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Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Model of variable speed constant frequency double fed wind power generation system and analysis of its operating performance  

Science Conference Proceedings (OSTI)

Structure of variable speed constant frequency double fed wind power generation system (WPGS) was analyzed, and its model was established. Maximum power point tracking (MPPT) control, constant power control and vector control for WPGS were discussed. ... Keywords: operating performance, variable speed constant frequency, vector control, wind power generation system

Pan Tinglong; Ji Zhicheng

2009-06-01T23:59:59.000Z

2

Extreme Wind Speeds: Publications  

Science Conference Proceedings (OSTI)

... "Algorithms for Generating Large Sets of Synthetic Directional Wind Speed Data for Hurricane, Thunderstorm, and Synoptic Winds," NIST Technical ...

2013-08-19T23:59:59.000Z

3

wind speed | OpenEI  

Open Energy Info (EERE)

speed speed Dataset Summary Description GIS data for offshore wind speed (meters/second). Specified to Exclusive Economic Zones (EEZ).Wind resource based on NOAA blended sea winds and monthly wind speed at 30km resolution, using a 0.11 wind sheer to extrapolate 10m - 90m. Annual average >= 10 months of data, no nulls. Source National Renewable Energy Laboratory (NREL) Date Released Unknown Date Updated Unknown Keywords GIS global NOAA NREL offshore wind wind speed Data application/zip icon Download Shapefile (zip, 18.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Other or unspecified, see optional comment below Comment Please cite NREL and NOAA Rate this dataset Usefulness of the metadata

4

Comparison on control strategies of the grid-side converter of variable speed constant frequency doubly-fed wind power generation system  

Science Conference Proceedings (OSTI)

Direct power control, vector control based on d-q synchronous rotating reference frame and ?-? static reference frame for the grid-side converter of variable speed constant frequency doubly-fed wind turbines are analyzed. System simulation ... Keywords: ?-? static reference frame, d-q rotating reference frame, direct power control, doubly-fed wind power generation system, grid-side converter

Xian-Ming Zhou; Ting-Long Pan; Zhi-Cheng Ji

2009-06-01T23:59:59.000Z

5

Forecasting Solar Wind Speeds  

E-Print Network (OSTI)

By explicitly taking into account effects of Alfven waves, I derive from a simple energetics argument a fundamental relation which predicts solar wind (SW) speeds in the vicinity of the earth from physical properties on the sun. Kojima et al. recently found from their observations that a ratio of surface magnetic field strength to an expansion factor of open magnetic flux tubes is a good indicator of the SW speed. I show by using the derived relation that this nice correlation is an evidence of the Alfven wave which accelerates SW in expanding flux tubes. The observations further require that fluctuation amplitudes of magnetic field lines at the surface should be almost universal in different coronal holes, which needs to be tested by future observations.

Takeru K. Suzuki

2006-02-03T23:59:59.000Z

6

OpenEI - wind speed  

Open Energy Info (EERE)

NREL GIS Data: Global NREL GIS Data: Global Offshore Wind http://en.openei.org/datasets/node/869 GIS data for offshore wind speed (meters/second).  Specified to Exclusive Economic Zones (EEZ).Wind resource based on NOAA blended sea winds and monthly wind speed at 30km resolution, using a 0.11 wind sheer to extrapolate 10m - 90m.  Annual average  >= 10 months of data, no nulls. License

Type of License:  Other (please specify below)

7

LIDAR wind speed measurements of evolving wind fields  

E-Print Network (OSTI)

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. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios. Nomenclature a decay parameter for exponential coherence al decrement parameter for transverse coherence (l ? {u, v, w}) bl offset parameter for transverse coherence (l ? {u, v, w}) D longitudinal distance between two points or measurement preview distance F focal distance f frequency (Hz) ? LIDAR measurement angle off of longitudinal direction k wind velocity wavenumber (m?1) ? wavelength (m) R range along LIDAR beam r scan radius for spinning LIDAR scenario ri,j distance between two points in the yz plane U mean wind speed (m/s) ?i,j average mean wind speed between two points in the yz plane ? azimuth angle in the rotor plane ?2 xy(f) Coherence between signals x and y

Eric Simley; Lucy Y. Pao; Neil Kelley; Bonnie Jonkman; Rod Frehlich

2012-01-01T23:59:59.000Z

8

Numerical wind speed simulation model  

DOE Green Energy (OSTI)

A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.

Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.

1981-09-01T23:59:59.000Z

9

Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1  

E-Print Network (OSTI)

Virtual Wind Speed Sensor for Wind Turbines Andrew Kusiak1 ; Haiyang Zheng2 ; and Zijun Zhang3 Abstract: A data-driven approach for development of a virtual wind-speed sensor for wind turbines is presented. The virtual wind-speed sensor is built from historical wind-farm data by data-mining algorithms

Kusiak, Andrew

10

Discussion of “Ultimate Wind Load Design Gust Wind Speeds ...  

Science Conference Proceedings (OSTI)

... Ind. Aerodyn., 97(3–4), 120–131. Peterka, JA (2001). “Database of peak gust wind speeds, Texas Tech/ CSU.” Extreme winds and wind effects on ...

2013-08-19T23:59:59.000Z

11

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

E-Print Network (OSTI)

?? 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)

Capps, Scott Blair

2010-01-01T23:59:59.000Z

12

United States Wind Resource Map: Annual Average Wind Speed at...  

Wind Powering America (EERE)

and atmospheric effects may cause the wind speed to depart from the map estimates. Expert advice should be sought in placing wind turbines and estimating their energy production....

13

Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution  

SciTech Connect

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.

Zhou, Yuyu; Smith, Steven J.

2013-09-09T23:59:59.000Z

14

Dual-speed wind turbine generation  

SciTech Connect

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.

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

1996-10-01T23:59:59.000Z

15

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

Open Energy Info (EERE)

maps at 10m and 50m above surface maps at 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data 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. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 36.3 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 2000 - 2004 License License Other or unspecified, see optional comment below

16

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

Open Energy Info (EERE)

10m and 50m above 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data 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. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL ocean offshore QuikScat SWERA UNEP wind Data application/msword icon Download Documentation (doc, 53.8 KiB) application/zip icon Download Data (zip, 41 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/2000 - 12/31/2004

17

Reference wind speed distributions and height profiles for wind turbine design and performance evaluation applications. [USA  

DOE Green Energy (OSTI)

The purpose of this report is to provide a set of reference or standard values of wind profiles, wind speed distributions and their effects on wind turbine performance for engineering design applications. Based on measured Weibull distribution parameters, representative average, low, and high variance data are given for height profiles of mean, 25 percentile, and 75 percentile wind speeds; and for wind speed probability density (velocity frequency) functions and cumulative probability (velocity duration) functions at selected heights. Results of a sensitivity analysis of the dependence of wind turbine performance parameters on cut-in speed, and rated speed for various mean wind and wind variance regimes are also presented. Wind turbine performance is expressed in terms of capacity factor (ratio of mean power output to rated power) and recovery factor (ratio of mean energy output to energy theoretically available in the wind). The representative high, mean, and low variance cases were determined from calculated Weibull distributions at 140 sites across the Continental U.S., and all of the representative functions are evaluated at mean wind speeds of 4, 5, 6, 7, and 8 m/s at standard 10 m level.

Justus, C.G.; Hargraves, W.R.; Mikhail, A.

1976-08-01T23:59:59.000Z

18

Low Wind Speed Technology Phase I: Prototype Multi-Megawatt Low Wind Speed Turbine; General Electric Wind Energy, LLC  

SciTech Connect

This fact sheet describes a subcontract with GE Wind Energy to develop an advanced prototype turbine to significantly reduce energy costs (COE) in low wind speed environments.

2006-03-01T23:59:59.000Z

19

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

Open Energy Info (EERE)

data 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.

...

20

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

Open Energy Info (EERE)

data 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.

...

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Modelling and forecasting wind speed intensity for weather risk management  

Science Conference Proceedings (OSTI)

The main interest of the wind speed modelling is on the short-term forecast of wind speed intensity and direction. Recently, its relationship with electricity production by wind farms has been studied. In fact, electricity producers are interested in ... Keywords: ARFIMA-FIGARCH, Auto Regressive Gamma, Gamma Auto Regressive, Weather risk management, Wind speed modelling, Wind speed simulation

Massimiliano Caporin; Juliusz Pre

2012-11-01T23:59:59.000Z

22

Understanding Inertial and Frequency Response of Wind Power Plants: Preprint  

DOE Green Energy (OSTI)

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).

