Sample records for frequency wind speed

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. 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)

  6. 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

  7. 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)

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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....

  13. 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....

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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'...

  20. 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

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. The probable source of certain spurious frequencies found in the output of a variable speed generating system using slip recovery

    SciTech Connect (OSTI)

    Carlin, P.W.

    1989-06-01T23:59:59.000Z

    As part of US Department of Energy-sponsored research on wind energy, a Mod-O wind turbine was used to drive a variable-speed, wound-rotor, induction generator. Energy resulting from the slip frequency voltage in the generator rotor was rectified to dc, inverted back to utility frequency ac, and injected into the power line. Spurious changing frequencies displayed in the generator output by a spectrum analyzer are caused by ripple on the dc link. No resonances of any of these moving frequencies were seen in spite of the presence of a bank of power factor correcting capacitors. 5 figs.

  1. 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.

  2. Wind/PV Generation for Frequency Regulation and Oscillation Damping in the Eastern Interconnection

    SciTech Connect (OSTI)

    Liu, Yong [The University of Tennessee, Knoxville; Gracia, Jose R [ORNL; Hadley, Stanton W [ORNL; Liu, Yilu [ORNL

    2013-12-01T23:59:59.000Z

    This report presents the control of renewable energy sources, including the variable-speed wind generators and solar photovoltaic (PV) generators, for frequency regulation and inter-area oscillation damping in the U.S. Eastern Interconnection (EI). In this report, based on the user-defined wind/PV generator electrical control model and the 16,000-bus Eastern Interconnection dynamic model, the additional controllers for frequency regulation and inter-area oscillation damping are developed and incorporated and the potential contributions of renewable energy sources to the EI system frequency regulation and inter-area oscillation damping are evaluated.

  3. 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

  4. Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation

    E-Print Network [OSTI]

    Wind Turbine Pitch Angle Controllers for Grid Frequency Stabilisation Clemens Jauch Risø National Laboratory Wind Energy Department P.O. Box 49 DK-4000 Roskilde, Denmark clemens.jauch@risoe.dk Abstract: In this paper it is investigated how active-stall wind turbines can contribute to the stabilisation of the power

  5. Low frequency noise from MW wind turbines --mechanisms of generation

    E-Print Network [OSTI]

    Low frequency noise from MW wind turbines -- mechanisms of generation and its modeling Helge MW wind turbines -- mechanisms of generation and its modeling Department: Department of Wind Energy turbine has been simulated with a noise prediction model from NASA in US. Running the model

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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 ...

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Seasonal Forecasting of Extreme Wind and Precipitation Frequencies in Europe

    E-Print Network [OSTI]

    Feigon, Brooke

    Seasonal Forecasting of Extreme Wind and Precipitation Frequencies in Europe Matthew J. Swann;Abstract Flood and wind damage to property and livelihoods resulting from extreme precipitation events variability of these extreme events can be closely related to the large-scale atmospheric circulation

  19. 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)

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  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. 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

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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...

  20. 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...

  1. 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...

  2. 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

  3. 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.

  4. 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

  5. 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 ...

  6. 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...

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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. ...

  12. 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 ...

  13. 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

  14. 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)

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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

  20. This paper presents stability analysis of wind farms in frequency domain. The interaction between the wind

    E-Print Network [OSTI]

    Bak, Claus Leth

    in order to emphasize differences between the two wind farms. Keywords: offshore wind farms, stability with full-scale back-to-back converters are more and more used in large offshore wind farms. This affects offshore wind farms tend to be bigger and bigger with more and more complex structures which can introduce

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

    SciTech Connect (OSTI)

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

    2012-03-01T23:59:59.000Z

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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. Solar internal sound speed as inferred from combined BiSON and LOWL oscillation frequencies

    E-Print Network [OSTI]

    Sarbani Basu; W. J. Chaplin; J. Christensen-Dalsgaard; Y. Elsworth; G. R. Isaak; R. New; J. Schou; M. J. Thompson; S. Tomczyk

    1997-02-12T23:59:59.000Z

    Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure of much of the solar interior avoiding systematic errors that are introduced when different data sets are combined, i.e., principally the effects of solar cycle changes on the frequencies. Unfortunately, the LOWL data set contains very few of the lowest-degree modes, which are essential for determining reliably the structure of the solar core - in addition, these lowest-degree data have fairly large associated uncertainties. However, observations made by the Birmingham Solar-Oscillations Network (BiSON) in integrated sunlight provide high-accuracy measurements of a large number of low-degree modes. In this paper we demonstrate that the low-degree mode set of the LOWL data can be successfully combined with the more accurate BiSON data, provided the observations are contemporaneous for those frequencies where the solar-cycle-induced effects are important. We show that this leads to a factor-of-two decrease in the error on the inferred sound speed in the solar core. We find that the solar sound speed is higher than in solar models for r < 0.2Rsun. The density of the solar core is, however, lower than that in solar models.

  9. Wind Power Forecasting Error Frequency Analyses for Operational Power System Studies: Preprint

    SciTech Connect (OSTI)

    Florita, A.; Hodge, B. M.; Milligan, M.

    2012-08-01T23:59:59.000Z

    The examination of wind power forecasting errors is crucial for optimal unit commitment and economic dispatch of power systems with significant wind power penetrations. This scheduling process includes both renewable and nonrenewable generators, and the incorporation of wind power forecasts will become increasingly important as wind fleets constitute a larger portion of generation portfolios. This research considers the Western Wind and Solar Integration Study database of wind power forecasts and numerical actualizations. This database comprises more than 30,000 locations spread over the western United States, with a total wind power capacity of 960 GW. Error analyses for individual sites and for specific balancing areas are performed using the database, quantifying the fit to theoretical distributions through goodness-of-fit metrics. Insights into wind-power forecasting error distributions are established for various levels of temporal and spatial resolution, contrasts made among the frequency distribution alternatives, and recommendations put forth for harnessing the results. Empirical data are used to produce more realistic site-level forecasts than previously employed, such that higher resolution operational studies are possible. This research feeds into a larger work of renewable integration through the links wind power forecasting has with various operational issues, such as stochastic unit commitment and flexible reserve level determination.

  10. 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.

  11. 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.

  12. Models for Impact Assessment of Wind-Based Power Generation on Frequency Control

    E-Print Network [OSTI]

    Liberzon, Daniel

    the impact of different renewable penetration sce- narios on system frequency performance metrics. In order communication and control; new loads, such as plug-in hybrid electric vehicles (PHEV); advanced power- gration of new renewable-based electricity generation sources, e.g., wind and solar. Focusing on renewable

  13. Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

    SciTech Connect (OSTI)

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

    2011-12-01T23:59:59.000Z

    In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

  14. 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...

  15. 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...

