mass density distributions, general elastic crosssection properties and geometric stiffness effects due to internal stresses. A compact, linear formulation for aerodynamic forces with associated stiffness and damping terms is established and added to the structural model...

  18. Torsional Performance of Wind Turbine Blades

    Branner, Kim; Berring, Peter; Berggreen, Christian; Knudsen, Henrik W.

    2007-01-01

    The present work investigates how well different finite element modeling techniques can predict bending and torsion behavior of a wind turbine blade. Two shell models are investigated. One model has element offsets and the other has the elements at the mid-thickness surfaces of the model. The last...... two models investigated use a combination of shell and solid elements. The results from the numerical investigations are compared with measurements from testing of a section of a full-scale wind turbine blade. It is found that only the combined shell/solid models give reliable results in torsion. Both...

  19. Mooring system design for floating wind turbines

    Laks, Annika

    2014-01-01

    Recently, there has been a lot of research on floating wind turbines. These structures have to be moored for a station keeping, which is relatively straightforward for deep waters. In transitional water depths (35-70 m) however, it is not obvious how to find a good, cost-efficient mooring system.In this thesis a catenary mooring system for a typical floating wind turbine is designed with different options for the cables: chains, metal and synthetic rope, mixed type and clump weights. The anal...

  20. CFD for wind and tidal offshore turbines

    Montlaur, Adeline

    2015-01-01

    The book encompasses novel CFD techniques to compute offshore wind and tidal applications. Computational fluid dynamics (CFD) techniques are regarded as the main design tool to explore the new engineering challenges presented by offshore wind and tidal turbines for energy generation. The difficulty and costs of undertaking experimental tests in offshore environments have increased the interest in the field of CFD which is used to design appropriate turbines and blades, understand fluid flow physical phenomena associated with offshore environments, predict power production or characterise offshore environments, amongst other topics.

  1. Model Predictive Control of Wind Turbines

    Henriksen, Lars Christian

    nonlinear model predictive controller has been devised and tested under simplified conditions. At present, the nonlinear model predictive controller is however not expected to be an realistic option for real world application as the computation burden is to heavy to achieve real-time performance. This......Wind turbines play a major role in the transformation from a fossil fuel based energy production to a more sustainable production of energy. Total-cost-of-ownership is an important parameter when investors decide in which energy technology they should place their capital. Modern wind turbines are...

  2. Aerodynamic analysis of rotor-nacelle interactions for wind turbines

    This paper presents a numerical method for investigating rotor-nacelle aerodynamic interactions of an horizontal axis wind turbine. The flowfield around the turbine and nacelle is described by the Reynolds averaged Navier-Stokes equations. The k - ? model has been chosen for the closure of time-averaged turbulent flow equations. The turbine is modeled using the actuator disk concept. Most of the nacelle region is represented by its real geometrical shape as wall boundary, except for the cooling system (radiator) of the electric generator which is modeled as a permeable surface with some prescribed pressure jump. An unstructured Control-Volume Finite Element Method has been developed to solve the resulting governing equations. The main purpose of this paper is to establish the relationship between the nacelle wind speed and free stream wind speed for an isolated turbine, in order to assess the impacts of the variation of some operational parameters (e.g. blade pitch angle changes) on this relationship. The simulation results have been compared with the experimental data (from typical a stall-controlled wind turbine rated more than 600kW and commercially available). In general, good agreements have been found proving the validity of the proposed method. It has been concluded that the accuracy of the predicted results depends mainly on the prescribed pressure jump across the permeable surface representing the generator cooling system. (author)

  3. Optimization of wind farm turbines layout using an evolutive algorithm

    The optimum wind farm configuration problem is discussed in this paper and an evolutive algorithm to optimize the wind farm layout is proposed. The algorithm's optimization process is based on a global wind farm cost model using the initial investment and the present value of the yearly net cash flow during the entire wind-farm life span. The proposed algorithm calculates the yearly income due to the sale of the net generated energy taking into account the individual wind turbine loss of production due to wake decay effects and it can deal with areas or terrains with non-uniform load-bearing capacity soil and different roughness length for every wind direction or restrictions such as forbidden areas or limitations in the number of wind turbines or the investment. The results are first favorably compared with those previously published and a second collection of test cases is used to proof the performance and suitability of the proposed evolutive algorithm to find the optimum wind farm configuration. (author)

  4. Optimization of wind farm turbines layout using an evolutive algorithm

    Gonzalez, Javier Serrano; Santos, Jesus Riquelme; Payan, Manuel Burgos [Department of Electrical Engineering, Av. de los Descubrimientos, University of Sevilla, Sevilla (Spain); Gonzalez Rodriguez, Angel G. [Department of Electronic Engineering and Automatic, University of Jaen, Jaen (Spain); Mora, Jose Castro [Persan S.A., Sevilla (Spain)

    2010-08-15

    The optimum wind farm configuration problem is discussed in this paper and an evolutive algorithm to optimize the wind farm layout is proposed. The algorithm's optimization process is based on a global wind farm cost model using the initial investment and the present value of the yearly net cash flow during the entire wind-farm life span. The proposed algorithm calculates the yearly income due to the sale of the net generated energy taking into account the individual wind turbine loss of production due to wake decay effects and it can deal with areas or terrains with non-uniform load-bearing capacity soil and different roughness length for every wind direction or restrictions such as forbidden areas or limitations in the number of wind turbines or the investment. The results are first favorably compared with those previously published and a second collection of test cases is used to proof the performance and suitability of the proposed evolutive algorithm to find the optimum wind farm configuration. (author)

  5. Amplitude modulation of wind turbine noise

    Makarewicz, Rufin

    2013-01-01

    Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2).

  6. Amplitude modulation of wind turbine noise

    Makarewicz, Rufin; Golebiewski, Roman

    2013-01-01

    Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and mi...

  7. Minimum Thrust Load Control for Floating Wind Turbine

    Christiansen, Søren; Bak, Thomas; Knudsen, Torben

    — Offshore wind energy capitalizes on the higher and less turbulent wind at sea. Shallow water sites are profitable for deployment of monopile wind turbines at water depths of up to 30 meters. Beyond 30 meters, the wind is even stronger and less turbulent. At these depths, floating wind turbines be...

  8. Methods and apparatus for rotor load control in wind turbines

    Moroz, Emilian Mieczyslaw

    2006-08-22

    A wind turbine having a rotor, at least one rotor blade, and a plurality of generators, of which a first generator is configured to provide power to an electric grid and a second generator is configured to provide power to the wind turbine during times of grid loss. The wind turbine is configured to utilize power provided by the second generator to reduce loads on the wind turbine during times of grid loss.

  9. Wind Turbine Noise and Natural Sounds : Masking, Propagation and Modeling

    Bolin, Karl

    2009-01-01

    Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. Ambient sounds influence the audibility of wind turbine noise. Models for assessing two commonly occurring natural ambient sounds namely vegetation sound and sound from breaking waves are pres...

  10. Impact of wind turbines on birdlife

    An overview of wind energy programmes is presented, as well as an analysis of recent studies on the title subject and data on the attitude of nature conservation organisations both from the USA and Europe. The studies were analyzed for legitimacy of assumptions and validity of the conclusions. Most of the wind energy programs and all European studies deal with bird kills and disturbance in coastal areas. The number of victims per turbine per year in this type of area appears to be acceptable. The disturbing effect of wind turbines on breeding birds appears to be negligible. The disturbance of resting and migrating birds by wind turbines however is reasonably clear. As a result of international concern several sites have been designated where siting of wind turbines is prohibited. Well known examples are wetlands of international importance (Ramsar-convention) and European Community Special Protection Areas. Major concern among conservationists is the location of many valuable and vulnerable environmental resources outside the protected areas. Negative attitudes towards wind energy projects are not particularly due to avian considerations, but rather to a general objective to protect landscapes and habitats, undisturbed by human infrastructures and disturbance. It is concluded that all new locations for wind energy projects should be weighed on the disturbance aspect. Reference data for such a weigh are available for coastal areas, although the impact on local migration between feeding grounds and high water refugee areas needs further research. Future research is also needed for application of wind energy both on off-shore locations, grasslands and farmlands. Wind energy developers and conservationists should have a close contact in order to establish consensus on how to deal with remaining uncertainties. 7 figs., 9 tabs., 5 appendices, 37 refs