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

2012-07-01T23:59:59.000Z

23

Quantifying hurricane wind speed with undersea sound  

E-Print Network (OSTI)

Hurricanes, powerful storms with wind speeds that can exceed 80 m/s, are one of the most destructive natural disasters known to man. While current satellite technology has made it possible to effectively detect and track ...

Wilson, Joshua David

2006-01-01T23:59:59.000Z

24

The Autocorrelation of Hourly Wind Speed Observations  

Science Conference Proceedings (OSTI)

The autocorrelation of hourly wind speed observations is estimated for seven stations on the west coast of Canada at selected lags ranging from one hour to two months. The estimated autocorrelation function is fitted by a model that includes a ...

Arthur C. Brett; Stanton E. Tuller

1991-06-01T23:59:59.000Z

25

Wind Speed Forecasting for Power System Operation  

E-Print Network (OSTI)

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 operation in terms of the efficiency of the system. The goal of this dissertation is to develop advanced statistical wind speed predictive models to reduce the uncertainties in wind, especially the short-term future wind speed. Moreover, a criterion is proposed to evaluate the performance of models. Cost reduction in power system operation, as proposed, is more realistic than prevalent criteria, such as, root mean square error (RMSE) and absolute mean error (MAE). Two advanced space-time statistical models are introduced for short-term wind speed forecasting. One is a modified regime-switching, space-time wind speed fore- casting model, which allows the forecast regimes to vary according to the dominant wind direction and seasons. Thus, it avoids a subjective choice of regimes. The other one is a novel model that incorporates a new variable, geostrophic wind, which has strong influence on the surface wind, into one of the advanced space-time statistical forecasting models. This model is motivated by the lack of improvement in forecast accuracy when using air pressure and temperature directly. Using geostrophic wind in the model is not only critical, it also has a meaningful geophysical interpretation. The importance of model evaluation is emphasized in the dissertation as well. Rather than using RMSE or MAE, the performance of both wind forecasting models mentioned above are assessed by economic benefits with real wind farm data from Pacific Northwest of the U.S and West Texas. Wind forecasts are incorporated into power system economic dispatch models, and the power system operation cost is used as a loss measure for the performance of the forecasting models. From another perspective, the new criterion leads to cost-effective scheduling of system-wide wind generation with potential economic benefits arising from the system-wide generation of cost savings and ancillary services cost savings. As an illustration, the integrated forecasts and economic dispatch framework are applied to the Electric Reliability Council of Texas (ERCOT) equivalent 24- bus system. Compared with persistence and autoregressive models, the first model suggests that cost savings from integration of wind power could be on the scale of tens of millions of dollars. For the second model, numerical simulations suggest that the overall generation cost can be reduced by up to 6.6% using look-ahead dispatch coupled with spatio-temporal wind forecast as compared with dispatch with persistent wind forecast model.

Zhu, Xinxin

2013-08-01T23:59:59.000Z

26

LIDAR Wind Speed Measurements of Evolving Wind Fields  

DOE Green Energy (OSTI)

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

27

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect

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.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

28

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

SciTech Connect

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.

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

1995-11-01T23:59:59.000Z

29

The Wind Speed Profile At Offshore Wind Farm Sites  

E-Print Network (OSTI)

Using Monin-Obukhov theory the vertical wind speed profile can be predicted from the wind speed at one height, when the two parameters Monin-Obukhov length and sea surface roughness are known. The applicability of this theory for wind power prediction at offshore sites is investigated using data from the measurement program Rdsand in the Danish Baltic Sea. Different methods to estimate the two parameters are discussed and compared. Significant deviations to the theory are found for near-neutral and stable conditions, where the measured wind shear is larger than predicted. A simple correction method to account for this effect has been developed and tested.

Bernhard Lange Sren; Bernhard Lange; Sřren E. Larsen; Jřrgen Hřjstrup; Rebecca Barthelmie

2002-01-01T23:59:59.000Z

30

Unsafe at Any (Wind) Speed?  

