Sample records for wind speed direction

  1. 0 Riso-R-434 Wind Speed and Direction

    E-Print Network [OSTI]

    meteorological statistics for the area as it was considered a possible site for a nuclear power plant. \\ \\ Duringm I 0 Riso-R-434 t Wind Speed and Direction Changes due to Terrain Effects revealed-4000 Roskilde, Denmark May 1983 #12;RISÃ?-R-434 WIND SPEED AND DIRECTION CHANGES DUE TO TERRAIN EFFECTS

  2. 1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction and erosion

    E-Print Network [OSTI]

    from the surface but unless it corresponds to a high wind-speed (the potential to transport a single rainfall event. When high wind-speeds and heavy rainfall combine there is an increased potential1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction

  3. Ris-R-Report Analysis of vertical wind direction and speed

    E-Print Network [OSTI]

    Risø-R-Report Analysis of vertical wind direction and speed gradients for data from the met. mast Cariou, Rozenn Wagner, Julia Gottschall Title: Analysis of vertical wind direction and speed gradients.): The task of this project has been to study the vertical gradient of the wind direction from experimental

  4. SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS

    E-Print Network [OSTI]

    Hennon, Christopher C.

    SCALAR WIND SPEED AND DIRECTION TROPICAL CYCLONE RETRIEVALS FOR CONICAL SCANNING SCATTEROMETERS--Scatterometer measurements of ocean vector winds (OVW) are significantly degraded in the presence of the precipitation, especially in tropical cyclones. This paper presents a new ocean hurricane/typhoon wind vector retrieval

  5. Ris-R-Report LIDAR Wind Speed Measurements from a

    E-Print Network [OSTI]

    , the spinner axis's vertical tilt and the wind turbine's yaw relative to the mean wind speed direction: Data Files 54 Appendix B: Wind Speed Vertical Profile 55 Appendix C: Sonic Cup Comparison 59Risø-R-Report LIDAR Wind Speed Measurements from a Rotating Spinner: "SpinnerEx 2009" Nikolas

  6. Forecasting wind speed financial return

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2013-01-01T23:59:59.000Z

    The prediction of wind speed is very important when dealing with the production of energy through wind turbines. In this paper, we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model that has been shown to be able to reproduce accurately the statistical behavior of wind speed. The model is used to forecast, one step ahead, wind speed. In order to check the validity of the model we show, as indicator of goodness, the root mean square error and mean absolute error between real data and predicted ones. We also compare our forecasting results with those of a persistence model. At last, we show an application of the model to predict financial indicators like the Internal Rate of Return, Duration and Convexity.

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

    E-Print Network [OSTI]

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

  8. VARIABLE SPEED WIND TURBINE

    E-Print Network [OSTI]

    Chatinderpal Singh

    Wind energy is currently the fastest-growing renewable source of energy in India; India is a key market for the wind industry, presenting substantial opportunities for both the international and domestic players. In India the research is carried out on wind energy utilization on big ways.There are still many unsolved challenges in expanding wind power, and there are numerous problems of interest to systems and control researchers. In this paper we study the pitch control mechanism of wind turbine. The pitch control system is one of the most widely used control techniques to regulate the output power of a wind turbine generator. The pitch angle is controlled to keep the generator power at rated power by reducing the angle of the blades. By regulating, the angle of stalling, fast torque changes from the wind will be reutilized. It also describes the design of the pitch controller and discusses the response of the pitch-controlled system to wind velocity variations. The pitch control system is found to have a large output power variation and a large settling time.

  9. Wind speed vertical distribution at Mt. Graham

    E-Print Network [OSTI]

    Hagelin, S; Lascaux, F

    2010-01-01T23:59:59.000Z

    The characterization of the wind speed vertical distribution V(h) is fundamental for an astronomical site for many different reasons: (1) the wind speed shear contributes to trigger optical turbulence in the whole troposphere, (2) a few of the astroclimatic parameters such as the wavefront coherence time (tau_0) depends directly on V(h), (3) the equivalent velocity V_0, controlling the frequency at which the adaptive optics systems have to run to work properly, depends on the vertical distribution of the wind speed and optical turbulence. Also, a too strong wind speed near the ground can introduce vibrations in the telescope structures. The wind speed at a precise pressure (200 hPa) has frequently been used to retrieve indications concerning the tau_0 and the frequency limits imposed to all instrumentation based on adaptive optics systems, but more recently it has been proved that V_200 (wind speed at 200 hPa) alone is not sufficient to provide exhaustive elements concerning this topic and that the vertical d...

  10. Surface wind speed distributions| Implications for climate and wind power.

    E-Print Network [OSTI]

    Capps, Scott Blair

    2010-01-01T23:59:59.000Z

    ?? Surface constituent and energy fluxes, and wind power depend non-linearly on wind speed and are sensitive to the tails of the wind distribution. Until… (more)

  11. Wind Speed Prediction Via Time Series Modeling.

    E-Print Network [OSTI]

    Alexander, Daniel

    2009-01-01T23:59:59.000Z

    ??Projected construction of nearby wind farms motivates this study of statistical forecasting of wind speed, for which accurate prediction is critically important to the fluid… (more)

  12. Wind Speed Forecasting for Power System Operation

    E-Print Network [OSTI]

    Zhu, Xinxin

    2013-07-22T23:59:59.000Z

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  13. Dual-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Handman, D. [Flowind Corp., San Rafael, CA (United States)] [Flowind Corp., San Rafael, CA (United States)

    1996-10-01T23:59:59.000Z

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

  14. Wind Speed Data Analysis using Wavelet Transform

    E-Print Network [OSTI]

    S. Avdakovic; A. Lukac; A. Nuhanovic; M. Music

    Abstract—Renewable energy systems are becoming a topic of great interest and investment in the world. In recent years wind power generation has experienced a very fast development in the whole world. For planning and successful implementations of good wind power plant projects, wind potential measurements are required. In these projects, of great importance is the effective choice of the micro location for wind potential measurements, installation of the measurement station with the appropriate measuring equipment, its maintenance and analysis of the gained data on wind potential characteristics. In this paper, a wavelet transform has been applied to analyze the wind speed data in the context of insight in the characteristics of the wind and the selection of suitable locations that could be the subject of a wind farm construction. This approach shows that it can be a useful tool in investigation of wind potential. Keywords—Wind potential, Wind speed data, Wavelet transform.

  15. DIRECT REGULATION OF LARGE SPEED EXCURSIONS FOR VARIABLE SPEED WIND W. E. Leithead, D. J. Leith, F. Hardan, H.Markou

    E-Print Network [OSTI]

    Duffy, Ken

    the rotor blades at the maximum permissible rate, thereby exploiting the maximum capability of the actuation to adjust the pitch angle of the rotor blades to maintain the peak rotor speed excursion below 15 turbine aims to maintain the rotor speed within a permitted range. However, this requirement can

  16. Wind: wind speed and wind power density maps at 10m and 50m above...

    Open Energy Info (EERE)

    files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer....

  17. Wind: wind speed and wind power density GIS data at 10m and 50m...

    Open Energy Info (EERE)

    files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer....

  18. Control strategy of a variable speed wind turbine with multipole permanent magnet synchronous generator

    E-Print Network [OSTI]

    values. Keywords: permanent magnet synchronous generator, variable speed wind turbine, direct driven wind). A multipole synchronous generator connected to a power converter can operate at low speeds, so that a gear canControl strategy of a variable speed wind turbine with multipole permanent magnet synchronous

  19. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect (OSTI)

    Simley, E.; Pao, L. Y.

    2012-07-01T23:59:59.000Z

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

  20. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P.

    1995-11-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. in extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  1. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.

    1996-10-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy analyzed uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  2. Variable speed operation of generators with rotor-speed feedback in wind power applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Migliore, P. [National Renewable Energy Lab., Golden, CO (United States)

    1996-11-01T23:59:59.000Z

    The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up, and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy the authors analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

  3. Statistical Analysis of Environment Canada's Wind Speed Data

    E-Print Network [OSTI]

    Taylor, James H.

    Statistical Analysis of Environment Canada's Wind Speed Data Someshwar Singh Department Brunswick-Fredericton New Brunswick, Canada Email: jtaylor@unb.ca Abstract--Wind energy utilities use wind. This paper reports on a study of the histories of wind speed forecasts and actual wind speed data available

  4. Direct drive wind turbine

    DOE Patents [OSTI]

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

    2006-10-10T23:59:59.000Z

    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.

  5. Direct drive wind turbine

    DOE Patents [OSTI]

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

    2006-07-11T23:59:59.000Z

    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.

  6. Direct drive wind turbine

    DOE Patents [OSTI]

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

    2006-09-19T23:59:59.000Z

    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.

  7. Direct drive wind turbine

    DOE Patents [OSTI]

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

    2007-02-27T23:59:59.000Z

    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.

  8. Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1 , Richard EMILION2 , Ted'Orléans), UMR CNRS 6628 Université d'Orléans, France. Abstract: Wind energy production is very sensitive to instantaneous wind speed fluctuations. Thus rapid variation of wind speed due to changes in the local

  9. Dynamic simulation of dual-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    1996-10-01T23:59:59.000Z

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

  10. Pitch-controlled variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    2000-03-01T23:59:59.000Z

    Wind energy is a viable option to complement other types of pollution-free generation. In the early development of wind energy, the majority of wind turbines were operated at constant speed. Recently, the number of variable-speed wind turbines installed in wind farms has increased and more wind turbine manufacturers are making variable-speed wind turbines. This paper covers the operation of variable-speed wind turbines with pitch control. The system the authors considered is controlled to generate maximum energy while minimizing loads. The maximization of energy was only carried out on a static basis and only drive train loads were considered as a constraint. In medium wind speeds, the generator and power converter control the wind turbine to capture maximum energy from the wind. In the high wind speed region, the wind turbine is controlled to maintain the aerodynamic power produced by the wind turbine. Two methods to adjust the aerodynamic power were investigated: pitch control and generator load control, both of which are employed to control the operation of the wind turbine. The analysis and simulation shows that the wind turbine can be operated at its optimum energy capture while minimizing the load on the wind turbine for a wide range of wind speeds.

  11. IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE IMAGING RADIOMETER (HIRAD)

    E-Print Network [OSTI]

    Ruf, Christopher

    IMPROVED MICROWAVE REMOTE SENSING OF HURRICANE WIND SPEED AND RAIN RATES USING THE HURRICANE) that measures wind speed and rain rate along the ground track directly beneath the aircraft. This paper presents are presented, which illustrate wind speed and rain rate measurement spatial resolutions and swath coverage. 1

  12. Robust STATCOM control for the stabilisation of fixed-speed wind turbines during low voltages

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    and rotor- speed instability and more so if the wind turbine is connected to a weak grid. To prevent is still being produced by squirrel-cage induction generators (SCIGs) which are directly connected to the grid and operate at an almost fixed-speed [3]. They are advantageous as wind generators for their low

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

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

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

  14. Probabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging

    E-Print Network [OSTI]

    Raftery, Adrian

    distribution; Numerical weather prediction; Skewed distribution; Truncated data; Wind energy. 1. INTRODUCTION- native. Purely statistical methods have been applied to short-range forecasts for wind speed only a fewProbabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging J. Mc

  15. Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution

    SciTech Connect (OSTI)

    Zhou, Yuyu; Smith, Steven J.

    2013-09-09T23:59:59.000Z

    Wind power, a renewable energy source, can play an important role in electrical energy generation. Information regarding wind energy potential is important both for energy related modeling and for decision-making in the policy community. While wind speed datasets with high spatial and temporal resolution are often ultimately used for detailed planning, simpler assumptions are often used in analysis work. An accurate representation of the wind speed frequency distribution is needed in order to properly characterize wind energy potential. Using a power density method, this study estimated global variation in wind parameters as fitted to a Weibull density function using NCEP/CFSR reanalysis data. The estimated Weibull distribution performs well in fitting the time series wind speed data at the global level according to R2, root mean square error, and power density error. The spatial, decadal, and seasonal patterns of wind speed distribution were then evaluated. We also analyzed the potential error in wind power estimation when a commonly assumed Rayleigh distribution (Weibull k = 2) is used. We find that the assumption of the same Weibull parameter across large regions can result in substantial errors. While large-scale wind speed data is often presented in the form of average wind speeds, these results highlight the need to also provide information on the wind speed distribution.

  16. Hi-Q Rotor - Low Wind Speed Technology

    SciTech Connect (OSTI)

    Todd E. Mills; Judy Tatum

    2010-01-11T23:59:59.000Z

    The project objective was to optimize the performance of the Hi-Q Rotor. Early research funded by the California Energy Commission indicated the design might be advantageous over state-of-the-art turbines for collecting wind energy in low wind conditions. The Hi-Q Rotor is a new kind of rotor targeted for harvesting wind in Class 2, 3, and 4 sites, and has application in areas that are closer to cities, or 'load centers.' An advantage of the Hi-Q Rotor is that the rotor has non-conventional blade tips, producing less turbulence, and is quieter than standard wind turbine blades which is critical to the low-wind populated urban sites. Unlike state-of-the-art propeller type blades, the Hi-Q Rotor has six blades connected by end caps. In this phase of the research funded by DOE's Inventions and Innovation Program, the goal was to improve the current design by building a series of theoretical and numeric models, and composite prototypes to determine a best of class device. Development of the rotor was performed by aeronautical engineering and design firm, DARcorporation. From this investigation, an optimized design was determined and an 8-foot diameter, full-scale rotor was built and mounted using a Bergey LX-1 generator and furling system which were adapted to support the rotor. The Hi-Q Rotor was then tested side-by-side against the state-of-the-art Bergey XL-1 at the Alternative Energy Institute's Wind Test Center at West Texas State University for six weeks, and real time measurements of power generated were collected and compared. Early wind tunnel testing showed that the cut-in-speed of the Hi-Q rotor is much lower than a conventional tested HAWT enabling the Hi-Q Wind Turbine to begin collecting energy before a conventional HAWT has started spinning. Also, torque at low wind speeds for the Hi-Q Wind Turbine is higher than the tested conventional HAWT and enabled the wind turbine to generate power at lower wind speeds. Based on the data collected, the results of our first full-scale prototype wind turbine proved that higher energy can be captured at lower wind speeds with the new Hi-Q Rotor. The Hi-Q Rotor is almost 15% more productive than the Bergey from 6 m/s to 8 m/s, making it ideal in Class 3, 4, and 5 wind sites and has application in the critical and heretofore untapped areas that are closer to cities, 'load centers,' and may even be used directly in urban areas. The additional advantage of the Hi-Q Rotor's non-conventional blade tips, which eliminates most air turbulence, is noise reduction which makes it doubly ideal for populated urban areas. Hi-Q Products recommends one final stage of development to take the Hi-Q Rotor through Technology Readiness Levels 8-9. During this stage of development, the rotor will be redesigned to further increase efficiency, match the rotor to a more suitable generator, and lower the cost of manufacturing by redesigning the structure to allow for production in larger quantities at lower cost. Before taking the rotor to market and commercialization, it is necessary to further optimize the performance by finding a better generator and autofurling system, ones more suitable for lower wind speeds and rpms should be used in all future testing. The potential impact of this fully developed technology will be the expansion and proliferation of energy renewal into the heretofore untapped Class 2, 3, 4, and 5 Wind Sites, or the large underutilized sites where the wind speed is broken by physical features such as mountains, buildings, and trees. Market estimates by 2011, if low wind speed technology can be developed are well above: 13 million homes, 675,000 commercial buildings, 250,000 public facilities. Estimated commercial exploitation of the Hi-Q Rotor show potential increase in U.S. energy gained through the clean, renewable wind energy found in low and very low wind speed sites. This new energy source would greatly impact greenhouse emissions as well as the public sector's growing energy demands.

  17. The wind speed profile at offshore wind farm sites Bernhard Lange(1)

    E-Print Network [OSTI]

    Heinemann, Detlev

    The wind speed profile at offshore wind farm sites Bernhard Lange(1) , Søren E. Larsen(2) , Jørgen in Europe will come from offshore sites. The first large offshore wind farms are #12;currently being built feasibility of offshore wind power utilisation depends on the favourable wind conditions offshore compared

  18. Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms

    E-Print Network [OSTI]

    Pryor, Sara C.

    Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms Sten Frandsen*, Rebecca areas.As is often the need for offshore wind farms, the model handles a regular array geometry for offshore wind farms, the model handles a priori a regular array geometry with straight rows of wind

  19. A study of wind-speed maxima near the surface over the south central United States

    E-Print Network [OSTI]

    Beckman, Samuel Karl

    2012-06-07T23:59:59.000Z

    -1960) and the Oklahoma City radiosonde station data for the time period June, 1966 to May, 1967. They also showed that the higher the monthly, mean, wind speed, the more likely that the wind direction was from the south. Bonner (1968) states, "Strong early morning...) (Member) (Member) May 1973 ABSTRACT A Study of Wind-Speed Maxima near the Surface over the South Central United States (May 1973) Samuel K. Beckman, B. S. , Kansas State University Directed by: Professor Walter K. Henry Radiosonde and rawinsonde...

  20. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND for conditions important for offshore wind energy utilisation are compared and tested: Four models tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

  1. MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    MODELLING THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

  2. Design and Test of a Variable Speed Wind Turbine System Employing a Direct Drive Axial Flux Synchronization Generator: 29 October 2002 - 31 December 2005

    SciTech Connect (OSTI)

    Lipo, T. A.; Tenca, P.

    2006-07-01T23:59:59.000Z

    The goal of this funded research project is the definition, analytical investigation, modeling, and prototype realization of a current-source conversion topology tailored to high-power wind turbines.

  3. Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at

    E-Print Network [OSTI]

    Q: When planning a wind farm, how are wind resources estimated? And if the average wind speed is known at 10 meters is there a general rule for estimating the wind speed at larger heights above ground level? The wind resource at a wind farm can be estimated in two ways: by measurement or by modeling

  4. Microsoft Word - idaho_wind_speed_summary.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ft. Hall, ID Sites Wheat Grass Ridge Average Wind Speeds Site 0001 (66 ft. (20m) tower, erected week of 11101, data started on 11201) N. 42 deg. 44.762', W. 112 deg. 41.011'...

  5. Probabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging

    E-Print Network [OSTI]

    Washington at Seattle, University of

    is to issue deterministic forecasts based on numerical weather prediction models. Uncertainty canProbabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging J. Mc discretization than is seen in other weather quantities. The prevailing paradigm in weather forecasting

  6. Microsoft Word - utah_wind_speed_summary.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Jeff Anderson Site Castle Valley, Utah Average Wind Speeds Site 0006 (66 ft. (20m) tower, data started on 110601, data ended 112102) N. 38.635 deg., W. 109.397 deg. Elevation...

  7. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, The Gaussian Predictability of Wind Speeds1

    E-Print Network [OSTI]

    Monahan, Adam Hugh

    and wind power [e.g. Lange and Focken, 2005; Costa26 et al., 2008; Ma et al., 2009; Soman et al., 2010; Giebel et al., 2011]. Wind power predic-27 tion models may be entirely empirical, based on statistical, the vector winds contain34 information about both speed and direction and have the practical advantage

  8. The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle

    E-Print Network [OSTI]

    Richardson, John

    The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle Matthias R. Aellig Alamos National Lab., Los Alamos, NM 87545 Abstract We investigate the helium abundance in the solar wind of 1994 and early 2000 are analyzed. In agreement with similar work for previous solar cycles, we find

  9. MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY

    SciTech Connect (OSTI)

    Garrett, A; Robert Kurzeja, R; Eliel Villa-Aleman, E; Cary Tuckfield, C; Malcolm Pendergast, M

    2009-01-20T23:59:59.000Z

    The Savannah River National Laboratory (SRNL) collected thermal imagery and ground truth data at two commercial power plant cooling lakes to investigate the applicability of laboratory empirical correlations between surface heat flux and wind speed, and statistics derived from thermal imagery. SRNL demonstrated in a previous paper [1] that a linear relationship exists between the standard deviation of image temperature and surface heat flux. In this paper, SRNL will show that the skewness of the temperature distribution derived from cooling lake thermal images correlates with instantaneous wind speed measured at the same location. SRNL collected thermal imagery, surface meteorology and water temperatures from helicopters and boats at the Comanche Peak and H. B. Robinson nuclear power plant cooling lakes. SRNL found that decreasing skewness correlated with increasing wind speed, as was the case for the laboratory experiments. Simple linear and orthogonal regression models both explained about 50% of the variance in the skewness - wind speed plots. A nonlinear (logistic) regression model produced a better fit to the data, apparently because the thermal convection and resulting skewness are related to wind speed in a highly nonlinear way in nearly calm and in windy conditions.

  10. The amount of power in the wind is very dependent on the speed of the wind. Because the power in the wind

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    the potential benefits of a wind power installation, wind speeds and other characteristics of a site's wind for potential wind power sites. However, these maps do not elimi- nate the need for more precise and thoroughThe amount of power in the wind is very dependent on the speed of the wind. Because the power

  11. ARE660 Wind Generator: Low Wind Speed Technology for Small Turbine Development

    SciTech Connect (OSTI)

    Robert W. Preus; DOE Project Officer - Keith Bennett

    2008-04-23T23:59:59.000Z

    This project is for the design of a wind turbine that can generate most or all of the net energy required for homes and small businesses in moderately windy areas. The purpose is to expand the current market for residential wind generators by providing cost effective power in a lower wind regime than current technology has made available, as well as reduce noise and improve reliability and safety. Robert W. Preus’ experience designing and/or maintaining residential wind generators of many configurations helped identify the need for an improved experience of safety for the consumer. Current small wind products have unreliable or no method of stopping the wind generator in fault or high wind conditions. Consumers and their neighbors do not want to hear their wind generators. In addition, with current technology, only sites with unusually high wind speeds provide payback times that are acceptable for the on-grid user. Abundant Renewable Energy’s (ARE) basic original concept for the ARE660 was a combination of a stall controlled variable speed small wind generator and automatic fail safe furling for shutdown. The stall control for a small wind generator is not novel, but has not been developed for a variable speed application with a permanent magnet alternator (PMA). The fail safe furling approach for shutdown has not been used to our knowledge.

  12. Why do meteorologists use wind vanes? Wind vanes are used to determine the direction of the wind. Wind

    E-Print Network [OSTI]

    Nebraska-Lincoln, University of

    Fun Facts Why do meteorologists use wind vanes? Wind vanes are used to determine the direction of the wind. Wind· vanes are also called weather vanes. What do wind vanes look like on a weather station? Wind vanes that are on weather stations look a lot like the one you· made! The biggest differences

  13. Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b

    E-Print Network [OSTI]

    Vogel, Richard M.

    Probability distributions for offshore wind speeds Eugene C. Morgan a,*, Matthew Lackner b Wind turbine energy output Weibull distribution Extreme wind a b s t r a c t In planning offshore wind farms, short-term wind speeds play a central role in estimating various engi- neering parameters

  14. Mining Markov chain transition matrix from wind speed time series data Zhe Song a,

    E-Print Network [OSTI]

    Kusiak, Andrew

    ). Knowing how wind behaves at specific wind farms is extremely important for today's power systems in termsMining Markov chain transition matrix from wind speed time series data Zhe Song a, , Xiulin Geng Wind speed time series Wind power Evolutionary algorithms Markov chain Optimization a b s t r a c

  15. Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

    E-Print Network [OSTI]

    Chen, Zhe

    presents a simulation model of a wind power plant based on a MW-level variable speed wind turbineAncillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants Weihao Hu with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory

  16. Prediction of wind speed profiles for short-term forecasting in the offshore environment R.J. Barthelmie and G. Giebel

    E-Print Network [OSTI]

    in the forecast wind speed/power output might be anticipated using a directional rather than a constant bias for the calibration phase. A further advantage is that statistical techniques can predict power output directly rather than having to take the additional step of predicting power output from wind speed through the power

  17. United States- Land Based and Offshore Annual Average Wind Speed at 100 Meters

    Broader source: Energy.gov [DOE]

    Full-size, high resolution version of the 100-meter land-based and offshore wind speed resource map.

  18. A Robust STATCOM Control to Augment LVRT capability of Fixed Speed Wind Turbines

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    A Robust STATCOM Control to Augment LVRT capability of Fixed Speed Wind Turbines M. J. Hossain, H Compensator (STATCOM) to enhance the Low-Voltage Ride- Through (LVRT) capability of fixed-speed wind turbines cost and maintenance due to rugged brushless construction. Constant speed wind turbines equipped

  19. Simultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements

    E-Print Network [OSTI]

    Ruf, Christopher

    to simultaneously retrieve the vertical profile of precipitation and the near-surface wind speed. ResultsSimultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements simultaneously estimates the over ocean near-surface wind speed and rain rate profile using data from a 10.7 GHz

  20. Wind speed influence on phytoplankton bloom dynamics in the Southern Ocean Marginal Ice Zone

    E-Print Network [OSTI]

    Fitch, Dillon T; Moore, J. Keith

    2007-01-01T23:59:59.000Z

    Niebauer, H. J. (1982), Wind and melt driven circulation inJ. K. Moore (2007), Wind speed influence on phytoplanktonby the NASA Ocean Vector Winds Science Team. Data are

  1. Laboratory implementation of variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Zinger, D.S. [Northern Illinois University, DeKalb, IL (United States)] [Northern Illinois University, DeKalb, IL (United States); Miller, A.A. [Univ. of Idaho, Moscow, ID (United States)] [Univ. of Idaho, Moscow, ID (United States); Muljadi, E.; Butterfield, C.P.; Robinson, M.C. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States)

    1996-07-01T23:59:59.000Z

    To improve the performance of wind turbines, various control schemes such as variable speed operation have been proposed. Testing of these control algorithms on a full scale system is very expensive. To test these systems simulation, we developed programs and small scale laboratory experiments. We used this system to verify a control method that attempts to keep the turbine operating at its peak power coefficient. Both the simulations and the experiments verified the principle of operation of this control scheme.

  2. Ris-PhD-Report Accounting for the speed shear in wind

    E-Print Network [OSTI]

    Risø-PhD-Report Accounting for the speed shear in wind turbine power performance measurement Rozenn for the speed shear in wind turbine power performance measurement Division: Wind Energy Division Abstract: The power curve of a wind turbine is the primary char- acteristic of the machine as it is the basis

  3. Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction

    E-Print Network [OSTI]

    Zender, Charles

    data, all from 2000 to 2005. Wind speed mean, 90th percentile, standard deviation, and Weibull shape and energy fluxes depend nonlinearly on wind speed magnitude, are sensitive to the tails of the wind statistics, particularly in the Southern Hemisphere storm track, consistent with the hypothesis. These wind

  4. Solar wind suprathermal electron Stahl widths across high-speed stream structures

    SciTech Connect (OSTI)

    Skoug, Ruth M [Los Alamos National Laboratory; Steinberg, John T [Los Alamos National Laboratory; Goodrich, Katherine A [Los Alamos National Laboratory; Anderson, Brett R [DARTMUTH UNIV.

    2011-01-03T23:59:59.000Z

    Suprathermal electrons (100-1500 eV) observed in the solar wind typically show a strahl distribution, that is, a beam directed away from the Sun along the magnetic field direction. The strahl width observed at 1 AU is highly variable, ranging from 10-70 degrees. The obsenred finite width of the strahl results from the competition between beam focusing as the interplanetary magnetic field strength drops with distance from the Sun, and pitch-angle scattering as the beam interacts with the solar wind plasma in transit from the sun. Here we examine strahl width, observed with ACE SWEPAM across high-speed stream structures to investigate variations in electron scattering as a function of local plasma characteristics. We find that narrow strahls (less than 20 degrees wide), indicating reduced scattering, are observed within high-speed streams. Narrow strahls are also observed in both very low temperature solar wind, in association with ICMEs. Case studies of high-speed streams typically show the strahl narrowing at the leading edge of the stream. In some cases, the strahl narrows at the reverse shock or pressure wave, in other cases at the stream interface. The narrowing can either occur discontinuously or gradually over a period of hours. Within the high-speed wind, the strahl remains narrow for a period of hours to days, and then gradually broadens. The strahl width is roughly constant at all energies across these structures. For some fraction of high-speed streams, counterstreaming is associated with passage of the corotating interaction region. In these cases, we find the widths of the two counterstreaming beams frequently differ by more than 40 degrees. This dramatic difference in strahl width contrasts with observations in the solar wind as a whole, in which counterstreaming strahls typically differ in width by less than 20 degrees.

  5. EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS

    E-Print Network [OSTI]

    EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE), Curtin University of Technology, WA Abstract: Variable speed wind turbine generators provide the opportunity to capture more power than fixed speed turbines. However the variable speed machine output can

  6. Systematic Controller Design Methodology for Variable-Speed Wind Turbines

    SciTech Connect (OSTI)

    Hand, M. M.; Balas, M. J.

    2002-02-01T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three operational regions. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized.

  7. Control strategy for variable-speed, stall-regulated wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Pierce, K.; Migliore, P.

    1998-04-01T23:59:59.000Z

    A variable-speed, constant-pitch wind turbine was investigated to evaluate the feasibility of constraining its rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. A computational model was developed, and simulations were conducted of operation in high turbulent winds. Results indicated that rotor speed and power output were well regulated. 7 refs., 7 figs.