  11. An investigation of the levels of electromagnetic radiation generated by wind turbines

    The issue of electromagnetic interference is arising with some regularity as various wind energy projects throughout the UK reach the stage where local authority planning approval is sought. To many of the parties involved, wind turbines represent an unknown quantity and hence objections to their siting must be expected. Wind turbines may cause electromagnetic interference through two quite distinct processes. The first occurs when the wind turbine scatters electromagnetic signals passing through the area of the site and essentially, provides a second path between the transmitter and receiver of the signal. The second source of interference arises when signals generated within the wind turbine itself affect communications equipment or, indeed, any electronic circuitry. A case in point is a wind farm project under development by Bonython Estates of Cornwall. The aim of this project was to investigate the emissions from the wind turbines proposed for the Bonython development. This was achieved by means of field measurements on existing installations. (author)

  12. Effectiveness of Changing Wind Turbine Cut-in Speed to Reduce Bat Fatalities at Wind Facilities

    Huso, Manuela M. P. [Oregon State Univ., Corvallis, OR (United States); Hayes, John P. [Univ. of Florida, Gainesville, FL (United States)

    2009-04-01

    This report details an experiment on the effectiveness of changing wind turbine cut-in speed on reducing bat fatality from wind turbines at the Casselman Wind Project in Somerset County, Pennsylvania.

  13. Wind energy and the trend towards megawatt turbines

    The economic potential for wind energy in Europe and the trend towards megawatt turbines is discussed. It is expected that the portion of wind energy in the total power production in Europe will rise to 2 percent in 2000. Presently, the power generation by wind energy is economically feasible for wind turbines with a capacity of 300 to 400 k W. The present technologic evolution indicates that larger and lighter wind turbines will be developed. A clear trend towards megawatt turbines in wind parks or clusters is observed. Commercially developed megawatt turbines are expected to become available during the coming 3 to 5 years. (A.S.)

  14. Repetitive model predictive approach to individual pitch control of wind turbines

    Adegas, Fabiano Daher; Stoustrup, Jakob; Odgaard, Peter Fogh

    2011-01-01

    Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use this....... A simulation comparison betweeen the proposed controller and an industry-standard PID controller shows better mitigation of drive-train, blade and tower loads.......Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use this...... peculiar disturbance pattern to better attenuate loads and regulate power by controlling the blade pitch angles individually. A novel model predictive (MPC) approach for individual pitch control of wind turbines is proposed in this paper. A repetitive wind disturbance model is incorporated into the MPC...

  15. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    Taufik Roni Sahroni

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting...

  16. Two LQRI based Blade Pitch Controls for Wind Turbines

    Sungsu Park

    2012-06-01

    Full Text Available As the wind turbine size has been increasing and their mechanical components are built lighter, the reduction of the structural loads becomes a very important task of wind turbine control in addition to maximum wind power capture. In this paper, we present a separate set of collective and individual pitch control algorithms. Both pitch control algorithms use the LQR control technique with integral action (LQRI, and utilize Kalman filters to estimate system states and wind speed. Compared to previous works in this area, our pitch control algorithms can control rotor speed and blade bending moments at the same time to improve the trade-off between rotor speed regulation and load reduction, while both collective and individual pitch controls can be designed separately. Simulation results show that the proposed collective and individual pitch controllers achieve very good rotor speed regulation and significant reduction of blade bending moments.

  17. Adaptive pitch control for load mitigation of wind turbines

    Yuan, Yuan; Tang, J.

    2015-04-01

    In this research, model reference adaptive control is examined for the pitch control of wind turbines that may suffer from reduced life owing to extreme loads and fatigue when operated under a high wind speed. Specifically, we aim at making a trade-off between the maximum energy captured and the load induced. The adaptive controller is designed to track the optimal generator speed and at the same time to mitigate component loads under turbulent wind field and other uncertainties. The proposed algorithm is tested on the NREL offshore 5-MW baseline wind turbine, and its performance is compared with that those of the gain scheduled proportional integral (GSPI) control and the disturbance accommodating control (DAC). The results show that the blade root flapwise load can be reduced at a slight expense of optimal power output. The generator speed regulation under adaptive controller is better than DAC.

  18. WIND TURBINE OPERATION PARAMETER CHARACTERISTICS AT A GIVEN WIND SPEED

    Zdzisław Kamiński

    2014-06-01

    Full Text Available This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.

  19. Wind Turbine Contingency Control Through Generator De-Rating

    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.

  20. Duration Test Report for the Entegrity EW50 Wind Turbine

    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.

  1. Power Electronics as key technology in wind turbines

    Blaabjerg, Frede

    This paper discuss the development in wind turbines in a two-decade perspective looking at the technology based on track records. Different power electronic topologies for interfacing the wind turbine to the grid are discussed and related to the possibility for the wind turbine to act as a power...

  2. Miniature horizontal axis wind turbine system for multipurpose application

    A MWT (miniature wind turbine) has received great attention recently for powering WISP (Wireless Intelligent Sensor Platform). In this study, two MHAWTs (miniature horizontal axis wind turbines) with and without gear transmission were designed and fabricated. A physics-based model was proposed and the optimal load resistances of the MHAWTs were predicted. The open circuit voltages, output powers and net efficiencies were measured under various ambient winds and load resistances. The experimental results showed the optimal load resistances matched well with the predicted results; the MHAWT without gear obtained higher output power at the wind speed of 2 m/s to 6 m/s, while the geared MHAWT exhibited better performance at the wind speed higher than 6 m/s. In addition, a DCM (discontinuous conduction mode) buck-boost converter was adopted as an interface circuit to maximize the charging power from MHAWTs to rechargeable batteries, exhibiting maximum efficiencies above 85%. The charging power reached about 8 mW and 36 mW at the wind speeds of 4 m/s and 6 m/s respectively, which indicated that the MHAWTs were capable for sufficient energy harvesting for powering low-power electronics continuously. - Highlights: • Performance of the miniature wind turbines with and without gears was compared. • The physics-based model was established and proved successfully. • The interface circuit with efficiency of more than 85% was designed

  3. Optimizing wind turbine control system parameters

    Schluter, L.L. [Sandia National Labs., Albuquerque, NM (United States); Vachon, W.A. [Vachon (W.A.) and Associates, Inc., Manchester, MA (United States)

    1993-08-01

    The impending expiration of the levelized period in the Interim Standard Offer Number 4 (ISO4) utility contracts for purchasing wind-generated power in California mandates, more than ever, that windplants be operated in a cost-effective manner. Operating plans and approaches are needed that maximize the net revenue from wind parks--after accounting for operation and maintenance costs. This paper describes a design tool that makes it possible to tailor a control system of a wind turbine (WT) to maximize energy production while minimizing the financial consequences of fatigue damage to key structural components. Plans for code enhancements to include expert systems and fuzzy logic are discussed, and typical results are presented in which the code is applied to study the controls of a generic Danish 15-m horizontal axis wind turbine (HAWT).

  4. Power Electronics Converters for Wind Turbine Systems

    Blaabjerg, Frede; Liserre, Marco; Ma, Ke

    2012-01-01

    The steady growth of installed wind power together with the upscaling of the single wind turbine power capability has pushed the research and development of power converters toward full-scale power conversion, lowered cost pr kW, increased power density, and also the need for higher reliability. In...... this paper, power converter technologies are reviewed with focus on existing ones and on those that have potential for higher power but which have not been yet adopted due to the important risk associated with the high-power industry. The power converters are classified into single- and multicell...... topologies, in the latter case with attention to series connection and parallel connection either electrical or magnetic ones (multiphase/windings machines/transformers). It is concluded that as the power level increases in wind turbines, medium-voltage power converters will be a dominant power converter...

  5. Wind resource estimation and siting of wind turbines

    Lundtang Petersen, Erik; Mortensen, N.G.; Landberg, L.

    Detailed knowledge of the characteristics of the natural wind is necessary for the design, planning and operational aspect of wind energy systems. Here, we shall only be concerned with those meteorological aspects of wind energy planning that are termed wind resource estimation. The estimation of...... the wind resource ranges from the overall estimation of the mean energy content of the wind over a large area - called regional assessment - to the prediction of the average yearly energy production of a specific wind turbine at a specific location - called siting. A regional assessment will most...... deviations in the anticipated power production and thereby lead to considerable uncertainty in the assessment of the economic benefits of installing wind power....