  16. Experimental frequency-dependent rotordynamic coefficients for a load-on-pad, high-speed, flexible-pivot tilting-pad bearing

    E-Print Network [OSTI]

    Rodriguez Colmenares, Luis Emigdio

    2004-09-30T23:59:59.000Z

    This thesis provides experimental frequency dependent stiffness and damping coefficient results for a high-speed, lightly loaded, flexible-pivot tilting-pad bearing, with a load-on-pad configuration. Test conditions include four shaft speeds (6000...

  17. 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)

  18. 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...

  19. 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...

  20. Comparing Two Types of Magnetically- Coupled Adjustable Speed Drives with Variable Frequency Drives in Pump and Fan Applications

    E-Print Network [OSTI]

    Anderson, K. J.; Chvala, W. D.

    This paper presents the results from laboratory tests on MagnaDrive Corporations fixed-magnet magnetically-coupled adjustable speed drive (MC-ASD) and Coyote Electronics electromagnetic MC-ASD as compared to a typical variable frequency drive (VFD...

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. Western Wind and Solar Integration Study Phase 3 -- Frequency Response and Transient Stability (Report and Executive Summary)

    SciTech Connect (OSTI)

    Miller, N. W.; Shao, M.; Pajic, S.; D'Aquila, R.

    2014-12-01T23:59:59.000Z

    The primary objectives of Phase 3 of the Western Wind and Solar Integration Study (WWSIS-3) were to examine the large-scale transient stability and frequency response of the Western Interconnection with high wind and solar penetration, and to identify means to mitigate any adverse performance impacts via transmission reinforcements, storage, advanced control capabilities, or other alternatives.

  14. 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.

  15. 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.

  16. Power and Frequency Control as it Relates to Wind-Powered Generation

    E-Print Network [OSTI]

    Lacommare, Kristina S H

    2011-01-01T23:59:59.000Z

    of large amounts of wind power production might requirewill be satisfactory as wind power provides an increasing64   7.2   Wind Power in Relation to System

  17. 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)

  18. 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

  19. 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.

  20. 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

  1. 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...

  2. 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...

  3. A New Wind Turbine Control Method to Smooth Power Generation. Modelling and Comparison to Wind Turbine Frequency Control.

    E-Print Network [OSTI]

    Solberg, Olov

    2012-01-01T23:59:59.000Z

    ??Following the significant increase of world wide installed wind power during the first decade of the 21st century, transmission system operators are faced with new… (more)

  4. Energy Transfer via Solar Wind Driven Ultra Low Frequency Waves in the Earth's Magnetosphere

    E-Print Network [OSTI]

    Hartinger, Michael David

    2012-01-01T23:59:59.000Z

    on how various energy sources from the solar wind ultimatelymodes. The solar wind is an important energy source for ULFmodes. The solar wind is an important energy source for ULF

  5. 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....

  6. Encoding, application and association of radio frequency identification tags on high speed manufacturing lines

    E-Print Network [OSTI]

    Fonseca, Herbert Moreti, 1973-

    2004-01-01T23:59:59.000Z

    One of the entry points of radio frequency identification technology in supply chain applications is at the manufacturing line, after production, as packaged goods leave for the next link of the network of suppliers, ...

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. Incorporating DFIG-Based Wind Power Generator in Microgird Frequency Stabilization.

    E-Print Network [OSTI]

    Fakhari Moghadam Arani, Mohammadreza

    2012-01-01T23:59:59.000Z

    ??Although wind power as a renewable energy is assumed to be an all-round advantageous source of energy, its intermittent nature can cause difficulties, especially in… (more)

  1. Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation

    SciTech Connect (OSTI)

    Mackin, Peter; Daschmans, R.; Williams, B.; Haney, B.; Hung, R.; Ellis, J.

    2010-12-20T23:59:59.000Z

    Utility Systems Efficiencies, Inc. was tasked by Lawrence Berkeley National Laboratory (LBNL) to conduct dynamic simulation studies of the three U.S. interconnections (Eastern, Western, and Texas). The simulations were prepared in support of LBNL's project for the Federal Energy Regulatory Commission to study frequency-response-related issues that must be addressed to operate the power system reliably with large amounts of variable renewable generation. The objective of the simulation studies of each interconnection was to assess the effects of different amounts of wind generation on frequency behavior of each interconnection following a sudden loss of generation. The scenarios created to study these effects considered an operating circumstance in which system load is at or close to its minimum. The event studied was the sudden loss of the largest amount of generation recorded within each interconnection. The simulations calculated the impact of this event on interconnection frequency for three levels of wind generation. In addition to varying the amount of wind generation, the simulations varied the amount of operating reserves between a high level representative of current operating practices and a low level representative of the minimum required by present operating rules.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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...

  1. Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation

    E-Print Network [OSTI]

    Mackin, Peter

    2011-01-01T23:59:59.000Z

    North America Dynamic Wind Generator Modeling Update, Basedperformed by the WECC Wind Generator Modeling Group and theTo model the interactions between wind generators and the

  2. Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation

    E-Print Network [OSTI]

    Mackin, Peter

    2011-01-01T23:59:59.000Z

    Performance of Wind Power Generation Working Group. ” IECwith Increased Wind Generation 9. Siemens Power Technologiesit Relates to Wind-Powered Generation. LBNL-XXXX. Berkeley:

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Power and Frequency Control as it Relates to Wind-Powered Generation

    SciTech Connect (OSTI)

    Lacommare, Kristina S H

    2010-12-20T23:59:59.000Z

    This report is a part of an investigation of the ability of the U.S. power system to accommodate large scale additions of wind generation. The objectives of this report are to describe principles by which large multi-area power systems are controlled and to anticipate how the introduction of large amounts of wind power production might require control protocols to be changed. The operation of a power system is described in terms of primary and secondary control actions. Primary control is fast, autonomous, and provides the first-line corrective action in disturbances; secondary control takes place on a follow-up time scale and manages the deployment of resources to ensure reliable and economic operation. This report anticipates that the present fundamental primary and secondary control protocols will be satisfactory as wind power provides an increasing fraction of the total production, provided that appropriate attention is paid to the timing of primary control response, to short term wind forecasting, and to management of reserves for control action.

  9. Robust 1550-nm single-frequency all-fiber ns-pulsed fiber amplifier for wind-turbine predictive control by wind lidar

    E-Print Network [OSTI]

    Oldenburg, Carl von Ossietzky Universität

    Oldenburg, Germany ABSTRACT Scaling of the power yield of offshore wind farms relies on the capacity powers [1]. To reach the ambitious and politically motivated aims of Multi-GW offshore wind farms belongs to this category. Clustered in wind farms, today's wind turbines produce Megawatt-level output

  10. Power and Frequency Control as it Relates to Wind-Powered Generation

    E-Print Network [OSTI]

    Lacommare, Kristina S H

    2011-01-01T23:59:59.000Z

    20. Typical simulated response of WECC system frequencies to38. Sample A – Response of WECC system frequency to loss ofP-C2A P-C2B RES1 RES2 VLD WECC Balancing area 1 Area Control

  11. 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 .