  8. The Probability Distribution of Land Surface Wind Speeds ADAM H. MONAHAN AND YANPING HE

    E-Print Network [OSTI]

    He, Yanping

    al. 2004), wind extremes (e.g., Gastineau and Soden 2009), and wind power climatologies (e.g., Troen) and the prediction of the wind power re- source and extreme surface winds in present and future climates (e.g., TroenThe Probability Distribution of Land Surface Wind Speeds ADAM H. MONAHAN AND YANPING HE School

  9. Ris National Laboratory DTU Wind Energy Department

    E-Print Network [OSTI]

    wind speed, wind direction relative to the spinner and flow inclination angle. A wind tunnel concept anemometer is a wind measurement concept in which measurements of wind speed in the flow over a wind turbine on a modified 300kW wind turbine spinner, was mounted with three 1D sonic wind speed sensors. The flow around

  10. Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System

    E-Print Network [OSTI]

    Gui, Lichuan

    Tracking an Aerodynamic Model in a Wind Tunnel with a Stereo High-speed Imaging System Lichuan Gui in wind tunnel tests with a stereo high-speed imaging system. The imaging system includes two high angle, pitch angle and yaw angle of the aerodynamic model in the wind tunnel. Tests and simulations were

  11. Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems

    E-Print Network [OSTI]

    Boyer, Edmond

    Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems B. Beltran, T. Ahmed power generation in variable speed wind energy conversion systems (VS-WECS). These systems have two (National Renewable Energy Laboratory) wind turbine simulator FAST (Fatigue, Aerodynamics, Structures

  12. Interpolating wind speed normals from the sparse Dutch network to a high resolution

    E-Print Network [OSTI]

    Stoffelen, Ad

    , we had potential wind speed time series with 30 years of data (with at least 20 yearly and monthly by Verkaik (Verkaik, 2001). The method is a five-step procedure: 1 Use series of (potential) wind to calculate (potential) normals at measuring sites 2 Calculate wind speed normals at the top of the surface

  13. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, E.

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

  14. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-01-01T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  15. Variable Speed Wind Turbine Generator with Zero-sequence Filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  16. Effects of turbulence on power generation for variable-speed wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Buhl, M.L. Jr.

    1996-11-01T23:59:59.000Z

    One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.

  17. Low Wind Speed Turbine Development Project Report: November 4, 2002 - December 31, 2006

    SciTech Connect (OSTI)

    Mikhail, A.

    2009-01-01T23:59:59.000Z

    This report summarizes work conducted by Clipper Windpower under the DOE Low Wind Speed Turbine project. The objective of this project was to produce a wind turbine that can lower the cost of energy.

  18. Forecasting of wind speed using wavelets analysis and cascade-correlation neural networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for the city of Perpignan (south of France). In this sense, forecasting average wind speeds was the main such as sunlight, wind, rain or geothermal heat. Wind energy is actually one of the fastest-growing forms of electricity generation because wind is a clean, indigenous and inexhaustible energy resource that can generate

  19. The effect of wind speed fluctuations on the performance of a wind-powered membrane system for brackish water desalination 

    E-Print Network [OSTI]

    Park, Gavin L.; Schäfer, Andrea; Richards, Bryce S.

    2011-01-01T23:59:59.000Z

    A wind-powered reverse osmosis membrane (wind-membrane) system without energy storage was tested using synthetic brackish water (2750 and 5500 mg/L NaCl) over a range of simulated wind speeds under both steady-state and ...

  20. Low Wind Speed Turbine Developments in Convoloid Gearing: Final Technical Report, June 2005 - October 2008

    SciTech Connect (OSTI)

    Genesis Partners LP

    2010-08-01T23:59:59.000Z

    This report presents the results of a study conducted by Genesis Partners LP as part of the United States Department of Energy Wind Energy Research Program to develop wind technology that will enable wind systems to compete in regions having low wind speeds. The purpose of the program is to reduce the cost of electricity from large wind systems in areas having Class 4 winds to 3 cents per kWh for onshore systems or 5 cents per kWh for offshore systems. This work builds upon previous activities under the WindPACT project, the Next Generation Turbine project, and Phase I of the Low Wind Speed Turbine (LWST) project. This project is concerned with the development of more cost-effective gearing for speed increasers for wind turbines.

  1. Master's thesis: "Wind speed measurements in an offshore wind farm by remote sensing: Comparison of radar satellite TerraSAR-X and ground-based

    E-Print Network [OSTI]

    Peinke, Joachim

    Master's thesis: "Wind speed measurements in an offshore wind farm by remote sensing: Comparison of the Offshore wind farm alpha ventus with 12 wind turbines, substation and met mast Fino1. Southerly winds cause (wake) caused by wind farms and especially for the interaction of large offshore wind farms, which can

  2. Low Wind Speed Technology Phase II: Investigation of the Application of Medium-Voltage Variable-Speed Drive Technology to Improve the Cost of Energy from Low Wind Speed Turbines; Behnke, Erdman and Whitaker Engineering, Inc.

    SciTech Connect (OSTI)

    Not Available

    2006-03-01T23:59:59.000Z

    This fact sheet describes a subcontract with Behnke, Erdman & Whitaker Engineering, Inc. to test the feasibility of applying medium-voltage variable-speed drive technology to low wind speed turbines.

  3. A conservative control strategy for variable-speed stall-regulated wind turbines

    SciTech Connect (OSTI)

    Muljadi, E.; Pierce, K.; Migliore, P.

    2000-02-08T23:59:59.000Z

    Simulation models of a variable-speed, fixed-pitch wind turbine were investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled to cause the wind turbine to operate near maximum efficiency. Using the developed models, simulations were conducted of operation in turbulent winds. Results indicated that rotor speed and power output were well regulated. Preliminary investigations of system dynamics showed that, compared to fixed-speed operation, variable-speed operation caused cyclic loading amplitude to be reduced for the turbine blades and low-speed shaft and slightly increased for the tower loads. This result suggests a favorable impact on fatigue life from implementation of the proposed control strategy.

  4. Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms

    E-Print Network [OSTI]

    Pryor, Sara C.

    Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore@globalnet.co.uk · WEB SITE: www.multi-science.co.uk #12;Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms R.J. Barthelmie1,2, J. Badger3, S.C. Pryor2, C.B. Hasager3, M

  5. An examination of loads and responses of a wind turbine undergoing variable-speed operation

    SciTech Connect (OSTI)

    Wright, A.D.; Buhl, M.L. Jr.; Bir, G.S.

    1996-11-01T23:59:59.000Z

    The National Renewable Energy Laboratory has recently developed the ability to predict turbine loads and responses for machines undergoing variable-speed operation. The wind industry has debated the potential benefits of operating wind turbine sat variable speeds for some time. Turbine system dynamic responses (structural response, resonance, and component interactions) are an important consideration for variable-speed operation of wind turbines. The authors have implemented simple, variable-speed control algorithms for both the FAST and ADAMS dynamics codes. The control algorithm is a simple one, allowing the turbine to track the optimum power coefficient (C{sub p}). The objective of this paper is to show turbine loads and responses for a particular two-bladed, teetering-hub, downwind turbine undergoing variable-speed operation. The authors examined the response of the machine to various turbulent wind inflow conditions. In addition, they compare the structural responses under fixed-speed and variable-speed operation. For this paper, they restrict their comparisons to those wind-speed ranges for which limiting power by some additional control strategy (blade pitch or aileron control, for example) is not necessary. The objective here is to develop a basic understanding of the differences in loads and responses between the fixed-speed and variable-speed operation of this wind turbine configuration.

  6. Ris0-M-2829 2 Extreme Values ofWind Speeds

    E-Print Network [OSTI]

    Ris0-M-2829 2 Extreme Values ofWind Speeds overthe Great Belt Region N.O. Jensen and B. Nielsen Ris events 9 4 Extrapolation to the 50-year storm 11 5 Discussion of the 50-year wind 15 6 Crosswind extremes for extreme values of wind speeds. The data material was obtained from a 70-m mast on a small island, Sprog0

  7. The Impacts of Wind Speed Trends and Long-term Variability in Relation to Hydroelectric

    E-Print Network [OSTI]

    Kohfeld, Karen

    The Impacts of Wind Speed Trends and Long- term Variability in Relation to Hydroelectric Reservoir and Long-term Variability in Relation to Hydroelectric Reservoir Inflows on Wind Power in the Pacific through diversification. In hydroelectric dominated systems, like the PNW, the benefits of wind power can

  8. EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with data from the offshore field measurement Rødsand by extrapolating the measured 10 m wind

  9. Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy turbine technology has undergone rapid developments. Growth in size and the optimization of wind turbines

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

    E-Print Network [OSTI]

    Hu, Weihao

    Individual Pitch Control for Mitigation of Power Fluctuation of Variable Speed Wind Turbines, China mcheng@seu.edu.cn Abstract-- Grid connected wind turbines are the sources of power fluctuations presents an individual pitch control (IPC) strategy to mitigate the wind turbine power fluctuation at both

  11. An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel

    E-Print Network [OSTI]

    Stanford University

    An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy

  12. Magnetic-Driven Winds from Post-AGB Stars: Solutions for High Speed Winds and Extreme Collimation

    E-Print Network [OSTI]

    Guillermo Garcia-Segura; Jose Alberto Lopez; Jose Franco

    2004-09-24T23:59:59.000Z

    This paper explores the effects of post-AGB winds driven solely by magnetic pressure from the stellar surface. It is found that winds can reach high speeds under this assumption, and lead to the formation of highly collimated proto-planetary nebulae. Bipolar knotty jets with periodic features and constant velocity are well reproduced by the models. Several wind models with terminal velocities from a few tens of $\\kms$ up to $10^3$ $\\kms$ are calculated, yielding outflows with linear momenta in the range $10^{36}-10^{40} \\gcms$, and kinetic energies in the range $10^{42}-10^{47} $ erg. These results are in accord with recent observations of proto-planetary nebulae that have pointed out serious energy and momentum deficits if radiation pressure is considered as the only driver for these outflows. Our models strengthen the notion that the large mass-loss rates of post-AGB stars, together with the short transition times from the late AGB to the planetary nebula stage, could be directly linked with the generation of strong magnetic fields during this transition stage.

  13. First and second order semi-Markov chains for wind speed modeling

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2012-01-01T23:59:59.000Z

    The increasing interest in renewable energy, particularly in wind, has given rise to the necessity of accurate models for the generation of good synthetic wind speed data. Markov chains are often used with this purpose but better models are needed to reproduce the statistical properties of wind speed data. We downloaded a database, freely available from the web, in which are included wind speed data taken from L.S.I. -Lastem station (Italy) and sampled every 10 minutes. With the aim of reproducing the statistical properties of this data we propose the use of three semi-Markov models. We generate synthetic time series for wind speed by means of Monte Carlo simulations. The time lagged autocorrelation is then used to compare statistical properties of the proposed models with those of real data and also with a synthetic time series generated though a simple Markov chain.

  14. Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous

    E-Print Network [OSTI]

    Chen, Zhe

    1 Abstract--A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine of this variable speed wind turbine based on multiple generators drive-train configuration. Index Terms--Wind power

  15. LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011

    SciTech Connect (OSTI)

    Dunne, F.; Simley, E.; Pao, L.Y.

    2011-10-01T23:59:59.000Z

    This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feed-forward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

  16. E-Print Network 3.0 - annual wind speeds Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Search Powered by Explorit Topic List Advanced Search Sample search results for: annual wind speeds Page: << < 1 2 3 4 5 > >> 1 This document will help you understand the...

  17. Wind speed forecasting at different time scales: a non parametric approach

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2013-01-01T23:59:59.000Z

    The prediction of wind speed is one of the most important aspects when dealing with renewable energy. In this paper we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model, that reproduces accurately the statistical behavior of wind speed, to forecast wind speed one step ahead for different time scales and for very long time horizon maintaining the goodness of prediction. In order to check the main features of the model we show, as indicator of goodness, the root mean square error between real data and predicted ones and we compare our forecasting results with those of a persistence model.

  18. Ris-R-1563(EN) ACCUWIND -Accurate Wind Speed

    E-Print Network [OSTI]

    : Wind Energy Department Risø-R-1563(EN) July 2006 ISSN 0106-2840 ISBN 87-550-3526-4 Contract no.: NNE5

  19. Tuesday, 31 July, 2012 Rapid radiation belt losses occurring during high speed solar wind stream1

    E-Print Network [OSTI]

    Otago, University of

    Tuesday, 31 July, 2012 1 Rapid radiation belt losses occurring during high speed solar wind stream1 Raita11 Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland12 Abstract. Recent geomagnetic disturbances triggered by the arrival of a Solar14 Wind Stream Interface (SWSI). In the current

  20. EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES

    E-Print Network [OSTI]

    Heinemann, Detlev

    EVALUATION OF MODELS FOR THE VERTICAL EXTRAPOLATION OF WIND SPEED MEASUREMENTS AT OFFSHORE SITES important for offshore wind energy utilisation are discussed and tested: Four models for the surface tested with measurements from the offshore field measurement Rødsand by extrapolating the measured 10 m

  1. Wind turbine having a direct-drive drivetrain

    DOE Patents [OSTI]

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

    2011-02-22T23:59:59.000Z

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

  2. UNIVERSITY OF CALIFORNIA, Surface Wind Speed Distributions: Implications for Climate and Wind Power

    E-Print Network [OSTI]

    Zender, Charles

    and Wind Power DISSERTATION submitted in partial satisfaction of the requirements for the degree of DOCTOR . . . . . . . . . . . . . . . . . 19 1.3 Global Ocean Wind Power and Surface Layer Stability . . . . . . . . 23 1.3.1 Global Winds . . . . . . 27 1.4 Usable Offshore Wind Power . . . . . . . . . . . . . . . . . . . . . . . 31 1.4.1 Wind Turbine

  3. Euler-Bernoulli Implementation of Spherical Anemometers for High Wind Speed Calculations via Strain Gauges

    E-Print Network [OSTI]

    Castillo, Davis

    2011-08-08T23:59:59.000Z

    New measuring methods continue to be developed in the field of wind anemometry for various environments subject to low-speed and high-speed flows, turbulent-present flows, and ideal and non-ideal flows. As a result, anemometry has taken different...

  4. Effect of wind speed on the growth of the upper convective zone in a solar pond

    E-Print Network [OSTI]

    McMinn, Steven Lee

    2012-06-07T23:59:59.000Z

    LIST OF FIGURES CHAPTER Page 111 Vi I INTRODUCTION LITERATURE REVIEW III EXPERIMENTAL APPARATUS IV RESULTS 14 21 V ENTRAINMENT AS A FUNCTION OF RICHARDSON NUMBER 32 VI CONCLUSIONS AND RECOMMENDATIONS 44 REFERENCES APPENDIX 1 APPENDIX 2... speed. 11. Thickness of UCZ for 9. 6 m/s wind speed. 12. Thickness of UCZ for 15. 0 m/s wind speed. 52 53 54 55 56 57 58 13. Horizontal and vertical coordinates of 25 locations for measuring cross section air velocities. . . . . . 59 14. Air...

  5. Fixed-Speed and Variable-Slip Wind Turbines Providing Spinning Reserves to the Grid: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Singh, M.; Gevorgian, V.

    2012-11-01T23:59:59.000Z

    As the level of wind penetration increases, wind turbine technology must move from merely generating power from wind to taking a role in supporting the bulk power system. Wind turbines should have the capability to provide inertial response and primary frequency (governor) response so they can support the frequency stability of the grid. To provide governor response, wind turbines should be able to generate less power than the available wind power and hold the rest in reserve, ready to be accessed as needed. This paper explores several ways to control wind turbine output to enable reserve-holding capability. This paper focuses on fixed-speed (also known as Type 1) and variable-slip (also known as Type 2) turbines.

  6. 100-Year Return Value Estimates for Ocean Wind Speed and Significant Wave Height from the ERA-40 Data

    E-Print Network [OSTI]

    Haak, Hein

    and time variability of significant wave height and wind speed on the prediction of their extreme values of this dataset makes it ideal for the study of extreme wind and wave phenomena over the whole globe. Initial100-Year Return Value Estimates for Ocean Wind Speed and Significant Wave Height from the ERA-40

  7. Adaptive pitch control for variable speed wind turbines

    DOE Patents [OSTI]

    Johnson, Kathryn E. (Boulder, CO); Fingersh, Lee Jay (Westminster, CO)

    2012-05-08T23:59:59.000Z

    An adaptive method for adjusting blade pitch angle, and controllers implementing such a method, for achieving higher power coefficients. Average power coefficients are determined for first and second periods of operation for the wind turbine. When the average power coefficient for the second time period is larger than for the first, a pitch increment, which may be generated based on the power coefficients, is added (or the sign is retained) to the nominal pitch angle value for the wind turbine. When the average power coefficient for the second time period is less than for the first, the pitch increment is subtracted (or the sign is changed). A control signal is generated based on the adapted pitch angle value and sent to blade pitch actuators that act to change the pitch angle of the wind turbine to the new or modified pitch angle setting, and this process is iteratively performed.

  8. Probabilistic Forecasts of Wind Speed: Ensemble Model Output Statistics

    E-Print Network [OSTI]

    Washington at Seattle, University of

    . Over the past two decades, ensembles of numerical weather prediction (NWP) models have been developed and phrases: Continuous ranked probability score; Density forecast; Ensem- ble system; Numerical weather prediction; Heteroskedastic censored regression; Tobit model; Wind energy. 1 #12;1 Introduction Accurate

  9. Passively cooled direct drive wind turbine

    DOE Patents [OSTI]

    Costin, Daniel P. (Chelsea, VT)

    2008-03-18T23:59:59.000Z

    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.

  10. EXPERIENCES WITH SONIC WIND SENSORS IN OPERATIONAL CONDITIONS Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    ) uses conventional cup anemometers and wind vanes to measure wind speed and direction. Although the KNMI sonic considered in the previous evaluation. The advanced sensor has the required wind speed range up. An uncertainty of the wind speed of maximally 2 % at all wind directions is required for the wind profile

  11. Self-excited induction generator for variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Gregory, B. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Broad, D. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering] [Colorado State Univ., Fort Collins, CO (United States). Dept. of Electrical Engineering

    1996-10-01T23:59:59.000Z

    When an induction generator is connected to a utility bus, the voltage and frequency at the terminal of the generator are the same as the voltage and frequency of the utility. The reactive power needed by the induction generator is supplied by the utility and the real power is returned to the utility. The rotor speed varies within a very limited range, and the reactive power requirement must be transported through a long line feeder, thus creating additional transmission losses. The energy captured by a wind turbine can be increased if the rotor speed can be adjusted to follow wind speed variations. For small applications such as battery charging or water pumping, a stand alone operation can be implemented without the need to maintain the output frequency output of the generator. A self- excited induction generator is a good candidate for a stand alone operation where the wind turbine is operated at variable speed. Thus the performance of the wind turbine can be unproved. In this paper, we examine a self-excited induction generator operated in a stand alone mode. A potential application for battery charging is given. The output power of the generator will be controlled to improve the performance of the wind turbine.

  12. Wind speed modeled as a semi-Markov process with memory

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2012-01-01T23:59:59.000Z

    The increasing interest in renewable energy, particularly in wind, has given rise to the necessity of accurate models for the generation of good synthetic wind speed data. Markov chains are often used with this purpose but better models are needed to reproduce the statistical properties of wind speed data. In a previous paper we showed that semi-Markov processes are more appropriate for this purpose but to reach an accurate reproduction of real data features high order model should be used. In this work we introduce an indexed semi-Markov process that is able to fit real data. We downloaded a database, freely available from the web, in which are included wind speed data taken from L.S.I. -Lastem station (Italy) and sampled every 10 minutes. We then generate synthetic time series for wind speed by means of Monte Carlo simulations. The time lagged autocorrelation is then used to compare statistical properties of the proposed model with those of real data and also with a synthetic time series generated though a ...

  13. On the relationship between temperature and wind speed in the atmospheric surface layer

    E-Print Network [OSTI]

    Pierrard, John Martin

    2012-06-07T23:59:59.000Z

    LIBRAR& A AN m os??E " "" ON THE RELATIONSHIP BETWEEN T" MP. "RATURE AND WIND SPEED IN THE ATMOSPHERIC SURFACE LAYER A Thesis John Me Pierrard Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... logarithmically with height+ Also, the choice of a method of determination of the roughness length must be governed by an awareness of possible errors in the wind speed meas- urementso The system used to collect the data employed in this study is susceptible...

  14. Wind Direct Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDIT REPORTOpenWende NewSowitec do BrasilGmbHWeardale TaskEnergy LtdWhiteWindWind

  15. The Influence of Boundary Layer Processes on the Diurnal Variation of the Climatological Near-Surface Wind Speed Probability Distribution over Land*

    E-Print Network [OSTI]

    He, Yanping

    diurnally varying vertical structure of the leading three climatological moments of near-surface wind speed-Surface Wind Speed Probability Distribution over Land* YANPING HE School of Earth and Ocean Sciences wind speed probability distribution is essential for surface flux estimation and wind power management

  16. Wind turbine having a direct-drive drivetrain

    DOE Patents [OSTI]

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

    2008-10-07T23:59:59.000Z

    A wind turbine (100) comprising an electrical generator (108) that includes a rotor assembly (112). A wind rotor (104) that includes a wind rotor hub (124) is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle (160) via a bearing assembly (180). The wind rotor hub includes an opening (244) having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity (380) inside the wind rotor hub. The spindle is attached to a turret (140) supported by a tower (136). Each of the spindle, turret and tower has an interior cavity (172, 176, 368) that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system (276) for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  17. Robust STATCOM Control for the Enhancement of Fault Ride-Through Capability of Fixed Speed Wind Generators

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    -slip relationships as well as through simulations. The wind generator is a highly nonlinear system, which is modelled power generation. This type of wind generator always consumes reactive power from the grid. WhenRobust STATCOM Control for the Enhancement of Fault Ride-Through Capability of Fixed Speed Wind

  18. High resolution reanalysis of wind speeds over the British Isles for wind energy integration 

    E-Print Network [OSTI]

    Hawkins, Samuel Lennon

    2012-11-29T23:59:59.000Z

    The UK has highly ambitious targets for wind development, particularly offshore, where over 30GW of capacity is proposed for development. Integrating such a large amount of variable generation presents enormous challenges. ...

  19. Solar Wind Sources in the Late Declining Phase of Cycle 23: Effects of the Weak Solar Polar Field on High Speed Streams

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    Isenberg, P.A. (eds. ) Solar Wind Nine, AIP Conf. Proc. 471,AT SOLAR MINIMUM Solar Wind Sources in the Late Decliningfor their high speed solar wind streams that dominate the

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

    E-Print Network [OSTI]

    Ding, Yu

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

  1. Systematic approach for PID controller design for pitch-regulated, variable-speed wind turbines

    SciTech Connect (OSTI)

    Hand, M.M. [National Renewable Energy Lab., Golden, CO (United States); Balas, M.J. [Univ. of Colorado, Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

    1997-11-01T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. 2 refs., 9 figs.

  2. Low Wind Speed Turbine Project Phase II: The Application of Medium-Voltage Electrical Apparatus to the Class of Variable Speed Multi-Megawatt Low Wind Speed Turbines; 15 June 2004--30 April 2005

    SciTech Connect (OSTI)

    Erdman, W.; Behnke, M.

    2005-11-01T23:59:59.000Z

    Kilowatt ratings of modern wind turbines have progressed rapidly from 50 kW to 1,800 kW over the past 25 years, with 3.0- to 7.5-MW turbines expected in the next 5 years. The premise of this study is simple: The rapid growth of wind turbine power ratings and the corresponding growth in turbine electrical generation systems and associated controls are quickly making low-voltage (LV) electrical design approaches cost-ineffective. This report provides design detail and compares the cost of energy (COE) between commercial LV-class wind power machines and emerging medium-voltage (MV)-class multi-megawatt wind technology. The key finding is that a 2.5% reduction in the COE can be achieved by moving from LV to MV systems. This is a conservative estimate, with a 3% to 3.5% reduction believed to be attainable once purchase orders to support a 250-turbine/year production level are placed. This evaluation considers capital costs as well as installation, maintenance, and training requirements for wind turbine maintenance personnel. Subsystems investigated include the generator, pendant cables, variable-speed converter, and padmount transformer with switchgear. Both current-source and voltage-source converter/inverter MV topologies are compared against their low-voltage, voltage-source counterparts at the 3.0-, 5.0-, and 7.5-MW levels.

  3. RESEARCH ARTICLE Controlling speed and direction during interception

    E-Print Network [OSTI]

    . Turning rate was controlled using a steering wheel and speed was controlled using a foot pedal (Wann and Land 2000), braking (Lee 1976; Yilmaz and Warren 1995), and fly ball catching (Chapman 1968

  4. Occurrence of high-speed solar wind streams over the Grand Modern Maximum

    E-Print Network [OSTI]

    Mursula, Kalevi; Holappa, Lauri

    2015-01-01T23:59:59.000Z

    In the declining phase of the solar cycle, when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity in the near-Earth space. Here, using a novel definition of geomagnetic activity at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged solar wind speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onwards. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each solar cycle 16-23. For most cycles the HSS activity clearly maximizes during one year...

  5. Wind Resource Assessment in Europe Using Emergy

    E-Print Network [OSTI]

    Paudel, Subodh; Santarelli, Massimo; Martin, Viktoria; Lacarriere, Bruno; Le Corre, Olivier

    2014-01-01T23:59:59.000Z

    mance characteristics of wind generator. The wind speed atcharacteristics of the wind generator. When wind speed is

  6. Effect of Tip-Speed Constraints on the Optimized Design of a Wind Turbine

    SciTech Connect (OSTI)

    Dykes, K.; Resor, B.; Platt, A.; Guo, Y.; Ning, A.; King, R.; Parsons, T.; Petch, D.; Veers, P.

    2014-10-01T23:59:59.000Z

    This study investigates the effect of tip-velocity constraints on system levelized cost of energy (LCOE). The results indicate that a change in maximum tip speed from 80 to 100~m/s could produce a 32% decrease in gearbox weight (a 33% reduction in cost) which would result in an overall reduction of 1%-9% in system LCOE depending on the design approach. Three 100~m/s design cases were considered including a low tip-speed ratio/high-solidity rotor design, a high tip-speed ratio/ low-solidity rotor design, and finally a flexible blade design in which a high tip-speed ratio was used along with removing the tip deflection constraint on the rotor design. In all three cases, the significant reduction in gearbox weight caused by the higher tip-speed and lower overall gear ratio was counterbalanced by increased weights for the rotor and/or other drivetrain components and the tower. As a result, the increased costs of either the rotor or drivetrain components offset the overall reduction in turbine costs from down-sizing the gearbox. Other system costs were not significantly affected, whereas energy production was slightly reduced in the 100~m/s case low tip-speed ratio case and increased in the high tip-speed ratio case. This resulted in system cost of energy reductions moving from the 80~m/s design to the 100~m/s designs of 1.2% for the low tip-speed ratio, 4.6% for the high tip-speed ratio, and 9.5% for the final flexible case (the latter result is optimistic because the impact of deflection of the flexible blade on power production was not modeled). Overall, the results demonstrate that there is a trade-off in system design between the maximum tip velocity and the overall wind plant cost of energy, and there are many trade-offs within the overall system in designing a turbine for a high maximum tip velocity.

  7. IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 23, NO. 2, JUNE 2008 551 Sliding Mode Power Control of Variable-Speed Wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in variable-speed wind energy conversion sys- tems (VS-WECS). These systems have two operation regions de of Variable-Speed Wind Energy Conversion Systems Brice Beltran, Tarek Ahmed-Ali, and Mohamed El Hachemi (newton meter). Tg Generator torque in the rotor side (newton meter). Ths High-speed torque (newton meter

  8. E-Print Network 3.0 - atmospheric wind sensor Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to measure wind speed, wind direction, air... temperature, atmospheric pressure and solar radiation. The sensors and data-logger are mounted on 25-m high... calibration of...

  9. Vertical axis wind turbine

    SciTech Connect (OSTI)

    Kato, Y.; Seki, K.; Shimizu, Y.

    1981-01-27T23:59:59.000Z

    Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.

  10. Methods and apparatus for reducing peak wind turbine loads

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw

    2007-02-13T23:59:59.000Z

    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.

  11. Repetitive substorms caused by Alfvenic waves of the interplanetary magnetic field during high-speed solar wind streams

    E-Print Network [OSTI]

    Lyons, Larry

    , but they may be locally generated from stream-stream interaction effects or amplified Alfve´n waves originating-speed solar wind streams D.-Y. Lee,1 L. R. Lyons,2 K. C. Kim,1 J.-H. Baek,3 K.-H. Kim,3 H.-J. Kim,1 J. Weygand wind streams, J. Geophys. Res., 111, A12214, doi:10.1029/2006JA011685. 1. Introduction [2] During

  12. OPERATIONAL TEST OF SONIC WIND SENSORS AT KNMI Wiel M.F. Wauben

    E-Print Network [OSTI]

    Wauben, Wiel

    of transfer functions for wind direction, - speed and - gust that account for the change from one sensor vanes to measure wind speed and direction. Although the KNMI cup and vane meet WMO requirements into account by a wind direction and - speed dependent correction that is applied in the sensor software

  13. Comparing Pulsed Doppler LIDAR with SODAR and Direct Measurements for Wind Assessment

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Pichugina, Y. L.

    2007-07-01T23:59:59.000Z

    There is a pressing need for good wind-speed measurements at greater and greater heights to assess the availability of the resource in terms of power production and to identify any frequently occurring atmospheric structural characteristics that may create turbulence that impacts the operational reliability and lifetime of wind turbines and their components. In this paper, we summarize the results of a short study that compares the relative accuracies of wind speeds derived from a high-resolution pulsed Doppler LIDAR operated by the National Oceanic and Atmospheric Administration (NOAA) and a midrange Doppler SODAR with wind speeds measured by four levels of tower-based sonic anemometry up to a height of 116 m.

  14. Steady decline of east Asian monsoon winds, 19692000: Evidence from direct ground measurements of wind speed

    E-Print Network [OSTI]

    Robock, Alan

    of the winter monsoon, while the summer cooling in central south China and warming over the South China Sea greenhouse gas emission, while the summer decline is associated with local cooling over south-central China for Remote Sensing and Spatial Analysis, Department of Ecology, Evolution and Natural Resourc

  15. Development and Validation of WECC Variable Speed Wind Turbine Dynamic Models for Grid Integration Studies

    SciTech Connect (OSTI)

    Behnke, M.; Ellis, A.; Kazachkov, Y.; McCoy, T.; Muljadi, E.; Price, W.; Sanchez-Gasca, J.