  6. Damping Wind and Wave Loads on a Floating Wind Turbine

    Torben Knudsen

    2013-08-01

    Full Text Available Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due to the partly unconstrained movement of the platform and ocean wave excitation. If this additional complexity is not dealt with properly, this may lead to a significant increase in the structural loads and, potentially, instability of the controlled system. In this paper, the wave excitation is investigated, and we show the influence that both wind speed, wave frequencies and misalignment between wind and waves have on the system dynamics. A new control model is derived that extends standard turbine models to include the hydrodynamics, additional platform degrees of freedom, the platform mooring system and tower side-side motion, including gyroscopic effects. The models support a model-based design that includes estimators for wind speed and wave frequency. The design is applied to a number of examples representing different wind and wave conditions and successfully demonstrates a reduction in the structural oscillations, while improving power performance.

  7. Dynamic Model of a Wind Turbine for the Electric Energy Generation

    José de Jesús Rubio; Luis Arturo Soriano; Wen Yu

    2014-01-01

    A novel dynamic model is introduced for the modeling of the wind turbine behavior. The objective of the wind turbine is the electric energy generation. The analytic model has the characteristic that considers a rotatory tower. Experiments show the validity of the proposed method.

  8. Modelling and Analysis of DFIG Wind Turbine Harmonics Generated in Grids

    Chilambuchelvan, A.; B.BabyPriya,

    2010-01-01

    In this paper an analytic technique for modelling harmonics is proposed for a DFIG wind turbine connected to the grid. An algorithm based on Hilbert transform for the analysis of harmonics in power systems isdeveloped. The simulation results prove the effectiveness of the Hilbert Transform (HT) for power harmonic analysis in DFIG wind turbine connected to a grid.

  9. European wind turbine testing procedure developments. Task 1: Measurement method to verify wind turbine performance characteristics

    Hunter, R.; Friis Pedersen, T.; Dunbabin, P.; Antoniou, I.; Frandsen, S.; Klug, H.; Albers, A.; Lee, W.K.

    2001-01-01

    There is currently significant standardisation work ongoing in the context of wind farm energy yield warranty assessment and wind turbine power performance testing. A standards maintenance team is revising the current IEC (EN) 61400-12 Ed 1 standard for wind turbine power performance testing. The standard is being divided into four documents. Two of them are drafted for evaluation and verification of complete wind farms and of individual wind turbines within wind farms. This document, and the project it describes, has been designed to help provide a solid technical foundation for this revised standard. The work was wide ranging and addressed 'grey' areas of knowledge, regarding existing methodologies or to carry out basic research in support of fundamentally new procedures. The work has given rise to recommendations in all areas of the work, including site calibration procedures, nacelle anemometry, multi-variate regression analysis and density normalisation. (au)

  10. Wind Turbine Control Impact on Stability of Wind Farms Based on Real-Life Systems Analysis

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2012-01-01

    This paper presents stability analysis of wind farms in frequency domain. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply investigated. Two wind farms (i.e. Horns Rev II and Karnice) are taken in to consideration in the study. It is shown that wind farm components such as long HVAC cables and park transformers can introduce significant low-frequency series resonances seen form the wind turbine terminals which can affect wind turbine ...

  11. Enhancing wind turbines efficiency with passive reconfiguration of flexible blades

    Cognet, Vincent P. A.; Thiria, Benjamin; Courrech Du Pont, Sylvain; MSC Team; PMMH Team

    2015-11-01

    Nature provides excellent examples where flexible materials are advantageous in a fluid stream. By folding, leaves decrease the drag caused by air stream; and birds' flapping is much more efficient with flexible wings. Motivated by this, we investigate the effect of flexible blades on the performance of a wind turbine. The effect of chordwise flexible blades is studied both experimentally and theoretically on a small wind turbine in steady state. Four parameters are varied: the wind velocity, the resisting torque, the pitch angle, and the blade's bending modulus. We find an optimum efficiency with respect to the bending modulus. By tuning our four parameters, the wind turbine with flexible blades has a high-efficiency range significantly larger than rigid blades', and, furthermore enhances the operating range. These results are all the more important as one of the current issues concerning wind turbines is the enlargement of their operating range. To explain these results, we propose a simple two-dimensional model by discretising the blade along the radius. We take into account the variation of drag and lift coefficients with the bending ability. This model matches experimental observations and demonstrates the contribution of the reconfiguration of the blade. Matiere et Systemes Complexes.

  12. Behavior of bats at wind turbines

    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.; Frank J. Bonaccorso; Johnson, Douglas H; Heist, Kevin; Dalton, David C.

    2014-01-01

    Bats are dying in unprecedented numbers at wind turbines, but causes of their susceptibility are unknown. Fatalities peak during low-wind conditions in late summer and autumn and primarily involve species that evolved to roost in trees. Common behaviors of “tree bats” might put them at risk, yet the difficulty of observing high-flying nocturnal animals has limited our understanding of their behaviors around tall structures. We used thermal surveillance cameras for, to our knowledge, the first...

  13. Can road traffic mask sound from wind turbines? Response to wind turbine sound at different levels of road traffic sound

    Pedersen, Eja; van den Berg, Frits; Bakker, Roel; Bouma, Jelte

    2010-01-01

    Wind turbines are favoured in the switch-over to renewable energy. Suitable sites for further developments could be difficult to find as the sound emitted from the rotor blades calls for a sufficient distance to residents to avoid negative effects. The aim of this study was to explore if road traffic sound could mask wind turbine sound or, in contrast, increases annoyance due to wind turbine noise. Annoyance of road traffic and wind turbine noise was measured in the WINDFARMperception survey ...

  14. Wind turbines in your environment? Wind turbines and economic aspects

    The wind energy industry has demonstrated its maturity and technical reliability. Because it will play an increasing role on the power generation market, the question of the cost and profitability of the wind energy has become of prime importance. Two main traps must be avoided: the first should be to deny the present and future economical interest of wind energy because of its supplementary cost with respect to conventional power generation techniques. The second trap should be to underestimate the economical progresses that wind energy must carry on to ensure its large scale development. Therefore, some advantageous pricing and regulatory conditions are necessary to allow the development of this emerging energy source. This document presents: the cost of a wind power project (initial investment, financial incentives); the profitability of a project (cost of a kWh of wind power origin, retail price, warranty of power supply capacity, indirect environmental costs, value of decentralized production); economical interest of wind power (energy efficiency, employment, financial advantages for the local economy); and who are the investors. (J.S.)

  15. Noise measurements in 4 wind turbine farms

    The title wind turbine arrays are situated in Herbayum (Newinco 23PI250), Callantsoog (Bouma 160/20), Noordoostpolder (Windmaster WM300), and Ulketocht (Newinco 500 kW). Measurements were carried out by means of the so-called Ecofys Correlating Noise Meter to determine the source level of the wind turbines. The resulting source level as a function of the wind speed is interpolated to a source level for a wind speed of 8 m/s at 10 m height, on the basis of which the noise contours can be calculated. The noise contours are determined to analyze the noise load for people living in the neighbourhood of the wind parks. The source levels are compared with values as indicated in certificates, which are granted on the basis of a so-called Restricted Quality Certificate (BKC, abbreviated in Dutch) or the new standard NNI 6096/2 for the above-mentioned wind turbines. In general the results of this study agree quite well with the certified values. 12 figs., 7 tabs., 6 refs

  16. Built-Environment Wind Turbine Roadmap

    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.

  17. Learning in wind turbine development

    Kamp, Linda Manon

    2002-01-01

    Both the Netherlands and Denmark started to develop wind energy in the 1970s. Reasons were the oil crisis and the Club of Rome report, which warned of imminent shortages of traditional energy sources like oil and gas. Both countries started this development around 1975 and their governments gave active support. Furthermore, both countries have a comparable wind regime. However, the result of the development of wind energy in each country is very different. In the year 2000, Denmark had a flou...

  18. Low Cost Small Wind Turbine Generators for Developing Countries:

    Ani, S.O.