  12. 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...

  13. Optimal Core Dimensional Ratios for Minimizing Winding Loss in High-Frequency

    E-Print Network [OSTI]

    to optimum provides a 32% savings in power loss compared to another popular core shape. Further improvements in power loss could be achieved by using optimized core shapes. Improvements to software for shape. This optimum aspect ratio is a function of frequency and other parameters. Significant increases in power loss

  14. 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

  15. 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

  16. Importance of Second-Order Difference-Frequency Wave-Diffraction Forces in the Validation of a Fast Semi-Submersible Floating Wind Turbine Model: Preprint

    SciTech Connect (OSTI)

    Couling, A. J.; Goupee, A. J.; Robertson, A. N.; Jonkman, J. M.

    2013-06-01T23:59:59.000Z

    To better access the abundant offshore wind resource, efforts across the world are being undertaken to develop and improve floating offshore wind turbine technologies. A critical aspect of creating reliable, mature floating wind turbine technology is the development, verification, and validation of efficient computer-aided-engineering (CAE) tools that can be relied upon in the design process. The National Renewable Energy Laboratory (NREL) has created a comprehensive, coupled analysis CAE tool for floating wind turbines, FAST, which has been verified and utilized in numerous floating wind turbine studies. Several efforts are currently underway that leverage the extensive 1/50th-scale DeepCwind wind/wave basin model test dataset, obtained at the Maritime Research Institute Netherlands (MARIN) in 2011, to validate the floating platform functionality of FAST to complement its already validated aerodynamic and structural simulation capabilities. In this paper, further work is undertaken to continue this validation. In particular, the ability of FAST to replicate global response behaviors associated with dynamic wind forces, second-order difference-frequency wave-diffraction forces and their interaction with one another are investigated.

  17. 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......

  18. 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......

  19. 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...

  20. Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation

    E-Print Network [OSTI]

    Mackin, Peter

    2011-01-01T23:59:59.000Z

    wind turbine through a gearbox, and uses a conventional "squirrel cage" induction generator directly connected to the grid.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Impacts of Providing Inertial Response on Dynamic Loads of Wind Turbine Drivetrains: Preprint

    SciTech Connect (OSTI)

    Girsang, I. P.; Dhupia, J.; Singh, M.; Gevorgian, V.; Muljadi, E.; Jonkman, J.

    2014-09-01T23:59:59.000Z

    There has been growing demand from the power industry for wind power plants to support power system operations. One such requirement is for wind turbines to provide ancillary services in the form of inertial response. When the grid frequency drops, it is essential for wind turbine generators (WTGs) to inject kinetic energy stored in their inertia into the grid to help arrest the frequency decline. However, the impacts of inertial response on the structural loads of the wind turbine have not been given much attention. To bridge this gap, this paper utilizes a holistic model for both fixed-speed and variable-speed WTGs by integrating the aeroelastic wind turbine model in FAST, developed by the National Renewable Energy Laboratory, with the electromechanical drivetrain model in SimDriveline and SimPowerSystems.

  7. 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

  8. 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

  9. Stability effects of frequency controllers and transmission line configurations on power systems with integration of wind power

    E-Print Network [OSTI]

    Abdelhalim, Hussein Mohamed

    2012-01-01T23:59:59.000Z

    This thesis investigates the stability effects of the integration of wind power on multi-machine power systems. First, the small-signal stability effects of turbine governors connected to synchronous generators in the ...

  10. Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation

    E-Print Network [OSTI]

    Mackin, Peter

    2011-01-01T23:59:59.000Z

    on work performed by the WECC Wind Generator Modeling GroupModeling Approach in the WECC. ” IEEE Transactions on PowerNational Laboratory. 11. WECC. 2008. WECC Standard BAL-002-

  11. Effects of winds and Caribbean eddies on the frequency of Loop Current eddy shedding: A numerical model study

    E-Print Network [OSTI]

    of Hispaniola, warm eddies are spun up by the local wind stress curl. This type of eddy drifts southwestward for spin up and drift from Hispaniola is about 100 days. Satellite data indicate the existence

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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....

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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...

  8. 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...

  9. 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)

  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. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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 ...

  17. 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

  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. 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 ...

  20. 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

  1. 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

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

    E-Print Network [OSTI]

    Kahn, E.

    2011-01-01T23:59:59.000Z

    ON METHODOLOGY: FROM WIND POWER FREQUENCY TO LOSS-OF-LOADJ.P. , "Some Aspects of Wind Power Statistics, " J. of Appl.J • J METHODOLOGY: FROM WIND POWER FREQUENCY TO LOSS-OF-LOAD

  3. 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 [

  4. 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

  5. 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

  6. 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

  7. 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...

  8. 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.

  9. 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 ...

  10. 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 ...

  11. Prototype bucket foundation for wind turbines

    E-Print Network [OSTI]

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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. the problem by speeding up a workload with parallel pro-cessing at a lower clock frequency (and lower voltage). But

    E-Print Network [OSTI]

    Cho, Sangyeun

    6 , 2 0 0 8 M I C R O P R O C E S S O R R E P O R T REPORT M I C R O P R O C E S S O R T H E I N S I D E R ' S G U I D E T O M I C R O P R O C E S S O R H A R D WA R E www.MPRonline.com #12;between 2 and frequency.2 This article is based on our paper, "Corollaries to Amdahl's Law for Energy,"3 from IEEE

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. Analysis of wind turbine vibrations based on SCADA data

    E-Print Network [OSTI]

    Andrew Kusiak; Zijun Zhang

    2010-01-01T23:59:59.000Z

    Vibrations of a wind turbine have a negative impact on its performance. Mitigating this undesirable impact requires knowledge of the relationship between the vibrations and other wind turbine parameters that could be potentially modified. Three approaches for ranking the impact importance of measurable turbine parameters on the vibrations of the drive train and the tower are discussed. They include the predictor importance analysis, the global sensitivity analysis, and the correlation coefficient analysis versed in data mining and statistics. To decouple the impact of wind speed on the vibrations of the drive train and the tower, the analysis is performed on data sets with narrow speed ranges. Wavelet analysis is applied to filter noisy accelerometer data. To exclude the impact malfunctions on the vibration analysis, the data are analyzed in a frequency domain. Data-mining algorithms are used to build models with turbine parameters of interest as inputs, and the vibrations of drive train and tower as outputs. The performance of each model is thoroughly evaluated based on metrics widely used in the wind industry. The neural network algorithm outperforms other classifiers and is considered to be the most promising approach to study wind turbine vibrations. ?DOI: 10.1115/1.4001461?