    2007-09-01T23:59:59.000Z

    This paper describes reduced-order, simplified wind turbine models for analyzing the stability impact of large arrays of wind turbines with a single point of network interconnection.

  16. Application of Ensemble Sensitivity Analysis to Observation Targeting for Short-term Wind Speed Forecasting

    SciTech Connect (OSTI)

    Zack, J; Natenberg, E; Young, S; Manobianco, J; Kamath, C

    2010-02-21T23:59:59.000Z

    The operators of electrical grids, sometimes referred to as Balancing Authorities (BA), typically make critical decisions on how to most reliably and economically balance electrical load and generation in time frames ranging from a few minutes to six hours ahead. At higher levels of wind power generation, there is an increasing need to improve the accuracy of 0- to 6-hour ahead wind power forecasts. Forecasts on this time scale have typically been strongly dependent on short-term trends indicated by the time series of power production and meteorological data from a wind farm. Additional input information is often available from the output of Numerical Weather Prediction (NWP) models and occasionally from off-site meteorological towers in the region surrounding the wind generation facility. A widely proposed approach to improve short-term forecasts is the deployment of off-site meteorological towers at locations upstream from the wind generation facility in order to sense approaching wind perturbations. While conceptually appealing, it turns out that, in practice, it is often very difficult to derive significant benefit in forecast performance from this approach. The difficulty is rooted in the fact that the type, scale, and amplitude of the processes controlling wind variability at a site change from day to day if not from hour to hour. Thus, a location that provides some useful forecast information for one time may not be a useful predictor a few hours later. Indeed, some processes that cause significant changes in wind power production operate predominantly in the vertical direction and thus cannot be monitored by employing a network of sensors at off-site locations. Hence, it is very challenging to determine the type of sensors and deployment locations to get the most benefit for a specific short-term forecast application. Two tools recently developed in the meteorological research community have the potential to help determine the locations and parameters to measure in order to get the maximum positive impact on forecast performance for a particular site and short-term look-ahead period. Both tools rely on the use of NWP models to assess the sensitivity of a forecast for a particular location to measurements made at a prior time (i.e. the look-ahead period) at points surrounding the target location. The fundamental hypothesis is that points and variables with high sensitivity are good candidates for measurements since information at those points are likely to have the most impact on the forecast for the desired parameter, location and look-ahead period. One approach is called the adjoint method (Errico and Vukicevic, 1992; Errico, 1997) and the other newer approach is known as Ensemble Sensitivity Analysis (ESA; Ancell and Hakim 2007; Torn and Hakim 2008). Both approaches have been tested on large-scale atmospheric prediction problems (e.g. forecasting pressure or precipitation over a relatively large region 24 hours ahead) but neither has been applied to mesoscale space-time scales of winds or any other variables near the surface of the earth. A number of factors suggest that ESA is better suited for short-term wind forecasting applications. One of the most significant advantages of this approach is that it is not necessary to linearize the mathematical representation of the processes in the underlying atmospheric model as required by the adjoint approach. Such a linearization may be especially problematic for the application of short-term forecasting of boundary layer winds in complex terrain since non-linear shifts in the structure of boundary layer due to atmospheric stability changes are a critical part of the wind power production forecast problem. The specific objective of work described in this paper is to test the ESA as a tool to identify measurement locations and variables that have the greatest positive impact on the accuracy of wind forecasts in the 0- to 6-hour look-ahead periods for the wind generation area of California's Tehachapi Pass during the warm (high generation) season. The paper is organized

  17. Vertical axis wind turbine

    SciTech Connect (OSTI)

    Kato, Y.; Seki, K.; Shimizu, Y.

    1981-01-27T23:59:59.000Z

    Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with the axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of the vertical rotary axis.

  18. Choosing wind power plant locations and sizes based on electric reliability measures using multiple-year wind speed measurements

    SciTech Connect (OSTI)

    Milligan, M.R.; Artig, R.

    1999-07-08T23:59:59.000Z

    To project the US potential to meet future electricity demands with wind energy, estimates of available wind resource and costs to access that resource are critical. The US Department of Energy (DOE) Energy Information Administration (EIA) annually estimates the US market penetration of wind in its Annual Energy Outlook series. For these estimates, the EIA uses wind resource data developed by the Pacific Northwest National Laboratory for each region of the country. However, the EIA multiplies the cost of windpower by several factors, some as large as 3, to account for resource quality, market factors associated with accessing the resource, electric grid impacts, and rapid growth in the wind industry. This paper examines the rationale behind these additional costs and suggests alternatives.

  19. Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum

    E-Print Network [OSTI]

    Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W

    2015-01-01T23:59:59.000Z

    Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

  20. Wind velocity measurements using a pulsed LIDAR system: first results

    E-Print Network [OSTI]

    Peinke, Joachim

    . A laser beam of 1.54 µm wavelength takes measurements of the wind speed in beamwise direction. To obtain the three-dimensinal wind vector, the beam is inclined by 30 from vertical direction and measurements 12345 t [s] vh[m/s] Figure 2. Segment of measured time series of the horizontal wind speed magnitude vh

  1. Direct and Inverse Cascades in the Wind-Driven Sea

    E-Print Network [OSTI]

    Zakharov, Vladimir E

    2015-01-01T23:59:59.000Z

    We offer a new form for the S(nl) term in the Hasselmann kinetic equation for squared wave amplitudes of wind-driven gravity wave. This form of S(nl) makes possible to rewrite in differential form the conservation laws for energy, momentum, and wave action, and introduce their fluxes by a natural way. We show that the stationary kinetic equation has a family of exact Kolmogorov-type solutions governed by the fluxes of motion constants: wave action, energy, and momentum. The simple "local" model for S(nl) term that is equivalent to the "diffusion approximation" is studied in details. In this case, Kolmogorov spectra are found in the explicit form. We show that a general solution of the stationary kinetic equation behind the spectral peak is described by the Kolmogorov-type solution with frequency-dependent fluxes. The domains of "inverse cascade" and "direct cascade" can be separated by natural way. The spectrum in the universal domain is close to $\\omega^{-4}$.

  2. Review of Wind Turbine Wake Models and Future Directions (Presentation)

    SciTech Connect (OSTI)

    Churchfield, M. J.

    2013-08-01T23:59:59.000Z

    This presentation gives a brief overview to wind turbine wake modeling, ranging from models used in the 1980s up to the present. The presentation shows the strengths and weaknesses of various models and discusses the needs of the wind energy industry and research sectors. Both power production and loads analysis are discussed.

  3. Remote sensing of total integrated water vapor, wind speed, and cloud liquid water over the ocean using the Special Sensor Microwave/Imager (SSM/I)

    E-Print Network [OSTI]

    Manning, Norman Willis William

    2012-06-07T23:59:59.000Z

    A modified D-matrix retrieval method is the basis of the refined total integrated water vapor (TIWV), total integrated cloud liquid water (CLW), and surface wind speed (WS) retrieval methods that are developed. The 85 GHZ polarization difference...

  4. Wind Fields over the Great Lakes Measured by the SeaWinds Scatterometer on the QuikSCAT Satellite

    E-Print Network [OSTI]

    Wind Fields over the Great Lakes Measured by the SeaWinds Scatterometer on the QuikSCAT Satellite for wind retrieval over the Great Lakes on a daily basis. We use data acquired by the SeaWinds Scatterometer on the QuikSCAT (QSCAT) satellite launched in June 1999 to derive wind speeds and directions over

  5. Multivariate analysis and prediction of wind turbine response to varying wind field characteristics based on machine learning

    E-Print Network [OSTI]

    Stanford University

    are often described by time-dependent statistical parameters such as mean wind speed, turbulence intensity, mean wind direction and vertical mean wind profile, which depends on the surface roughness (e.g. landMultivariate analysis and prediction of wind turbine response to varying wind field characteristics

  6. E-Print Network 3.0 - accurate wind speed Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Brigham Young University Collection: Engineering 4 Mesoscale modelling for an offshore wind farm Jake Badger*, Rebecca Barthelmie, Sten Frandsen, Merete Bruun Christiansen...

  7. Calibration of the Merrill-G.A.L.C.I.T. wind-tunnel, and a suggestion for a variable cross-section on a small high-speed wind-tunnel.

    E-Print Network [OSTI]

    Schwarzenbach, Jean Christophe

    1942-01-01T23:59:59.000Z

    ??Speed, power and flow inclination calibration tests run in the Merrill-GALCIT wind-tunnel are described and results presented. A description of the new balance-system is included.… (more)

  8. NIST BUILDING SCIENCE SERIES 180 Database-Assisted Design for Wind

    E-Print Network [OSTI]

    climatological information on extreme wind speeds and their direction-dependence can be used in conjunction; aerodynamics; extreme winds; database-assisted design; structural dynamics; wind directionality; wind forcesNIST BUILDING SCIENCE SERIES 180 Database-Assisted Design for Wind: Concepts, Software

  9. High-Speed Optical Spectroscopy of a Cataclysmic Variable Wind BZ Camelopardalis

    E-Print Network [OSTI]

    Ringwald, F A

    1997-01-01T23:59:59.000Z

    BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H alpha. We have since obtained spectra with 0.4-Angstroms/pixel dispersion and 60-s time resolution. We find a wind much faster and more rapidly variable than the radiatively accelerated winds of OB stars, Wolf-Rayet stars, or luminous blue variables. Instead of showing blob ejection, the whole wind of BZ Cam appears to turn on and off. We use this to measure the acceleration law of a CV wind for the first time. The velocity increases linearly with time, attaining blue edge velocities near -3000 km/s, and absorption velocities near -1700 km/s, in 6 to 8 min after starting near rest. We also find a subsequent linear deceleration to nearly rest in 30 to 40 min, perhaps an effect of dilution as the wind expands. No periodicity from rotational outflow is obvious. This wind is e...

  10. Structural optimisation of permanent magnet direct drive generators for 5MW wind turbines 

    E-Print Network [OSTI]

    Zavvos, Aristeidis

    2013-11-28T23:59:59.000Z

    This thesis focuses on permanent magnet "direct drive" electrical generators for wind turbines with large power output. A variety of such generator topologies is reviewed, tested and optimised in an attempt to increase ...

  11. Wind motor applications for transportation

    SciTech Connect (OSTI)

    Lysenko, G.P.; Grigoriev, B.V.; Karpin, K.B. [Moscow Aviation Inst. (Russian Federation)

    1996-12-31T23:59:59.000Z

    Motion equation for a vehicle equipped with a wind motor allows, taking into account the drag coefficients, to determine the optimal wind drag velocity in the wind motor`s plane, and hence, obtain all the necessary data for the wind wheel blades geometrical parameters definition. This optimal drag velocity significantly differs from the flow drag velocity which determines the maximum wind motor power. Solution of the motion equation with low drag coefficients indicates that the vehicle speed against the wind may be twice as the wind speed. One of possible transportation wind motor applications is its use on various ships. A ship with such a wind motor may be substantially easier to steer, and if certain devices are available, may proceed in autonomous control mode. Besides, it is capable of moving within narrow fairways. The cruise speed of a sailing boat and wind-motored ship were compared provided that the wind velocity direction changes along a harmonic law with regard to the motion direction. Mean dimensionless speed of the wind-motored ship appears to be by 20--25% higher than that of a sailing boat. There was analyzed a possibility of using the wind motors on planet rovers in Mars or Venus atmospheric conditions. A Mars rover power and motor system has been assessed for the power level of 3 kW.

  12. High-Speed Optical Spectroscopy of a Cataclysmic Variable Wind: BZ Camelopardalis

    E-Print Network [OSTI]

    F. A. Ringwald; T. Naylor

    1997-10-02T23:59:59.000Z

    BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H alpha. We have since obtained spectra with 0.4-Angstroms/pixel dispersion and 60-s time resolution. We find a wind much faster and more rapidly variable than the radiatively accelerated winds of OB stars, Wolf-Rayet stars, or luminous blue variables. Instead of showing blob ejection, the whole wind of BZ Cam appears to turn on and off. We use this to measure the acceleration law of a CV wind for the first time. The velocity increases linearly with time, attaining blue edge velocities near -3000 km/s, and absorption velocities near -1700 km/s, in 6 to 8 min after starting near rest. We also find a subsequent linear deceleration to nearly rest in 30 to 40 min, perhaps an effect of dilution as the wind expands. No periodicity from rotational outflow is obvious. This wind is erratic and incessantly variable, and perhaps bipolar and face-on, but not highly collimated. The P Cygni absorption events trace out sawtooth waves, occurring within 30 to 40 white dwarf radii from the disk. This is the approximate size of the disk, as well as the disk/wind transition region recently postulated by Knigge and Drew. We estimate a distance of 830 +/- 160 pc, and an orbital inclination i such that 12 < i(degrees) < 40.

  13. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2003 ­ August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  14. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2003 ­ May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  15. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle June 1, 2005 ­ August 31, 2005 Prepared for United States Department...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  16. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2004 ­ August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  17. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  18. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 ­ February 28, 2005 Prepared for United States.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  19. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  20. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2003 ­ November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  1. WIND DATA REPORT FALMOUTH, MA

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT FALMOUTH, MA June1, 2004 to August 31, 2004. Prepared for Massachusetts Technology...................................................................................................................... 8 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

  2. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle March 1, 2005 ­ May 31, 2005 Prepared for United States Department.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  3. WIND DATA REPORT Presque Isle

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Presque Isle December 1, 2004 ­ December 1, 2005 Prepared for United States ......................................................................................................... 9 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  4. The solar wind interaction with Mars: Recent progress and future directions The Sun has a powerful influence on planetary atmospheres.

    E-Print Network [OSTI]

    California at Berkeley, University of

    Editorial The solar wind interaction with Mars: Recent progress and future directions The Sun has field, because the solar wind can interact directly with the upper atmo- sphere. Neutral particles in the upper atmosphere are ionized by solar photons and through interactions with solar wind charged particles

  5. Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

    SciTech Connect (OSTI)

    Bluestein, H.B.; LaDue, J.G.; Stein, H.; Speheger, D. [Oklahoma Univ., Norman, OK (United States); Unruh, W.P. [Los Alamos National Lab., NM (United States)

    1993-03-01T23:59:59.000Z

    Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL`s fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.

  6. Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

    SciTech Connect (OSTI)

    Bluestein, H.B.; LaDue, J.G.; Stein, H.; Speheger, D. (Oklahoma Univ., Norman, OK (United States)); Unruh, W.P. (Los Alamos National Lab., NM (United States))

    1993-01-01T23:59:59.000Z

    Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL's fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.

  7. Wind pro?le assessment for wind power purposes.

    E-Print Network [OSTI]

    Sointu, Iida

    2014-01-01T23:59:59.000Z

    ??Preliminary estimation of wind speed at the wind turbine hub height is critically important when planning new wind farms. Wind turbine power output is proportional… (more)

  8. Wind Power Plant Prediction by Using Neural Networks: Preprint

    SciTech Connect (OSTI)

    Liu, Z.; Gao, W.; Wan, Y. H.; Muljadi, E.

    2012-08-01T23:59:59.000Z

    This paper introduces a method of short-term wind power prediction for a wind power plant by training neural networks based on historical data of wind speed and wind direction. The model proposed is shown to achieve a high accuracy with respect to the measured data.

  9. MAPping Foehn Winds in the Austrian Alps

    E-Print Network [OSTI]

    Gohm, Alexander

    and the flow above mountain-top level 3. Study the vertical and cross-gap distribution of wind speed-valley horizontal wind speed ("measured") vertical wind speed (calculated) total wind speed & streamlines -20 -10 0 October 1999 ­ TEACO2 calculated 2D winds down-valley horizontal wind speed ("measured") vertical wind

  10. Variable-speed wind power system with improved energy capture via multilevel conversion

    DOE Patents [OSTI]

    Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

    2005-05-31T23:59:59.000Z

    A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

  11. An application of vortex cancellation to vortex generator techniques in low speed wind tunnels

    E-Print Network [OSTI]

    Mount, Glynn O., Jr

    2012-06-07T23:59:59.000Z

    'lugs/ft-sec Axial distance between sets of vortex generators root chord lengths /Y Vertical dimension of duct cross section Tube height/Y in. none ~St i t ()i ()2 (), ( )?q Measured at station g 1 Measured at Station 0 8 Upstream srl... to accomplish these objectives. The usefulness of many of them was limited because they were either too expensive, they could not be installed easily in existing wind tunnels, or their use involved excessive energy dissipation. Vortex Generators In 1/46 a...

  12. Simulated performance of an airborne lidar wind shear detection system

    E-Print Network [OSTI]

    Griffith, Kenneth Scott

    2012-06-07T23:59:59.000Z

    in the microburst test case. Journal model is Applied Optics. CHAPTER II THE WIND SHEAR HAZARD 2. 1 The Wind Shear Phenomenon Wind shear can be defined as a change in wind direction and/or speed over relatively short distances. i Wind shear can occur at any... and sea ? breeze fronts. These clear air winds move at speeds of 15 to 40 knots over large distances. rhtrrM~s Prost i ? arhiog the ar e of t a sitio bet eea t o separate ai masses having different temperatures and humidities. The change in wind...

  13. Bias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction

    E-Print Network [OSTI]

    Washington at Seattle, University of

    from numerical weather prediction models, which is based on a state-of-the-art circular-processing techniques for forecasts from numerical weather prediction models tend to become ineffective or inapplicableBias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction Le

  14. Refinement of a semi-empirical model for the microwave emissivity of the sea surface as a function of wind speed

    E-Print Network [OSTI]

    Kohn, David Jacob

    2012-06-07T23:59:59.000Z

    as the wind speed increases-instead of being switched on at 7 m/s. These changes yield an improved sea surface model that is within 2% of the sea surface emissivity given by the Wentz sea surface emissivity functions....

  15. Simulation of winds as seen by a rotating vertical axis wind turbine blade

    SciTech Connect (OSTI)

    George, R.L.

    1984-02-01T23:59:59.000Z

    The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array (VPA) project. Simulations were run of the rotationally sampled wind speed relative to the earth, as well as the tangential and radial wind speeds, which are relative to the rotating wind turbine blade. Spectral analysis is used to compare and assess wind simulations from the different wind regimes, as well as from alternate wind measurement techniques. The variance in the wind speed at frequencies at or above the blade rotation rate is computed for all cases, and is used to quantitatively compare the VAWT simulations with Horizontal Axis Wind Turbine (HAWT) simulations. Qualitative comparisons are also made with direct wind measurements from a VAWT blade.

  16. WIND DATA REPORT January -December, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January - December, 2003 Prepared for Fox Islands Electric Cooperative...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  17. WIND DATA REPORT January -March, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January - March, 2004 Prepared for Fox Islands Electric Cooperative...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  18. ANNUAL WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    ANNUAL WIND DATA REPORT Thompson Island March 1, 2002 ­ February 28, 2003 Prepared.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distributions

  19. WIND DATA REPORT Deer Island Parking Lot

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Parking Lot May 1, 2003 ­ July 15, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  20. WIND DATA REPORT Deer Island Outfall

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Deer Island Outfall August 18, 2003 ­ December 4, 2003 Prepared for Massachusetts...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 7 Wind Speed Distributions

  1. Quality Control and Verification of Weather Radar Wind Profiles IWAN HOLLEMAN

    E-Print Network [OSTI]

    Stoffelen, Ad

    - tions of the vertical velocity, which is a sum of the vertical wind velocity and the hydrometeor fall. 1986). Profiles of wind speed and direction, hydrometeor fall speed, and divergence have been obtainedQuality Control and Verification of Weather Radar Wind Profiles IWAN HOLLEMAN Royal Netherlands

  2. Preliminary design and viability consideration of external, shroud-based stators in wind turbine generators

    E-Print Network [OSTI]

    Shoemaker-Trejo, Nathaniel (Nathaniel Joseph)

    2012-01-01T23:59:59.000Z

    Horizontal-axis wind turbine designs often included gearboxes or large direct-drive generators to compensate for the low peripheral speeds of the turbine hub. To take advantage of high blade tip speeds, an alternative ...

  3. Estimated global ocean wind power potential from QuikSCAT observations, accounting for turbine characteristics and siting

    E-Print Network [OSTI]

    Capps, Scott B; Zender, Charles S

    2010-01-01T23:59:59.000Z

    observations, vertical wind speed profile estimation giventhe wind speed profile is reduced, increasing vertical windvertical wind shear with respect to surface layer stability. Wind speeds

  4. Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines

    SciTech Connect (OSTI)

    Maples, B.; Hand, M.; Musial, W.

    2010-10-01T23:59:59.000Z

    This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

  5. Peak Power Bi-directional Transfer From High Speed Flywheel to Electrical Regulated Bus Voltage System

    E-Print Network [OSTI]

    Szabados, Barna

    were performed to determine the energy transfer capabilities of a flywheel coupled high speed permanent magnet synchronous machine through the proposed system's energy storage tank. Results are presented

  6. Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines

    SciTech Connect (OSTI)

    Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

    2004-11-16T23:59:59.000Z

    In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

  7. Distributed Wind Energy in Idaho

    SciTech Connect (OSTI)

    Gardner, John; Ferguson, James; Ahmed-Zaid, Said; Johnson, Kathryn; Haynes, Todd; Bennett, Keith

    2009-01-31T23:59:59.000Z

    Project Objective: This project is a research and development program aimed at furthering distributed wind technology. In particular, this project addresses some of the barriers to distributed wind energy utilization in Idaho. Background: At its core, the technological challenge inherent in Wind Energy is the transformation of a highly variable form of energy to one which is compatible with the commercial power grid or another useful application. A major economic barrier to the success of distributed wind technology is the relatively high capital investment (and related long payback periods) associated with wind turbines. This project will carry out fundamental research and technology development to address both the technological and economic barriers. � Active drive train control holds the potential to improve the overall efficiency of a turbine system by allowing variable speed turbine operation while ensuring a tight control of generator shaft speed, thus greatly simplifying power conditioning. � Recent blade aerodynamic advancements have been focused on large, utility-scale wind turbine generators (WTGs) as opposed to smaller WTGs designed for distributed generation. Because of Reynolds Number considerations, blade designs do not scale well. Blades which are aerodynamically optimized for distributed-scale WTGs can potentially reduce the cost of electricity by increasing shaft-torque in a given wind speed. � Grid-connected electric generators typically operate at a fixed speed. If a generator were able to economically operate at multiple speeds, it could potentially convert more of the wind�s energy to electricity, thus reducing the cost of electricity. This research directly supports the stated goal of the Wind and Hydropower Technologies Program for Distributed Wind Energy Technology: By 2007, reduce the cost of electricity from distributed wind systems to 10 to 15 cents/kWh in Class 3 wind resources, the same level that is currently achievable in Class 5 winds.

  8. Distributed Compression for Condition Monitoring of Wind Farms

    E-Print Network [OSTI]

    Cheng, Samuel

    wind generation is high due to high wind speeds and import of power where the speeds are low. To make

  9. Review of Wind Energy Forecasting Methods for Modeling Ramping Events

    SciTech Connect (OSTI)

    Wharton, S; Lundquist, J K; Marjanovic, N; Williams, J L; Rhodes, M; Chow, T K; Maxwell, R

    2011-03-28T23:59:59.000Z

    Tall onshore wind turbines, with hub heights between 80 m and 100 m, can extract large amounts of energy from the atmosphere since they generally encounter higher wind speeds, but they face challenges given the complexity of boundary layer flows. This complexity of the lowest layers of the atmosphere, where wind turbines reside, has made conventional modeling efforts less than ideal. To meet the nation's goal of increasing wind power into the U.S. electrical grid, the accuracy of wind power forecasts must be improved. In this report, the Lawrence Livermore National Laboratory, in collaboration with the University of Colorado at Boulder, University of California at Berkeley, and Colorado School of Mines, evaluates innovative approaches to forecasting sudden changes in wind speed or 'ramping events' at an onshore, multimegawatt wind farm. The forecast simulations are compared to observations of wind speed and direction from tall meteorological towers and a remote-sensing Sound Detection and Ranging (SODAR) instrument. Ramping events, i.e., sudden increases or decreases in wind speed and hence, power generated by a turbine, are especially problematic for wind farm operators. Sudden changes in wind speed or direction can lead to large power generation differences across a wind farm and are very difficult to predict with current forecasting tools. Here, we quantify the ability of three models, mesoscale WRF, WRF-LES, and PF.WRF, which vary in sophistication and required user expertise, to predict three ramping events at a North American wind farm.

  10. A WRF Ensemble for Improved Wind Speed Forecasts at Turbine Height ADAM J. DEPPE AND WILLIAM A. GALLUS JR.

    E-Print Network [OSTI]

    McCalley, James D.

    . 1. Introduction In recent years, wind energy production has under- gone rapid growth, and the U over both space and time. Therefore, the production rates of wind energy fluctuate more strongly than percentage of total power per capita coming from wind energy in 2010 (Department of Energy 2010). Even fewer

  11. Analyses of possible changes in intense and extreme wind speeds over northern Europe under climate change scenarios

    E-Print Network [OSTI]

    Pryor, Sara C.

    towards increased energy density and thus wind power generation potential over the course of the C21st. Clausen Wind Energy Division, Risø-DTU National Laboratory for Sustainable Energy, Frederiksborgvej 399 downscaling Á Scandinavia Á Wind climates Á Energy density 1 Context and objectives 1.1 Introduction

  12. SODAR Wind Resource Measurement Results at Falmouth, MA Prepared for

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    of Massachusetts at Amherst. The data were collected to estimate the wind resource for possible wind turbines to well over 100 m. The operation of a SODAR and the SODAR data are described in this report. SODAR Technology The UMass ART VT-1 SODAR measures wind speed and direction at multiple heights using an acoustic

  13. Wind Power Resource Assessment in Ohio and Puerto Rico

    E-Print Network [OSTI]

    Womeldorf, Carole

    Wind Power Resource Assessment in Ohio and Puerto Rico: A Motivational and Educational Tool Juan University, Athens, Ohio Abstract This paper presents an educational guide and example of a wind resource calculations. New data representing wind speed and direction for locations in Ohio and Puerto Rico

  14. Low Wind Speed Technology Phase I: Evaluation of Design and Construction Approaches for Economical Hybrid Steel/Concrete Wind Turbine Towers; BERGER/ABAM Engineers Inc.

    SciTech Connect (OSTI)

    Not Available

    2006-03-01T23:59:59.000Z

    This fact sheet describes a subcontract with BERGER/ABAM Engineers Inc. to study the economic feasibility of concrete and hybrid concrete/steel wind turbine towers.

  15. 20% Wind Energy 20% Wind Energy

    E-Print Network [OSTI]

    Powell, Warren B.

    (government, industry, utilities, NGOs) Analyzes wind's potential contributions to energy security, economic · Transmission a challenge #12;Wind Power Class Resource Potential Wind Power Density at 50 m W/m 2 Wind Speed20% Wind Energy by 2030 20% Wind Energy by 2030 #12;Presentation and Objectives Overview Background

  16. WIND DATA REPORT December, 2003 February 29, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Orleans December, 2003 ­ February 29, 2004 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  17. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME December 1st 2005 to February 28th 2006.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  18. WIND DATA REPORT August 28 -December 31, 2002

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven August 28 - December 31, 2002 Prepared for Fox Islands Electric...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  19. WIND DATA REPORT September 1, 2003 November 31, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Mt. Tom September 1, 2003 ­ November 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  20. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME June 1st 2006 to August 31th 2006 Prepared.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  1. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME September 1st 2006 to November 30th 2006.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  2. WIND DATA REPORT October 27, 2003 November 31, 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Orleans October 27, 2003 ­ November 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  3. WIND DATA REPORT September 1 2003 November 30 2003

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Paxton, MA September 1 2003 ­ November 30 2003 by James F. Manwell Anthony F.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  4. WIND DATA REPORT December 1 2003 February 29 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Paxton, MA December 1 2003 ­ February 29 2004 Prepared for Diane Dillman, Paxton.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  5. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME December 1, 2006 ­ February 28, 2007...................................................................................................................... 7 Wind Speed Time Series............................................................................................................. 8 Wind Speed Distributions

  6. WIND DATA REPORT December 1, 2003 February 29, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Mt. Tom December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts Technology.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  7. WIND DATA REPORT Camden Hills Regional High School, ME

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Camden Hills Regional High School, ME March 1st 2006 to May 31th 2006 Prepared.................................................................................................................... 10 Wind Speed Time Series........................................................................................................... 10 Wind Speed Distributions

  8. WIND DATA REPORT March 1, 2004 May 31, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Eastham March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  9. WIND DATA REPORT January 1, 2004 December 31, 2004

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Vinalhaven January 1, 2004 ­ December 31, 2004 Prepared for Fox Islands Electric...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  10. Interconnection of Direct-drive Wind Turbines Using A Series Connected DC Grid.

    E-Print Network [OSTI]

    Veilleux, Etienne

    2010-01-01T23:59:59.000Z

    ??This thesis presents the concept of a "distributed HVDC converter" for offshore wind farms. The proposed converter topology allows series interconnection of wind turbines obviating… (more)

  11. Connecting speeds, directions and arrival times of 22 coronal mass ejections from the Sun to 1 AU

    E-Print Network [OSTI]

    Möstl, C; Hall, J R; Liewer, P C; De Jong, E M; Colaninno, R C; Veronig, A M; Rollett, T; Temmer, M; Peinhart, V; Davies, J A; Lugaz, N; Liu, Y D; Farrugia, C J; Luhmann, J G; Vršnak, B; Harrison, R A; Galvin, A B

    2014-01-01T23:59:59.000Z

    Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather, and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to $2700 \\: km \\: s^{-1}$). We track the CMEs to $34.9 \\pm 7.1$ degrees elongation from the Sun with J-maps constructed using the SATPLOT tool, resulting in prediction lead times of $-26.4 \\pm 15.3$ hours. The geometrical models we use assume different CME front shapes (Fixed-$\\Phi$, Harmonic Mean, S...