    2013-01-01

    Wind energy accounts for an increasing percentage of the energy supplied to the electricity network. Electricity generation from wind is now cheaper than other renewables and almost cost competitive with other conventional sources of electricity generation. However, this impressive growth is largely due to advances in large wind turbines, particularly off-shore wind turbines. Small wind turbines on the other hand have not been developing at such an impressive rate. In the past few years, an a...

  19. Large wind turbine development in Europe

    Zervos, A. [Center for Renewable Energy Sources, Attikis (Greece)

    1996-12-31

    During the last few years we have witnessed in Europe the development of a new generation of wind turbines ranging from 1000-1500 kW size. They are presently being tested and they are scheduled to reach the market in late 1996 early 1997. The European Commission has played a key role by funding the research leading to the development of these turbines. The most visible initiative at present is the WEGA program - the development, together with Europe`s leading wind industry players of a new generation of turbines in the MW range. By the year 1997 different European manufacturers will have introduced almost a dozen new MW machine types to the international market, half of them rated at 1.5 MW. 3 refs., 3 tabs.

  20. Wind Turbine Tribology Seminar - A Recap

    Errichello, R.; Sheng, S.; Keller, J.; Greco, A.

    2012-02-01

    Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication, and wear. It is an important phenomenon that not only impacts the design and operation of wind turbine gearboxes, but also their subsequent maintenance requirements and overall reliability. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The Wind Turbine Tribology Seminar was convened to explore the state-of-the-art in wind turbine tribology and lubricant technologies, raise industry awareness of a very complex topic, present the science behind each technology, and identify possible R&D areas. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of tribology by acknowledged experts, the National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), and the U.S. Department of Energy (DOE) hosted a wind turbine tribology seminar. It was held at the Renaissance Boulder Flatiron Hotel in Broomfield, Colorado on November 15-17, 2011. This report is a summary of the content and conclusions. The presentations given at the meeting can be downloaded. Interested readers who were not at the meeting may wish to consult the detailed publications listed in the bibliography section, obtain the cited articles in the public domain, or contact the authors directly.

  1. Aeroelastic Optimization of MW Wind Turbines

    Hansen, Morten Hartvig; Zahle, Frederik

    This report contains the results from the Energy Development and Demonstration Project “Aeroelastic Optimization of MW wind turbine” (AeroOpt). The project has had the following five Work Packages: 1. Geometric non-linear, anisotropic beamelement forHAWC2 2. Closed-loop eigenvalue analysis of...

  2. Wooden wind turbine blade manufacturing process

    Coleman, Clint (Warren, VT)

    1986-01-01

    A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis.

  3. Evaluation of airfoils for small wind turbines

    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 ...

  4. Review paper on wind turbine aerodynamics

    Hansen, Martin Otto Laver; Aagaard Madsen, Helge

    2011-01-01

    The paper describes the development and description of the aerodynamic models used to estimate the aerodynamic loads on wind turbine constructions. This includes a status of the capabilities of computation fluid dynamics and the need for reliable airfoil data for the simpler engineering models...

  5. Infrasound from Wind Turbines Could Affect Humans

    Salt, Alec N.; Kaltenbach, James A.

    2011-01-01

    Wind turbines generate low-frequency sounds that affect the ear. The ear is superficially similar to a microphone, converting mechanical sound waves into electrical signals, but does this by complex physiologic processes. Serious misconceptions about low-frequency sound and the ear have resulted from a failure to consider in detail how the ear…

  6. Torsional Performance of Wind Turbine Blades

    Berring, Peter; Branner, Kim; Berggreen, Christian; Knudsen, Henrik W.

    2007-01-01

    The complete 3D static responses of two different eight meter long wind turbine blade sections were tested. To experimentally investigate the 3D response, an advanced 3D digital optical deformation measuring system (ARAMIS 2M and 4M) was applied in this work. This system measures the full-field d...

  7. Perceptions of environmental impacts of wind turbines

    Local wind turbine planning often stresses noise and visual impacts, without considering the externalities of central energy supply options. This situation calls for a coordination between national and local planning procedures, as well as for a program of information and education directed at the planning profession. (author)

  8. Development of Superconducting Wind Turbine Generators

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2012-01-01

    In this paper the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational s...

  9. Dynamic Response of Flexible Wind Turbine Blade

    Yu-qiao Zheng

    2013-07-01

    Full Text Available Aiming at the non-stationary and stall flutter problems of wind turbine blade caused by transient load fluctuations, the dynamic properties of wind turbine were studied, the blade was simplify to a cantilever beam in case of the action of shear deformation and cross section rotating effect were considered in this analysis, equations of the blade were established based on D'Alemberts' principle and the principle of virtual displacement. The dynamic response of the wind turbine was solved by using the finite element method under the transient load environment. A 29.2 m rotor blade, previously reported in specialized literature, was chosen as a case study to validate dynamic behaviour predicted by a Timoshenko beam model. It is concluded that despite its simplicity, The cross-sectional shear-deformation  has great influence on  dynamic response of the blade.Dynamic model is sufficiently accurate to serve as a design tool for the recursive analyses required during design and optimization stages of wind turbines using only readily available computational tools.

  10. Fatigue Life of Wind Turbine Blades

    Thoft-Christensen, Palle

    The present paper analyses the possibility of reducing the expected damage accumulation during tower passage by modifying the wind turbine tower design from a traditional mono-tower to a tripod. Due to a narrow stagnation zone the stress reversals and hence the damage accumulation in the blades is...... substantial smaller in the tripod tower design compared to the mono-tower....

  11. Infrasound from Wind Turbines Could Affect Humans

    Salt, Alec N.; Kaltenbach, James A.

    2011-01-01

    Wind turbines generate low-frequency sounds that affect the ear. The ear is superficially similar to a microphone, converting mechanical sound waves into electrical signals, but does this by complex physiologic processes. Serious misconceptions about low-frequency sound and the ear have resulted from a failure to consider in detail how the ear…

  12. Root region airfoil for wind turbine

    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.

  13. Scour protection around offshore wind turbines. Monopiles

    Nielsen, Anders Wedel; Sumer, B. Mutlu; Fredsøe, Jørgen; Christensen, Erik Damgaard

    stability of the mono-pile and change for instance the natural frequency of the dynamic response odf an offshore wind turbine in an unfacorable manner. The most importans flow process with regard to transport of sediment and sinking of the scour protection in found to be the horseshoe vortex. It is found...

  14. Aero-acoustic Computations of Wind Turbines

    Shen, Wen Zhong; Michelsen, Jess; Sørensen, Jens Nørkær

    A numerical algorithm for acoustic noise generation is extended to 3D flows. The approach involves two parts comprising a viscous incompressible flow part and an inviscid acoustic part. In order to simulate noise generated from a wind turbine, the incompressible and acoustic equations are written...

  15. Floating axis wind turbines for offshore power generation—a conceptual study

    The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

  16. Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines

    Zhang, Yunqian; Hu, Weihao; Chen, Zhe; Cheng, Ming

    2012-01-01

    Grid connected wind turbines are the sources of power fluctuations during continuous operation due to wind speed variation, wind shear and tower shadow effects. This paper presents an individual pitch control (IPC) strategy to mitigate the wind turbine power fluctuation at both above and below the...... rated wind speed conditions. Three pitch angles are adjusted separately according to the generator output power and the azimuth angle of the wind turbine. The IPC strategy scheme is proposed and the individual pitch controller is designed. The simulations are performed on the NREL (National Renewable...... Energy Laboratory) 1.5MW upwind reference wind turbine model. The simulation results are presented and discussed to show the validity of the proposed control method....