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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...

  11. 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...

  12. 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)

  13. 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...

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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

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

    SciTech Connect (OSTI)

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

    2006-03-01T23:59:59.000Z

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

  20. Eastern Frequency Response Study

    SciTech Connect (OSTI)

    Miller, N.W.; Shao, M.; Pajic, S.; D'Aquila, R.

    2013-05-01T23:59:59.000Z

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  1. 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)

  2. 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

  3. 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

  4. 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

  5. Investigation of self-excited induction generators for wind turbine applications

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.; Sallan, J.; Sanz, M.

    2000-02-28T23:59:59.000Z

    The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency only within a small range of wind speed variation. The variable-speed operation allows an increase in energy captured and reduces both the torque peaks in the drive train and the power fluctuations sent to the utility. In variable-speed operation, an induction generator needs an interface to convert the variable frequency output of the generator to the fixed frequency at the utility. This interface can be simplified by using a self-excited generator because a simple diode bridge is required to perform the ac/dc conversion. The subsequent dc/ac conversion can be performed using different techniques. The use of a thyristor bridge is readily available for large power conversion and has a lower cost and higher reliability. The firing angle of the inverter bridge can be controlled to track the optimum power curve of the wind turbine. With only diodes and thyristors used in power conversion, the system can be scaled up to a very high voltage and high power applications. This paper analyzes the operation of such a system applied to a 1/3-hp self-excited induction generator. It includes the simulations and tests performed for the different excitation configurations.

  6. 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

  7. 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

  8. 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.

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

    E-Print Network [OSTI]

    Kahn, E.

    2011-01-01T23:59:59.000Z

    ON METHODOLOGY: FROM WIND POWER FREQUENCY TO LOSS-OF-LOADJ.P. , "Some Aspects of Wind Power Statistics, " J. of Appl.S£CTION Reliability of Wind Power From Dispersed Sites: A Pr

  10. 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

  11. 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

  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. 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...

  14. 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

  15. Statistical Features of the Wind Field over the Indian Ccean for the period 1998-2008

    E-Print Network [OSTI]

    Polnikov, Vladislav; Sannasiraj, S A

    2011-01-01T23:59:59.000Z

    We have done a statistical analysis of the wind field from the archive of NCEP/NOAA over the Indian Ocean for the period 1998-2008yy, which is given on a grid 1x1.25 of latitude-longitude with 3h time-step. Initial analysis includes mapping the average wind fields and fields of mean density of the wind-kinetic-energy flux , obtained with different periods of time averaging T, as well as the assessment of 11-year trends in these fields. The subsequent analysis is concerned with partition of the Indian ocean area into 6 zones, provided by the spatial inhomogeneity of the analyzed wind field. This analysis includes: a) an assessment of temporal variations for the wind speed field averaged over the Ocean and the zones and for the field of wind-energy flux; b) construction of time history series of these fields averaged with different scales, and estimating frequency spectra of these series; c) finding the extremes of the wind field (in the zones of Indian Ocean); d) construction of histograms of the wind field; ...

  16. 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 ...

  17. 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...

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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).

  6. Hurricane wind fields needed to assess risk to offshore wind farms

    E-Print Network [OSTI]

    Jaramillo, Paulina

    LETTER Hurricane wind fields needed to assess risk to offshore wind farms In their paper in PNAS losses attributable to hurricane activity at four hypothetical offshore wind farm sites. We found one a 20-y typical wind farm lifetime. They combined a county annual landfall frequency probability density

  7. 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

  8. 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

  9. 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...

  10. 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...

  11. Economical Aspects of Adjustable Speed Drives in Pumping Systems

    E-Print Network [OSTI]

    Hovstadius, G.

    Speed variations of pumps have become increasingly popular as the technology to produce variable frequency drives has progressed. Variable speed drives have many advantages compared to throttle valves when it comes to regulation of flow. They offer...

  12. Long-Term Wind Power Variability

    SciTech Connect (OSTI)

    Wan, Y. H.

    2012-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  13. Resonant Vibrations Resulting from the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine

    SciTech Connect (OSTI)

    Fleming, P.; Wright, A. D.; Finersh, L. J.

    2010-12-01T23:59:59.000Z

    The CART3 (Controls Advanced Research Turbine, 3-bladed) at the National Wind Technology Center has recently been converted from a 2-bladed constant speed machine to a 3-bladed variable speed machine designed specically for controls research. The purpose of this conversion was to develop an advanced controls field-testing platform which has the more typical 3-bladed configuration. A result of this conversion was the emergence of several resonant vibrations, some of which initially prevented operation of the turbine until they could be explained and resolved. In this paper, the investigations into these vibrations are presented as 'lessons-learned'. Additionally, a frequency-domain technique called waterfall plotting is discussed and its usefulness in this research is illustrated.

  14. 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.

  15. Abstract--The offshore wind farm with installed back-to-back power converter in wind turbines is studied. As an

    E-Print Network [OSTI]

    Bak, Claus Leth

    Abstract--The offshore wind farm with installed back-to- back power converter in wind turbines is studied. As an example the Burbo Bank offshore wind farm with Siemens Wind Power wind turbines is taken installed in wind turbines are presented. Harmonic load flow analysis and impedance frequency

  16. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect (OSTI)

    Coulter, R

    2005-01-01T23:59:59.000Z

    The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

  17. 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.

  18. Wind shear climatology for large wind turbine generators

    SciTech Connect (OSTI)

    Elliott, D.L.; Wendell, L.L.; Heflick, S.K.

    1982-10-01T23:59:59.000Z

    Climatological wind shear analyses relevant to the design and operation of multimegawatt wind turbines are provided. Insight is provided for relating the wind experienced by a rotating blade in a shear flow to the analysis results. A simple analysis of the wind experienced by a rotating blade for three types of wind shear profiles under steady-state conditions is presented in graphical form. Comparisons of the magnitude and frequency of the variations in 1) the wind sensed by a single blade element, 2) the sum, and 3) the difference of the winds sensed by opposite blade elements show strong sensitivity to profile shape. These three items represent forcing functions that can be related to 1) flatwise bending moment, 2) torque on the shaft, and 3) teeter angle. A computer model was constructed to simulate rotational sampling of 10-s sampled winds from a tall tower for three different types of large wind turbines. Time series produced by the model indicated that the forcing functions on a rotating blade vary according to the shear profile encountered during each revolution as opposed to a profile derived from average wind conditions, e.g., hourly average winds. An analysis scheme was developed to establish a climatology of wind shear profiles derived from 10-s sampled winds and hourly average winds measured over a one-year period at several levels on a tall tower. Because of the sensitivity of the forcing function variability to profile shape, the analyses performed and presented are in the form of joint frequency distributions of velocity differences of the the top-to-hub versus the hub-to-bottom portion of disks of rotation for the three turbine configurations.