  12. Wind-wave measurements in a shallow estuary: Trinity Bay, Texas

    E-Print Network [OSTI]

    Dupuis, Keith Wade

    2009-05-15T23:59:59.000Z

    direction changes. The Shallow WAves Nearshore numerical model was implemented in a Galveston Bay (GB; encompassing TB) computational domain. The model was forced with wind speeds and directions measured on-site and in four surrounding locations maintained...

  13. Analysis of Alongwind Tall Building Response to Transient Nonstationary Winds

    E-Print Network [OSTI]

    Chen, Xinzhong

    where the mean wind speed is characterized by a time-invariant vertical profile and a single time of time varying mean wind speed, mean wind speed vertical profile, and spatial correlation of wind flows in terms of its unique mean wind speed vertical profile, rapid time varying mean wind speed

  14. 10MW Class Direct Drive HTS Wind Turbine: Cooperative Research and Development Final Report, CRADA Number CRD-08-00312

    SciTech Connect (OSTI)

    Musial, W.

    2011-05-01T23:59:59.000Z

    This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes.

  15. Space-time forecasting and evaluation of wind speed with statistical tests for comparing accuracy of spatial predictions

    E-Print Network [OSTI]

    Hering, Amanda S.

    2010-10-12T23:59:59.000Z

    ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 11 Comparing the predictive distributions for the models when the TDD model produces the best forecast (top panel) and when the BST model produces the best forecast (bottom panel). The small vertical line on the x-axis of each plot represents... of wind to benefit humans is not a new concept. Historically, wind- mills have been used to pump water from wells or to grind grain for centuries. But fast- forwarding into the 21st century, ?windmills? are being used to generate electricity. Wind turbines...

  16. An Efficient Wide-Speed Direct Torque Control Based on Fuzzy Logic Technique.

    E-Print Network [OSTI]

    Zhao, Jibo

    2012-01-01T23:59:59.000Z

    ??Conventional Direct Torque Control (CDTC) system faces the problems of high flux and torque ripples, and has difficulty in improving the performance of dynamic torque… (more)

  17. Variable-Speed Wind Turbine Controller Systematic Design Methodology: A Comparison of Non-Linear and Linear Model-Based Designs

    SciTech Connect (OSTI)

    Hand, M. M.

    1999-07-30T23:59:59.000Z

    Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper focuses on controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative (PID) controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship of the two opposing metrics is easily visualized. Traditional controller design generally consists of linearizing a model about an operating point. This step was taken for two different operating points, and the systematic design approach was used. A comparison of the optimal regions selected using the n on-linear model and the two linear models shows similarities. The linearization point selection does, however, affect the turbine performance slightly. Exploitation of the simplicity of the model allows surfaces consisting of operation under a wide range of gain values to be created. This methodology provides a means of visually observing turbine performance based upon the two metrics chosen for this study. Design of a PID controller is simplified, and it is possible to ascertain the best possible combination of controller parameters. The wide, flat surfaces indicate that a PID controller is very robust in this variable-speed wind turbine application.

  18. Aeroacoustic Testing of Wind Turbine Airfoils: February 20, 2004 - February 19, 2008

    SciTech Connect (OSTI)

    Devenport, W.; Burdisso, R. A.; Camargo, H.; Crede, E.; Remillieux, M.; Rasnick, M.; Van Seeters, P.

    2010-05-01T23:59:59.000Z

    The U.S. Department of Energy (DOE), working through its National Renewable Energy Laboratory (NREL), is engaged in a comprehensive research effort to improve the understanding of wind turbine aeroacoustics. The motivation for this effort is the desire to exploit the large expanse of low wind speed sites that tend to be close to U.S. load centers. Quiet wind turbines are an inducement to widespread deployment, so the goal of NREL's aeroacoustic research is to develop tools that the U.S. wind industry can use in developing and deploying highly efficient, quiet wind turbines at low wind speed sites. NREL's National Wind Technology Center (NWTC) is implementing a multifaceted approach that includes wind tunnel tests, field tests, and theoretical analyses in direct support of low wind speed turbine development by its industry partners. NWTC researchers are working hand in hand with engineers in industry to ensure that research findings are available to support ongoing design decisions.

  19. Hydrodynamics and drive-train dynamics of a direct-drive floating wind turbine 

    E-Print Network [OSTI]

    Sethuraman, Latha

    2014-06-30T23:59:59.000Z

    Floating wind turbines (FWTs) are considered a new lease of opportunity for sustaining growth from offshore wind energy. In recent years, several new concepts have emerged, with only a few making it to demonstration or ...

  20. Guide to Using the WIND Toolkit Validation Code

    SciTech Connect (OSTI)

    Lieberman-Cribbin, W.; Draxl, C.; Clifton, A.

    2014-12-01T23:59:59.000Z

    In response to the U.S. Department of Energy's goal of using 20% wind energy by 2030, the Wind Integration National Dataset (WIND) Toolkit was created to provide information on wind speed, wind direction, temperature, surface air pressure, and air density on more than 126,000 locations across the United States from 2007 to 2013. The numerical weather prediction model output, gridded at 2-km and at a 5-minute resolution, was further converted to detail the wind power production time series of existing and potential wind facility sites. For users of the dataset it is important that the information presented in the WIND Toolkit is accurate and that errors are known, as then corrective steps can be taken. Therefore, we provide validation code written in R that will be made public to provide users with tools to validate data of their own locations. Validation is based on statistical analyses of wind speed, using error metrics such as bias, root-mean-square error, centered root-mean-square error, mean absolute error, and percent error. Plots of diurnal cycles, annual cycles, wind roses, histograms of wind speed, and quantile-quantile plots are created to visualize how well observational data compares to model data. Ideally, validation will confirm beneficial locations to utilize wind energy and encourage regional wind integration studies using the WIND Toolkit.

  1. Wind direction Charlotte Bay Hasager, Morten Nielsen and Merete Bruun Christiansen

    E-Print Network [OSTI]

    . At this site a large offshore wind farm (80 2MW-turbines) is in operation. The study includes spatial analysis offshore meteorological observations collected within the wind farm. Focus of the case study.hasager@risoe.dk Quantitative remote sensing: Horns Rev wind farm case study Abstract Observations from ERS-2 SAR

  2. Strong wind forcing of the ocean

    E-Print Network [OSTI]

    Zedler, Sarah E.

    2007-01-01T23:59:59.000Z

    of mesoscale and steady wind driven 1. Introduction 2. Modelparameterization at high wind speeds 1. Introduction 2. DataSupplementary Formulae 1. Wind Stress 2. Rankine Vortex A .

  3. Low Speed Virtual Wind Tunnel Simulation For Educational Studies In Introducing Computational Fluid Dynamics And Flow Visualization

    E-Print Network [OSTI]

    Yang, Cher-Chiang

    2008-05-05T23:59:59.000Z

    ............................................................................................................... 25 3.2.4. Starting FlowLab ...................................................................................................................... 26 3.2.5. Geometry Settings... OF THE PROGRAMMING....................................................................... 52 v List of Figures FIGURE 2.1 ? COST AND TIME RELATIONSHIP WITH RESPECT TO CFD AND WIND TUNNELS............................. 5 FIGURE 2.2 - BOEING 777 DESIGN...

  4. Wind energy resource atlas. Volume 2. The North Central Region

    SciTech Connect (OSTI)

    Freeman, D.L.; Hadley, D.L.; Elliott, D.L.; Barchet, W.R.; George, R.L.

    1981-02-01T23:59:59.000Z

    The North Central atlas assimilates six collections of wind resource data: one for the region and one for each of the five states that compose the North Central region (Iowa, Minnesota, Nebraska, North Dakota, and South Dakota). At the state level, features of the climate, topography and wind resource are discussed in greater detail than is provided in the regional discussion, and that data locations on which the assessment is based are mapped. Variations, over several time scales, in the wind resource at selected stations in each state are shown on graphs of monthly average and international wind speed and power, and hourly average wind speed for each season. Other graphs present speed direction and duration frequencies of the wind at these locations.

  5. Wind energy resource atlas. Volume 3. Great Lakes Region

    SciTech Connect (OSTI)

    Paton, D.L.; Bass, A.; Smith, D.G.; Elliott, D.L.; Barchet, W.R.; George, R.L.

    1981-02-01T23:59:59.000Z

    The Great Lakes Region atlas assimilates six collections of wind resource data, one for the region and one for each of the five states that compose the Great Lakes region: Illinois, Indiana, Michigan, Ohio, Wisconsin. At the state level, features of the climate, topography, and wind resource are discussed in greater detail than in the regional discussion and the data locations on which the assessment is based are mapped. Variations over several time scales in the wind resource at selected stations in each state are shown on graphs of monthly average and interannual wind speed and power, and of hourly average wind speed for each season. Other graphs present speed, direction, and duration frequencies of the wind at these locations.

  6. Wind energy resource atlas. Volume 7. The south central region

    SciTech Connect (OSTI)

    Edwards, R.L.; Graves, L.F.; Sprankle, A.C.; Elliott, D.L.; Barchet, W.R.; George, R.L.

    1981-03-01T23:59:59.000Z

    This atlas of the south central region combines seven collections of wind resource data: one for the region, and one for each of the six states (Arkansas, Kansas, Louisiana, Missouri, Oklahoma, and Texas). At the state level, features of the climate, topography, and wind resource are discussed in greater detail than that provided in the regional discussion, and the data locations on which the assessment is based are mapped. Variations, over several time scales, in the wind resource at selected stations in each state are shown on graphs of monthly average and interannual wind speed and power, and hourly average wind speed for each season. Other graphs present speed, direction, and duration frequencies of the wind at these locations.

  7. Integration of offshore wind farms through High Voltage Direct Current networks.

    E-Print Network [OSTI]

    Livermore, Luke

    2013-01-01T23:59:59.000Z

    ??The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC)… (more)

  8. Study of the Reliability Enhancement of Wind Turbines Employing Direct-drive Technology.

    E-Print Network [OSTI]

    Sara George, Reeba

    2012-01-01T23:59:59.000Z

    ??In traditional wind turbines employing gearboxes, the blades spin a shaft that is connected through a gearbox to the generator. The multiple wheels and bearings… (more)

  9. A Study of Thermal Wind in the Vicinity of a Jet Stream

    E-Print Network [OSTI]

    Cunningham, Newton William

    2012-06-07T23:59:59.000Z

    concern ourselves only with the in- strumentation of the 8-29 since it is the aircraft which collected the data for this study. -8- The observations of wind speed and direction were obtained by the APN-66, an automatic pilot-navigator which measured..., these columns may be subdivided into nine general areas; time, position, altitude, winds, temperature, humidity, clouds, turbulence and aircraft data (indicated air speed, true air speed, drift, etc. ). This study is concerned only with the time, position...

  10. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    Energy Efficiency and Renewable Energy, Wind and HydropowerSpeed Sites. ” European Wind Energy Association. Marseille,Innovation and the price of wind energy in the US. ” Energy

  11. WP2 IEA Wind Task 26:The Past and Future Cost of Wind Energy

    E-Print Network [OSTI]

    Lantz, Eric

    2014-01-01T23:59:59.000Z

    Speed Sites. ” European Wind Energy Association. Marseille,Innovation and the price of wind energy in the US. ” EnergyThe Economics of Wind Energy. ” Renewable and Sustainable

  12. E-Print Network 3.0 - ac adjustable speed Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    speed wind turbine concept 50 4.1 Variable speed wind turbine... of a variable speed wind turbine with DFIG 54 4.4 Doubly-fed induction generator control 57 4.4.1 System......

  13. E-Print Network 3.0 - adjustable speed ac Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    speed wind turbine concept 50 4.1 Variable speed wind turbine... of a variable speed wind turbine with DFIG 54 4.4 Doubly-fed induction generator control 57 4.4.1 System......

  14. Towards a reliability assessment of the Cn2 and wind speed vertical profiles retrieved from GeMS

    E-Print Network [OSTI]

    Neichel, Benoit; Guesalaga, Andrés R; Lascaux, Franck; Béchet, Clémentine

    2014-01-01T23:59:59.000Z

    The advent of a new generation of Adaptive Optics systems called Wide Field AO (WFAO) mark the beginning of a new era. By using multiple Guide Stars (GSs), either Laser Guide Stars (LGSs) or Natural Guide Stars (NGSs), WFAO significantly increases the field of view of the AO-corrected images, and the fraction of the sky that can benefit from such correction. Different typologies of WFAO have been studied over the past years. They all require multiple GSs to perform a tomographic analysis of the atmospheric turbulence. One of the fundamental aspects of the new WFAO systems is the knowledge of the spatio-temporal distribution of the turbulence above the telescope. One way to get to this information is to use the telemetry data provided by the WFAO system itself. Indeed, it has been demonstrated that WFAO systems allows one to derive the Cn2 and wind profile in the main turbulence layers (see e.g. Cortes et al. 2012). This method has the evident advantage to provide information on the turbulence stratification t...

  15. Method and apparatus for digitally based high speed x-ray spectrometer for direct coupled use with continuous discharge preamplifiers

    DOE Patents [OSTI]

    Warburton, William K. (1300 Mills St., Menlo Park, CA 94025)

    1998-01-01T23:59:59.000Z

    A high speed, digitally based, signal processing system which accepts directly coupled input data from a detector with a continuous discharge type preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system's principal elements are an analog signal conditioning section, a combinatorial logic section which implements digital triangular filtering and pileup inspection, and a microprocessor which accepts values captured by the logic section and uses them to compute x-ray energy values. Operating without pole-zero correction, the system achieves high resolution by capturing, in conjunction with each peak value from the digital filter, an associated value of the unfiltered signal, and using this latter signal to correct the former for errors which arise from its local slope terms. This correction greatly reduces both energy resolution degradation and peak centroid shifting in the output spectrum as a function of input count rate. When the noise of this correction is excessive, a modification allows two filtered averages of the signal to be captured and a corrected peak amplitude computed therefrom.

  16. On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

    SciTech Connect (OSTI)

    Bluestein, H.B. (Oklahoma Univ., Norman, OK (USA). School of Meteorology); Unruh, W.P. (Los Alamos National Lab., NM (USA))

    1991-01-01T23:59:59.000Z

    Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamos National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs.

  17. Design of a high angle of attack robotic sting mount for tests in a low speed wind tunnel

    E-Print Network [OSTI]

    Kubler, Tommy Jack

    1989-01-01T23:59:59.000Z

    AMPLIFIER SPECIFICATIONS . 92 97 G PROGRAM FLOWCHART: HIALST 100 H HARS INSTALLATION PROCEDURES 118 I ASSEMBLY DRAWINGS J ACKNOWLEDGEMENTS 137 142 VITA 143 LIST OF TABLES Table Page 1 Wear psd plastic materials considered 2 Maximum predicted... wings level in the tunnel to minimize effects on lateral-directional coefficients. 4. A 36 inch long model must be maintained near the center of the tunnel where the dynamic pressure variation does not exceed 0. 4%. 5. The mechanical system must...

  18. Candidate wind turbine generator site: annual data summary, January 1981-December 1981

    SciTech Connect (OSTI)

    Sandusky, W.F.; Buck, J.W.; Renne, D.S.; Hadley, D.L.; Abbey, O.B.

    1982-07-01T23:59:59.000Z

    Summarized hourly meteorological data for 34 candidate and wind turbine generator sites for calendar year 1981 are presented. These data are collected for the purpose of evaluating the wind energy potential at these sites and are used to assist in selection of potential sites for installation and testing of large wind turbines in electric utility systems. For each site, wind speed, direction, and distribution data are given in eight tables. Use of information from these tables, with information about specific wind turbines, should allow the user to estimate the potential for wind energy production at each site.

  19. RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT

    E-Print Network [OSTI]

    Kahn, E.

    2011-01-01T23:59:59.000Z

    PG&E 4:00 p.m. Summer Wind Generator Model Wind Array ELCCexpect from an array of wind generators spread over a largean array of dispersed wind generators will be. wind speed

  20. Wind turbine

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  1. Technology Improvement Opportunities for Low Wind Speed Turbines and Implications for Cost of Energy Reduction: July 9, 2005 - July 8, 2006

    SciTech Connect (OSTI)

    Cohen, J.; Schweizer, T.; Laxson, A.; Butterfield, S.; Schreck, S.; Fingersh, L.; Veers, P.; Ashwill, T.

    2008-02-01T23:59:59.000Z

    This report analyzes the status of wind energy technology in 2002 and describes the potential for technology advancements to reduce the cost and increase the performance of wind turbines.

  2. Wind energy conversion system

    DOE Patents [OSTI]

    Longrigg, Paul (Golden, CO)

    1987-01-01T23:59:59.000Z

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  3. Seismic experiments provide new clues to earthquake wave directionality and growth speed PASADENA, Calif.--In recent years, seismologists thought they were getting a handle on how an earthquake

    E-Print Network [OSTI]

    Seismic experiments provide new clues to earthquake wave directionality and growth speed PASADENA that direction. The phenomenon has to do with the basic ways rupture fronts (generating seismic waves

  4. Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Coulter, Richard; Ritsche, Michael

    Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH. The balloon-borne sounding system (SONDE) provides in situ measurements (vertical profiles) of both the thermodynamic state of the atmosphere, and the wind speed and direction.

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

    E-Print Network [OSTI]

    Peinke, Joachim

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

  6. On prediction of wind-borne plumes with simple models of turbulent transport

    E-Print Network [OSTI]

    Schwarz, Katherine; Patzek, Tad; Silin, Dmitriy

    2008-01-01T23:59:59.000Z

    of x, and the vertical wind speed of gas above ground wass x 10 Vertical gas velocity, horizontal wind speed = 1 m/ss x 10 Vertical gas velocity, horizontal wind speed = 5 m/s

  7. Wind energy conversion system

    SciTech Connect (OSTI)

    Longrigg, P.

    1987-03-17T23:59:59.000Z

    This patent describes a wind energy conversion system comprising: a propeller rotatable by force of wind; a generator of electricity mechanically coupled to the propeller for converting power of the wind to electric power for use by an electric load; means coupled between the generator and the electric load for varying the electric power drawn by the electric load to alter the electric loading of the generator; means for electro-optically sensing the speed of the wind at a location upwind from the propeller; and means coupled between the sensing means and the power varying means for operating the power varying means to adjust the electric load of the generator in accordance with a sensed value of wind speed to thereby obtain a desired ratio of wind speed to the speed of a tip of a blade of the propeller.

  8. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 40, NO. 2, MARCH/APRIL 2004 565 Modeling and Control of a Variable-Speed

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    . The advantages of the proposed system are reduced harmonic injection to power grid, wide speed operation range. It can be directly applied to wind power generators, small-scale hydroelectric generators, stand Identifier 10.1109/TIA.2004.824504 Fig. 1. Traditional wind power generation systems. (a) Variable

  9. High-pressure late cycle direct injection of natural gas in a rail medium speed diesel engine

    SciTech Connect (OSTI)

    Wakenell, J.F.; O'Neal, G.B.; Baker, Q.A.

    1987-01-01T23:59:59.000Z

    The performance of an Electro-Motive Division (EMD) 567B, two-cylinder locomotive research engine, when operated on high-pressure/late-cycle injection of natural gas, is presented in this paper. A redesign and fabrication of the fuel system was undertaken to facilitate the consumption of natural gas. A small percentage of No.2 diesel fuel (DF-2) was used to ignite the natural gas. Engine performance, while running natural gas, resulted in matching rated speed and power with slightly lower thermal efficiency. Full power was achieved with a ratio of 99 percent natural gas and 1 percent diesel fuel. However, at high natural gas to diesel fuel ratios, audible knock was detected. The primary objective of the project was to establish technical feasibility of, and basic technology for, operating medium-speed rail diesel engines on high-pressure natural gas. Secondary objectives were to attain adequate engine performance levels for rail application, develop a system oriented toward retrofit of in-service locomotives, and realize any potential improvements in thermal efficiency due to use of the high-pressure/late-cycle approach.

  10. WIND ENERGY Wind Energ. 2013; 00:112

    E-Print Network [OSTI]

    WIND ENERGY Wind Energ. 2013; 00:1­12 DOI: 10.1002/we RESEARCH ARTICLE Model predictive control in wind speed, ensuring certain power gradients, with an insignificant loss in energy production rejection, model predictive control, convex optimization, wind power control, energy storage, power output

  11. Design and Test of DC Voltage Link Conversion System and Brushless Doubly-Fed Induction Generator for Variable-Speed Wind Energy Applications: August 1999--May 2003

    SciTech Connect (OSTI)

    Lipo, T.A.; Panda, D.; Zarko, D.

    2005-11-01T23:59:59.000Z

    This report describes four low-cost alternative power converters for processing the power developed by a doubly fed wound-rotor induction generator for wind energy conversion systems.

  12. The Solar Wind Energy Flux

    E-Print Network [OSTI]

    Chat, G Le; Meyer-Vernet, N

    2012-01-01T23:59:59.000Z

    The solar-wind energy flux measured near the ecliptic is known to be independent of the solar-wind speed. Using plasma data from Helios, Ulysses, and Wind covering a large range of latitudes and time, we show that the solar-wind energy flux is independent of the solar-wind speed and latitude within 10%, and that this quantity varies weakly over the solar cycle. In other words the energy flux appears as a global solar constant. We also show that the very high speed solar-wind (VSW > 700 km/s) has the same mean energy flux as the slower wind (VSW < 700 km/s), but with a different histogram. We use this result to deduce a relation between the solar-wind speed and density, which formalizes the anti-correlation between these quantities.

  13. Wind Technology Advancements and Impacts on Western Wind Resources (Presentation)

    SciTech Connect (OSTI)

    Robichaud, R.

    2014-09-01T23:59:59.000Z

    Robi Robichaud made this presentation at the Bureau of Land Management West-wide Wind Opportunities and Constraints Mapping (WWOCM) Project public meeting in Denver, Colorado in September 2014. This presentation outlines recent wind technology advancements, evolving turbine technologies, and industry challenges. The presentation includes maps of mean wind speeds at 50-m, 80-m, and 100-m hub heights on BLM lands. Robichaud also presented on the difference in mean wind speeds from 80m to 100m in Wyoming.

  14. National Wind Technology Center (Fact Sheet), National Wind Technology...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    hydrokinetic (MHK) energy devices are high-force, low-speed machines, similar to wind turbines that convert the kinetic energy of a moving fluid into electrical energy....

  15. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    corresponding to extreme winds for di?erent stations andin turn would lead to extreme downscaled wind speed changeextreme quintiles or more exacting classi?cations of wind

  16. Analyzing Effects of Turbulence on Power Generation Using Wind Plant Monitoring Data: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Chowdhury, S.; Hodge, B. M.

    2014-01-01T23:59:59.000Z

    In this paper, a methodology is developed to analyze how ambient and wake turbulence affects the power generation of a single wind turbine within an array of turbines. Using monitoring data from a wind power plant, we selected two sets of wind and power data for turbines on the edge of the wind plant that resemble (i) an out-of-wake scenario (i.e., when the turbine directly faces incoming winds) and (ii) an in-wake scenario (i.e., when the turbine is under the wake of other turbines). For each set of data, two surrogate models were then developed to represent the turbine power generation (i) as a function of the wind speed; and (ii) as a function of the wind speed and turbulence intensity. Support vector regression was adopted for the development of the surrogate models. Three types of uncertainties in the turbine power generation were also investigated: (i) the uncertainty in power generation with respect to the published/reported power curve, (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) under the same wind conditions, the turbine generates different power between the in-wake and out-of-wake scenarios, (ii) a turbine generally produces more power under the in-wake scenario than under the out-of-wake scenario, (iii) the power generation is sensitive to turbulence intensity even when the wind speed is greater than the turbine rated speed, and (iv) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.

  17. Turbine Inflow Characterization at the National Wind Technology Center: Preprint

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

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

  18. Turbine Inflow Characterization at the National Wind Technology Center

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

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

  19. Performance of propeller wind turbines

    SciTech Connect (OSTI)

    Wortman, A.

    1983-11-01T23:59:59.000Z

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

  20. Modeling of wind farm controllers Poul Srensen1

    E-Print Network [OSTI]

    and dead band. Two types of wind farms are presented. The first using variable speed wind turbines with doubly fed induction generators and fixed speed wind turbines with active stall control. Keywords: wind the wind turbines have increased in size, the costs have been reduced, and the controllability developed

  1. Design of a wind turbine-generator system considering the conformability to wind velocity fluctuations

    SciTech Connect (OSTI)

    Wakui, Tetsuya; Hashizume, Takumi; Outa, Eisuke

    1999-07-01T23:59:59.000Z

    The conformability of the rated power output of the wind turbine-generator system and of the wind turbine type to wind velocity fluctuations are investigated with a simulation model. The authors examine three types of wind turbines: the Darrieus-Savonius hybrid, the Darrieus proper and the Propeller. These systems are mainly operated at a constant tip speed ratio, which refers to a maximum power coefficient points. As a computed result of the net extracting power, the Darrieus turbine proper has little conformability to wind velocity fluctuations because of its output characteristics. As for the other turbines, large-scale systems do not always have an advantage over small-scale systems as the effect of its dynamic characteristics. Furthermore, it is confirmed that the net extracting power of the Propeller turbine, under wind direction fluctuation, is much reduced when compared with the hybrid wind turbine. Thus, the authors conclude that the appropriate rated power output of the system exists with relation to the wind turbine type for each wind condition.

  2. Fig. 1. One hour measured irradiance and wind speed data with 0.2 seconds, 3 seconds and 1 minute (interpolated) sampling time.

    E-Print Network [OSTI]

    Sera, Dezso

    new power plants based on renewable energy, with wind and photovoltaic (PV) representing the main Studies Catalin I. Ciontea, Dezso Sera, Florin Iov Department of Energy Technology, Aalborg University cic of the renewable energy based generators on the distribution network is related to the voltage variations due

  3. International Statistical Review (2012), 80, 1, 223 doi:10.1111/j.1751-5823.2011.00168.x Short-Term Wind Speed Forecasting

    E-Print Network [OSTI]

    Genton, Marc G.

    2012-01-01T23:59:59.000Z

    @stat.tamu.edu Summary The emphasis on renewable energy and concerns about the environment have led to large-scale wind mix and develop diverse sources of clean, renewable energy. Cost-effective energy that can be produced to 1990), to increase the amount of renewable energy to 20% of the energy supply, and to reduce

  4. Wind/Wave Misalignment in the Loads Analysis of a Floating Offshore Wind Turbine: Preprint

    SciTech Connect (OSTI)

    Barj, L.; Stewart, S.; Stewart, G.; Lackner, M.; Jonkman, J.; Robertson, A.

    2014-02-01T23:59:59.000Z

    Wind resources far from the shore and in deeper seas have encouraged the offshore wind industry to look into floating platforms. The International Electrotechnical Commission (IEC) is developing a new technical specification for the design of floating offshore wind turbines that extends existing design standards for land-based and fixed-bottom offshore wind turbines. The work summarized in this paper supports the development of best practices and simulation requirements in the loads analysis of floating offshore wind turbines by examining the impact of wind/wave misalignment on the system loads under normal operation. Simulations of the OC3-Hywind floating offshore wind turbine system under a wide range of wind speeds, significant wave heights, peak-spectral periods and wind/wave misalignments have been carried out with the aero-servo-hydro-elastic tool FAST [4]. The extreme and fatigue loads have been calculated for all the simulations. The extreme and fatigue loading as a function of wind/wave misalignment have been represented as load roses and a directional binning sensitivity study has been carried out. This study focused on identifying the number and type of wind/wave misalignment simulations needed to accurately capture the extreme and fatigue loads of the system in all possible metocean conditions considered, and for a down-selected set identified as the generic US East Coast site. For this axisymmetric platform, perpendicular wind and waves play an important role in the support structure and including these cases in the design loads analysis can improve the estimation of extreme and fatigue loads. However, most structural locations see their highest extreme and fatigue loads with aligned wind and waves. These results are specific to the spar type platform, but it is expected that the results presented here will be similar to other floating platforms.

  5. Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

    DOE Patents [OSTI]

    He, J.; Rote, D.M.

    1996-05-21T23:59:59.000Z

    A stabilization and propulsion system are disclosed comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with the superconducting magnets mounted on the magnetic levitation vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the superconducting magnets on the vehicle. 12 figs.

  6. accretion disk winds: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and can obtain radiatively driven winds accelerated up to the it relativistic speed. For less luminous cases, disk winds are transonic types passing through saddle type...

  7. accretion disk wind: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and can obtain radiatively driven winds accelerated up to the it relativistic speed. For less luminous cases, disk winds are transonic types passing through saddle type...

  8. Design of PM generator for avertical axis wind turbine.

    E-Print Network [OSTI]

    Rynkiewicz, Mateusz

    2012-01-01T23:59:59.000Z

    ?? The task in this project is to design a generator for a vertical axis wind turbine withpower rated to 20kW at a wind speed… (more)

  9. Aerodynamic interference between two Darrieus wind turbines

    SciTech Connect (OSTI)

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

    1981-04-01T23:59:59.000Z

    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.

  10. Optimization of a Small Passive Wind Turbine Generator with Multiobjective Genetic Algorithms

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : Multiobjective Optimization, Genetic Algorithms, Wind Energy, Vertical Axis Wind Turbine hal-00763673,version1 achieved by controlling the speed of a Wind Turbine Generator (WTG). In particular, the rotor speed should vary in accordance with the wind speed by maintaining the tip speed ratio to the value that maximizes

  11. agb stellar winds: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    variations in the location and appearance of the critical curves where the wind speed equals the slow, Alfven, and fast speed. Larger dead zones cause effective, fairly...