  17. Transient stability of DFIG wind turbines at an external short-circuit fault

    Sun, Tao; Chen, Zhe; Blaabjerg, Frede

    2005-07-01

    The fast development of wind power generation brings new requirements for wind turbine integration into the network. After clearance of an external short-circuit fault, grid-connected wind turbines should restore their normal operation without power loss caused by disconnections. This article concentrates on the transient stability of variable speed wind turbines with doubly fed induction generators (DFIGs) at an external short-circuit fault. A simulation model of a MW-level variable speed wind turbine with a DFIG developed in PSCAD/EMTDC is presented and the control and protection schemes are described in detail. The transient process of grid-connected wind turbines with DFIGs at an external short-circuit fault is analysed, and in critical post-fault situations a measure is proposed for the voltage recovery of DFIG wind turbines after fault clearance. Simulation results demonstrate that in uncritical post-fault situations the control schemes are able to restore the wind turbine's normal operation without disconnections. It is also proved that the proposed measure is effective in re-establishing the voltage at the wind turbine terminal in critical post-fault situations. Copyright

  18. Leasing wind turbines (and its alternatives)

    The financing of wind farms has historically consisted of a mixture of traditional debt and equity, with debt generally being provided by high street or specialist banks, through inter-company loans, or from International Funding Agencies (IFA's) via National Funding Agencies in developing countries. The use of more innovative financing methods has to date been limited. One possible methods of attracting finance for wind farms is the leasing of wind turbines, and this paper sets out the reasons leasing is particularly appropriate for renewable energy (RE) projects (in particular wind farms), the effect leasing may have on returns available to investors, and some of the obstacles that have to be overcome by the RE and wind industry to increase the utilisation of leasing. This paper concludes by discussing the possibility of using a pan-European leasing company as means of providing overseas aid to developing countries, thereby facilitating the implementation of wind energy in these important regions. (Author)

  19. Control of Next Generation Aircraft and Wind Turbines

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  20. Grid fault and design-basis for wind turbines. Final report

    Hansen, A.D.; Cutululis, N.A.; Markou, H.; Soerensen, Poul; Iov, F.

    2010-01-15

    This is the final report of a Danish research project 'Grid fault and design-basis for wind turbines'. The objective of this project has been to assess and analyze the consequences of the new grid connection requirements for the fatigue and ultimate structural loads of wind turbines. The fulfillment of the grid connection requirements poses challenges for the design of both the electrical system and the mechanical structure of wind turbines. The development of wind turbine models and novel control strategies to fulfill the TSO's requirements are of vital importance in this design. Dynamic models and different fault ride-through control strategies have been developed and assessed in this project for three different wind turbine concepts (active stall wind turbine, variable speed doublyfed induction generator wind turbine, variable speed multipole permanent magnet wind turbine). A computer approach for the quantification of the wind turbines structural loads caused by the fault ride-through grid requirement, has been proposed and exemplified for the case of an active stall wind turbine. This approach relies on the combination of knowledge from complimentary simulation tools, which have expertise in different specialized design areas for wind turbines. In order to quantify the impact of the grid faults and grid requirements fulfillment on wind turbines structural loads and thus on their lifetime, a rainflow and a statistical analysis for fatigue and ultimate structural loads, respectively, have been performed and compared for two cases, i.e. one when the turbine is immediately disconnected from the grid when a grid fault occurs and one when the turbine is equipped with a fault ride-through controller and therefore it is able to remain connected to the grid during the grid fault. Different storm control strategies, that enable variable speed wind turbines to produce power at wind speeds higher than 25m/s and up to 50m/s without substantially increasing the structural loads, have also been proposed and investigated during the project. Statistics in terms of mean value and standard deviation have been analysed and rainflow calculations have been performed to estimate the impact over the lifetime of a variable speed wind turbine. (author)

  1. Cooperative wind turbine control for maximizing wind farm power using sequential convex programming

    Highlights: • The continuous wake model describes well the wake profile behind a wind turbine. • The wind farm power function describes well the power production of a wind farm. • Cooperative control increases the wind farm power efficiency by 7.3% in average. • SCP can be employed to efficiently optimize the control actions of wind turbines. - Abstract: This paper describes the use of a cooperative wind farm control approach to improve the power production of a wind farm. The power production by a downstream wind turbine can decrease significantly due to reduced wind speed caused by the upstream wind turbines, thereby lowering the overall wind farm power production efficiency. In spite of the interactions among the wind turbines, the conventional (greedy) wind turbine control strategy tries to maximize the power of each individual wind turbine by controlling its yaw angle, its blade pitch angle and its generator torque. To maximize the overall wind farm power production while taking the wake interference into account, this study employs a cooperative control strategy. We first derive the wind farm power as a differentiable function of the control actions for the wind turbines in a wind farm. The wind farm power function is then maximized using sequential convex programming (SCP) to determine the optimum coordinated control actions for the wind turbines. Using an example wind farm site and available wind data, we show how the cooperative control strategy improves the power production of the wind farm

  2. Economic Analysis of Wind Turbine Installation in Taiwan

    Jeeng-Min Ling; Kunkerati Lublertlop

    2015-01-01

    The wind speed characteristics are analyzed statistically based on a long-term hourly data record to evaluate the proper wind energy potential. The annual average wind speed and wind power density are investigated and compared by some significant indices, wind energy output and capacity factor, to show the variations of proper wind turbine specifications of installation in different locations of Taiwan. The minimum cost of wind energy is used to assess the economical feasibility for turbine i...

  3. Electrical Aspects of Wind Turbines

    Chen, Zhe; Blaabjerg, Frede

    2009-01-01

    This is the most authoritative single volume on offshore wind power yet published. Distinguished experts, mainly from Europe's leading universities, have contributed a collection of peer reviewed papers on the interfaces between wind power technology and marine engineering. The range of issues co...

  4. Power Performance Test Report for the SWIFT Wind Turbine

    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.

  5. Control Logic Algorithm for Medium Scale Wind Turbines

    Osama Abdel Hakeem Abdel Sattar

    2012-01-01

    Full Text Available Recently, sustainable attention has been drawn to renewable energy sources. Wind energy systems as renewable source of energy have been extensively studied because of its benefits as an environmentally friendly clean energy, inexhaustible, safe and a low-cost for long term. Because of its unpredictable availability, power management control algorithms are essential to extract as much power as possible from the wind during its availability durations. This paper is motivated for proposing the main control algorithm for wind turbines each incorporating two generators. The proposed main algorithm contains several sub algorithm models (strategies for power control, pitch control, status checking, starting, grid connection, normal and emergency shutdown that are studied, designed and also, tested under operation. The testing phase shows that in the high wind speed range, the pitch control seems the most relevant to release a power margin. While in the low wind speed range, the increase of the rotation speed is more convenient.

  6. Lift Augmentation for Vertical Axis Wind Turbines

    Gerald M Angle II

    2010-12-01

    Full Text Available The concept of harnessing wind power has been around for centuries, and is first recorded by the Persians in 900 AD. These early uses of wind power were for the processing of food, particularly grinding grains, and consisted of stationary blades around a horizontal axis, the precursor to today’s horizontal axis wind turbines (HAWT. Technology for these wind mills was essentially the same until the 1930’s when advances in aircraft propeller theories were applied to the blades of the turbine. During this development period, which has since remained basically unchanged, the design push was for increasingly larger propellers requiring heavy and costly transmissions, generators, and support towers to be installed. An alternative concept to the HAWT was developed by Georges Darrieus [5], which utilized a vertical shaft and is known as a vertical axis wind turbine (VAWT. The scientific development of the concept did not gain strong attention until the 1970’s due to the perceived low efficiency of this style. This perception was due in part to the portion of the blade’s rotary path that is adverse to the generation of power. This efficiency loss can be minimized by the mechanical movement of the blade, relative to the airflow during the upwind portion of the blades’ rotational path. Since, circulation control can alter the forces generated by an airfoil, it could be used to increase the efficiency of a VAWT by increasing the torque produced on the downwind portion of the path, while removing the need for a physical change in angle of attack. With the recent upturn in petroleum costs and global warming concerns, interest in renewable energy technologies have been reinvigorated, in particular the desire for advanced wind energy technologies, including the application of lift augmentation techniques. One of these techniques is to utilize circulation control to enhance the lifting capacity of the blades based on the location of the blade in the turbine’s rotation. Though this technology can be applied to any wind turbine, whether horizontal or vertical axis, this paper focuses on the application of circulation control for VAWT’s due primarily to reduced hardware complexities and to increase the performance of this design thus helping to level the playing field between the two styles. This performance enhancement coupled with the ability to locate the primary components near the ground allows for easier installation, troubleshooting, maintenance, and future improvement of the circulation control sub-system. By varying the circulation control performance with the blade position, the coefficient of performance, Cp, of the wind turbine can be altered. This variation in Cp resembles a change in the effective solidity factor, the non-dimensional characteristic that accounts for the number of turbine blades, chord length, and turbine radius. The solidity factor is typically used in the design of a wind turbine with its peak performance occurring at various tip speed ratios, at different solidity factors. Prior to the construction of physical models, analytical methods, namely a vortex model, was used to estimate the performance enhancement potential of the blade force augmentation via circulation control. These results were then used to construct and test a wind tunnel blade section model to obtain lift and drag values for a full range of rotational angles. These results were then supplied to the vortex model which indicated that through the addition of circulation control to the blades of a vertical axis wind turbine an approximately 20% improvement in the annual energy production, and consequently the capacity factor, could be achieved.