  19. 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 ...

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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 ...

  10. 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

  11. 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

  12. The Heating & Acceleration of the Solar Wind

    E-Print Network [OSTI]

    Wurtele, Jonathan

    The Heating & Acceleration of the Solar Wind Eliot Quataert (UC Berkeley) Collaborators: Steve & Slow Winds · The Puzzle of the High Frequency Cascade (or the lack thereof ....) · Possible Solutions #12;Background · Heating required to accelerate the solar wind · Early models invoked e- conduction

  13. 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

  14. 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

  15. 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

  16. 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...

  17. 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...

  18. Guidelines for reducing dynamic loads in two-bladed teetering-hub downwind wind turbines

    SciTech Connect (OSTI)

    Wright, A.D.; Bir, G.S.; Butterfield, C.D.

    1995-06-01T23:59:59.000Z

    A major goal of the federal Wind Energy Program is the rapid development and validation of structural models to determine loads and response for a wide variety of different wind turbine configurations operating under extreme conditions. Such codes are crucial to the successful design of future advanced wind turbines. In previous papers the authors described steps they took to develop a model of a two-bladed teetering-hub downwind wind turbine using ADAMS{reg_sign} (Automatic Dynamic Analysis of Mechanical Systems), as well as comparison of model predictions to test data. In this paper they show the use of this analytical model to study the influence of various turbine parameters on predicted system loads. They concentrate their study on turbine response in the frequency range of six to ten times the rotor rotational frequency (6P to 10P). Their goal is to identify the most important parameters which influence the response of this type of machine in this frequency range and give turbine designers some general design guidelines for designing two-bladed teetering-hub machines to be less susceptible to vibration. They study the effects of such parameters as blade edgewise and flapwise stiffness, tower top stiffness, blade tip-brake mass, low-speed shaft stiffness, nacelle mass momenta of inertia, and rotor speed. They show which parameters can be varied in order to make the turbine less responsive to such atmospheric inputs as wind shear and tower shadow. They then give designers a set of design guidelines in order to show how these machines can be designed to be less responsive to these inputs.

  19. Multi-frequency observations of SNR J0453-6829 in the LMC; A composite supernova remnant with a pulsar wind nebula

    E-Print Network [OSTI]

    Haberl, F; Bozzetto, L M; Crawford, E J; Points, S D; Pietsch, W; De Horta, A Y; Tothill, N; Payne, J L; Sasaki, M

    2012-01-01T23:59:59.000Z

    The Large Magellanic Cloud (LMC) is rich in supernova remnants (SNRs) which can be investigated in detail with radio, optical and X-ray observations. SNR J0453-6829 is an X-ray and radio-bright remnant in the LMC, within which previous studies revealed the presence of a pulsar wind nebula (PWN), making it one of the most interesting SNRs in the Local Group of galaxies. We study the emission of SNR J0453-6829 to improve our understanding of its morphology, spectrum, and thus the emission mechanisms in the shell and the PWN of the remnant. We obtained new radio data with the Australia Telescope Compact Array and analysed archival XMM-Newton observations of SNR J0453-6829. We studied the morphology of SNR J0453-6829 from radio, optical and X-ray images and investigated the energy spectra in the different parts of the remnant. Our radio results confirm that this LMC SNR hosts a typical PWN. The prominent central core of the PWN exhibits a radio spectral index alpha_Core of -0.04+/-0.04, while in the rest of the S...

  20. 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.

  1. Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach: Preprint

    SciTech Connect (OSTI)

    Guo, Y.; Keller, J.; Parker, R. G.

    2012-06-01T23:59:59.000Z

    The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

  2. 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

  3. 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

  4. 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

  5. PROBABILISTIC HAZARD ASSESSMENT FOR TORNADOES, STRAIGHT-LINE WIND, AND EXTREME PRECIPITATION AT THE SAVANNAH RIVER SITE

    SciTech Connect (OSTI)

    Werth, D.; (NOEMAIL), A.; Shine, G.

    2013-12-04T23:59:59.000Z

    Recent data sets for three meteorological phenomena with the potential to inflict damage on SRS facilities - tornadoes, straight winds, and heavy precipitation - are analyzed using appropriate statistical techniques to estimate occurrence probabilities for these events in the future. Summaries of the results for DOE-mandated return periods and comparisons to similar calculations performed in 1998 by Weber, et al., are given. Using tornado statistics for the states of Georgia and South Carolina, we calculated the probability per year of any location within a 2? square area surrounding SRS being struck by a tornado (the ‘strike’ probability) and the probability that any point will experience winds above set thresholds. The strike probability was calculated to be 1.15E-3 (1 chance in 870) per year and wind speeds for DOE mandated return periods of 50,000 years, 125,000 years, and 1E+7 years (USDOE, 2012) were estimated to be 136 mph, 151 mph and 221 mph, respectively. In 1998 the strike probability for SRS was estimated to be 3.53 E-4 and the return period wind speeds were 148 mph every 50,000 years and 180 mph every 125,000 years. A 1E+7 year tornado wind speed was not calculated in 1998; however a 3E+6 year wind speed was 260 mph. The lower wind speeds resulting from this most recent analysis are largely due to new data since 1998, and to a lesser degree differences in the models used. By contrast, default tornado wind speeds taken from ANSI/ANS-2.3-2011 are somewhat higher: 161 mph for return periods of 50,000 years, 173 mph every 125,000 years, and 230 mph every 1E+7 years (ANS, 2011). Although the ANS model and the SRS models are very similar, the region defined in ANS 2.3 that encompasses the SRS also includes areas of the Great Plains and lower Midwest, regions with much higher occurrence frequencies of strong tornadoes. The SRS straight wind values associated with various return periods were calculated by fitting existing wind data to a Gumbel distribution, and extrapolating the values for any return period from the tail of that function. For the DOE mandated return periods, we expect straight winds of 123 mph every 2500 years, and 132mph every 6250 years at any point within the SRS. These values are similar to those from the W98 report (which also used the Gumbel distribution for wind speeds) which gave wind speeds of 115mph and 122 mph for return periods of 2500 years and 6250 years, respectively. For extreme precipitation accumulation periods, we compared the fits of three different theoretical extreme-value distributions, and in the end decided to maintain the use of the Gumbel distribution for each period. The DOE mandated 6-hr accumulated rainfall for return periods of 2500 years and 6250 years was estimated as 7.8 inches and 8.4 inches, respectively. For the 24- hr rainfall return periods of 10,000 years and 25,000 years, total rainfall estimates were 10.4 inches and 11.1 inches, respectively. These values are substantially lower than comparable values provided in the W98 report. This is largely a consequence of the W98 use of a different extreme value distribution with its corresponding higher extreme probabilities.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Description and Simulation of Gust Front Wind Field Lijuan Wanga

    E-Print Network [OSTI]

    Kareem, Ahsan

    -stationarity of the wind field associated with these extreme events poses serious challenges in their modelingDescription and Simulation of Gust Front Wind Field Lijuan Wanga , Ahsan Kareemb a Nat front wind field is proposed based on the time-frequency description of the wind field. Traditionally

  16. 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...