Science Conference Proceedings (OSTI)

The goal of this research was to examine the relative safety and stability of stationary motor vehicles exposed to severe winds. The focus was on private passenger vehicles. 1) The behavior of two instrumented storm-chase vehicles that were ...

Thomas Schmidlin; Barbara Hammer; Paul King; Yuichi Ono; L. Scott Miller; Gregory Thumann

2002-12-01T23:59:59.000Z

31

Sampling Wind Data for Mean Wind Speed Estimation  

Science Conference Proceedings (OSTI)

Two sampling techniques are applied to wind data at 3 h intervals for six stations in the Great Plains region in the United States in order to investigate the reduction in the number of data needed to estimate the mean wind speed. One-in-k ...

Mark Jong; Gary Thomann

1981-03-01T23:59:59.000Z

32

The Probability Distribution of Land Surface Wind Speeds  

Science Conference Proceedings (OSTI)

The probability density function (pdf) of land surface wind speeds is characterized using a global network of observations. Daytime surface wind speeds are shown to be broadly consistent with the Weibull distribution, while nighttime surface wind ...

Adam H. Monahan; Yanping He; Norman McFarlane; Aiguo Dai

2011-08-01T23:59:59.000Z

33

Extreme learning machine based wind speed estimation and sensorless control for wind turbine power generation system  

Science Conference Proceedings (OSTI)

This paper proposes a precise real-time wind speed estimation method and sensorless control for variable-speed variable-pitch wind turbine power generation system (WTPGS). The wind speed estimation is realized by a nonlinear input-output mapping extreme ... Keywords: Extreme learning machine, Sensorless control, Wind speed estimation, Wind turbine power generation system

Si Wu; Youyi Wang; Shijie Cheng

2013-02-01T23:59:59.000Z

34

LIDAR Wind Speed Measurements of Evolving Wind Fields  

Science Conference Proceedings (OSTI)

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 that are 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 the validity of physicist G.I. Taylor's 1938 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 using the National Renewable Energy Laboratory's (NREL's) 5-megawatt turbine model to create a more realistic measurement model. A simple model of wind evolution was applied to a frozen wind field that was used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements were also evaluated using a large eddy simulation (LES) of a stable boundary layer that was provided by the National Center for Atmospheric Research. The LIDAR measurement scenario investigated consists of a hub-mounted LIDAR that scans a circle of points upwind of the turbine in order to estimate the wind speed component in the mean wind direction. Different combinations of the preview distance that is located upwind of the rotor and the radius of the scan circle were analyzed. It was found that the dominant source of measurement error for short preview distances is the detection of transverse and vertical wind speeds from the line-of-sight LIDAR measurement. It was discovered in previous studies that, in the absence of wind evolution, the dominant source of error for large preview distances is the spatial averaging caused by the LIDAR's sampling volume. However, by introducing wind evolution, the dominant source of error for large preview distances was found to be the coherence loss caused by evolving turbulence. Different measurement geometries were compared using the bandwidth for which the measurement coherence remained above 0.5 and also the area under the measurement coherence curve. Results showed that, by increasing the intensity of wind evolution, the measurement coherence decreases. Using the coherence bandwidth metric, the optimal preview distance for a fixed-scan radius remained almost constant for low and moderate amounts of wind evolution. For the wind field with the simple wind evolution model introduced, the optimal preview distance for a scan radius of 75% blade span (47.25 meters) was found to be 80 meters. Using the LES wind field, the optimal preview distance was 65 meters. When comparing scan geometries using the area under the coherence curve, results showed that, as the intensity of wind evolution increases, the optimal preview distance decreases.

Simley, E.; Pao, L. Y.; Kelley, N.; Jonkman, B.; Frehlich, R.

2012-01-01T23:59:59.000Z

35

Time Series Models to Simulate and Forecast Wind Speed and Wind Power  

Science Conference Proceedings (OSTI)

A general approach for modeling wind speed and wind power is described. Because wind power is a function of wind speed, the methodology is based on the development of a model of wind speed. Values of wind power are estimated by applying the ...