  7. Optimization and Reliability Problems in Structural Design of Wind Turbines

    Sørensen, John Dalsgaard

    2007-01-01

    Reliability-based cost-benefit optimization formulations for wind turbines are presented. Some of the improtant aspects for stochastic modeling of loads, strengths and models uncertainties for wind turbines are described. Single wind turbines and wind turbines in wind farms with wake effects are...... discussed. Limit state equations are presented for fatigue limit states and for ultimate limit states with extreme wind load, and illustrated by bending failure. Illustrative examples are presented, and as a part of the results optimal reliability levels are obtained which corresponds to an annual...... reliability index equal to 3. An example with fatigue failure indicates that the reliability level is almost the same for single wind turbines and for wind turbines in wind farms if the wake effects are modeled equivalently in the design equation and the limit state equation....

  8. Development of a gust model for the design of large wind turbines

    Verheij, F.J.

    1988-01-01

    Wind input containing reliable and useful information is of great importance for a proper design of wind turbines. The development of wind energy applications from small wind turbines to medium size and large wind turbines and recently windfarms requires a development of the wind input for the design of each to these categories of wind turbines. The development of wind input for the design of wind turbines, in the form of a gust model, is described. It appears that small wind turbines, large wind turbines and wind turbines placed in windfarms all require specific wind input for their design. 7 figs., 7 refs.

  9. 75 FR 27583 - Job Corps: Final Finding of No Significant Impact (FONSI) for Small Vertical Wind Turbine and...

    2010-05-17

    ... Turbine and Solar Installation at the Paul Simon Job Corps Center Located at 3348 South Kedzie Avenue...), gives final notice of the proposed construction of a small vertical axis wind turbine and solar cells at... Finding of No Significant Impact (FONSI) for Small Vertical Wind Turbine and Solar Installation at...

  10. The Mod-2 wind turbine development project

    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.

  11. Mod-2 wind turbine development project

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

    1981-07-01

    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 US Department of Energy and the Lewis Research Center of the National Aeronautics and Space Administration, is described. The Mod-2 is a larger (2.5-MW power rating) horizontal-axis wind turbine designed for the generation of electrical power on utility networks. Three machines have been 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.

  12. System Reliability for Offshore Wind Turbines

    Marquez-Dominguez, Sergio; Sørensen, John Dalsgaard

    2013-01-01

    Deeper waters and harsher environments are the main factors that make the electricity generated by offshore wind turbines (OWTs) expensive due to high costs of the substructure, operation & maintenance and installation. The key goal of development is to decrease the cost of energy (CoE). In...... consequence, a rational treatment of uncertainties is done in order to assess the reliability of critical details in OWTs. Limit state equations are formulated for fatigue critical details which are not influenced by wake effects generated in offshore wind farms. Furthermore, typical bi-linear S-N curves are...... in inspections or measurements from condition monitoring systems. Finally, an example is established to illustrate the practical application of this framework for jacket type wind turbine substructure considering system effects....

  13. Effects of wind turbines on UHF television reception: field tests in Denmark, November 1991

    As a result of a planning application for a wind farm comprising 20 wind turbines at Tynewydd Farm, Gilfach Goch in Mid Glamorgan, it became necessary to produce a Report discussing any detrimental effects the proposal might have on UHF television reception. In order to make that Report as definitive as possible, it was decided to carry out field tests on the exact model of wind turbine to be used to Tynewydd. This required a field trip to Denmark, and the opportunity was taken to make measurements on two other models of turbine at the same time. This Report presents the analysis of the results for all three turbines. (Author)

  14. Dynamic Behavior of DFIG Wind Turbine Under Grid Fault Conditions

    Omer Elfaki Elbashir; Wang Zezhong; Liu Qihui

    2014-01-01

    The use of doubly fed induction generators (DFIGs) in wind turbines has become quite common over the last few years. These machines provide variable speed and are driven with a power converter which is sized for a small percentage of the turbine-rated power. This paper presents a detailed model of induction generator coupled to wind turbine system. Modeling and simulation of induction machine using vector control computing technique is done. DFIG wind turbine is an integrated part of distribu...

  15. Observer Backstepping Control for Variable Speed Wind Turbine

    Galeazzi, Roberto; Gryning, Mikkel Peter Sidoroff; Blanke, Mogens

    This paper presents an observer backstepping controller as feasible solution to variable speed control of wind turbines to maximize wind power capture when operating between cut-in and rated wind speeds. The wind turbine is modeled as a two-mass drive-train system controlled by the generator torque...

  16. Wind-tunnel simulations of wind-turbine arrays in neutral and non-neutral winds

    Wind tunnel simulations have been made of a neutral atmospheric boundary layer (ABL), a stable layer and an unstable layer, typical of offshore conditions, in order to better understand wake development and turbine-wake interactions. Measurements of the wake of a single turbine showed a slower reduction of the velocity deficit for the stable case, and a more rapid reduction for the unstable case, compared with the neutral. It is proposed that there are two effects of non-neutral conditions, indirect and direct. Indirect effects are seen in the earlier part of the wake, influenced by the turbulence level in the ABL but not by buoyancy forces directly; direct effects, caused by buoyancy forces, are seen further downstream. In the stable case, direct effects were seen from about 3 rotor diameters, while for the unstable case they were not seen until about 10 diameters. Two-point measurements in the wakes of four turbines aligned with the flow, compared with those of the ABL, exhibited very different flow characteristics, suggesting a lateral oscillation of the wakes of the later turbines. The effects of laterally adjacent turbines, in a 3-wide x 4-deep array, but with closer-than-typical lateral spacing (2.4 diameters) so as to give early interaction in the short array, were also investigated, and showed only limited interaction

  17. A Shrouded Wind Turbine Generating High Output Power with Wind-lens Technology

    Yuji Ohya

    2010-03-01

    Full Text Available We have developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind turbine, for a given turbine diameter and wind speed. This is because a low-pressure region, due to a strong vortex formation behind the broad brim, draws more mass flow to the wind turbine inside the diffuser shroud.

  18. A Shrouded Wind Turbine Generating High Output Power with Wind-lens Technology

    Yuji Ohya; Takashi Karasudani

    2010-01-01

    We have developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind turbine, for a given turbine diameter and wind speed. This is because a low-pressure region, due to a strong vortex formation behind the broad brim, draws more mass flow to the wind turbine inside the diffu...

  19. Large mills attract the wind. Wind and noise measurements of high wind turbines

    It appears that under specific weather conditions wind turbines produce more noise than expected, according to the theory that wind speed increases with height on a logarithmic scale. However, from the results of the project on the title subject it appears that this correlation between wind speed and height is not correct for a stabile atmosphere: in that case wind speed increases more with height and subsequently the turbine will produce more noise

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

    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.

  1. Generators of Modern Wind Turbines

    Chen, Zhe

    2008-01-01

    In this paper, various types of wind generator configurations, including power electronic grid interfaces, drive trains, are described The performance in power systems is briefed. Then the optimization of generator system is presented. Some investigation results are presented and discussed....