  17. 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...

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  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. Turbine set with a generator feeding a network of constant frequency

    SciTech Connect (OSTI)

    Spirk, F.

    1983-01-11T23:59:59.000Z

    In a turbine set with an axial flow which is traversed by water and which is coupled to a generator feeding a network of constant frequency, the flow turbine is a propeller turbine with nonadjustable blades. The stator winding of the generator is connected to the network by means of a frequency-controllable converter, in particular a direct converter. The speed of rotation of the turbine set is controllable continuously according to the power to be delivered. In the case of an asynchronous design of the generator, it is advisable to provide the stator with a waterproof jacket on the inside and to flange it into the turbine tube, since the rotor with its cage winding is swept by water.

  11. Precision electronic speed controller for an alternating-current

    DOE Patents [OSTI]

    Bolie, Victor W. (Albuquerque, NM)

    1988-01-01T23:59:59.000Z

    A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for and is particularly suitable for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. In the preferred embodiment, the motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of readonly memories, and a pair of digital-to-analog converters.

  12. 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.

  13. 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

  14. 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...

  15. 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

  16. 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.

  17. 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

  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. 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

  1. Adjustable speed drive for residential applications

    SciTech Connect (OSTI)

    Jungreis, A.M.; Kelley, A.W. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Electrical and Computer Engineering] [North Carolina State Univ., Raleigh, NC (United States). Dept. of Electrical and Computer Engineering

    1995-11-01T23:59:59.000Z

    This paper describes a demonstration of an adjustable speed drive suitable for use in residential applications such as compressors and fans in heat pumps, air conditioners, and refrigerators. The adjustable speed drive uses only a four-diode rectifier and a six-transistor six-diode inverter and does not require a source-frequency filter inductor or capacitor. Motor speed is adjusted with source-frequency phase control eliminating the switching loss and electromagnetic interference caused by the more commonly used high-frequency pulse-width modulation. Low source-current distortion and high power factor are obtained at a full-load operating point which is found using a parametric analysis.

  2. 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.

  3. 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).

  4. 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.

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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...

  18. Variable Frequency Pump Drives

    E-Print Network [OSTI]

    Karassik, I. J.; Petraccaro, L. L.; McGuire, J. T.

    -frequency electric motor drive. What is happenin9 with variable frequency driven pun,ps is a classical illustration that evolution in technical products takes place not only because of changes in the processes served by these products, or because of innovations...-pole 3550 rpm squirrel caqe induction motor became available in the early 1930s that high pressure pumps operating at that speed could be buil t. And now, in the 1980s, the development of the solid-state, variable frequency electric motor drive...

  19. 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 ...

  20. 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...

  1. A comparison of predicted and observed turbulent wind fields present in natural and internal wind park environments

    SciTech Connect (OSTI)

    Kelly, N D; Wright, A D

    1991-10-01T23:59:59.000Z

    This paper assesses the accuracy of simulated wind fields for both the natural flow and that within a wind park environment. The simulated fields are compared with the observed ones in both the time and frequency domains. Actual measurements of the wind fields and the derived kinematic scaling parameters upwind and downwind of a large San Gorgonio Pass wind park are used. The deviations in the modeled wind field from the observed are discussed. 10 refs., 6 figs., 2 tabs.

  2. Comparison of Loss in Single-Layer and Multi-Layer Windings with a DC Component

    E-Print Network [OSTI]

    depth. This can be effective, but single-layer windings can also be advantageous for high frequency. INTRODUCTION In magnetic components for modern high-frequency power converters, winding losses can be high advantages at high frequency and in some cases a single-layer winding may be better than any feasible multi

  3. 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.

  4. 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.

  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. 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...

  13. Flexible dynamics of floating wind turbines

    E-Print Network [OSTI]

    Luypaert, Thomas (Thomas J.)

    2012-01-01T23:59:59.000Z

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

  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. Operating Modes of a Teeter-Rotor Wind Turbine

    SciTech Connect (OSTI)

    Bir, G. S. (National Renewable Energy Laboratory); Stol, K. (University of Colorado at Boulder)

    1999-02-25T23:59:59.000Z

    We examine the operating modes of a two-bladed teetered wind turbine. Because of the gyroscopic asymmetry of its rotor, this turbine's dynamics can be quite distinct from those of a turbine with three or more blades. This asymmetry leads to system equations with periodic coefficients that are solved using the Floquet approach to extract the correct modal parameters. The system equations are derived using a simple analytical model with four degrees of freedom: cacelle yaw, rotor teeter, and flapping associated with each blade. Results confirm that the turbine modes become more dominated by the centrifugal and gyroscopic effects as the rotor speed increases. They gyroscopic effect may also cause dynamic instability. Under certain design conditions, yaw and teeter modal frequencies may coalesce.

  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. Fast Verification of Wind Turbine Power Summary of Project Results

    E-Print Network [OSTI]

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

  11. 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.

  12. 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.

  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. 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.

  19. 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...

  20. 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

  1. 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.

  2. 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

  3. accurate frequency dependent: Topics by E-print Network

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

    and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power...

  4. 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...

  5. 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.

  6. 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.

  7. Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.121) Track: Technical

    E-Print Network [OSTI]

    in turbulence intensity in wakes behind wind turbines can imply a significant reduction in fatigue lifetime by a stochastic part and a deterministic, sinusoidal part with frequency Behind a wind turbine a wake is formed intensity in wakes behind wind turbines can imply a significant reduction in the fatigue lifetime of wind

  8. Loading and Response of Offshore Wind Turbine Support Structures: Prediction with Comparison to Measured Data

    E-Print Network [OSTI]

    Sweetman, Bert

    Loading and Response of Offshore Wind Turbine Support Structures: Prediction with Comparison, offshore wind support platforms differ from oil platforms is several important ways: First, wind platforms is often closer to frequencies at which there is meaningful wave energy. Second, wind farms often include

  9. Statistical Characterization of Zonal and Meridional Ocean Wind Stress SARAH T. GILLE

    E-Print Network [OSTI]

    Gille, Sarah T.

    fully captures the range of extreme wind events seen in the raw swath data. Frequency spectraStatistical Characterization of Zonal and Meridional Ocean Wind Stress SARAH T. GILLE Scripps) ABSTRACT Four years of ocean vector wind data are used to evaluate statistics of wind stress over the ocean

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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...