Barbara G. Brown; Richard W. Katz; Allan H. Murphy

1984-08-01T23:59:59.000Z

36

Wind speed PDF classification using Dirichlet mixtures Rudy CALIF1  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

37

Dynamic simulation of dual-speed wind turbine generation  

SciTech Connect

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.

Muljadi, E.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

38

United States Wind Resource Map: Annual Average Wind Speed at...  

Wind Powering America (EERE)

80 m 01-APR-2011 2.1.1 Wind Speed ms >10.5 10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 < 4.0 Source: Wind resource estimates developed by AWS Truepower, LLC for...

39

Extreme Wind Speed Data Sets: Texas Tech/CSU  

Science Conference Proceedings (OSTI)

... B-indicates a beacon tower exposure. ... 93839 Memphis TN 4 3 1968 123 107 WIND SPEEDS GREATER ... [ SED Home | Extreme Winds Home | Data ...

2013-09-27T23:59:59.000Z

40

Can Satellite Sampling of Offshore Wind Speeds Realistically Represent Wind Speed Distributions?  

Science Conference Proceedings (OSTI)

Wind speeds over the oceans are required for a range of applications but are difficult to obtain through in situ methods. Hence, remote sensing tools, which also offer the possibility of describing spatial variability, represent an attractive ...

R. J. Barthelmie; S. C. Pryor

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Sliding mode control law for a variable speed wind turbine  

Science Conference Proceedings (OSTI)

Modern wind turbines are designed in order to work in variable speed operations. To perform this task, wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed ... Keywords: modeling and simulation, variable structure control, wind turbine control

Oscar Barambones; Jose Maria Gonzalez De Durana; Patxi Alkorta; Jose Antonio Ramos; Manuel De La Sen

2011-02-01T23:59:59.000Z

42

Short-Term Wind Speed Forecasting for Power System Operations  

E-Print Network (OSTI)

Global large scale penetration of wind energy is accompanied by significant challenges due to the intermittent and unstable nature of wind. High quality short-term wind speed forecasting is critical to reliable and secure power system operations. This paper gives an overview of the current status of worldwide wind power developments and future trends, and reviews some statistical short-term wind speed forecasting models, including traditional time series models and advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular the need for realistic loss functions. New challenges in wind speed forecasting regarding ramp events and offshore wind farms are also presented.

Xinxin Zhu; Marc G. Genton

2011-01-01T23:59:59.000Z

43

Wind speed modeling and prediction in wind farms using fuzzy logic  

Science Conference Proceedings (OSTI)

In this paper, the upcoming wind speed is forecasted using the stochastic characteristics of wind speed of previous years. The wind speed is estimated in the fuzzy inference system and simulated with the fuzzy logic. The simulation results illustrate ... Keywords: fuzzy, prediction, wind farm

Shahram Javadi; Zeinab Hojjatinia

2012-01-01T23:59:59.000Z

44

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

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

45

Power quality analysis of wind generator connected to the weak grid during low wind speed  

Science Conference Proceedings (OSTI)

Power quality analysis based on measurements performed on wind generator during low wind speed is presented in the paper. Wind generator is connected via 10 kV cable to the distribution network, where grid is weak with low value of short-circuit power. ... Keywords: distribution network, harmonics, power quality, wind speed, wind turbine

Aleksandar Nikolic; Branka Kostic; Maja Markovic; Sasa Minic; Srdjan Milosavljevic

2011-07-01T23:59:59.000Z

46

Stability analysis of a variable-speed wind turbine  

DOE Green Energy (OSTI)

This paper examines the elastomechanical stability of a four-bladed wind turbine over a specific rotor speed range. Stability modes, frequencies, and dampings are extracted using a specialized modal processor developed at NREL that post-processes the response data generated by the ADAMS simulation code. The processor can analyze a turbine with an arbitrary number of rotor blades and offers a novel capability of isolating stability modes that become locked at a single frequency. Results indicate that over a certain rotor speed range, the tower lateral mode and the rotor regressive in-plane mode coalesce, resulting in a self-excited instability. Additional results show the effect of tower and nacelle parameters on the stability boundaries.