  12. Sustainable Development and Kish Island Environment Protection, using Wind Energy

    E-Print Network [OSTI]

    Amir Gandomkar

    Abstract—Kish Islands in South of Iran is located in coastal water near Hormozgan Province. Based on the wind 3-hour statistics in Kish station, the mean annual windspeed in this Island is 8.6 knot (4.3 m/s). The maximum windspeed recorded in this stations 47 knot (23.5 m/s). In 45.7 percent of recorded times, windspeed has been Zero or less than 8 knot which is not suitable to use the wind energy. But in 54.3 percent of recorded times, windspeed has been more than 8 knot and suitable to use wind energy to run turbines. In 40.2 percent of recorded times, windspeed has been between 8 to 16 knot, in 13 percent of times between 16 to 24 knot and in 1 percent of times it has been higher than 24 knot. In this station, the direction of winds higher than 8 is west and wind direction in Kish station is stable in most times of the year.With regard to high – speed and stable direction winds during the year and also shallow coasts near this is land, it is possible to build offshore wind farms near Kish Island and utilize wind energy produce the electricity required in this Island during most of the year.

  13. Wind Resource Assessment of Gujarat (India)

    SciTech Connect (OSTI)

    Draxl, C.; Purkayastha, A.; Parker, Z.

    2014-07-01T23:59:59.000Z

    India is one of the largest wind energy markets in the world. In 1986 Gujarat was the first Indian state to install a wind power project. In February 2013, the installed wind capacity in Gujarat was 3,093 MW. Due to the uncertainty around existing wind energy assessments in India, this analysis uses the Weather Research and Forecasting (WRF) model to simulate the wind at current hub heights for one year to provide more precise estimates of wind resources in Gujarat. The WRF model allows for accurate simulations of winds near the surface and at heights important for wind energy purposes. While previous resource assessments published wind power density, we focus on average wind speeds, which can be converted to wind power densities by the user with methods of their choice. The wind resource estimates in this study show regions with average annual wind speeds of more than 8 m/s.

  14. NREL: Wind Research - New 100-Meter Map Keeps Pace with Growing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New 100-Meter Map Keeps Pace with Growing Wind Technology An illustrated map of the United States shows the average wind speeds of land-based and offshore wind speed The new 100-m...

  15. Operational behavior of a double-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Reddy, Sivananda Kumjula

    2005-01-01T23:59:59.000Z

    Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation ...

  16. Synoptic and local influences on boundary layer processes, with an application to California wind power

    E-Print Network [OSTI]

    Mansbach, David K.

    2010-01-01T23:59:59.000Z

    th percentiles of daily wind speeds (vertical axis) largelyand warm SST. Mean vertical pro?les of wind speed from EPICspeed at the wind farm sites, since inversion strength is largely controlled by the vertical

  17. Description of the Columbia Basin Wind Energy Study (CBWES)

    SciTech Connect (OSTI)

    Berg, Larry K.; Pekour, Mikhail S.; Nelson, Danny A.

    2012-10-01T23:59:59.000Z

    The purpose of this Technical Report is to provide background information about the Columbia Basin Wind Energy Study (CBWES). This study, which was supported by the U.S. Department of Energy’s Wind and Water Power Program, was conducted from 16 November 2010 through 21 March 2012 at a field site in northeastern Oregon. The primary goal of the study was to provide profiles of wind speed and wind direction over the depth of the boundary layer in an operating wind farm located in an area of complex terrain. Measurements from propeller and vane anemometers mounted on a 62 m tall tower, Doppler Sodar, and Radar Wind Profiler were combined into a single data product to provide the best estimate of the winds above the site during the first part of CBWES. An additional goal of the study was to provide measurements of Turbulence Kinetic Energy (TKE) near the surface. To address this specific goal, sonic anemometers were mounted at two heights on the 62 m tower on 23 April 2011. Prior to the deployment of the sonic anemometers on the tall tower, a single sonic anemometer was deployed on a short tower 3.1 m tall that was located just to the south of the radar wind profiler. Data from the radar wind profiler, as well as the wind profile data product are available from the Atmospheric Radiation Measurements (ARM) Data Archive (http://www.arm.gov/data/campaigns). Data from the sonic anemometers are available from the authors.

  18. Ris R 1068EN Extreme Winds

    E-Print Network [OSTI]

    Ris R 1068EN Extreme Winds in Denmark Leif Kristensen and Ole Rathmann Ris National Laboratory of this investigationis to study, on basis of climatologicalrecords, how large extreme wind speeds are in various parts;Abstract Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates

  19. A doubly-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Thomas, Andrew J. (Andrew Joseph), 1981-

    2004-01-01T23:59:59.000Z

    Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...

  20. Dynamic valuation model For wind development in regard to land value, proximity to transmission lines, and capacity factor

    E-Print Network [OSTI]

    Nikandrou, Paul

    2009-01-01T23:59:59.000Z

    Developing a wind farm involves many variables that can make or break the success of a potential wind farm project. Some variables such as wind data (capacity factor, wind rose, wind speed, etc.) are readily available in ...

  1. Development of an Offshore Direct-Drive Wind Turbine Model by Using a Flexible Multibody Simulation (Poster)

    SciTech Connect (OSTI)

    Bergua, R.; Jove, J.; Campbell, J.; Guo, Y.; Van Dam, J.

    2014-05-01T23:59:59.000Z

    Modern wind turbines are complex, highly-coupled systems. The dynamic interaction between various components is especially pronounced for multi-megawatt wind turbines. As a result, design process is generally split in several phases. First step consists of creating a global aero-elastic model that includes essential dynamics of structural components using the minimum-possible number of degrees of freedom (d.o.f.). The most important simplifications concern drivetrain and rotor-nacelle assembly (RNA). This approach has been shown valid for several wind turbine configurations. Nevertheless, with increasing size of wind turbines, any simplified design approach must be validated. The present work deals with the comparison and validation of the two modeling approaches for directdrive offshore wind turbines. ARNA/drivetrain model idealized as collection of lumped masses and springs is compared to a detailed Finite Element Method (FEM) based model. The comparison between models focuses on dynamic loads concerning drivetrain system. The comparison is performed in several operational conditions in order to explore the range of validity of the simplified model. Finally, the paper proposes a numerical-based workflow to assess the validity of simplified models of RNA/drivetrain in an aero-elastic global WT model.

  2. Models for Assessing Power Fluctuations from Large Wind Farms N. A. Cutululis1)

    E-Print Network [OSTI]

    typical and worst case power fluctuations using the geographical sitting of wind turbines as an input comprehensive, with one year of wind speeds and power from all individual wind turbines in the wind farms of the fluctuating nature of wind speeds, the increasing use of wind turbines for power generation has caused more

  3. First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    correlation plot for vertical wind speed (w) with both HCHOtemperature with vertical wind speed during half-hour? w · c where w is the vertical wind speed, c is the tracer

  4. Directions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directions Where We Are Directions The Bradbury Science Museum is located at 1350 Central Avenue Los Alamos, NM 87544 Los Alamos (elevation 7,355 feet) is perched high atop the...

  5. Using satellite data for mapping offshore wind resources and wakes

    E-Print Network [OSTI]

    (no wind) Horns Rev Offshore Wind Farm Blaavandshuk Met. mast N #12;Wind Horns Rev Wind speed map from · Wake near large offshore wind farms is quantified in space and time · Software for usersUsing satellite data for mapping offshore wind resources and wakes Charlotte Bay Hasager, Merete

  6. A comparison of spanwise aerodynamic loads estimated from measured bending moments versus direct pressure measurements on horizontal axis wind turbine blades

    SciTech Connect (OSTI)

    Simms, D A; Butterfield, C P

    1991-10-01T23:59:59.000Z

    Two methods can be used to determine aerodynamic loads on a rotating wind turbine blade. The first is to make direct pressure measurements on the blade surface. This is a difficult process requiring costly pressure instrumentation. The second method uses measured flap bending moments in conjunction with analytical techniques to estimate airloads. This method, called ALEST, was originally developed for use on helicopter rotors and was modified for use on horizontal axis wind turbine blades. Estimating airloads using flap bending moments in much simpler and less costly because measurements can be made with conventional strain gages and equipment. This paper presents results of airload estimates obtained using both methods under a variety of operating conditions. Insights on the limitations and usefulness of the ALEST bending moment technique are also included. 10 refs., 6 figs.

  7. Analysis of the effects of integrating wind turbines into a conventional utility: a case study. Revised final report

    SciTech Connect (OSTI)

    Goldenblatt, M.K.; Wegley, H.L.; Miller, A.H.

    1983-03-01T23:59:59.000Z

    The impact on a utility incorporating wind turbine generation due to wind speed sampling frequency, wind turbine performance model, and wind speed forecasting accuracy is examined. The utility analyzed in this study was the Los Angeles Department of Water and Power, and the wind turbine assumed was the MOD-2. The sensitivity of the economic value of wind turbine generation to wind speed sampling frequency and wind turbine modeling technique is examined as well as the impact of wind forecasting accuracy on utility operation and production costs. Wind speed data from San Gorgonio Pass, California during 1979 are used to estimate wind turbine performance using four different simulation methods. (LEW)

  8. Dynamic analysis of a 5 megawatt offshore floating wind turbine

    E-Print Network [OSTI]

    Harriger, Evan Michael

    2011-01-01T23:59:59.000Z

    wind turbine. Rating Control Rotor Radius Rated Wind Speed Towerwind turbine is used in this design, however there are slight modifications of the tower.of the tower. Figure 2.3: NREL 5 MW Reference Wind Turbine [

  9. Wind Regimes in Complex Terrain of the Great Valley of Eastern Tennessee

    SciTech Connect (OSTI)

    Birdwell, Kevin R [ORNL

    2011-05-01T23:59:59.000Z

    This research was designed to provide an understanding of physical wind mechanisms within the complex terrain of the Great Valley of Eastern Tennessee to assess the impacts of regional air flow with regard to synoptic and mesoscale weather changes, wind direction shifts, and air quality. Meteorological data from 2008 2009 were analyzed from 13 meteorological sites along with associated upper level data. Up to 15 ancillary sites were used for reference. Two-step complete linkage and K-means cluster analyses, synoptic weather studies, and ambient meteorological comparisons were performed to generate hourly wind classifications. These wind regimes revealed seasonal variations of underlying physical wind mechanisms (forced channeled, vertically coupled, pressure-driven, and thermally-driven winds). Synoptic and ambient meteorological analysis (mixing depth, pressure gradient, pressure gradient ratio, atmospheric and surface stability) suggested up to 93% accuracy for the clustered results. Probabilistic prediction schemes of wind flow and wind class change were developed through characterization of flow change data and wind class succession. Data analysis revealed that wind flow in the Great Valley was dominated by forced channeled winds (45 67%) and vertically coupled flow (22 38%). Down-valley pressure-driven and thermally-driven winds also played significant roles (0 17% and 2 20%, respectively), usually accompanied by convergent wind patterns (15 20%) and large wind direction shifts, especially in the Central/Upper Great Valley. The behavior of most wind regimes was associated with detectable pressure differences between the Lower and Upper Great Valley. Mixing depth and synoptic pressure gradients were significant contributors to wind pattern behavior. Up to 15 wind classes and 10 sub-classes were identified in the Central Great Valley with 67 joined classes for the Great Valley at-large. Two-thirds of Great Valley at-large flow was defined by 12 classes. Winds flowed on-axis only 40% of the time. The Great Smoky Mountains helped create down-valley pressure-driven winds, downslope mountain breezes, and divergent air flow. The Cumberland Mountains and Plateau were associated with wind speed reductions in the Central Great Valley, Emory Gap Flow, weak thermally-driven winds, and northwesterly down sloping. Ridge-and-valley terrain enhanced wind direction reversals, pressure-driven winds, as well as locally and regionally produced thermally-driven flow.

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

    E-Print Network [OSTI]

    (2) , Peder Enevoldsen (2) , Leo Thesbjerg (3) (1): Wind Energy Department, Risø of measuring the power curve is by using the wind speed at hub height. The assumption behind this is that the wind speed is representative of the wind over the whole turbine rotor. While this assumption

  11. Global ocean wind power sensitivity to surface layer stability

    E-Print Network [OSTI]

    Capps, Scott B; Zender, Charles S

    2009-01-01T23:59:59.000Z

    observa- tions, vertical wind speed profile estimation givenspeed differences compared to over the Gulf Stream, 80 m wind power is relatively smaller because of reduced verticalvertical momentum transfer over the Gulf Stream and North Atlantic Current results in sub-logarithmic wind profiles, reduced 80 – 10 m wind speed

  12. Journal of Wind Engineering and Industrial Aerodynamics 90 (2002) 201221

    E-Print Network [OSTI]

    Pryor, Sara C.

    due largely to lower surface roughness [1]. An additional benefit to offshore location of wind farms characteristics in the near-shore and offshore environment using data from the Danish wind monitoring network. In this relatively high wind speed environment the temporal auto-correlation of wind speeds measured in the offshore

  13. Use of synthetic aperture radar for offshore wind resource assessment and wind farm development in the UK 

    E-Print Network [OSTI]

    Cameron, Iain Dickson

    2008-01-01T23:59:59.000Z

    The UK has an abundant offshore wind resource with offshore wind farming set to grow rapidly over the coming years. Optimisation of energy production is of the utmost importance and accurate estimates of wind speed distributions are critical...

  14. Wind farm electrical system

    DOE Patents [OSTI]

    Erdman, William L.; Lettenmaier, Terry M.

    2006-07-04T23:59:59.000Z

    An approach to wind farm design using variable speed wind turbines with low pulse number electrical output. The output of multiple wind turbines are aggregated to create a high pulse number electrical output at a point of common coupling with a utility grid network. Power quality at each individual wind turbine falls short of utility standards, but the aggregated output at the point of common coupling is within acceptable tolerances for utility power quality. The approach for aggregating low pulse number electrical output from multiple wind turbines relies upon a pad mounted transformer at each wind turbine that performs phase multiplication on the output of each wind turbine. Phase multiplication converts a modified square wave from the wind turbine into a 6 pulse output. Phase shifting of the 6 pulse output from each wind turbine allows the aggregated output of multiple wind turbines to be a 24 pulse approximation of a sine wave. Additional filtering and VAR control is embedded within the wind farm to take advantage of the wind farm's electrical impedence characteristics to further enhance power quality at the point of common coupling.

  15. Floating offshore wind farms : demand planning & logistical challenges of electricity generation

    E-Print Network [OSTI]

    Nnadili, Christopher Dozie, 1978-

    2009-01-01T23:59:59.000Z

    Floating offshore wind farms are likely to become the next paradigm in electricity generation from wind energy mainly because of the near constant high wind speeds in an offshore environment as opposed to the erratic wind ...

  16. The effects of energy storage properties and forecast accuracy on mitigating variability in wind power generation

    E-Print Network [OSTI]

    Jaworsky, Christina A

    2013-01-01T23:59:59.000Z

    Electricity generation from wind power is increasing worldwide. Wind power can offset traditional fossil fuel generators which is beneficial to the environment. However, wind generation is unpredictable. Wind speeds have ...

  17. ANALYSIS OF THE PERFORMANCE AND COST EFFECTIVENESS OF NINE SMALL WIND ENERGY CONVERSION SYSTEMS FUNDED BY THE DOE SMALL GRANTS PROGRAM

    E-Print Network [OSTI]

    Kay, J.

    2009-01-01T23:59:59.000Z

    relationship between potential wind speed and theoreticalfirm contracts. Potential wind investors face considerable15 with optimism the potential that wind, photovoltaic, and

  18. Non-Stationary Spectral Estimation for Wind Turbine Induction Generator Faults Detection

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - or indirect-drive, fixed- or variable-speed turbine generators, advanced signal processing tools are requiredNon-Stationary Spectral Estimation for Wind Turbine Induction Generator Faults Detection El Houssin- rine current turbine farms implies to minimize and predict maintenance operations. In direct

  19. Influence of Thermal Stratification on Wind Profiles for Heights up to 140 m

    E-Print Network [OSTI]

    Heinemann, Detlev

    .energiemeteorologie.de The vertical wind speed profile has to be know for many wind power applications. Although the large effect speeds are not measured or predicted in the hubheight of the wind turbine. For the vertical trans stratification of the boundary layer has also an important influence on the vertical wind speed profile. Only

  20. Measured wind turbine loads and their dependence on inflow parameters L. Manuel & L. D. Nelson

    E-Print Network [OSTI]

    Manuel, Lance

    of the hub-height horizontal wind speed as well as secondary pa- rameters such as Reynolds stresses, vertical to other previous studies, but we do not bin the data sets by wind speed since dependen- cies in one wind turbine loads. Inflow parameters might include, for example, mean wind speed, turbu- lence intensity

  1. Sensitivity of the wind stress and storm surges to surface drag

    E-Print Network [OSTI]

    Vries, Hans de

    - 29 April 2009 , CD zU ln~ #12;Background Air-Sea Interaction High and/or extreme wind speeds , CD ? #12;Background Air-Sea Interaction High and/or extreme wind speeds ­ Dynamics Sensitivity High and/or extreme wind speeds ­ Dynamics Sensitivity of the wind stress and storm surges to surface

  2. Uncovering wind turbine properties through two-dimensional stochastic modeling of wind dynamics

    E-Print Network [OSTI]

    Raischel, Frank; Lopes, Vitor V; Lind, Pedro G

    2012-01-01T23:59:59.000Z

    Using a method for stochastic data analysis, borrowed from statistical physics, we analyze synthetic data from a Markov chain model that reproduces measurements of wind speed and power production in a wind park in Portugal. From the theoretical point of view we argue that our methods can be used to extract unknown functional relations between two variables. We first show that indeed our analysis retrieves the power performance curve, which yields the relationship between wind speed and power production and discuss how such procedure can be extended for extracting functional relationships between pairs of physical variables in general. Second, we show how specific features, such as the turbine rated wind speed or the descriptive wind speed statistics, can be related with the equations describing the evolution of power production and wind speed at single wind turbines.

  3. Aleutian Pribilof Islands Wind Energy Feasibility Study

    SciTech Connect (OSTI)

    Bruce A. Wright

    2012-03-27T23:59:59.000Z

    Under this project, the Aleutian Pribilof Islands Association (APIA) conducted wind feasibility studies for Adak, False Pass, Nikolski, Sand Point and St. George. The DOE funds were also be used to continue APIA's role as project coordinator, to expand the communication network quality between all participants and with other wind interest groups in the state and to provide continued education and training opportunities for regional participants. This DOE project began 09/01/2005. We completed the economic and technical feasibility studies for Adak. These were funded by the Alaska Energy Authority. Both wind and hydro appear to be viable renewable energy options for Adak. In False Pass the wind resource is generally good but the site has high turbulence. This would require special care with turbine selection and operations. False Pass may be more suitable for a tidal project. APIA is funded to complete a False Pass tidal feasibility study in 2012. Nikolski has superb potential for wind power development with Class 7 wind power density, moderate wind shear, bi-directional winds and low turbulence. APIA secured nearly $1M from the United States Department of Agriculture Rural Utilities Service Assistance to Rural Communities with Extremely High Energy Costs to install a 65kW wind turbine. The measured average power density and wind speed at Sand Point measured at 20m (66ft), are 424 W/m2 and 6.7 m/s (14.9 mph) respectively. Two 500kW Vestas turbines were installed and when fully integrated in 2012 are expected to provide a cost effective and clean source of electricity, reduce overall diesel fuel consumption estimated at 130,000 gallons/year and decrease air emissions associated with the consumption of diesel fuel. St. George Island has a Class 7 wind resource, which is superior for wind power development. The current strategy, led by Alaska Energy Authority, is to upgrade the St. George electrical distribution system and power plant. Avian studies in Nikolski and Sand Point have allowed for proper wind turbine siting without killing birds, especially endangered species and bald eagles. APIA continues coordinating and looking for funding opportunities for regional renewable energy projects. An important goal for APIA has been, and will continue to be, to involve community members with renewable energy projects and energy conservation efforts.

  4. Evaluation of global wind power Cristina L. Archer and Mark Z. Jacobson

    E-Print Network [OSTI]

    Evaluation of global wind power Cristina L. Archer and Mark Z. Jacobson Department of Civil the world's wind power potential for the first time from data. Wind speeds are calculated at 80 m, the hub% of all reporting stations experience annual mean wind speeds ! 6.9 m/s at 80 m (i.e., wind power class 3

  5. Wind climatology of Schiphol Andrew Stepek, Xueli Wang and Dirk Wolters

    E-Print Network [OSTI]

    Haak, Hein

    Wind climatology of Schiphol Andrew Stepek, Xueli Wang and Dirk Wolters De Bilt, May 2012 #12;2 Contents Summary 2 Introduction 3 Data 3 Hourly wind measurements 3 Yearly averages of wind speed measurements 4 Quality and sources of error 6 Method 7 Trends in wind speed 7 Definition of cross and tail wind

  6. Is the Weibull distribution really suited for wind statistics modeling and wind power evaluation?

    E-Print Network [OSTI]

    Drobinski, Philippe

    2012-01-01T23:59:59.000Z

    Wind speed statistics is generally modeled using the Weibull distribution. This distribution is convenient since it fully characterizes analytically with only two parameters (the shape and scale parameters) the shape of distribution and the different moments of the wind speed (mean, standard deviation, skewness and kurtosis). This distribution is broadly used in the wind energy sector to produce maps of wind energy potential. However, the Weibull distribution is based on empirical rather than physical justification and might display strong limitations for its applications. The philosophy of this article is based on the modeling of the wind components instead of the wind speed itself. This provides more physical insights on the validity domain of the Weibull distribution as a possible relevant model for wind statistics and the quantification of the error made by using such a distribution. We thereby propose alternative expressions of more suited wind speed distribution.

  7. Winds of change?: Projections of near-surface winds under climate change scenarios

    E-Print Network [OSTI]

    Pryor, Sara C.

    a downscaling technique to generate probability distributions of wind speeds at sites in northern Europe on renewable energy resources including wind-power. 2. Data [4] Ten coupled Global Climate Models (GCMs) fromWinds of change?: Projections of near-surface winds under climate change scenarios S. C. Pryor,1 J

  8. MSU-Wind Applications Center: Wind Resource Worksheet Theoretical Power Calculation

    E-Print Network [OSTI]

    Dyer, Bill

    MSU-Wind Applications Center: Wind Resource Worksheet Theoretical Power Calculation Equations: A= swept area = air density v= velocity R= universal gas constant Steps: 1. Measure wind speed from fan. = ___________/(________*________)= _________kg/m3 5. Theoretical Power a. Low Setting Theoretical Wind Power i. Power= ½*______*______*______*.59

  9. Wind resources and wind farm wake effects offshore observed from satellite

    E-Print Network [OSTI]

    Wind resources and wind farm wake effects offshore observed from satellite Charlotte Bay Hasager, Wind Energy Department, Roskilde, Denmark Charlotte.hasager@risoe.dk, poul.astrup@risoe.dk, merete.bruun.Christiansen@risoe.dk, morten.Nielsen@risoe.dk, r.barthelmie@risoe.dk Abstract: Satellite observations of ocean wind speed

  10. Assessing Long-Term Wind Conditions by Combining Different Measure-Correlate-Predict Algorithms: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Chowdhury, S.; Messac, A.; Hodge, B. M.

    2013-08-01T23:59:59.000Z

    This paper significantly advances the hybrid measure-correlate-predict (MCP) methodology, enabling it to account for variations of both wind speed and direction. The advanced hybrid MCP method uses the recorded data of multiple reference stations to estimate the long-term wind condition at a target wind plant site. The results show that the accuracy of the hybrid MCP method is highly sensitive to the combination of the individual MCP algorithms and reference stations. It was also found that the best combination of MCP algorithms varies based on the length of the correlation period.

  11. Wind induced circulation on the outer continental shelf of Texas, spring 1982

    E-Print Network [OSTI]

    Beard, Daniel Walker

    1984-01-01T23:59:59.000Z

    offshore of Freeport, TX, about 150 km north of the current meter moorings at 95'W. Buoy 42002 is approximately 240 km southeast of the moorings at 26'N, 93. 5'W. The buoys are designed to measure wind speed and direction continuously, but the final data... which may be exceeded by 5% of the coherence values determined from two randomly related time series [Groves and Zetler, 1964]. 20 CHAPTER III RESULTS Wind Data Wind velocity vectors for buoys 42002 (offshore) and 42008 (nearshore) for March 1...

  12. PSO (FU 2101) Ensemble-forecasts for wind power

    E-Print Network [OSTI]

    PSO (FU 2101) Ensemble-forecasts for wind power Wind Power Ensemble Forecasting Using Wind Speed the problems of (i) transforming the meteorological ensembles to wind power ensembles and, (ii) correcting) data. However, quite often the actual wind power production is outside the range of ensemble forecast

  13. Wind Farm Power Prediction: A Data-Mining Approach

    E-Print Network [OSTI]

    Kusiak, Andrew

    into a wind power plant. A number of different approaches have been used in forecasting wind speed and windWind Farm Power Prediction: A Data-Mining Approach Andrew Kusiak*, Haiyang Zheng and Zhe Song, IA 52242­1527, USA In this paper, models for short- and long-term prediction of wind farm power

  14. RisR1238(EN) Extreme Winds over Denmark

    E-Print Network [OSTI]

    Risø­R­1238(EN) Extreme Winds over Denmark from the NCEP/NCAR Reanalysis Helmut P. Frank Wind Laboratory, Roskilde, Denmark May 2001 #12;Abstract An extreme wind analysis of wind speed calculatedPa, and geostrophic winds at 850 hPa, 1000 hPa, and at the sea level are analyzed. At 10 m height the expected extreme

  15. Optimum propeller wind turbines

    SciTech Connect (OSTI)

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

    1983-11-01T23:59:59.000Z

    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.

  16. The effect of high penetration of wind power on primary frequency control of power systems.

    E-Print Network [OSTI]

    Motamed, Bardia

    2013-01-01T23:59:59.000Z

    ??In this work, a power system with wind power units and hydro power units are considered. The hydro power unit and variable speed wind turbine… (more)

  17. E-Print Network 3.0 - aggregated wind power Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and the increased wind power penetration in power systems the main trend for modern wind turbines is clearly... variable speed operation and grid connection via ... Source: Ris...

  18. Quantifying the system balancing cost when wind energy is incorporated into electricity generation system.

    E-Print Network [OSTI]

    Issaeva, Natalia

    2009-01-01T23:59:59.000Z

    ??Incorporation of wind energy into the electricity generation system requires a detailed analysis of wind speed in order to minimize system balancing cost and avoid… (more)

  19. Top 10 Things You Didn't Know About Wind Power | Department of...

    Energy Savers [EERE]

    turbines are getting taller to reach higher altitudes where it's even windier. See the Energy Department's wind resource maps to find average wind speeds in your state or...

  20. Active control system for high speed windmills

    DOE Patents [OSTI]

    Avery, Don E. (45-437 Akimala St., Honolulu, HI 96744)

    1988-01-01T23:59:59.000Z

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

  1. Active control system for high speed windmills

    DOE Patents [OSTI]

    Avery, D.E.

    1988-01-12T23:59:59.000Z

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  2. Direct

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,PhysicsDileepDirac Charge Dynamcs inDirect

  3. Wind Resource Assessment in Europe Using Emergy

    E-Print Network [OSTI]

    Paudel, Subodh; Santarelli, Massimo; Martin, Viktoria; Lacarriere, Bruno; Le Corre, Olivier

    2014-01-01T23:59:59.000Z

    of wind turbine assessment based on energy, exergy, LCA andLCA and emergy) in the case of sustainability assessment of windLCA does. In emergy analysis, direct and indirect inputs of wind

  4. Microphysical Structure of the Marine Boundary Layer under Strong Wind and Spray Formation as Seen from Simulations Using a 2D Explicit

    E-Print Network [OSTI]

    Mark, Pinsky

    in the vertical profiles of wind speed occurring with in- creasing wind speeds were attributed to a decrease generation is de- termined by a source function depending on the background wind speed assumed in the surface roughness and the drag coefficient for wind speeds exceeding about 33 m s21 . This decrease

  5. Solar Wind Forecasting with Coronal Holes

    E-Print Network [OSTI]

    S. Robbins; C. J. Henney; J. W. Harvey

    2007-01-09T23:59:59.000Z

    An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric magnetograms (e.g., Wang-Sheeley model) to estimate the open field line configuration. Rather than requiring the use of a full magnetic synoptic map, the method presented here can be used to forecast solar wind velocities and magnetic polarity from a single coronal hole image, along with a single magnetic full-disk image. The coronal hole parameters used in this study are estimated with Kitt Peak Vacuum Telescope He I 1083 nm spectrograms and photospheric magnetograms. Solar wind and coronal hole data for the period between May 1992 and September 2003 are investigated. The new model is found to be accurate to within 10% of observed solar wind measurements for its best one-month periods, and it has a linear correlation coefficient of ~0.38 for the full 11 years studied. Using a single estimated coronal hole map, the model can forecast the Earth directed solar wind velocity up to 8.5 days in advance. In addition, this method can be used with any source of coronal hole area and location data.

  6. Wind derivatives: hedging wind risk:.

    E-Print Network [OSTI]

    Hoyer, S.A.