  2. Modern control design for flexible wind turbines

    Wright, Alan Duane

    Control can improve energy capture and reduce dynamic loads in wind turbines. In the 1970s and 1980s wind turbines used classical control designs to regulate power and speed. The methods used, however, were not always successful. These systems often had bandwidths large enough to destabilize low-damped flexible modes leading to high dynamic load fatigue failures. Modern turbines are larger, mounted on taller towers, and are more dynamically active than their predecessors. Control systems to regulate turbine power and maintain stable closed-loop behavior in the presence of turbulent wind inflow will be critical for these designs. New advanced control approaches and paradigms must account for low-damped flexible modes in order to reduce structural dynamic loading and achieve the 20--25 year operational life required of today's machines. This thesis applies modern state-space control design methods to a two-bladed teetering hub upwind machine located at the National Wind Technology Center. The design objective is to regulate turbine speed and enhance damping in several low-damped flexible modes of the turbine. Starting with simple control algorithms based on linear models, complexity is added incrementally until the desired performance is firmly established. The controls approach is based on the Disturbance Accommodating Control (DAC) method and provides accountability for wind-speed fluctuations. First, controls are designed using the single control input rotor collective pitch to stabilize the 1st drive-train torsion as well as the tower 1st fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances 1st drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections due to wind shear. Finally, results from these modern controls are compared to results from simpler classical controls in order to assess modern controller performance. These modern controls are shown to more effectively mitigate tower fore-aft motion, drive-train shaft torsion moments, and blade root flap bending moments when compared to the classical control approaches.

  3. Adaptive control algorithm for improving power capture of wind turbines in turbulent winds

    Diaz-Guerra, Lluis; Adegas, Fabiano Daher; Stoustrup, Jakob; Monros, Miriam

    The standard wind turbine (WT) control law modifies the torque applied to the generator as a quadratic function of the generator speed (K!2) while blades are positioned at some optimal pitch angle (). The value of K and should be properly selected such that energy capture is increased. In practice...... wind conditions. This paper present new analysis tools and an adaptive control law to increase the energy captured by a wind turbine. Due to its simplicity, it can be easily added to existing industry-standard controllers. The effectiveness of the proposed algorithm is assessed by simulations on a high......, the complex and time-varying aerodynamics a WT face due to turbulent winds make their determination a hard task. The selected constant parameters may maximize energy for a particular, but not all, wind regime conditions. Adaptivity can modify the controller to increase power capture under variable...

  4. Wind Turbine Experiments at Full Dynamic Similarity

    Miller, Mark; Kiefer, Janik; Westergaard, Carsten; Hultmark, Marcus

    2015-11-01

    Performing experiments with scaled-down wind turbines has traditionally been difficult due to the matching requirements of the two driving non-dimensional parameters, the Tip Speed Ratio (TSR) and the Reynolds number. Typically, full-size turbines must be used to provide the baseline cases for engineering models and computer simulations where flow similarity is required. We present a new approach to investigating wind turbine aerodynamics at full dynamic similarity by employing a high-pressure wind tunnel at Princeton University known as the High Reynolds number Test Facility (or HRTF). This facility allows for Reynolds numbers of up to 3 million (based on chord and velocity at the tip) while still matching the TSR, on a geometrically similar, small-scale model. The background development of this project is briefly presented including the design and manufacture of a model turbine. Following this the power, thrust and wake data are discussed, in particular the scaling dependence on the Reynolds number. Supported under NSF grant CBET-1435254 (program manager Gregory Rorrer).

  5. The Effect of Additional Mooring Chains on the Motion Performance of a Floating Wind Turbine with a Tension Leg Platform

    Jinping Ou; Nianxin Ren; Yugang Li

    2012-01-01

    In this study, two types of floating offshore wind turbine (FOWT) systems were proposed: a traditional tension leg platform (TLP) type and a new TLP type with additional mooring chains. They were both based on the National Renewable Energy Laboratory 5 MW offshore wind turbine model. Taking the coupled effect of dynamic response of the top wind turbine, tower support structure and lower mooring system into consideration, not only were the 1/60 scale model tests for the two floating wind turbi...

  6. Turbine Control Strategies for Wind Farm Power Optimization

    Mirzaei, Mahmood; Göçmen Bozkurt, Tuhfe; Giebel, Gregor; Sørensen, Poul Ejnar; Poulsen, Niels Kjølstad

    wind farms. One way of achieving these goals is to optimize the power generated by a wind farm. One optimization method is to choose appropriate operating points for the individual wind turbines in the farm. We have made three models of a wind farm based on three difference control strategies....... Basically, the control strategies determine the steady state operating points of the wind turbines. Except the control strategies of the individual wind turbines, the wind farm models are similar. Each model consists of a row of 5MW reference wind turbines. In the models we are able to optimize the...... different. This means that choosing an appropriate control strategy for the individual wind turbines will result in an increased power production of the wind farm....

  7. On Offshore wind turbine fatigue caused by wave influenced wind

    Kalvig Siri

    2015-01-01

    Full Text Available A wave influenced wind turbine simulator (WIWiTS is developed and results from these simulations are used for fatigue analyses. WIWiTS is based on the Simulator fOr Wind Farm Application (SOWFA developed at NREL. The simulations are transient with an unsteady Reynolds-Averaged Navier-Stokes (URANS approach. An actuator line representation of the turbine is placed in a domain where the wave and wind are either aligned with each other or opposed to each other. Simulations with four different wave states are compared to a reference case with no waves, but the inlet wind is the same for all cases. The wave will influence the wind field, which in turn affects the damage equivalent load both at the blade root and at the tower base. In a relatively low wind regime (8 m/s in a height of 400 m our simplified simulations show that the wave influenced wind increase the fatigue damage compared to a situation with no waves, especially for the cases where the wave opposes the wind field.

  8. Database on wind characteristics - Analyses of wind turbine design loads

    Larsen, G.C.; Hansen, K.S.

    2004-06-01

    The main objective of IEA R and D Wind Annex XVII - Database on Wind Characteristics - has been to provide wind energy planners, designers and researchers, as well as the international wind engineering community in general, with a source of actual wind field data (time series and resource data) observed in a wide range of different wind climates and terrain types. Connected to an extension of the initial Annex period, the scope for the continuation was widened to include also support to the international wind turbine standardisation efforts.. The project partners are Sweden, Norway, U.S.A., The Netherlands and Denmark, with Denmark as the Operating Agent. The reporting of the continuation of Annex XVII falls in two separate parts. Part one accounts in details for the available data in the established database bank, and part two describes various data analyses performed with the overall purpose of improving the design load cases with relevance for to wind turbine structures. The present report constitutes the second part of the Annex XVII reporting. Both fatigue and extreme load aspects are dealt with, however, with the main emphasis on the latter. The work has been supported by The Ministry of Environment and Energy, Danish Energy Agency, The Netherlands Agency for Energy and the Environment (NOVEM), The Norwegian Water Resources and Energy Administration (NVE), The Swedish National Energy Administration (STEM) and The Government of the United States of America. (au)

  9. Hydraulic Soft Yaw System for Multi MW Wind Turbines

    Stubkier, Søren

    the hydraulic model validated for further testing in the co-simulation environment. All test are performed according to the standard IEC 61400-1; Wind turbines- Part 1: Design requirements, why the load cases may be recognized from this standard. The model is further used for testing of the developed......Horizontal axis wind turbines utilize a yaw system to keep the rotor plane of the wind turbine perpendicular to the main wind direction. If the wind direction changes, the wind turbine follows the direction change by yawing. If the wind turbine does not yaw, there will be a reduction in produced...... energy and an increase in the loading of the wind turbine structure and components. This dissertation examines the hypothesis that there are advantages of basing a yaw system on hydraulic components instead of normal electrical components. This is done through a state of the art analysis followed by a...

  10. The sound of wind turbines keeps one busy

    A few reactions are given to the thesis 'The sounds of high winds. The effect of atmospheric stability on wind turbine sound and microphone noise' on the availability of wind at night and related production of noise

  11. Semiconductor Laser Lidar Wind Velocity Sensor for Turbine Control

    Rodrigo, Peter John; Hu, Qi; Pedersen, Christian

    2014-01-01

    A dual line-of-sight CW lidar that measures both wind speed and direction is presented . The wind lidar employs a semiconductor laser, which allows for inexpensive remote sensors geared towards enhanced control of wind turbines ....