  16. 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

  17. 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

  18. The Estimated Global Ocean Wind Power Potential from QuikSCAT Observations, Accounting for Turbine

    E-Print Network [OSTI]

    Zender, Charles

    The Estimated Global Ocean Wind Power Potential from QuikSCAT Observations, Accounting for Turbine: (949) 824-3256 Abstract For the first time, global ocean usable wind power is evaluated for modern offshore turbine characteristics including hub height, usable portion of the wind speed distri- bution

  19. Estimating Wind Turbine Parameters and Quantifying Their Effects on Dynamic Behavior

    E-Print Network [OSTI]

    Hiskens, Ian A.

    variable-speed wind turbines in grid stability studies. Often the values for model parameters are poorly parameters on the dynamic behavior of wind turbine generators. A parameter estimation process is then used [1], [2]. Accordingly, the impact of wind turbine generators (WTGs) on power system dynamic

  20. Analyzing the Effects of Temporal Wind Patterns on the Value ofWind-Generated Electricity at Different Sites in California and theNorthwest

    SciTech Connect (OSTI)

    Fripp, Matthias; Wiser, Ryan

    2006-05-31T23:59:59.000Z

    Wind power production varies on a diurnal and seasonal basis. In this report, we use wind speed data modeled by TrueWind Solutions, LLC (now AWS Truewind) to assess the effects of wind timing on the value of electric power from potential wind farm locations in California and the Northwest. (Data from this dataset are referred to as ''TrueWind data'' throughout this report.) The intra-annual wind speed variations reported in the TrueWind datasets have not previously been used in published work, however, so we also compare them to a collection of anemometer wind speed measurements and to a limited set of actual wind farm production data. The research reported in this paper seeks to answer three specific questions: (1) How large of an effect can the temporal variation of wind power have on the value of wind in different wind resource areas? (2) Which locations are affected most positively or negatively by the seasonal and diurnal timing of wind speeds? (3) How compatible are wind resources in the Northwest and California with wholesale power prices and loads in either region? The latter question is motivated by the fact that wind power projects in the Northwest could sell their output into California (and vice versa), and that California has an aggressive renewable energy policy that may ultimately yield such imports. Based on our research, we reach three key conclusions. (1) Temporal patterns have a moderate impact on the wholesale market value of wind power and a larger impact on the capacity factor during peak hours. The best-timed wind power sites have a wholesale market value that is up to 4 percent higher than the average market price, while the worst-timed sites have a market value that is up to 11 percent below the average market price. The best-timed wind sites could produce as much as 30-40 percent more power during peak hours than they do on average during the year, while the worst timed sites may produce 30-60 percent less power during peak hours. (2) Northwestern markets appear to be well served by Northwestern wind and poorly served by California wind; results are less clear for California markets. Both the modeled TrueWind data and the anemometer data indicate that many Northwestern wind sites are reasonably well-matched to the Northwest's historically winter-peaking wholesale electricity prices and loads, while most California sites are poorly matched to these prices and loads. However, the TrueWind data indicate that most California and Northwestern wind sites are poorly matched to California's summer-afternoon-peaking prices and loads, while the anemometer data suggest that many of these same sites are well matched to California's wholesale prices and loads. (3) TrueWind and anemometer data agree about wind speeds in most times and places, but disagree about California's summer afternoon wind speeds: The TrueWind data indicate that wind speeds at sites in California's coastal mountains and some Northwestern locations dip deeply during summer days and stay low through much of the afternoon. In contrast, the anemometer data indicate that winds at these sites begin to rise during the afternoon and are relatively strong when power is needed most. At other times and locations, the two datasets show good agreement. This disagreement may be due in part to time-varying wind shear between the anemometer heights (20-25m) and the TrueWind reference height (50m or 70m), but may also be due to modeling errors or data collection inconsistencies.

  1. 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...

  2. Wind loading on solar concentrators: some general considerations

    SciTech Connect (OSTI)

    Roschke, E. J.

    1984-05-01T23:59:59.000Z

    A survey has been completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view; current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed; recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly. Wind loads, i.e., forces and moments, are proportional to the square of the mean wind velocity. Forces are proportional to the square of concentrator diameter, and moments are proportional to the cube of diameter. Thus, wind loads have an important bearing on size selection from both cost and performance standpoints. It is concluded that sufficient information exists so that reasonably accurate predictions of wind loading are possible for a given paraboloidal concentrator configuration, provided that reliable and relevant wind conditions are specified. Such predictions will be useful to the design engineer and to the systems engineer as well. Information is lacking, however, on wind effects in field arrays of paraboloidal concentrators. Wind tunnel tests have been performed on model heliostat arrays, but there are important aerodynamic differences between heliostats and paraboloidal dishes.

  3. Wind Technologies & Evolving Opportunities (Presentation)

    SciTech Connect (OSTI)

    Robichaud, R.

    2014-07-01T23:59:59.000Z

    This presentation covers opportunities for wind technology; wind energy market trends; an overview of the National Wind Technology Center near Boulder, Colorado; wind energy price and cost trends; wind turbine technology improvements; and wind resource characterization improvements.

  4. A National Offshore Wind Strategy: Creating an Offshore Wind...

    Broader source: Energy.gov (indexed) [DOE]

    A National Offshore Wind Strategy: Creating an Offshore Wind Energy Industry in the United States A National Offshore Wind Strategy: Creating an Offshore Wind Energy Industry in...

  5. 20% Wind Energy by 2030 - Chapter 2: Wind Turbine Technology...

    Office of Environmental Management (EM)

    20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply U.S. Offshore Wind Manufacturing and Supply Chain Development Wind Program Accomplishments...

  6. Wind Powering America Webinar: Wind Power Economics: Past, Present...

    Broader source: Energy.gov (indexed) [DOE]

    Wind Powering America Webinar: Wind Power Economics: Past, Present, and Future Trends Wind Powering America Webinar: Wind Power Economics: Past, Present, and Future Trends November...

  7. Community Wind Handbook/Understand Your Wind Resource and Conduct...

    Open Energy Info (EERE)

    Wind Resource and Conduct a Preliminary Estimate < Community Wind Handbook Jump to: navigation, search WIND ENERGY STAKEHOLDER ENGAGEMENT & OUTREACHCommunity Wind Handbook...

  8. 2015 Iowa Wind Power Conference and Iowa Wind Energy Association...