    2013-01-01T23:59:59.000Z

    ??Wind derivatives are financial contracts that can be used to hedge or mitigate wind risk. In this thesis, the focus was on pricing these wind… (more)

  7. Numeric-modeling sensitivity analysis of the performance of wind turbine arrays

    SciTech Connect (OSTI)

    Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

    1982-06-01T23:59:59.000Z

    An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

  8. Mathematical and Computational Applications, Vol. 18, No. 3, pp. 408-420, 2013 MODELING AND CONTROL OF A VARIABLE SPEED

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    as variable speed variable pitch angle wind turbine due to its advantages in efficiency and the structure that is close to the ideal power curve where the energy efficiency is maximized below the nominal wind speed of 11 / and the power is limited to the nominal value above the nominal wind speed. Turbsim

  9. Wind tower service lift

    DOE Patents [OSTI]

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13T23:59:59.000Z

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  10. Observed and CAM3 GCM Sea Surface Wind

    E-Print Network [OSTI]

    Zender, Charles

    Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias climatological surface wind speed probability density functions (PDFs) estimated from observations and use them to evaluate, for the first time, contemporaneous wind PDFs predicted by a GCM. The ob- servations include NASA

  11. Investigation of Flow, Turbulence, and Dispersion within Built Environments

    E-Print Network [OSTI]

    Pan, Hansheng

    2011-01-01T23:59:59.000Z

    fluctuation and vertical mean wind speed reduced finefluctuation ( ? w ) and vertical mean wind speed (W) on DTFPwind speed; W -vertical mean wind speed; WD -wind direction;

  12. Offshore wind resource assessment through satellite images

    E-Print Network [OSTI]

    1 Slide no. 4 Offshore wind resource assessment through satellite images Charlotte Bay Hasager images for offshore wind ressource assessment in lieu of in-situ mast observations #12;4 Slide no Hasager, Dellwik, Nielsen and Furevik, 2004, Validation of ERS-2 SAR offshore wind-speed maps in the North

  13. Abstract--Wind power generation is growing rapidly. However, maintaining the wind turbine connection to grid is a real

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    1 Abstract--Wind power generation is growing rapidly. However, maintaining the wind turbine and the generator design. The fixed-speed wind turbine has the advantage of the low cost of A. F. Abdou and H. R advantages over the fixed-speed operation, such as maximum power capture, less mechanical stresses, and less

  14. Mesoscale Simulations of a Wind Ramping Event for Wind Energy Prediction

    SciTech Connect (OSTI)

    Rhodes, M; Lundquist, J K

    2011-09-21T23:59:59.000Z

    Ramping events, or rapid changes of wind speed and wind direction over a short period of time, present challenges to power grid operators in regions with significant penetrations of wind energy in the power grid portfolio. Improved predictions of wind power availability require adequate predictions of the timing of ramping events. For the ramping event investigated here, the Weather Research and Forecasting (WRF) model was run at three horizontal resolutions in 'mesoscale' mode: 8100m, 2700m, and 900m. Two Planetary Boundary Layer (PBL) schemes, the Yonsei University (YSU) and Mellor-Yamada-Janjic (MYJ) schemes, were run at each resolution as well. Simulations were not 'tuned' with nuanced choices of vertical resolution or tuning parameters so that these simulations may be considered 'out-of-the-box' tests of a numerical weather prediction code. Simulations are compared with sodar observations during a wind ramping event at a 'West Coast North America' wind farm. Despite differences in the boundary-layer schemes, no significant differences were observed in the abilities of the schemes to capture the timing of the ramping event. As collaborators have identified, the boundary conditions of these simulations probably dominate the physics of the simulations. They suggest that future investigations into characterization of ramping events employ ensembles of simulations, and that the ensembles include variations of boundary conditions. Furthermore, the failure of these simulations to capture not only the timing of the ramping event but the shape of the wind profile during the ramping event (regardless of its timing) indicates that the set-up and execution of such simulations for wind power forecasting requires skill and tuning of the simulations for a specific site.

  15. Wind power generating system

    SciTech Connect (OSTI)

    Schachle, Ch.; Schachle, E. C.; Schachle, J. R.; Schachle, P. J.

    1985-03-12T23:59:59.000Z

    Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse. In the event of dangerous but not clandestine problems developing in the system, a control circuit dumps hydraulic pressure from the unfeathering cylinder resulting in a predetermined, lower operating pressure produced by the pump. In the event that a problem of potentially cladestine consequence arises, the propeller unfeathering cylinder immediately unloads. Upon startup, a bypass around the motor is blocked, applying a pressure across the motor. The motor drives the generator until the generator reaches a predetermined speed whereupon the generator is placed in circuit with a utility grid and permitted to motor up to synchronous speed.

  16. Gone with the Wind - The Potential Tragedy of the Common Wind

    E-Print Network [OSTI]

    Lifshitz-Goldberg, Yaei

    2010-01-01T23:59:59.000Z

    a technical discussion of wind turbine wake ef- fects, seeCoherence in a Wind Turbine Wake, ENVTL. Rr s. LEIi-ERS 1-wind direction turbines are usually spaced even farther apart. See DWIA, Wake

  17. UNIVERSITY of CALIFORNIA INVESTIGATION OF HOW ANGLE OF ATTACK AFFECTS ROTOR SPEED

    E-Print Network [OSTI]

    Belanger, David P.

    -pitch blades is tested in UCSC's wind tunnel. The turbine is used to test how varying the blade angle affects the turbine's rotational speed at different wind speeds. The data are used to determine how the blade angle 27 Appendix A Wind Turbine Data 29 Appendix B Converting Blade Pitch to Needle Angle 33 Appendix C

  18. Coastal Ohio Wind Project for Reduced Barriers to Deployment of Offshore Wind Energy

    SciTech Connect (OSTI)

    Gorsevski, Peter; Afjeh, Abdollah; Jamali, Mohsin; Carroll, Michael

    2014-04-09T23:59:59.000Z

    The Coastal Ohio Wind Project was created to establish the viability of wind turbines on the coastal and offshore regions of Northern Ohio. The project’s main goal was to improve operational unit strategies used for environmental impact assessment of offshore turbines on lake wildlife by optimizing and fusing data from the multi-instrument surveillance system and providing an engineering analysis of potential design/operational alternatives for offshore wind turbines. The project also developed a general economic model for offshore WTG deployment to quantify potential revenue losses due to wind turbine shutdown related to ice and avian issues. In a previous phase of this project (Award Number: DE-FG36-06GO86096), we developed a surveillance system that was used to collect different parameters such as passage rates, flight paths, flight directions, and flight altitudes of nocturnal migrating species, movements of birds and bats, and bird calls for assessing patterns and peak passage rates during migration. To derive such parameters we used thermal IR imaging cameras, acoustic recorders, and marine radar Furuno (XANK250), which was coupled with a XIR3000B digitizing card from Russell Technologies and open source radR processing software. The integration yielded a development of different computational techniques and methods, which we further developed and optimized as a combined surveillance system. To accomplish this task we implemented marine radar calibration, optimization of processing parameters, and fusion of the multi-sensor data in order to make inferences about the potential avian targets. The main goal of the data fusion from the multi-sensor environment was aimed at reduction of uncertainties while providing acceptable confidence levels with detailed information about the migration patterns. Another component comprised of an assessment of wind resources in a near lake environment and an investigation of the effectiveness of ice coating materials to mitigate adverse effects of ice formation on wind turbine structures. Firstly, a Zephir LiDAR system was acquired and installed at Woodlands School in Huron, Ohio, which is located near Lake Erie. Wind resource data were obtained at ten measurement heights, 200m, 150m, 100m, 80m, 60m, 40m, 38m, 30m, 20m, and 10m. The Woodlands School’s wind turbine anemometer also measured the wind speed at the hub height. These data were collected for approximately one year. The hub anemometer data correlated well with the LiDAR wind speed measurements at the same height. The data also showed that on several days different power levels were recorded by the turbine at the same wind speed as indicated by the hub anemometer. The corresponding LiDAR data showed that this difference can be attributed to variability in the wind over the turbine rotor swept area, which the hub anemometer could not detect. The observation suggests that single point hub wind velocity measurements are inadequate to accurately estimate the power generated by a turbine at all times since the hub wind speed is not a good indicator of the wind speed over the turbine rotor swept area when winds are changing rapidly. To assess the effectiveness of ice coatings to mitigate the impact of ice on turbine structures, a closed-loop icing research tunnel (IRT) was designed and constructed. By controlling the temperature, air speed, water content and liquid droplet size, the tunnel enabled consistent and repeatable ice accretion under a variety of conditions with temperatures between approximately 0°C and -20°C and wind speeds up to 40 miles per hour in the tunnel’s test section. The tunnel’s cooling unit maintained the tunnel temperature within ±0.2°C. The coatings evaluated in the study were Boyd Coatings Research Company’s CRC6040R3, MicroPhase Coatings Inc.’s PhaseBreak TP, ESL and Flex coatings. Similar overall performance was observed in all coatings tested in that water droplets form on the test articles beginning at the stagnation region and spreading in the downstream direction in time. When compari

  19. Real time grid congestion management in presence of high penetration of wind energy

    E-Print Network [OSTI]

    Boyer, Edmond

    Real time grid congestion management in presence of high penetration of wind energy A. Vergnol1 , J », « Wind energy », « Variable speed drive » Abstract With the increased use of wind energy the power

  20. High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes

    DOE Patents [OSTI]

    De Doncker, R.W.A.A.

    1992-09-01T23:59:59.000Z

    The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and accurately to provide flux amplitude and angular position values for use by the vector rotator of a universal field-oriented (UFO) controller. Flux amplitude (linear or squared) is provided as feedback to tune the UFO controller for operation in direct and indirect field orientation modes and enables smooth transitions from one mode to the other. 3 figs.

  1. High speed flux feedback for tuning a universal field oriented controller capable of operating in direct and indirect field orientation modes

    SciTech Connect (OSTI)

    De Doncker, Rik W. A. A. (Schenectady, NY)

    1992-01-01T23:59:59.000Z

    The direct (d) and quadrature (q) components of flux, as sensed by flux sensors or determined from voltage and current measurements in a direct field orientation scheme, are processed rapidly and accurately to provide flux amplitude and angular position values for use by the vector rotator of a universal field-oriented (UFO) controller. Flux amplitude (linear or squared) is provided as feedback to tune the UFO controller for operation in direct and indirect field orientation modes and enables smooth transitions from one mode to the other.

  2. Pitfalls of modeling wind power using Markov chains

    E-Print Network [OSTI]

    Kirtley, James L., Jr.

    An increased penetration of wind turbines have given rise to a need for wind speed/power models that generate realistic synthetic data. Such data, for example, might be used in simulations to size energy storage or spinning ...

  3. Simulation and Optimization of Wind Farm Operations under Stochastic Conditions

    E-Print Network [OSTI]

    Byon, Eunshin

    2011-08-08T23:59:59.000Z

    generation model, wind speed model, and maintenance model. We provide practical insights gained by examining di erent maintenance strategies. To the best of our knowledge, our simulation model is the rst discrete-event simulation model for wind farm...

  4. Ris National Laboratory Satellite SAR applied in offshore wind

    E-Print Network [OSTI]

    Risø National Laboratory Satellite SAR applied in offshore wind ressource mapping: possibilities is to quantify the regional offshore wind climate for wind energy application based on satellite SAR ·Study of 85SAR(m/s) Hasager, Dellwik, Nielsen and Furevik, 2004, Validation of ERS-2 SAR offshore wind-speed maps

  5. Dynamic Simulation of DFIG Wind Turbines on FPGA Boards

    E-Print Network [OSTI]

    Zambreno, Joseph A.

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

  6. Wind resource assessment with a mesoscale non-hydrostatic model

    E-Print Network [OSTI]

    Boyer, Edmond

    Wind resource assessment with a mesoscale non- hydrostatic model Vincent Guénard, Center for Energy is developed for assessing the wind resource and its uncertainty. The work focuses on an existing wind farm mast measurements. The wind speed and turbulence fields are discussed. It is shown that the k

  7. Cambridge Danehy Park Wind Turbine Preliminary Project Assessment

    E-Print Network [OSTI]

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

  8. Ris-R-1330(EN) Wind Turbine Power Performance

    E-Print Network [OSTI]

    .1 Background 8 2.2 Problems 8 2.3 Input by the Manufacturers 9 2.4 Methods 10 2.4.1Method A 10 2.4.1.1 Site.2 Experiences from production assessments - The Questionable On-site Power Curve Measurement 4.2.1Background wind speed 5.7 Types of wind speed sensors 35 5.7.1Vector scalar wind speed cup anemometer 35 5

  9. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    Peinke, Joachim

    WIND ENERGY Wind Energ. (2014) Published online in Wiley Online Library (wileyonlinelibrary Correspondence M. Wächter, ForWind-Center for Wind Energy Research, Institute of Physics, Carl Von Ossietzky on the operation of wind energy converters (WECs) imposing different risks especially in terms of highly dynamic

  10. Wind Spires as an Alternative Energy Source

    SciTech Connect (OSTI)

    Majid Rashidi, Ph.D., P.E.

    2012-10-30T23:59:59.000Z

    This report discloses the design and development of an innovative wind tower system having an axisymmetric wind deflecting structure with a plurality of symmetrically mounted rooftop size wind turbines near the axisymmetric structure. The purpose of the wind deflecting structure is to increase the ambient wind speed that in turn results in an overall increase in the power capacity of the wind turbines. Two working prototypes were constructed and installed in the summer of 2009 and 2012 respectively. The system installed in the Summer of 2009 has a cylindrical wind deflecting structure, while the tower installed in 2012 has a spiral-shape wind deflecting structure. Each tower has 4 turbines, each rated at 1.65 KW Name-Plate-Rating. Before fabricating the full-size prototypes, computational fluid dynamic (CFD) analyses and scaled-down table-top models were used to predict the performance of the full-scale models. The performance results obtained from the full-size prototypes validated the results obtained from the computational models and those of the scaled-down models. The second prototype (spiral configuration) showed at a wind speed of 11 miles per hour (4.9 m/s) the power output of the system could reach 1,288 watt, when a typical turbine installation, with no wind deflecting structure, could produce only 200 watt by the same turbines at the same wind speed. At a wind speed of 18 miles per hour (8 m/sec), the spiral prototype produces 6,143 watt, while the power generated by the same turbines would be 1,412 watt in the absence of a wind deflecting structure under the same wind speed. Four US patents were allowed, and are in print, as the results of this project (US 7,540,706, US 7,679,209, US 7,845,904, and US 8,002,516).

  11. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power

    E-Print Network [OSTI]

    Hu, Weihao

    @et.aau.dk, csu@et.aau.dk, zch@et.aau.dk Abstract ­ Grid connected wind turbines are fluctuating power sources due on the power system small signal stability of wind turbines based on fixed-speed induction generators, doubly two interconnected power systems [9]. The wind power fluctuations produced by grid connected variable

  12. Torque on an exoplanet from an anisotropic evaporative wind

    E-Print Network [OSTI]

    Teyssandier, Jean; Adams, Fred C; Quillen, Alice C

    2015-01-01T23:59:59.000Z

    Winds from short-period Earth and Neptune mass exoplanets, driven by high energy radiation from a young star, may evaporate a significant fraction of a planet's mass. If the momentum flux from the evaporative wind is not aligned with the planet/star axis, then it can exert a torque on the planet's orbit. Using steady-state one-dimensional evaporative wind models we estimate this torque using a lag angle that depends on the product of the speed of the planet's upper atmosphere and a flow timescale for the wind to reach its sonic radius. We also estimate the momentum flux from time-dependent one-dimensional hydrodynamical simulations. We find that only in a very narrow regime in planet radius, mass and stellar radiation flux is a wind capable of exerting a significant torque on the planet's orbit. Similar to the Yarkovsky effect, the wind causes the planet to drift outward if atmospheric circulation is prograde (super-rotating) and in the opposite direction if the circulation is retrograde. A close-in super Ear...

  13. Stability Improvement of Wind Farms using Shunt and Series Compensation

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Air density, Rotor effective wind speed. A Swept area of the turbine blade. Tip speed ratio. Cp, Torsion damping. Tm, Tae, Te Mechanical, Aerodynamic, and Electrical torque. Lm, Lrr Mutual inductance

  14. South Carolina Opens Nation's Largest Wind Drivetrain Testing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Carolina. The facility will help test and validate new turbines, particularly for offshore wind- helping to speed deployment of next generation energy technology, reduce...

  15. South Carolina Opens Nation's Largest Wind Drivetrain Testing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Institute, the facility will help test and validate new turbines, particularly for offshore wind-helping to speed deployment of next generation energy technology, reduce costs...

  16. Simulations of an offshore wind farm using large eddy simulation and a torque-controlled actuator disc model

    E-Print Network [OSTI]

    Creech, Angus; Maguire, A Eoghan

    2014-01-01T23:59:59.000Z

    We present here a computational fluid dynamics (CFD) simulation of Lillgrund offshore wind farm, which is located in the {\\O}resund Strait between Sweden and Denmark. The simulation combines a dynamic representation of wind turbines embedded within a Large-Eddy Simulation CFD solver, and uses hr-adaptive meshing to increase or decrease mesh resolution where required. This allows the resolution of both large scale flow structures around the wind farm, and local flow conditions at individual turbines; consequently, the response of each turbine to local conditions can be modelled, as well as the resulting evolution of the turbine wakes. This paper provides a detailed description of the turbine model which simulates interactions between the wind, turbine rotors, and turbine generators by calculating the forces on the rotor, the body forces on the air, and instantaneous power output. This model was used to investigate a selection of key wind speeds and directions, investigating cases where a row of turbines would ...

  17. Measurement of turbulent wind velocities using a rotating boom apparatus

    SciTech Connect (OSTI)

    Sandborn, V.A.; Connell, J.R.

    1984-04-01T23:59:59.000Z

    The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

  18. Turbine Reliability and Operability Optimization through the use of Direct Detection Lidar Final Technical Report

    SciTech Connect (OSTI)

    Johnson, David K; Lewis, Matthew J; Pavlich, Jane C; Wright, Alan D; Johnson, Kathryn E; Pace, Andrew M

    2013-02-01T23:59:59.000Z

    The goal of this Department of Energy (DOE) project is to increase wind turbine efficiency and reliability with the use of a Light Detection and Ranging (LIDAR) system. The LIDAR provides wind speed and direction data that can be used to help mitigate the fatigue stress on the turbine blades and internal components caused by wind gusts, sub-optimal pointing and reactionary speed or RPM changes. This effort will have a significant impact on the operation and maintenance costs of turbines across the industry. During the course of the project, Michigan Aerospace Corporation (MAC) modified and tested a prototype direct detection wind LIDAR instrument; the resulting LIDAR design considered all aspects of wind turbine LIDAR operation from mounting, assembly, and environmental operating conditions to laser safety. Additionally, in co-operation with our partners, the National Renewable Energy Lab and the Colorado School of Mines, progress was made in LIDAR performance modeling as well as LIDAR feed forward control system modeling and simulation. The results of this investigation showed that using LIDAR measurements to change between baseline and extreme event controllers in a switching architecture can reduce damage equivalent loads on blades and tower, and produce higher mean power output due to fewer overspeed events. This DOE project has led to continued venture capital investment and engagement with leading turbine OEMs, wind farm developers, and wind farm owner/operators.

  19. Direct - drive permanent magnet synchronous generator design for hydrokinetic energy extraction .

    E-Print Network [OSTI]

    Kashyap, Amshumaan Raghunatha

    2013-01-01T23:59:59.000Z

    ??"Hydrokinetic turbines deliver lower shaft speeds when compared to both steam and wind turbines. Hence, a water wheel generator must operate at speeds as low… (more)

  20. The dominant X-ray wind in massive star binaries

    E-Print Network [OSTI]

    J. M. Pittard; I. R. Stevens

    2002-04-15T23:59:59.000Z

    We investigate which shocked wind is responsible for the majority of the X-ray emission in colliding wind binaries, an issue where there is some confusion in the literature, and which we show is more complicated than has been assumed. We find that where both winds rapidly cool (typically close binaries), the ratio of the wind speeds is often more important than the momentum ratio, because it controls the energy flux ratio, and the faster wind is generally the dominant emitter. When both winds are largely adiabatic (typically long-period binaries), the slower and denser wind will cool faster and the stronger wind generally dominates the X-ray luminosity.

  1. Stellar Winds on the Main-Sequence I: Wind Model

    E-Print Network [OSTI]

    Johnstone, C P; Lüftinger, T; Toth, G; Brott, I

    2015-01-01T23:59:59.000Z

    Aims: We develop a method for estimating the properties of stellar winds for low-mass main-sequence stars between masses of 0.4 and 1.1 solar masses at a range of distances from the star. Methods: We use 1D thermal pressure driven hydrodynamic wind models run using the Versatile Advection Code. Using in situ measurements of the solar wind, we produce models for the slow and fast components of the solar wind. We consider two radically different methods for scaling the base temperature of the wind to other stars: in Model A, we assume that wind temperatures are fundamentally linked to coronal temperatures, and in Model B, we assume that the sound speed at the base of the wind is a fixed fraction of the escape velocity. In Paper II of this series, we use observationally constrained rotational evolution models to derive wind mass loss rates. Results: Our model for the solar wind provides an excellent description of the real solar wind far from the solar surface, but is unrealistic within the solar corona. We run ...

  2. WIND ENERGY Wind Energ. (2014)

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    in the near wake. In conclusion, WiTTS performs satisfactorily in the rotor region of wind turbine wakes under neutral stability. Copyright © 2014 John Wiley & Sons, Ltd. KEYWORDS wind turbine wake; wake model; self in wind farms along several rows and columns. Because wind turbines generate wakes that propagate downwind

  3. Illinois Wind Workers Group

    SciTech Connect (OSTI)

    David G. Loomis

    2012-05-28T23:59:59.000Z

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  4. Short-term Wind Power Forecasting Using Advanced Statistical T.S. Nielsen1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Short-term Wind Power Forecasting Using Advanced Statistical Methods T.S. Nielsen1 , H. Madsen1 , H considered in the ANEMOS project for short-term fore- casting of wind power. The total procedure typically in for prediction of wind power or wind speed, estimating the uncertainty of the wind power forecast, and finally

  5. Impact of DFIG wind turbines on transient stability of power systems a review

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Impact of DFIG wind turbines on transient stability of power systems ­ a review Authors Na Abstract of wind farms are using variable speed wind turbines equipped with doubly-fed induction generators (DFIG) due to their advantages over other wind turbine generators. Therefore, the analysis of wind power

  6. Abstract--This paper addresses the problem of controlling wind energy conversion systems (WECS) which involve

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract-- This paper addresses the problem of controlling wind energy conversion systems (WECS-inverter. The goal of control is to maximize wind energy extraction and this needs letting the wind turbine rotor wind energy extraction) only for one wind speed value depending on the considered value of turbine

  7. Prediction, operations, and condition monitoring in wind energy Andrew Kusiak a,*, Zijun Zhang b

    E-Print Network [OSTI]

    Kusiak, Andrew

    Review Prediction, operations, and condition monitoring in wind energy Andrew Kusiak a,*, Zijun 2013 Available online 23 August 2013 Keywords: Wind energy Wind speed prediction Wind turbine control Condition monitoring and fault detection a b s t r a c t Recent developments in wind energy research

  8. The Use of Tall Tower Field Data for Estimating Wind Turbine Power Performance , J. Chapman1

    E-Print Network [OSTI]

    Manuel, Lance

    The Use of Tall Tower Field Data for Estimating Wind Turbine Power Performance A. Swift1 , J wind speed measurements on the TTU WISE 200m and 78m towers. A hypothetical wind turbine is shown. At potential wind turbine sites, it is uncommon to have wind measurements available at multiple heights. Then

  9. RAIN AND WIND ESTIMATION FROM SEAWINDS IN HURRICANES AT ULTRA HIGH RESOLUTION

    E-Print Network [OSTI]

    Long, David G.

    function (GMF) which relates wind to backscatter (0 ) is not well understood for extremely high wind speedsRAIN AND WIND ESTIMATION FROM SEAWINDS IN HURRICANES AT ULTRA HIGH RESOLUTION Brent A. Williams method for estimating wind and rain in hurricanes from SeaWinds at ultra-high resolution is developed. We

  10. Interaction between surface and atmosphere in a convective boundary layer /

    E-Print Network [OSTI]

    Garai, Anirban

    2013-01-01T23:59:59.000Z

    resulting in constant wind, and potential temperature andatmospheric wind speed, direction and potential temperatureatmospheric profiles (wind speed, potential temperature),

  11. Subhourly wind forecasting techniques for wind turbine operations

    SciTech Connect (OSTI)

    Wegley, H.L.; Kosorok, M.R.; Formica, W.J.

    1984-08-01T23:59:59.000Z

    Three models for making automated forecasts of subhourly wind and wind power fluctuations were examined to determine the models' appropriateness, accuracy, and reliability in wind forecasting for wind turbine operation. Such automated forecasts appear to have value not only in wind turbine control and operating strategies, but also in improving individual wind turbine control and operating strategies, but also in improving individual wind turbine operating strategies (such as determining when to attempt startup). A simple persistence model, an autoregressive model, and a generalized equivalent Markhov (GEM) model were developed and tested using spring season data from the WKY television tower located near Oklahoma City, Oklahoma. The three models represent a pure measurement approach, a pure statistical method and a statistical-dynamical model, respectively. Forecasting models of wind speed means and measures of deviations about the mean were developed and tested for all three forecasting techniques for the 45-meter level and for the 10-, 30- and 60-minute time intervals. The results of this exploratory study indicate that a persistence-based approach, using onsite measurements, will probably be superior in the 10-minute time frame. The GEM model appears to have the most potential in 30-minute and longer time frames, particularly when forecasting wind speed fluctuations. However, several improvements to the GEM model are suggested. In comparison to the other models, the autoregressive model performed poorly at all time frames; but, it is recommended that this model be upgraded to an autoregressive moving average (ARMA or ARIMA) model. The primary constraint in adapting the forecasting models to the production of wind turbine cluster power output forecasts is the lack of either actual data, or suitable models, for simulating wind turbine cluster performance.

  12. The solar wind in the outer heliosphere

    E-Print Network [OSTI]

    Richardson, John D.

    The solar wind evolves as it moves outward due to interactions with both itself and with the circum-heliospheric interstellar medium. The speed is, on average, constant out to 30 AU, then starts a slow decrease due to the ...

  13. Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine

    E-Print Network [OSTI]

    Hoen, Ben

    2010-01-01T23:59:59.000Z

    of Reduced Noise Operations of Wind Turbines on Neighborof Reduced Noise Operations of Wind Turbines on NeighborWind Speed (m/s) 3 Turbines (in operation at the time) Noise

  14. Q. J. R. Meteorol. Soc. (2004), 130, pp. 120 Using mesocale model winds for correcting wind-drift errors in radar

    E-Print Network [OSTI]

    Reading, University of

    the vertical shear of the horizontal wind. We assume the shear and the fall speed in the layer are constant rain because of the low fall speed of around 1 m s-1. Sampling these wind-induced fall streak patterns vertical profile of reflectivity shear fall streak wind drift 1. Introduction Operational radars around

  15. Soil moisture in complex terrain: quantifying effects on atmospheric boundary layer flow and providing improved surface boundary conditions for mesoscale models

    E-Print Network [OSTI]

    Daniels, Megan Hanako

    2010-01-01T23:59:59.000Z

    direction, (b) wind speed, (c) potential temperature, and (Airport of potential temperature, wind speed, winderrors (bias) for potential temperature, wind speed, wind

  16. Wind extremes in the North Sea Basin under climate change: An ensemble study of 12 CMIP5 GCMs

    E-Print Network [OSTI]

    Haak, Hein

    Wind extremes in the North Sea Basin under climate change: An ensemble study of 12 CMIP5 GCMs R. C levels and waves are generated by low atmospheric pressure and severe wind speeds during storm events. As a result of the geometry of the North Sea, not only the maximum wind speed is relevant, but also wind

  17. A Combined High Gain Observer and High-Order Sliding Mode Controller for a DFIG-Based Wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    simulator FAST. Index Terms--Wind turbine (WT), Doubly-Fed Induction Generator (DFIG), high gain observer using the NREL wind turbine simulator FAST. II. WIND TURBINE MODELING The global scheme for a grid-connected shaft speed and thus maintaining optimal power generation. The more variable speed wind turbines

  18. WindTurbineGenerator Introduction of the Renewable Micro-Grid Test-Bed

    E-Print Network [OSTI]

    Johnson, Eric E.

    Simulator Wind Turbine: PMSM, 3kW, 8.3A Wind Generator: PMSM, 3kW, 8.3A 3 AC/DC Converter & DC/AC Inverter Wind Turbine: Torque or Speed Control Wind Generator: PQ Control Cubicle #4: Energy Storage Generator #1 3kW, 8.3A Wind Turbine #1 3kW, 8.3A Wind Turbine #2 3kW Wind Generator #2 3kW RS232

  19. Currituck County- Wind Energy Systems Ordinance

    Broader source: Energy.gov [DOE]

    In January 2008, Currituck County adopted an ordinance to regulate the use of wind-energy systems. The ordinance directs any individual or organization wishing to install a wind-energy system to...

  20. Understanding Inertial and Frequency Response of Wind Power Plants: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Gevorgian, V.; Singh, M.; Santoso, S.

    2012-07-01T23:59:59.000Z

    The objective of this paper is to analyze and quantify the inertia and frequency responses of wind power plants with different wind turbine technologies (particularly those of fixed speed, variable slip with rotor-resistance controls, and variable speed with vector controls).

  1. Fuel Effects on Combustion and Emissions of a Direct-Inection Diesel Engine Operating at Moderate to High Engine Speed and Load

    SciTech Connect (OSTI)

    Szybist, James P [ORNL; Szymkowicz, Patrick G. [General Motors Corporation; Northrop, William F [General Motors Corporation

    2012-01-01T23:59:59.000Z

    It is advantageous to increase the specific power output of diesel engines and to operate them at higher load for a greater portion of a driving cycle to achieve better thermal efficiency and thus reduce vehicle fuel consumption. Such operation is limited by excessive smoke formation at retarded injection timing and high rates of cylinder pressure rise at more advanced timing. Given this window of operation, it is desired to understand the influence of fuel properties such that optimum combustion performance and emissions can be retained over the range of fuels commonly available in the marketplace. It has been shown in previous studies that varying cetane number (CN) of diesel fuel has little effect on ignition delay at high engine load due to the domination of high cylinder temperature on ignition kinetics. The work here experimentally confirms that finding but also shows that emissions and combustion performance vary according to fuel reactivity. Data are examined from a direct-injection single cylinder research engine for eight common diesel fuels including soy-based biodiesel blends at two high load operating points with no exhaust gas recirculation (EGR) and at a moderate load with four levels of EGR. It is shown in the work that at high engine load where combustion is controlled by mixing processes, CN and other fuel properties have little effect on engine performance, although lower CN fuels produce a small increase in noise, smoke and CO emissions. Biodiesel blends increase NOX emissions and decreases CO and smoke emissions at high load, but otherwise have little effect on performance. At moderate load, higher CN fuels are more tolerant to EGR due to their better chemical reactivity at retarded injection timing, but all fuels produce comparable thermal efficiency at advanced combustion phasing regardless of EGR. In contrast to the high load conditions, there was no increase in NOX emissions for biodiesel at the moderate load condition. It is concluded that although higher CN does not significantly alter ignition delay at moderate to high loads it has a dominant influence on the acceptable injection timing range. Apart from CN effects, fuel oxygen content plays an independent role in reducing some emissions. It is therefore recommended that compensation for fuel ignitability and oxygen content be included in combustion control strategies to optimize emissions and performance of future diesel engines.