  12. Design And Analysis Of Savonius Wind Turbine Blades

    Kshitija. M. Deshmukh,

    2015-11-01

    Full Text Available There are two kinds of wind turbines according to the axis of rotation to the ground, horizontal axis wind turbines (HAWT and vertical axis wind turbines (VAWT. VAWTs include both a drag type configuration like Savonius wind turbine and a lift-type configuration like Darrieus wind turbine. Savonius wind rotor has many advantages such as low starting speeds and no need for external torque for its starting. Moreover it is cheaper in construction and has low maintenance. It is independent of the wind direction and has a good starting torque at lower wind speeds. The experimental study conducted in this paper aims to investigate the effect of number of blades and other criteria that can affect the performance of the model of Savonius type wind turbine. The experiments used to compare 2, 3, and 4 blades wind turbines to show tip speed ratio, torque and power coefficient related with wind speed. A simulation using ANSYS 13.0 software will show pressure distribution of wind turbine. The results of study showed that number of blades influence the performance of wind turbine. Savonius model with three blades has the best performance at high tip speed ratio.

  13. Advanced CFD methods for wind turbine analysis

    Lynch, C. Eric

    2011-12-01

    Horizontal-axis wind turbines operate in a complex, inherently unsteady aerodynamic environment. Even when the rotor is not stalled, the flow over the blades is dominated by three-dimensional (3-D) effects. Stall is accompanied by massive flow separation and vortex shedding over the suction surface of the blades. Under yawed conditions, dynamic stall may be present as well. In all operating conditions, there is bluff-body shedding from the turbine nacelle and support structure which interacts with the rotor wake. In addition, the high aspect ratios of wind turbine blades make them very flexible, leading to substantial aeroelastic deformation of the blades, altering the aerodynamics. Finally, when situated in a wind farm, turbines must operate in the unsteady wake of upstream neighbors. Though computational fluid dynamics (CFD) has made significant inroads as a research tool, simple, inexpensive methods, such as blade element momentum (BEM) theory, are still the workhorses in wind turbine design and aeroelasticity applications. These methods generally assume a quasi-steady flowfield and use two-dimensional aerodynamic approximations with very limited empirical 3-D corrections. As a result, they are unable to accurately predict rotor loads near the edges of the operating envelope. CFD methods make very few limiting assumptions about the flowfield, and thus have much greater potential for predicting these flows. In this work, a range of unstructured grid CFD techniques for predicting wind turbine loads and aeroelasticity has been developed and applied to a wind turbine configuration of interest. First, a nearest neighbor search algorithm based on a k-dimensional tree data structure was used to improve the computational efficiency of an approximate unsteady actuator blade method. This method was then shown to predict root and tip vortex locations and strengths similar to an overset method on the same background mesh, but without the computational expense of modeling the blade surfaces. A hybrid Reynolds-averaged Navier-Stokes / Large Eddy Simulation (HRLES) turbulence model, previously developed for structured grids, was extended to an unstructured framework. It was demonstrated to improve predictions of unsteady loading and shedding frequency in massively separated cases. The sensitivity of the model to highly stretched grid topologies was also explored. For aeroelastic predictions, a methodology for tight coupling between an unstructured CFD solver and a computational structural dynamics tool was developed. Due to the lack of experimental data pertaining to a flexible turbine, the coupling algorithm was validated for a helicopter rotor, but the method is sufficiently general that it can be immediately applied to a wind turbine when suitable correlation data becomes available in the future. Finally, time-accurate overset rotor simulations of a complete turbine---blades, nacelle, and tower---were conducted using both RANS and HRLES turbulence models. The HRLES model was able to accurately predict rotor loads when stalled. In yawed flow, excellent correlations of mean blade loads with experimental data were obtained across the span, and wake asymmetry and unsteadiness were also well-predicted.

  14. A New Structure Based on Cascaded Multilevel Converter for Variable Speed Wind Turbine

    Deng, Fujin; Chen, Zhe

    -less cascaded multilevel converter interface based on PMSGs is developed to synthesize a desired high ac sinusoidal output voltage. The benefits of high power and high ac voltage make this structure possible to be applied in the wind power generation. In addition, the bulky transformer could be omitted. A......An alternative structure for variable speed wind turbine, using multiple permanent magnet synchronous generators (PMSGs) drive-train configuration and cascaded multilevel converter is proposed in this paper. This study presents a power electronic solution for the wind turbine. A transformer...... simulation model of 10 MW variable speed wind turbine based on PMSGs developed in PSCAD/EMTDC is presented. The dynamic performance of grid-connected wind turbine is analyzed. Simulation results shows that the proposed structure may be attractive in wind power generation....

  15. Integrating Structural Health Management with Contingency Control for Wind Turbines

    Kai Goebel

    2013-01-01

    Full Text Available 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 turbine blades with contingency control to balance the trade-offs between maintaining system health and energy capture. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

  16. A new generation of wind turbines; Une nouvelle generation d'eoliennes

    Nica, H. [Tesnic, Laval, PQ (Canada)

    2008-06-15

    Although homeowners have expressed a desire to use wind energy to supply their electricity needs, many technical barriers have stood in the way of installing wind turbines in urban settings. This was due in part to three-bladed vertical axis turbines, high technical costs, limited performances in urban settings and questionable aesthetics. Tesnic has considered these issues and proposed a completely different turbine that uses a different method for extracting energy from the wind. The first approved 3.6 kW model should appear by the end of 2009. This new turbine is based on the same principal of the steam turbine patented in 1913 by Nikola Tesla. Instead of having blades, the Tesla turbine used closely spaced parallel disks and was recognized as being very robust with a high efficiency rating. Tesnic's new wind powered turbine is a vertical axis turbine with a series of valves that directs the wind on a rotor assembly of disk space. A series of blades on its circumference redirects the wind through the assembly of discs and accelerates the rotation of the rotor. The turbine extracts the wind energy in several ways, including conventional drag and lift, adherence and the vortex effect. This gives a 50 per cent added value of efficiency compared to other wind powered turbines. The global market for small wind powered energy is in full expansion. It has been projected that small turbines with 1 kW capacity will be abundant by 2020. It was noted that for household wind powered energy, the market must consider issues of cost, low maintenance, noise pollution, visual aesthetics, durability and safety. Wind energy can also be used in several industries, including plastics, composites, light metals, textiles and electronics. 2 figs.

  17. Convergence of Extreme Loads for Offshore Wind Turbine Support Structures

    Stewart, Gordon; Lackner, Matthew; Sanjay R. Arwade; Myers, Andrew T.; Hallowell, Spencer

    2015-01-01

    Extreme loads of wind turbines are historically difficult to predict through simulation due to uncertainty in input conditions as well as in the simulation models. In addition, many long time series must be simulated for the statistics of the peak loads to become stationary. Offshore wind turbines require even more simulation due to the addition of stochastic wave loading. Floating offshore wind turbines, the subject of this paper, experience free-body motion as a result of wind and wave load...

  18. Collective pitch feedforward control of floating wind turbines using lidar

    Schlipf, David; Simley, Eric; Lemmer, Frank; Pao, Lucy; Cheng, Po Wen

    2015-01-01

    In this work a collective pitch feedforward controller for floating wind turbines is presented. The feedforward controller provides a pitch rate update to a conventional feedback controller based on a wind speed preview. The controller is designed similar to the one for onshore turbines, which has proven its capability to improve wind turbine control performance in field tests. In a first design step, perfect wind preview and a calm sea is assumed. Under these assumptions the feedforward cont...

  19. High Voltage Power Converter for Large Wind Turbine

    Sztykiel, Michal

    2014-01-01

    The increasing penetration of the wind energy has resulted in newly planned installations of offshore wind turbines. In order to minimize installation, material and transportation costs of the offshore wind power plants, large multi-MW wind turbine systems are being preferably employed and developed, which allow high power generation of each single unit. Nevertheless, further increase in the power ratings of the newly emerging turbines becomes a major concern related to the operating voltage ...

  20. Noise Pollution Prevention in Wind Turbines: Status and Recent Advances

    Greg Naterer; Marc A. Rosen; Ofelia Jianu

    2012-01-01

    The global push towards sustainability has led to increased interest in alternative power sources other than coal and fossil fuels. One of these sustainable sources is to harness energy from the wind through wind turbines. However, a significant hindrance preventing the widespread use of wind turbines is the noise they produce. This study reviews recent advances in the area of noise pollution from wind turbines. To date, there have been many different noise control studies. While there are ma...