    Energy Savers [EERE]

    2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional Energy Job Fair 2015 Iowa Wind Power Conference and Iowa Wind Energy Association Midwest Regional...

  9. Design of an ambient aerosol sampling system for high and medium speed applications

    E-Print Network [OSTI]

    Irshad, Hammad

    2012-06-07T23:59:59.000Z

    Two ambient sampling systems were designed and tested for high speed sampling application for a wind speed range of 4.47 m/s to 26.82 m/s. These systems will be used as inlets for sampling of bioaerosol from air. These systems consist of shrouded...

  10. Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle

    E-Print Network [OSTI]

    Virginia Tech

    Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle Haider N. Arafat-- A dynamic model is developed for a small, high- speed autonomous underwater vehicle. The vehicle has manner: 1) Wind angle and angle : From u = V cos , v = V sin sin , and w = V sin cos , we have tan

  11. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    wind turbine components (specifically, generators, bladeschangers. ” Wind turbine components such as blades, towers,17%). Wind turbine component exports (towers, blades,

  12. Wind Resource Assessment in Europe Using Emergy

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    In context of increasing use of renewable sources, it is of importance to correctly evaluate the actual sustainability of their implementation. Emergy analysis is one of the possible methods useful for such an assessment. This work aims to demonstrate how the emergy approach can be used to assess the sustainability of wind energy resource in Europe. The Emergy Index of Sustainability (EIS) and the Emergy Yield Ratio (EYR) are used to analyze 90 stations of European regions for three types of wind turbines. To do so, the simplified Chou wind turbine model is used for different set of parameters as: nominal power and size of the wind turbines, and cut-in and cut-out wind speeds. Based on the calculation of the emergy indices, a mapping is proposed to identify the most appropriate locations for an implementation of wind turbines in European regions. The influence of the wind turbine type on the sustainability is also analyzed, in link with the local wind resource. Thus, it is concluded that the emergy sustainabi...

  13. Combination of Speed Stroke Grinding and High Speed Grinding with Regard to Sustainability

    E-Print Network [OSTI]

    Linke, Barbara; M. Duscha; F. Klocke; Dornfeld, David

    2011-01-01T23:59:59.000Z

    Combination of Speed Stroke Grinding and High Speed Grindinghow the combination of speed stroke grinding and high speed4] Inasaki, I. , 1988, Speed Stroke Grinding of Advanced

  14. Resonant speed meter for gravitational wave detection

    E-Print Network [OSTI]

    Atsushi Nishizawa; Seiji Kawamura; Masa-aki Sakagami

    2008-05-01T23:59:59.000Z

    Gravitational-wave detectors have been well developed and operated with high sensitivity. However, they still suffer from mirror displacement noise. In this paper, we propose a resonant speed meter, as a displacement noise-canceled configuration based on a ring-shaped synchronous recycling interferometer. The remarkable feature of this interferometer is that, at certain frequencies, gravitational-wave signals are amplified, while displacement noises are not.

  15. 2011 Wind Technologies Market Report

    E-Print Network [OSTI]

    Bolinger, Mark

    2013-01-01T23:59:59.000Z

    and K. Porter. 2011. Wind Power and Electricity Markets.41 6. Wind Power Priceat Various Levels of Wind Power Capacity Penetration Wind

  16. 2009 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2010-01-01T23:59:59.000Z

    Prepared for the Utility Wind Integration Group. Arlington,Arizona Public Service Wind Integration Cost Impact Study.an Order Revising the Wind Integration Rate for Wind Powered

  17. 2010 Wind Technologies Market Report

    E-Print Network [OSTI]

    Wiser, Ryan

    2012-01-01T23:59:59.000Z

    2010. SPP WITF Wind Integration Study. Little Rock,an Order Revising the Wind Integration Rate for Wind PoweredPacifiCorp. 2010. 2010 Wind Integration Study. Portland,

  18. Wind Generation on Winnebago Tribal Lands

    SciTech Connect (OSTI)

    Multiple

    2009-09-30T23:59:59.000Z

    The Winnebago Wind Energy Study evaluated facility-scale, community-scale and commercial-scale wind development on Winnebago Tribal lands in northeastern Nebraska. The Winnebago Tribe of Nebraska has been pursuing wind development in various forms for nearly ten years. Wind monitoring utilizing loaned met towers from NREL took place during two different periods. From April 2001 to April 2002, a 20-meter met tower monitored wind data at the WinnaVegas Casino on the far eastern edge of the Winnebago reservation in Iowa. In late 2006, a 50-meter tower was installed, and subsequently monitored wind data at the WinnaVegas site from late 2006 through late 2008. Significant challenges with the NREL wind monitoring equipment limited the availability of valid data, but based on the available data, average wind speeds between 13.6 – 14.3 miles were indicated, reflecting a 2+/3- wind class. Based on the anticipated cost of energy produced by a WinnaVegas wind turbine, and the utility policies and rates in place at this time, a WinnaVegas wind project did not appear to make economic sense. However, if substantial grant funding were available for energy equipment at the casino site, and if either Woodbury REC backup rates were lower, or NIPCO was willing to pay more for wind power, a WinnaVegas wind project could be feasible. With funding remaining in the DOE-funded project budget,a number of other possible wind project locations on the Winnebago reservation were considered. in early 2009, a NPPD-owned met tower was installed at a site identified in the study pursuant to a verbal agreement with NPPD which provided for power from any ultimately developed project on the Western Winnebago site to be sold to NPPD. Results from the first seven months of wind monitoring at the Western Winnebago site were as expected at just over 7 meters per second at 50-meter tower height, reflecting Class 4 wind speeds, adequate for commercial development. If wind data collected in the remaining months of the twelve-month collection period is consistent with that collected in the first seven months, the Western Winnebago site may present an interesting opportunity for Winnebago. Given the distance to nearby substations, and high cost of interconnection at higher voltage transmission lines, Winnebago would likely need to be part of a larger project in order to reduce power costs to more attractive levels. Another alternative would be to pursue grant funding for a portion of development or equipment costs, which would also help reduce the cost of power produced. The NREL tower from the WinnaVegas site was taken down in late 2008, re-instrumented and installation attempted on the Thunderway site south of the Winnebago community. Based on projected wind speeds, current equipment costs, and the project’s proximity to substations for possible interconnection, a Thunderway community-scale wind project could also be feasible.

  19. Twin Groves Wind Energy Facility Cut-in Speeds

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

    and Karin Sinclair (National Renewable Energy Laboratory), Christy Johnson-Hughes (U.S. Fish and Wildlife Service), and Laurie K. Allen (U.S. Geological Survey) for providing...

  20. Dominican Republic - Annual Average Wind Speed at 80 meters

    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 phasesDataTranslocationDiurnal Cycle ofDoDocuments Dominican Republic -