  2. Wind Farm

    Office of Energy Efficiency and Renewable Energy (EERE)

    The wind farm in Greensburg, Kansas, was completed in spring 2010, and consists of ten 1.25 megawatt (MW) wind turbines that supply enough electricity to power every house, business, and municipal...

  3. Wasted Wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    why turbulent airflows are causing power losses and turbine failures in America's wind farms-and what to do about it April 1, 2014 Wasted Wind This aerial photo of Denmark's Horns...

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

    E-Print Network [OSTI]

    Tullis, Stephen

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

  5. Wind Energy

    Broader source: Energy.gov [DOE]

    Presentation covers wind energy at the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.

  6. QUIKSCAT MEASUREMENTS AND ECMWF WIND FORECASTS

    E-Print Network [OSTI]

    Malmberg, Anders

    . (2004) this forecast error was encountered when assimilating satellite measurements of zonal wind speeds between satellite measurements and meteorological forecasts of near-surface ocean winds. This type of covariance enters in assimilation techniques such as Kalman filtering. In all, six residual fields

  7. QUIKSCAT MEASUREMENTS AND ECMWF WIND FORECASTS

    E-Print Network [OSTI]

    Malmberg, Anders

    . (2004) this forecast error was encountered when assimilating satellite measurements of zonal wind speeds between satellite measurements and meteorological forecasts of near­surface ocean winds. This type of covariance enters in assimilation techniques such as Kalman filtering. In all, six residual fields

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

    SciTech Connect (OSTI)

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

    1984-09-01T23:59:59.000Z

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

  9. Assessing the local wind field at Sierra Grande Mountain in New Mexico with instrumentation

    SciTech Connect (OSTI)

    Barnett, K.M.; Reynolds, R.D.

    1981-05-01T23:59:59.000Z

    Six systems were installed on top of Sierra Grande, a nearly symmetrical mountain in New Mexico about halfway between Raton and Clayton, with a peak of 2659 m (8720 ft msl) standing over a wide mesa of approximately 1829 m (6000 ft msl). Two systems were on the peak, one at 10 m (33 ft) above the surface and the other at 20 m (66 ft) because the peak is often the most probable spot for the greatest wind energy. The two levels were needed to measure variations of speed with height. Four other systems with instruments at 10-m (33 ft) were located roughly north, east, south, and west from the center on secondary ridge lines to measure certain horizontal variations of the wind. The wind direction and speed were measured every 6 minutes, a time interval considerably shorter than the traditional 1 hour but long enough so that all WECS power outputs are expected to respond to these wind speed variations. All six systems were operated for a period of six months between 6 June 1979-5 December 1979.

  10. Hurricane Katrina Wind Investigation Report

    SciTech Connect (OSTI)

    Desjarlais, A. O.

    2007-08-15T23:59:59.000Z

    This investigation of roof damage caused by Hurricane Katrina is a joint effort of the Roofing Industry Committee on Weather Issues, Inc. (RICOWI) and the Oak Ridge National Laboratory/U.S. Department of Energy (ORNL/DOE). The Wind Investigation Program (WIP) was initiated in 1996. Hurricane damage that met the criteria of a major windstorm event did not materialize until Hurricanes Charley and Ivan occurred in August 2004. Hurricane Katrina presented a third opportunity for a wind damage investigation in August 29, 2005. The major objectives of the WIP are as follows: (1) to investigate the field performance of roofing assemblies after major wind events; (2) to factually describe roofing assembly performance and modes of failure; and (3) to formally report results of the investigations and damage modes for substantial wind speeds The goal of the WIP is to perform unbiased, detailed investigations by credible personnel from the roofing industry, the insurance industry, and academia. Data from these investigations will, it is hoped, lead to overall improvement in roofing products, systems, roofing application, and durability and a reduction in losses, which may lead to lower overall costs to the public. This report documents the results of an extensive and well-planned investigative effort. The following program changes were implemented as a result of the lessons learned during the Hurricane Charley and Ivan investigations: (1) A logistics team was deployed to damage areas immediately following landfall; (2) Aerial surveillance--imperative to target wind damage areas--was conducted; (3) Investigation teams were in place within 8 days; (4) Teams collected more detailed data; and (5) Teams took improved photographs and completed more detailed photo logs. Participating associations reviewed the results and lessons learned from the previous investigations and many have taken the following actions: (1) Moved forward with recommendations for new installation procedures; (2) Updated and improved application guidelines and manuals from associations and manufacturers; (3) Launched certified product installer programs; and (4) Submitted building code changes to improve product installation. Estimated wind speeds at the damage locations came from simulated hurricane models prepared by Applied Research Associates of Raleigh, North Carolina. A dynamic hurricane wind field model was calibrated to actual wind speeds measured at 12 inland and offshore stations. The maximum estimated peak gust wind speeds in Katrina were in the 120-130 mph range. Hurricane Katrina made landfall near Grand Isle, Louisiana, and traveled almost due north across the city of New Orleans. Hurricane winds hammered the coastline from Houma, Louisiana, to Pensacola, Florida. The severe flooding problems in New Orleans made it almost impossible for the investigating teams to function inside the city. Thus the WIP investigations were all conducted in areas east of the city. The six teams covered the coastal areas from Bay Saint Louis, Mississippi, on the west to Pascagoula, Mississippi, on the east. Six teams involving a total of 25 persons documented damage to both low slope and steep slope roofing systems. The teams collected specific information on each building examined, including type of structure (use or occupancy), wall construction, roof type, roof slope, building dimensions, roof deck, insulation, construction, and method of roof attachment. In addition, the teams noted terrain exposure and the estimated wind speeds at the building site from the Katrina wind speed map. With each team member assigned a specific duty, they described the damage in detail and illustrated important features with numerous color photos. Where possible, the points of damage initiation were identified and damage propagation described. Because the wind speeds in Katrina at landfall, where the investigations took place, were less than code-specified design speeds, one would expect roof damage to be minimal. One team speculated that damage to all roofs in the area they examined was les

  11. On the limiting aerodynamic roughness of the ocean in very strong winds

    E-Print Network [OSTI]

    Saltzman, Eric

    On the limiting aerodynamic roughness of the ocean in very strong winds M. A. Donelan,1 B. K. Haus January 2004; accepted 13 August 2004; published 28 September 2004. [1] The aerodynamic friction between, the ``aerodynamic roughness'') increases with the wind speed. Can one merely extrapolate this wind speed tendency

  12. Dynamic behaviour of a DFIG wind turbine subjected to power system faults

    E-Print Network [OSTI]

    of the dynamic interaction between variable speed DFIG wind turbines and the power system subjected by the Danish Transmission System Operator Energinet.dk. Keywords: doubly-fed induction generator (DFIG), wind turbines, the variable speed DFIG wind turbine with its dynamic behaviour and its ride-through capabil- ity

  13. Upper Ocean Response to Tropical Cyclone Wind Asymmetries S. Daniel Jacob and Lynn K. Shay

    E-Print Network [OSTI]

    Shay, Lynn K. "Nick"

    High Resolution Radiometer (AVHRR) images of SST. As a storm intensifies, the increasing wind speed may. However, the significant SST reduction induced by the increasing wind speed leads to reduced air to the atmosphere ( 20%) and vertical mixing at the base of the oceanic mixed layer ( 80%) induced by wind stress

  14. Discrepancies in the Prediction of Solar Wind using Potential Field Source Surface Model: An

    E-Print Network [OSTI]

    Zhao, Xuepu

    Discrepancies in the Prediction of Solar Wind using Potential Field Source Surface Model. This inverse relation has been made use of in the prediction of solar wind speed at 1 AU using a potential between the magnetic flux tube expansion factor (FTE) at the source surface and the solar wind speed

  15. Quantifying Errors Associated with Satellite Sampling of Offshore Wind S.C. Pryor1,2

    E-Print Network [OSTI]

    1 Quantifying Errors Associated with Satellite Sampling of Offshore Wind Speeds S.C. Pryor1,2 , R, Bloomington, IN47405, USA. Tel: 1-812-855-5155. Fax: 1-812-855-1661 Email: spryor@indiana.edu 2 Dept. of Wind an attractive proposition for measuring wind speeds over the oceans because in principle they also offer

  16. Soft-stall control versus furling control for small wind turbine power regulation

    SciTech Connect (OSTI)

    Muljadi, E.; Forsyth, T.; Butterfield, C.P.

    1998-07-01T23:59:59.000Z

    Many small wind turbines are designed to furl (turn) in high winds to regulate power and provide overspeed protection. Furling control results in poor energy capture at high wind speeds. This paper proposes an alternative control strategy for small wind turbines -- the soft-stall control method. The furling and soft-stall control strategies are compared using steady state analysis and dynamic simulation analysis. The soft-stall method is found to offer several advantages: increased energy production at high wind speeds, energy production which tracks the maximum power coefficient at low to medium wind speeds, reducing furling noise, and reduced thrust.

  17. Soft-Stall Control versus Furling Control for Small Wind Turbine Power Regulation

    SciTech Connect (OSTI)

    Muljadi, E.; Forsyth, T.; Butterfield, C. P.

    1998-07-01T23:59:59.000Z

    Many small wind turbines are designed to furl (turn) in high winds to regulate power and provide overspeed protection. Furling control results in poor energy capture at high wind speeds. This paper proposes an alternative control strategy for small wind turbines -- the soft-stall method. The furling and soft-stall control strategies are compared using steady state analysis and dynamic simulation analysis. The soft-stall method is found to offer several advantages: increased energy production at high wind speeds, energy production which tracks the maximum power coefficient at low to medium wind speeds, reduced furling noise, and reduced thrust.

  18. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena Lopez, Hugo Eduardo

    2008-10-10T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  19. Maximum power tracking control scheme for wind generator systems

    E-Print Network [OSTI]

    Mena, Hugo Eduardo

    2009-05-15T23:59:59.000Z

    The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

  20. Ris-PhD-Report Complex Terrain and Wind Lidars

    E-Print Network [OSTI]

    calculations over the same terrains. The lidar performance was also simulated with the commercial software WAs;#12;Author: Ferhat Bingöl Title: Complex terrain and wind lidars Division: Wind Energy Division Risø-PhD-52 and the comparison of the measurement data with the flow model outputs showed that the mean wind speed calculated

  1. Space-Time Prediction of Ocean Winds Anders Malmberg

    E-Print Network [OSTI]

    Malmberg, Anders

    -Temporal Dynamic Modelling #12;Ocean Wind Data Near-surface ocean winds are considered, since satellite grid; blue dots: satellite grid. #12;Meteorological Data - ECMWF Analyses and Forecasts FORECAST m/s 0 10 20 The images illustrate the east-west wind speed. #12;Satellite Data - Quik

  2. Control of Wind Turbines for Power Regulation and

    E-Print Network [OSTI]

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

  3. Taming Hurricanes With Arrays of Offshore Wind Turbines

    E-Print Network [OSTI]

    Firestone, Jeremy

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

  4. NACA0015 Measurements in LM Wind Tunnel and Turbulence

    E-Print Network [OSTI]

    NACA0015 Measurements in LM Wind Tunnel and Turbulence Generated Noise Franck Bertagnolio Risø, Denmark November 2008 #12;Author: Franck Bertagnolio Title: NACA0015 Measurements in LM Wind Tunnel on its surface and measured in the wind tunnel at LM Glasfiber at various inflow speeds, angles of attack

  5. The Solar Wind, CMEs and the Origins of Heliospheric Activity

    E-Print Network [OSTI]

    release o Coronal holes o Source of high-speed solar wind #12;peter.gallagher@tcd.ie #12;#12;peter Parker => Parker Spiral: r - r0 = -(v/ )( - 0) o Winding angle: o Inclined at ~45º at 1 AU and ~90º by 10The Solar Wind, CMEs and the Origins of Heliospheric Activity Peter T. Gallagher School of Physics

  6. IMPLEMENTATION OF WIND TURBINE CONTROLLERS W.E.Leithead

    E-Print Network [OSTI]

    Duffy, Ken

    IMPLEMENTATION OF WIND TURBINE CONTROLLERS D.J.Leith W.E.Leithead Department of Electronic-speed wind turbines are considered, namely, (1) accommodation of the strongly nonlinear rotor aerodynamics derived and extended to cater for all wind turbine configurations. A rigorous stability analysis

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

    SciTech Connect (OSTI)

    Clifton, A.

    2012-12-01T23:59:59.000Z

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

  8. A Disturbance Margin For Quantifying Limits on Power Smoothing by Wind Turbines

    E-Print Network [OSTI]

    Maggiore, Manfredi

    wind variation a wind turbine can absorb in variable speed mode while still being guaranteed to operate speed and generator torque to store and release energy. This ability must be constrained by turbine speed and generator torque limits. To date, work in the literature is conceptual and does not indicate

  9. Estimating long-term mean winds from short-term wind data

    SciTech Connect (OSTI)

    Barchet, W.R.; Davis, W.E.

    1983-08-01T23:59:59.000Z

    The estimation of long-term mean winds from short-term data is especially important in the area of wind energy. It is desirable to obtain reliable estimates of the long-term wind speed from as short a period of on-site measurements as possible. This study examined seven different methods of estimating the long-term average wind speed and compared the performance of these techniques. Three linear, three weather pattern, and one eigenvector methods were compared for measurement periods ranging from 3 months to 36 months. Average errors, both relative and absolute, and the rms errors in the techniques were determined. The best technique for less than 12 months of measurement was the eigenvector method using weekly mean wind speeds. However, this method was only slightly better than the linear adjusted method. When 12 or more months of data were used, the difference in errors between techniques was found to be slight.

  10. Wind and Wave Extremes over the World Oceans from Very Large Ensembles

    E-Print Network [OSTI]

    Breivik, Øyvind; Abdalla, Saleh; Bidlot, Jean-Raymond; Janssen, Peter A E M

    2014-01-01T23:59:59.000Z

    Global return values of marine wind speed and significant wave height are estimated from very large aggregates of archived ensemble forecasts at +240-h lead time. Long lead time ensures that the forecasts represent independent draws from the model climate. Compared with ERA-Interim, a reanalysis, the ensemble yields higher return estimates for both wind speed and significant wave height. Confidence intervals are much tighter due to the large size of the dataset. The period (9 yrs) is short enough to be considered stationary even with climate change. Furthermore, the ensemble is large enough for non-parametric 100-yr return estimates to be made from order statistics. These direct return estimates compare well with extreme value estimates outside areas with tropical cyclones. Like any method employing modeled fields, it is sensitive to tail biases in the numerical model, but we find that the biases are moderate outside areas with tropical cyclones.

  11. Performance Indicators of Wind Energy Production

    E-Print Network [OSTI]

    D'Amico, G; Prattico, F

    2015-01-01T23:59:59.000Z

    Modeling wind speed is one of the key element when dealing with the production of energy through wind turbines. A good model can be used for forecasting, site evaluation, turbines design and many other purposes. In this work we are interested in the analysis of the future financial cash flows generated by selling the electrical energy produced. We apply an indexed semi-Markov model of wind speed that has been shown, in previous investigation, to reproduce accurately the statistical behavior of wind speed. The model is applied to the evaluation of financial indicators like the Internal Rate of Return, semi-Elasticity and relative Convexity that are widely used for the assessment of the profitability of an investment and for the measurement and analysis of interest rate risk. We compare the computation of these indicators for real and synthetic data. Moreover, we propose a new indicator that can be used to compare the degree of utilization of different power plants.

  12. PowerJet Wind Turbine Project

    SciTech Connect (OSTI)

    Bartlett, Raymond J

    2008-11-30T23:59:59.000Z

    PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy�s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJet�s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assembly�including the electronic and mechanical controls designed, manufactured and field tested during the course of this project�proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOE�s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec

  13. Effectiveness of speed trailers on low-speed urban roadways

    E-Print Network [OSTI]

    Perrillo, Kerry Victoria

    1997-01-01T23:59:59.000Z

    Efforts are being made to use speed management methods to match operating speeds to posted speeds and to reduce the variability in vehicle speeds. The effectiveness of many different methods of speed management has not been documented. This thesis...

  14. 756 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 3, JULY 2013 Minimization of Wind Farm Operational

    E-Print Network [OSTI]

    Kusiak, Andrew

    756 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 3, JULY 2013 Minimization of Wind Farm) of wind turbine at time , denoted as 0 or 1. Energy consumed by an idle wind turbine. Electricity spot, and Guanglin Xu Abstract--Scheduling a wind farm in the presence of uncertain wind speed conditions

  15. Method and apparatus for reducing rotor blade deflections, loads, and/or peak rotational speed

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw; Pierce, Kirk Gee

    2006-10-17T23:59:59.000Z

    A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

  16. Abstract--In this paper, we present the voltage build up process and the terminal voltage control of an isolated wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of an isolated wind powered induction generator driven by a variable speed wind turbine using rotor flux oriented, but they can be set to operate within a given variation of speed. Unlike a grid connected induction generator and the speed, torque and fluxes as its outputs. Key words-- Wind energy system, Induction generator, Saturation

  17. Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines

    SciTech Connect (OSTI)

    Wei Qiao

    2012-05-29T23:59:59.000Z

    The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with characteristic frequencies in the current or current demodulated signals, where 1P stands for the shaft rotating frequency of a WTG; (4) Developed a wavelet filter for effective signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (5) Developed an effective adaptive noise cancellation method as an alternative to the wavelet filter method for signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (6) Developed a statistical analysis-based impulse detection method for effective fault signature extraction and evaluation of WTGs based on the 1P-invariant PSD of the current or current demodulated signals; (7) Validated the proposed current-based wind turbine CMFD technologies through extensive computer simulations and experiments for small direct-drive WTGs without gearboxes; and (8) Showed, through extensive experiments for small direct-drive WTGs, that the performance of the proposed current-based wind turbine CMFD technologies is comparable to traditional vibration-based methods. The proposed technologies have been successfully applied for detection of major failures in blades, shafts, bearings, and generators of small direct-drive WTGs. The proposed technologies can be easily integrated into existing wind turbine control, protection, and monitoring systems and can be implemented remotely from the wind turbines being monitored. The proposed technologies provide an alternative to vibration-sensor-based CMFD. This will reduce the cost and hardware complexity of wind turbine CMFD systems. The proposed technologies can also be combined with vibration-sensor-based methods to improve the accuracy and reliability of wind turbine CMFD systems. When there are problems with sensors, the proposed technologies will ensure proper CMFD for the wind turbines, including their sensing systems. In conclusion, the proposed technologies offer an effective means to achieve condition-based smart maintenance for wind turbines and have a gre

  18. Wind turbine

    SciTech Connect (OSTI)

    Abe, M.

    1982-01-19T23:59:59.000Z

    The improvement in a wind turbine comprises providing a tower with a freely liftable mount and adapting a nacelle which is fitted with a propeller windwheel consisting of a plurality of rotor blades and provided therein with means for conversion of wind energy to be shifted onto said mount attached to the tower. In case of a violent wind storm, the nacelle can be lowered down to the ground to protect the rotor blades from breakage due to the force of the wind. Required maintenance and inspection of the nacelle and replacement of rotor blades can be safely carried out on the ground.

  19. Analysis of wind power for battery charging

    SciTech Connect (OSTI)

    Muljadi, E.; Drouilhet, S.; Holz, R. [National Renewable Energy Lab., Golden, CO (United States); Gevorgian, V. [University of Armenia, Yerevan (Armenia). State Engineering

    1995-11-01T23:59:59.000Z

    One type of wind-powered battery charging will be explored in this paper. It consists of a wind turbine driving a permanent magnet alternator and operates at variable speed. The alternator is connected to a battery bank via a rectifier. The characteristic of the system depends on the wind turbine, the alternator, and the system configuration. If the electrical load does not match the wind turbine, the performance of the system will be degraded. By matching the electrical load to the wind turbine, the system can be improved significantly. This paper analyzes the properties of the system components. The effects of parameter variation and the system configuration on the system performance are investigated. Two basic methods of shaping the torque-speed characteristic of the generator are presented. The uncompensated as well as the compensated systems will be discussed. Control strategies to improve the system performance will be explored. Finally, a summary of the paper will be presented in the last section.

  20. A cyclic time-dependent Markov process to model daily patterns in wind turbine power production

    E-Print Network [OSTI]

    Scholz, Teresa; Estanqueiro, Ana

    2013-01-01T23:59:59.000Z

    Wind energy is becoming a top contributor to the renewable energy mix, which raises potential reliability issues for the grid due to the fluctuating nature of its source. To achieve adequate reserve commitment and to promote market participation, it is necessary to provide models that can capture daily patterns in wind power production. This paper presents a cyclic inhomogeneous Markov process, which is based on a three-dimensional state-space (wind power, speed and direction). Each time-dependent transition probability is expressed as a Bernstein polynomial. The model parameters are estimated by solving a constrained optimization problem: The objective function combines two maximum likelihood estimators, one to ensure that the Markov process long-term behavior reproduces the data accurately and another to capture daily fluctuations. A convex formulation for the overall optimization problem is presented and its applicability demonstrated through the analysis of a case-study. The proposed model is capable of r...

  1. ISET-Wind-Index Assessment of the Annual Available Wind Energy

    E-Print Network [OSTI]

    Berthold Hahn; Kurt Rohrig

    2003-01-01T23:59:59.000Z

    Particularly in years with wind speeds that are clearly below average, dissatisfaction of operators and even liquidity problems are sparked through the unexpected low annual power production. An objective standard for the evaluation of the respective “wind year ” is required for the internal estimation of the performance of wind farms, and for justification to share owners and banks. The annual wind conditions are composed from such a multitude of meteorological situations, differing from location to location, that the available wind energy at every individual location develops totally differently. A single code is therefore not sufficient to describe the “wind year ” in Germany and, moreover, the evaluation of annual available wind energy must be carried out separately for the smallest areas possible. With the support of the Gothaer Rückversicherungen AG, a procedure has been developed at ISET which provides the proportion of the respective annual available wind energy, in relation to the long-term average available wind energy, for each 10 km x 10 km sized plan area in Germany. This amount, the ISET-Wind-Index, is founded on wind measurements at locations that are typical for wind energy use and therefore presents an objective standard. The measurement grid is part of the “Scientific Measurement and Evaluation Programme ” (WMEP), which accompanies the “250 MW Wind ” project of the German Federal Ministry for Economy and Labour. The ISET-Wind-Index, which will be regularly updated, provides an objective standard for the estimation of annual available

  2. Wind load reduction for heliostats

    SciTech Connect (OSTI)

    Peterka, J.A.; Hosoya, N.; Bienkiewicz, B.; Cermak, J.E.

    1986-05-01T23:59:59.000Z

    This report presents the results of wind-tunnel tests supported through the Solar Energy Research Institute (SERI) by the Office of Solar Thermal Technology of the US Department of Energy as part of the SERI research effort on innovative concentrators. As gravity loads on drive mechanisms are reduced through stretched-membrane technology, the wind-load contribution of the required drive capacity increases in percentage. Reduction of wind loads can provide economy in support structure and heliostat drive. Wind-tunnel tests have been directed at finding methods to reduce wind loads on heliostats. The tests investigated primarily the mean forces, moments, and the possibility of measuring fluctuating forces in anticipation of reducing those forces. A significant increase in ability to predict heliostat wind loads and their reduction within a heliostat field was achieved.

  3. Sandia Wind Turbine Loads Database

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Sandia Wind Turbine Loads Database is divided into six files, each corresponding to approximately 16 years of simulation. The files are text files with data in columnar format. The 424MB zipped file containing six data files can be downloaded by the public. The files simulate 10-minute maximum loads for the NREL 5MW wind turbine. The details of the loads simulations can be found in the paper: “Decades of Wind Turbine Loads Simulations”, M. Barone, J. Paquette, B. Resor, and L. Manuel, AIAA2012-1288 (3.69MB PDF). Note that the site-average wind speed is 10 m/s (class I-B), not the 8.5 m/s reported in the paper.

  4. Amplitude modulation of wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01T23:59:59.000Z

    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).

  5. Enertech 2-kW high-reliability wind system. Phase II. Fabrication and testing

    SciTech Connect (OSTI)

    Cordes, J A; Johnson, B A

    1981-06-01T23:59:59.000Z

    A high-reliability wind machine rated for 2 kW in a 9 m/s wind has been developed. Activities are summarized that are centered on the fabrication and testing of prototypes of the wind machine. The test results verified that the wind machine met the power output specification and that the variable-pitch rotor effectively controlled the rotor speed for wind speeds up to 50 mph. Three prototypes of the wind machine were shipped to the Rocky Flats test center in September through November of 1979. Work was also performed to reduce the start-up wind speed. The start-up wind speed to the Enertech facility has been reduced to 4.5 m/s.

  6. TURBULENT HEATING OF THE DISTANT SOLAR WIND BY INTERSTELLAR PICKUP PROTONS IN A DECELERATING FLOW

    E-Print Network [OSTI]

    Isenberg, Philip A.

    Previous models of solar wind heating by interstellar pickup proton-driven turbulence have assumed that the wind speed is a constant in heliocentric radial position. However, the same pickup process, which is taken to ...

  7. Influence of large scale oscillations on upwelling-favorable coastal wind off central Chile

    E-Print Network [OSTI]

    Rahn, David A.

    2012-10-16T23:59:59.000Z

    Along the central coast of Chile is typically equatorward, upwelling-favorable wind associated with the southeast Pacific anticyclone. A coastal low-level jet often develops, and its wind speed is mostly controlled by the ...

  8. Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine

    E-Print Network [OSTI]

    Silva, Filipe Faria Da

    Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine-Frequency Control (LFC) is gradually shifted to Variable Speed Wind Turbines (VSWTs). In order to equip VSWT

  9. Quantifying the system balancing cost when wind energy is incorporated into electricity generation system 

    E-Print Network [OSTI]

    Issaeva, Natalia

    2009-01-01T23:59:59.000Z

    Incorporation of wind energy into the electricity generation system requires a detailed analysis of wind speed in order to minimize system balancing cost and avoid a significant mismatch between supply and demand. Power ...

  10. Definition of a 5-MW Reference Wind Turbine for Offshore System Development

    SciTech Connect (OSTI)

    Jonkman, J.; Butterfield, S.; Musial, W.; Scott, G.

    2009-02-01T23:59:59.000Z

    This report describes a three-bladed, upwind, variable-speed, variable blade-pitch-to-feather-controlled multimegawatt wind turbine model developed by NREL to support concept studies aimed at assessing offshore wind technology.

  11. Establishing a Comprehensive Wind Energy Program

    SciTech Connect (OSTI)

    Fleeter, Sanford [Purdue University

    2012-09-30T23:59:59.000Z

    This project was directed at establishing a comprehensive wind energy program in Indiana, including both educational and research components. A graduate/undergraduate course ME-514 - Fundamentals of Wind Energy has been established and offered and an interactive prediction of VAWT performance developed. Vertical axis wind turbines for education and research have been acquired, instrumented and installed on the roof top of a building on the Calumet campus and at West Lafayette (Kepner Lab). Computational Fluid Dynamics (CFD) calculations have been performed to simulate these urban wind environments. Also, modal dynamic testing of the West Lafayette VAWT has been performed and a novel horizontal axis design initiated. The 50-meter meteorological tower data obtained at the Purdue Beck Agricultural Research Center have been analyzed and the Purdue Reconfigurable Micro Wind Farm established and simulations directed at the investigation of wind farm configurations initiated. The virtual wind turbine and wind turbine farm simulation in the Visualization Lab has been initiated.

  12. Wind power resource assessment in complex urban environments: MIT campus case-study using CFD Analysis

    E-Print Network [OSTI]

    around buildings. The software model has been used to evaluate the wind energy potential on the campus-site. Comparisons between the measurements and the predicted wind speeds allowed validation of the software results of Technology, 2Meteodyn Objectives Conclusions References [1] TopoWind software, User Manual [2] Wind Resource

  13. Ris-PhD-24(EN) Stability and Control of Wind Farms in

    E-Print Network [OSTI]

    , wind turbines substitute the power production of conventional power plants. Therefore, wind turbines. The project is based on simulations of wind turbines in a power system simulations tool. Some of the models speed turbine and its controls. To simulate realistic grid operation the wind turbine models

  14. Calibrated Probabilistic Forecasting at the Stateline Wind Energy Center: The Regime-Switching

    E-Print Network [OSTI]

    Genton, Marc G.

    Calibrated Probabilistic Forecasting at the Stateline Wind Energy Center: The Regime at a wind energy site and fits a conditional predictive model for each regime. Geographically dispersed was applied to 2-hour-ahead forecasts of hourly average wind speed near the Stateline wind energy center

  15. Lidars in Wind Energy Jakob Mann, Ferhat Bingl, Torben Mikkelsen, Ioannis Antoniou, Mike

    E-Print Network [OSTI]

    Lidars in Wind Energy Jakob Mann, Ferhat Bingöl, Torben Mikkelsen, Ioannis Antoniou, Mike Courtney, Gunner Larsen, Ebba Dellwik Juan Jose Trujillo* and Hans E. Jørgensen Wind Energy Department Risø of the presentation · Introduction to wind energy · Accurate profiles of the mean wind speed · Wakes behind turbines

  16. Statistical analysis of wind energy in Chile David Watts a,b,*, Danilo Jara a

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    Data Bank Statistical analysis of wind energy in Chile David Watts a,b,*, Danilo Jara December 2010 Keywords: Wind Wind speed Energy Capacity factor Electricity Chile a b s t r a c t Bearing role in any future national energy generation matrix. With a view to understanding the local wind

  17. A Unified Framework for Reliability Assessment of Wind Energy Conversion Systems

    E-Print Network [OSTI]

    Liberzon, Daniel

    1 A Unified Framework for Reliability Assessment of Wind Energy Conversion Systems Sebastian S a framework for assessing wind energy conversion systems (WECS) reliability in the face of external based on wind energy are: the impact of wind speed variability on system reliability [1]; WECS' reaction

  18. 1 Introduction The development of wind energy use has led to

    E-Print Network [OSTI]

    Heinemann, Detlev

    1 Introduction The development of wind energy use has led to a noticeable contribution in of electricity by wind energy acts as a negative load leading to an increase in fluctuations of net load patterns conventional reserves have to be kept ready to replace the wind energy share in case of decreasing wind speeds

  19. AIR-FLOW STRUCTURE IN THE VERY CLOSE VICINITY OF WIND GENERATED WATER-WAVES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    to : , with the air-density, u and w the horizontal and vertical components of the wind speed, u* the friction and the viscous drag at the sea sur- face, we build two new microphysical devices: 1) the wind-speed vertical of the vertical profile of the normalized phase-averaged wind-speed in the air-viscous layer (1mm above water

  20. Wind forces on isolated and grouped mobile homes

    E-Print Network [OSTI]

    Oldham, Gary Albert

    1974-01-01T23:59:59.000Z

    . The roof is required by the Mobile Home Manufacturers Association's construction stand- ards to withstand an uplift wind load that is only 60X of the hori- zontal wind load. Therefore, if a mobile home is subjected to de- sign maximum wind speeds... to be vul- nerable to wind loads. The vulnerability of mobile homes to high winds can be attested by numerous reports of mobile home damage as a result of hurricane 1-4 and tornadic winds. The homes are damaged by being turned over, sliding into other...

  1. NREL National Wind Technology Center (NWTC): M2 Tower; Boulder, Colorado (Data)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jager, D.; Andreas, A.

    The National Wind Technology Center (NWTC), located at the foot of the Rocky Mountains near Boulder, Colorado, is a world-class research facility managed by NREL for the U.S. Department of Energy. NWTC researchers work with members of the wind energy industry to advance wind power technologies that lower the cost of wind energy through research and development of state-of-the-art wind turbine designs. NREL's Measurement and Instrument Data Center provides data from NWTC's M2 tower which are derived from instruments mounted on or near an 82 meter (270 foot) meteorological tower located at the western edge of the NWTC site and about 11 km (7 miles) west of Broomfield, and approximately 8 km (5 miles) south of Boulder, Colorado. The data represent the mean value of readings taken every two seconds and averaged over one minute. The wind speed and direction are measured at six heights on the tower and air temperature is measured at three heights. The dew point temperature, relative humidity, barometric pressure, totalized liquid precipitation, and global solar radiation are also available.

  2. E-Print Network 3.0 - advanced wind turbine Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    models and advanced control strategies... .139) Track: Technical VARIABLE SPEED WIND TURBINES - FAULT RIDE-THROUGH AND GRID SUPPORT CAPABILITIES... is on the fault ride through...

  3. Operational risk of a wind farm energy production by Extreme Value Theory and Copulas

    E-Print Network [OSTI]

    D'Amico, Guglielmo; Prattico, Flavio

    2014-01-01T23:59:59.000Z

    In this paper we use risk management techniques to evaluate the potential effects of those operational risks that affect the energy production of a wind farm. We concentrate our attention on three major risk factors: wind speed uncertainty, wind turbine reliability and interactions of wind turbines due mainly to their placement. As a first contribution, we show that the Weibull distribution, commonly used to fit recorded wind speed data, underestimates rare events. Therefore, in order to achieve a better estimation of the tail of the wind speed distribution, we advance a Generalized Pareto distribution. The wind turbines reliability is considered by modeling the failures events as a compound Poisson process. Finally, the use of Copula able us to consider the correlation between wind turbines that compose the wind farm. Once this procedure is set up, we show a sensitivity analysis and we also compare the results from the proposed procedure with those obtained by ignoring the aforementioned risk factors.

  4. Wind and Wave Extremes over the World Oceans From Very Large Forecast Ensembles

    E-Print Network [OSTI]

    Breivik, Øyvind; Abdalla, Saleh; Bidlot, Jean-Raymond

    2013-01-01T23:59:59.000Z

    Global return value estimates of significant wave height and 10-m neutral wind speed are estimated from very large aggregations of archived ECMWF ensemble forecasts at +240-h lead time from the period 2003-2012. The upper percentiles are found to match ENVISAT wind speed better than ERA-Interim (ERA-I), which tends to be biased low. The return estimates are significantly higher for both wind speed and wave height in the extratropics and the subtropics than what is found from ERA-I, but lower than what is reported by Caires and Sterl (2005) and Vinoth and Young (2011). The highest discrepancies between ERA-I and ENS240 are found in the hurricane-prone areas, suggesting that the ensemble comes closer than ERA-I in capturing the intensity of tropical cyclones. The width of the confidence intervals are typically reduced by 70% due to the size of the data sets. Finally, non-parametric estimates of return values were computed from the tail of the distribution. These direct return estimates compare very well with Ge...

  5. Wind Energy Leasing Handbook

    E-Print Network [OSTI]

    Balasundaram, Balabhaskar "Baski"

    Wind Energy Leasing Handbook Wind Energy Leasing Handbook E-1033 Oklahoma Cooperative Extension?..................................................................................................................... 31 What do wind developers consider in locating wind energy projects?............................................................................................ 37 How do companies and individuals invest in wind energy projects?....................................................................

  6. Wind: wind speed and wind power density GIS data at 10m and 50m above

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:SeadovCooperative JumpWilliamson County,Bay, OR) JumpPhoto from AlstomHomeSri

  7. Wind: wind speed and wind power density maps at 10m and 50m above surface

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:SeadovCooperative JumpWilliamson County,Bay, OR) JumpPhoto from AlstomHomeSriand 0.25

  8. 192 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 1, JANUARY 2013 Monitoring Wind Farms With Performance Curves

    E-Print Network [OSTI]

    Kusiak, Andrew

    to varying loads, which in turn lead to wind turbine faults, e.g., spalled bearings and fractured gears--Three different operational curves--the power curve, rotor curve, and blade pitch curve--are presented the reference curves of wind power, rotor speed, and blade pitch angle, with wind speed as an input variable

  9. Discrepancies in the prediction of solar wind using potential field source surface model: An investigation of possible sources

    E-Print Network [OSTI]

    California at Berkeley, University of

    Discrepancies in the prediction of solar wind using potential field source surface model expansion factor (FTE) at the source surface and the solar wind speed (SWS) observed at Earth, which has been made use of in the prediction of solar wind speed near the Earth with reasonable accuracy. However

  10. Main Coast Winds - Final Scientific Report

    SciTech Connect (OSTI)

    Jason Huckaby; Harley Lee

    2006-03-15T23:59:59.000Z

    The Maine Coast Wind Project was developed to investigate the cost-effectiveness of small, distributed wind systems on coastal sites in Maine. The restructuring of Maine's electric grid to support net metering allowed for the installation of small wind installations across the state (up to 100kW). The study performed adds insight to the difficulties of developing cost-effective distributed systems in coastal environments. The technical hurdles encountered with the chosen wind turbine, combined with the lower than expected wind speeds, did not provide a cost-effective return to make a distributed wind program economically feasible. While the turbine was accepted within the community, the low availability has been a negative.

  11. Analysis of a teetered, variable-speed rotor: final report

    SciTech Connect (OSTI)

    Weber, T.L.; Wilson, R.E.; Walker, S.N. (Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering) [Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering

    1991-06-01T23:59:59.000Z

    A computer model of a horizontal axis wind turbine (HOOT) with four structural degrees of freedom has been derived and verified. The four degrees of freedom include flapwise motion of the blades, teeter motion, and variable rotor speed. Options for the variable rotor speed include synchronous, induction, and constant-tip speed generator models with either start, stop, or normal operations. Verification is made by comparison with analytical solutions and mean and cyclic ESI-80 data. The Veers full-field turbulence model is used as a wind input for a synchronous and induction generator test case during normal operation. As a result of the comparison, it is concluded that the computer model can be used to predict accurately mean and cyclic loads with a turbulent wind input. 47 refs., 19 figs.

  12. Solar cyclical trend study of the mid-latitude, quiet-time, meridional, neutral winds at winter solstice conditions. Master's thesis

    SciTech Connect (OSTI)

    Breninger, R.L.

    1989-01-01T23:59:59.000Z

    Located within the region of the thermosphere is the major portion of the ionosphere. Distribution of the ionospheric plasma within this region is a function of atmospheric mass and energy transport. For the current study, the component of the neutral wind along the magnetic meridian is derived from ground-based ionosonde measurements of the F2 peak layer height. Meridional wind variations with respect to location, universal time, and level of solar activity are the focal points on this investigation. The primary timescale of interest covers a period of one solar cycle, from 1977 to 1987. Data from one station have been extended to 1965 to study the repetitive nature of solar activity on the meridional winds. Results of this study indicate a definite variation of wind speed and direction, which correlates with changing levels of solar activity. It is hoped that the results of this study will aid current efforts to develop ionospheric models and enhance their forecasting capabilities.

  13. Irregular wave runup and overtopping of revetments in the presence of wind

    E-Print Network [OSTI]

    Cinotto, Charles Matthew

    2012-06-07T23:59:59.000Z

    studies on the effects of wind on various wave characteristics including runup and overtopping. Resio (1987) divides the action of winds on overtopping into two distinct physical processes: (1) the increase of runup and overtopping due to wind energy... wind speeds. The difference in total energy between the spectra of Figure 4. 1 and Figures 4. 2 (and 4. 3) also increases with increasing wind speed because of the addition of the wind energy to the mechanical energy at the same peak. 30? 25 s u...

  14. Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet...

    Broader source: Energy.gov (indexed) [DOE]

    Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power Program (WWPP) Wind Energy Benefits, Wind Powering America (WPA) (Fact Sheet), Wind And Water Power...

  15. Wind parameters extraction from aircraft trajectories C. Hurtera,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Wind parameters extraction from aircraft trajectories C. Hurtera, , R. Alligiera,b , D. Gianazzaa traffic controllers need to know the current wind magnitude and direction since they impact every flying vessel. The wind may accel- erate or slow down an aircraft, depending on its relative direction

  16. Characteristics of Wind Turbines Under Normal and Fault Conditions: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C. P.; Parsons, B.; Ellis, A.

    2007-02-01T23:59:59.000Z

    This paper investigates the characteristics of a variable-speed wind turbine connected to a stiff or weak grid under normal and fault conditions and the role of reactive power compensation.

  17. Energy Department Releases New Land-Based/Offshore Wind Resource...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    shows the predicted mean annual wind speeds at 80-m height produced from AWS Truepower's data at a spatial resolution of 2.5 km and interpolated to a finer scale. Read more about...

  18. Experimental Investigation of Wind-Forced Drop Stability

    E-Print Network [OSTI]

    Schmucker, Jason

    2012-10-19T23:59:59.000Z

    aluminum (RA = 3.26 micrometers) floor of a tiltable wind tunnel and brought to critical conditions, when the drop begins to run downstream. Various combinations of drop size, inclination angle, and flow speed were employed. A measurement technique capable...

  19. Passive aeroelastic tailoring of wind turbine blades : a numerical analysis

    E-Print Network [OSTI]

    Deilmann, Christian

    2009-01-01T23:59:59.000Z

    This research aims to have an impact towards a sustainable energy supply. In wind power generation losses occur at tip speed ratios which the rotor was not designed for. Since the ideal blade shape changes nonlinearly with ...

  20. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    that includes wind turbine towers. 2011 Wind TechnologiesSets Other Wind Turbine Components Towers Wind-Poweredselected wind turbine components includes towers as well as

  1. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    that includes wind turbine towers. 2010 Wind TechnologiesImports : Other Wind Turbine Components Towers Wind-Poweredselected wind turbine components includes towers as well as

  2. Balancing of Wind Power.

    E-Print Network [OSTI]

    Ülker, Muhammed Akif

    2011-01-01T23:59:59.000Z

    ?? In the future, renewable energy share, especially wind power share, in electricity generation is expected to increase. Due to nature of the wind, wind… (more)

  3. Energy 101: Wind Turbines

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  4. Energy 101: Wind Turbines

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    See how wind turbines generate clean electricity from the power of the wind. Highlighted are the various parts and mechanisms of a modern wind turbine.

  5. NREL: Wind Research - Events

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Events Below are upcoming events related to wind energy technology. January 2015 2015 Wind Energy Systems Engineering Workshop January 14 - 15, 2015 Boulder, CO The third NREL Wind...

  6. Wind power and Wind power and

    E-Print Network [OSTI]

    Wind power and the CDM #12; Wind power and the CDM Emerging practices in developing wind power 2005 Jyoti P. Painuly, Niels-Erik Clausen, Jørgen Fenhann, Sami Kamel and Romeo Pacudan #12; WIND POWER AND THE CDM Emerging practices in developing wind power projects for the Clean Development Mechanism Energy

  7. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-11-01T23:59:59.000Z

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive-responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  8. NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-10-01T23:59:59.000Z

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive -- responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  9. Variability of wind power near Oklahoma City and implications for siting of wind turbines

    SciTech Connect (OSTI)

    Kessler, E.; Eyster, R.

    1987-09-01T23:59:59.000Z

    Data from five sites near Oklahoma City were examined to assess wind power availability. Wind turbines of identical manufacture were operated at three of the sites, one of which was also equipped with anemometers on a 100-ft tower. Comprehensive anemometric data were available from the other two sites. The study indicates that the average wind speed varies substantially over Oklahoma's rolling plains, which have often been nominally regarded as flat for purposes of wind power generation. Average wind differences may be as much as 5 mph at 20 ft above ground level, and 7 mph at 100 ft above ground level for elevation differences of about 200 ft above mean sea level, even in the absence of substantial features of local terrain. Local altitude above mean sea level seems to be as influential as the shape of local terrain in determining the average wind speed. The wind turbine used at a meteorologically instrumented site in the study produced the power expected from it for the wind regime in which it was situated. The observed variations of local wind imply variations in annual kWh of as much as a factor of four between identical turbines located at similar heights above ground level in shallow valleys and on hilltops or elevated extended flat areas. 17 refs., 39 figs., 11 tabs.

  10. On the Patterns of Wind-Power Input to the Ocean Circulation

    E-Print Network [OSTI]

    Roquet, Fabien

    Pathways of wind-power input into the ocean general circulation are analyzed using Ekman theory. Direct rates of wind work can be calculated through the wind stress acting on the surface geostrophic flow. However, because ...

  11. EA-1903: Kansas State University Zond Wind Energy Project, Manhattan, Kansas

    Broader source: Energy.gov [DOE]

    This EA evaluates the potential environmental impacts of a proposal to use Congressional Directed funds to develop the Great Plains Wind Energy Consortium aimed at increasing the penetration of wind energy via distributed wind power generation throughout the region.

  12. Wind Development on Tribal Lands

    SciTech Connect (OSTI)

    Ken Haukaas; Dale Osborn; Belvin Pete

    2008-01-18T23:59:59.000Z

    Background: The Rosebud Sioux Tribe (RST) is located in south central South Dakota near the Nebraska border. The nearest community of size is Valentine, Nebraska. The RST is a recipient of several Department of Energy grants, written by Distributed Generation Systems, Inc. (Disgen), for the purposes of assessing the feasibility of its wind resource and subsequently to fund the development of the project. Disgen, as the contracting entity to the RST for this project, has completed all the pre-construction activities, with the exception of the power purchase agreement and interconnection agreement, to commence financing and construction of the project. The focus of this financing is to maximize the economic benefits to the RST while achieving commercially reasonable rates of return and fees for the other parties involved. Each of the development activities required and its status is discussed below. Land Resource: The Owl Feather War Bonnet 30 MW Wind Project is located on RST Tribal Trust Land of approximately 680 acres adjacent to the community of St. Francis, South Dakota. The RST Tribal Council has voted on several occasions for the development of this land for wind energy purposes, as has the District of St. Francis. Actual footprint of wind farm will be approx. 50 acres. Wind Resource Assessment: The wind data has been collected from the site since May 1, 2001 and continues to be collected and analyzed. The latest projections indicate a net capacity factor of 42% at a hub height of 80 meters. The data has been collected utilizing an NRG 9300 Data logger System with instrumentation installed at 30, 40 and 65 meters on an existing KINI radio tower. The long-term annual average wind speed at 65-meters above ground level is 18.2 mph (8.1 mps) and 18.7 mph (8.4 mps) at 80-meters agl. The wind resource is excellent and supports project financing.

  13. Statistical Methods for Quantifying the Effect of the El NioSouthern Oscillation on Wind Power in the

    E-Print Network [OSTI]

    Katz, Richard

    Statistical Methods for Quantifying the Effect of the El Niño­Southern Oscillation on Wind Power­Southern Oscillation on Wind Power in the Northern Great Plains of the United States Bret R. Harper1, Richard W. Katz2 of the United States. In order to determine if ENSO has similar impacts on wind speed and wind power, we applied

  14. 1112 IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 25, NO. 4, DECEMBER 2010 Short-Horizon Prediction of Wind Power

    E-Print Network [OSTI]

    Kusiak, Andrew

    (wind energy in particular) has grown sig- nificantly in the last years. As a relatively new industry, wind energy must address numerous questions, including providing accurate short-term prediction of wind of the generated power [1]. Long-term wind speed and power prediction is of interest to management of energy

  15. On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN* AND DAVID S. NOLAN

    E-Print Network [OSTI]

    Nolan, David S.

    On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN independent of both the maximum wind speed and the radius of maximum winds (RMW). This can be seen winds change with height. Above 2-km height, vertical profiles of Vmaxnorm are nearly independent

  16. Use of Slip Ring Induction Generator for Wind Power Generation

    E-Print Network [OSTI]

    K Y Patil; D S Chavan

    Wind energy is now firmly established as a mature technology for electricity generation. There are different types of generators that can be used for wind energy generation, among which Slip ring Induction generator proves to be more advantageous. To analyse application of Slip ring Induction generator for wind power generation, an experimental model is developed and results are studied. As power generation from natural sources is the need today and variable speed wind energy is ample in amount in India, it is necessary to study more beneficial options for wind energy generating techniques. From this need a model is developed by using Slip ring Induction generator which is a type of Asynchronous generator.

  17. Power Performance Test Report for the SWIFT Wind Turbine

    SciTech Connect (OSTI)

    Mendoza, I.; Hur, J.

    2012-12-01T23:59:59.000Z

    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.

  18. Town of Kill Devil Hills- Wind Energy Systems Ordinance

    Broader source: Energy.gov [DOE]

    In October 2007, the town of Kill Devil Hills adopted an ordinance to regulate the use of wind-energy systems. The ordinance directs any individual or organization wishing to install a wind-energy...

  19. Aerodynamic pressure and flow-visualization measurement from a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.

    1988-11-01T23:59:59.000Z

    Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.

  20. Variable diameter wind turbine rotor blades

    DOE Patents [OSTI]

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

    2005-12-06T23:59:59.000Z

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

  1. aisi m2 high-speed: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    occur. Although current ... SooHoo, Kimberly E 2008-01-01 44 High speed air pneumatic wind shield wiping design MIT - DSpace Summary: In this creative design process a number of...

  2. A study of wind variability in the lower troposphere through power spectrum analysis at mesoscale frequencies

    E-Print Network [OSTI]

    Cornett, John Sheldon

    1966-01-01T23:59:59.000Z

    on the theoretical and practical application of the analysis method comes directly from this reference. B. Fundamental Assum tions of Power S ectrum Theor Consider a function of time X(t), such as wind speed, which is generated by a random process. Then the value... of the function X(t) at any particular point in time is a random variable. This random process may or may not have a Gaussian or normal distribution but it is a fundamental assumption (at least in the development of the theory) that the random process...

  3. Toward Controlled Wind Farm Output: Adjustable Power Filtering

    E-Print Network [OSTI]

    Lehn, Peter W.

    wind energy is extracted by the turbine blades. CP depends on the tip-speed ratio, , defined as = Rh structure for a fully-rated converter interfaced wind turbine. A singular perturbations decomposition the static curve that describes the aerodynamic conversion of energy by the bladed turbine rotor

  4. Distributed Wind Diffusion Model Overview (Presentation)

    SciTech Connect (OSTI)

    Preus, R.; Drury, E.; Sigrin, B.; Gleason, M.

    2014-07-01T23:59:59.000Z

    Distributed wind market demand is driven by current and future wind price and performance, along with several non-price market factors like financing terms, retail electricity rates and rate structures, future wind incentives, and others. We developed a new distributed wind technology diffusion model for the contiguous United States that combines hourly wind speed data at 200m resolution with high resolution electricity load data for various consumer segments (e.g., residential, commercial, industrial), electricity rates and rate structures for utility service territories, incentive data, and high resolution tree cover. The model first calculates the economics of distributed wind at high spatial resolution for each market segment, and then uses a Bass diffusion framework to estimate the evolution of market demand over time. The model provides a fundamental new tool for characterizing how distributed wind market potential could be impacted by a range of future conditions, such as electricity price escalations, improvements in wind generator performance and installed cost, and new financing structures. This paper describes model methodology and presents sample results for distributed wind market potential in the contiguous U.S. through 2050.

  5. ESTABLISHING A CONNECTION BETWEEN ACTIVE REGION OUTFLOWS AND THE SOLAR WIND: ABUNDANCE MEASUREMENTS WITH EIS/HINODE

    SciTech Connect (OSTI)

    Brooks, David H. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P., E-mail: dhbrooks@ssd5.nrl.navy.mil [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2011-01-20T23:59:59.000Z

    One of the most interesting discoveries from Hinode is the presence of persistent high-temperature high-speed outflows from the edges of active regions (ARs). EUV imaging spectrometer (EIS) measurements indicate that the outflows reach velocities of 50 km s{sup -1} with spectral line asymmetries approaching 200 km s{sup -1}. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. We use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a 5 day period in 2007 December. We find that Si is always enhanced over S by a factor of 3-4. This is generally consistent with the enhancement factor of low FIP elements measured in situ in the slow solar wind by non-spectroscopic methods. Plasma with a slow wind-like composition was therefore flowing from the edge of the AR for at least 5 days. Furthermore, on December 10 and 11, when the outflow from the western side was favorably oriented in the Earth direction, the Si/S ratio was found to match the value measured a few days later by the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer. These results provide strong observational evidence for a direct connection between the solar wind, and the coronal plasma in the outflow regions.

  6. Response of a vessel to waves at zero ship speed

    E-Print Network [OSTI]

    Response of a vessel to waves at zero ship speed: preliminary full scale experiments By: Kim Klaka of experiment were conducted ­ free roll decay tests and irregular wave tests. An inclining test was also with and without the mainsail hoisted, in very light winds. The irregular wave tests were conducted again in very

  7. Balancing of high speed, flexible rotating shafts across critical speeds

    E-Print Network [OSTI]

    White, Gary Paul

    1977-01-01T23:59:59.000Z

    this is equivalent to eliminating certain sen- sors. Once the influence coefficient matrix is square, the solution procedure is exactly that of the single speed case. The computed balance weights should now null the rotor vibration at the sensor ports which were... critical speed, The Sin- gle Speed and the Exact Point-Speed techniques were determined to be relatively ineffective over this speed range; however, the Least Squares procedure yields a dramatic decrease in rotor vibration over the entire speed range...

  8. The National Wind Technology Center

    SciTech Connect (OSTI)

    Thresher, R.W.; Hock, S.M. [National Renewable Energy Lab., Golden, CO (United States)] [National Renewable Energy Lab., Golden, CO (United States); Loose, R.R.; Cadogon, J.B.

    1994-07-01T23:59:59.000Z

    Wind energy research began at the Rocky Flats test site in 1976 when Rockwell International subcontracted with the Energy Research and Development Administration (ERDA). The Rocky Flats Plant was competitively selected from a number of ERDA facilities primarily because it experienced high instantaneous winds and provided a large, clear land area. By 1977, several small wind turbines were in place. During the facility`s peak of operation, in 1979-1980, researchers were testing as many as 23 small wind turbines of various configurations, including commercially available machines and prototype turbines developed under subcontract to Rocky Flats. Facilities also included 8-kW, 40-kW, and 225-kW dynamometers; a variable-speed test bed; a wind/hybrid test facility; a controlled velocity test facility (in Pueblo, Colorado); a modal test facility, and a multimegawatt switchgear facility. The main laboratory building was dedicated in July 1981 and was operated by the Rocky Flats Plant until 1984, when the Solar Energy Research Institute (SERI) and Rocky Flats wind energy programs were merged and transferred to SERI. SERI and now the National Renewable Energy Laboratory (NREL) continued to conduct wind turbine system component tests after 1987, when most program personnel were moved to the Denver WEst Office Park in Golden and site ownership was transferred back to Rocky Flats. The Combined Experiment test bed was installed and began operation in 1988, and the NREL structural test facility began operation in 1990. In 1993, the site`s operation was officially transferred to the DOE Golden Field Office that oversees NREL. This move was in anticipation of NREL`s renovation and reoccupation of the facility in 1994.

  9. Methods and apparatus for twist bend coupled (TCB) wind turbine blades

    DOE Patents [OSTI]

    Moroz, Emilian Mieczyslaw; LeMieux, David Lawrence; Pierce, Kirk Gee

    2006-10-10T23:59:59.000Z

    A method for controlling a wind turbine having twist bend coupled rotor blades on a rotor mechanically coupled to a generator includes determining a speed of a rotor blade tip of the wind turbine, measuring a current twist distribution and current blade loading, and adjusting a torque of a generator to change the speed of the rotor blade tip to thereby increase an energy capture power coefficient of the wind turbine.

  10. Ris-R-1464(EN) Wind farm models and control strategies

    E-Print Network [OSTI]

    Functional description of wind power plant 18 3.1 Power and frequency control 18 3.2 Reactive power of opportunities. Then simulation models are described, including wind turbine models for a fixed speed wind. Finally, some simulation examples and conclusions are presented. Risø National Laboratory Information

  11. Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms

    E-Print Network [OSTI]

    Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms is not used to supply baseload electric power today. Interconnecting wind farms through the transmission grid farms are interconnected in an array, wind speed correlation among sites decreases and so does

  12. Wind Power Production in the Urban Environment S.J. Kooiman, S.W. Tullis*

    E-Print Network [OSTI]

    Tullis, Stephen

    Wind Power Production in the Urban Environment S.J. Kooiman, S.W. Tullis* Department of Mechanical are typical deterrents to operating wind turbines. However, with the aerodynamic performance advantages and the heightened wind speeds around buildings, the application for these turbines may be more advantageous than

  13. LQG control of horizontal wind turbines for blades and tower loads alleviation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    LQG control of horizontal wind turbines for blades and tower loads alleviation A. Pintea*, N of power produced by two bladed horizontal variable speed wind turbines. The proposed controller ensures oscillations and with the tower bending tendency. Keywords: LQG control, Wind turbines, Multi-objective control

  14. Optimal Wind Conditions for the Survival of Larval Northern Anchovy, Engraulis mordax

    E-Print Network [OSTI]

    . There is a statistically sig- nificant relation between larva mortality rate and the frequency of calm, low wind speed periOptimal Wind Conditions for the Survival of Larval Northern Anchovy, Engraulis mordax: A Modeling- puter modeling. The hypothesis was as follows. While wind events dissipate layers of planktonic food

  15. Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON

    E-Print Network [OSTI]

    Genton, Marc G.

    Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON The technology to harvest electricity from wind energy is now advanced enough to make entire cities powered by it a reality be more realistically assessed with a loss measure that depends upon the power curve relating wind speed

  16. High-Order Sliding Mode Control of a DFIG-Based Wind Turbine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    High-Order Sliding Mode Control of a DFIG-Based Wind Turbine for Power Maximization and Grid Fault tolerance of a Doubly-Fed Induction Generator (DFIG)-based Wind Turbine (WT). These variable speed systems have several advantages over the traditional wind turbine operating methods, such as the reduction

  17. A Comparative Study of Time-Frequency Representations for Fault Detection in Wind Turbine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Comparative Study of Time-Frequency Representations for Fault Detection in Wind Turbine El of wind energy, minimization and prediction of maintenance operations in wind turbine is of key importance. In variable speed turbine generator, advanced signal processing tools are required to detect and diagnose

  18. Developing a Practical Wind Tunnel Test Engineering Course for Undergraduate Aerospace Engineering Students

    E-Print Network [OSTI]

    Recla, Benjamin Jeremiah

    2013-04-19T23:59:59.000Z

    This thesis describes the development and assessment of an undergraduate wind tunnel test engineering course utilizing the 7ft by 10ft Oran W. Nicks Low Speed Wind Tunnel (LSWT). Only 5 other universities in the United States have a wind tunnel...

  19. Advanced Signal Processing Techniques for Fault Detection and Diagnosis in a Wind Turbine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    rotor bars and bearing damages. Index Terms--Wind turbines, motor current signature analy- sis, time factors, such as wind speed and acoustic noise, wind parks are being mainly constructed offshore. Studies. Different methods of fault detection exist. These include monitoring of the acoustic vibration, internal

  20. Vibration Analysis of a Vertical Axis Wind Turbine Blade , S.Tullis 2

    E-Print Network [OSTI]

    Tullis, Stephen

    Vibration Analysis of a Vertical Axis Wind Turbine Blade K. Mc Laren 1 , S.Tullis 2 and S.Ziada 3 1 vibration source of a small-scale vertical axis wind turbine currently undergoing field-testing. The turbine at a blade-tip speed ratio (the ratio of the blade rotational velocity to the ambient wind velocity) of 1