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

1996-10-01T23:59:59.000Z

47

LQG Controller for a Variable Speed Pitch Regulated Wind Turbine  

Science Conference Proceedings (OSTI)

This paper deals with the design of LQG controllers for pitch regulated, variable speed wind turbines where the controller is used primarily for controlling the pitch angle through a collective pitch angle in the high wind speed in order to guarantee ... Keywords: LQG controller, Pitch control, Wind Trubine

Xingjia Yao; Shu Liu; Guangkun Shan; Zuoxia Xing; Changchun Guo; Chuanbao Yi

2009-08-01T23:59:59.000Z

48

Sliding mode control strategy for variable speed wind turbine  

Science Conference Proceedings (OSTI)

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a robust control for variable speed wind power generation that incorporates a doubly feed induction generator is described. ...

Oscar Barambones; Jose Maria Gonzalez De Durana

2009-09-01T23:59:59.000Z

49

Using ADCP Background Sound Levels to Estimate Wind Speed  

Science Conference Proceedings (OSTI)

It is well known that ambient sound is generated by wind through the process of wave breaking and bubble injection. The resulting sound levels are highly correlated with wind speed and, even though the physical process is not fully understood, ...

Len Zedel

2001-11-01T23:59:59.000Z

50

Simulated Atmospheric Rime Icing of Some Wind Speed Sensors  

Science Conference Proceedings (OSTI)

Four commercially available wind speed sensors have been tested in an icing wind tunnel to determine the relative susceptibility of each to atmospheric icing and to determine the influence of ire accumulations upon the operation and accuracy of ...

E. M. Gates; W. C. Thompson

1986-06-01T23:59:59.000Z

51

Control algorithms for effective operation of variable-speed wind turbines  

DOE Green Energy (OSTI)

This report describes a computer code, called ASYM and provides results from its application in simulating the control of the 34-m Test Bed vertical-axis wind turbine (VAWT) in Bushland, Texas. The code synthesizes dynamic wind speeds on a second-by-second basis in the time domain. The wind speeds conform to a predetermined spectral content governed by the hourly average wind speed that prevails at each hour of the simulation. The hourly average values are selected in a probabilistic sense through the application of Markov chains, but their cumulative frequency of occurrence conforms to a Rayleigh distribution that is governed by the mean annual wind speed of the site selected. The simulated wind speeds then drive a series of control algorithms that enable the code to predict key operational parameters such as number of annual starts and stops, annual energy production, and annual fatigue damage at a critically stressed joint on the wind turbine. This report also presents results from the application of ASYM that pertain to low wind speed cut-in and cut-out conditions and controlled operation near critical speed ranges that excite structural vibrations that can lead to accelerated fatigue damage.

Not Available

1993-10-01T23:59:59.000Z

52

Trends and Interannual Variability of Wind Speed Distributions in Minnesota  

Science Conference Proceedings (OSTI)

Near-surface wind speed variability is investigated at seven stations in and surrounding Minnesota for recent climate records of 22–35 yr in length. Analyses focus on mean annual wind speeds and on the 10th, 25th, 50th, 75th, and 90th percentiles ...

Katherine Klink

2002-11-01T23:59:59.000Z

53

Atmospheric Circulation Effects on Wind Speed Variability at Turbine Height  

Science Conference Proceedings (OSTI)

Mean monthly wind speed at 70 m above ground level is investigated for 11 sites in Minnesota for the period 1995–2003. Wind speeds at these sites show significant spatial and temporal coherence, with prolonged periods of above- and below-normal ...

Katherine Klink

2007-04-01T23:59:59.000Z

54

Ocean Wind Speed Climatology from Spaceborne SAR Imagery  

Science Conference Proceedings (OSTI)

Spaceborne synthetic aperture radar (SAR) imagery can make high-resolution (? 500 m) ocean wind speed measurements. We anticipate re-processing the full decade and a half of Radarsat-1 SAR imagery and generating a SAR wind speed archive. These data will ...

Frank M. Monaldo; Xiaofeng Li; William G. Pichel; Christopher R. Jackson

55

Estimation of Extreme Wind Speeds with Very Long Return Periods  

Science Conference Proceedings (OSTI)

Long series of hourly mean wind speeds and the maximum hourly 3-s gust are simulated for four sites in the British Isles in order to investigate methods for the determination of extreme wind speed events. The simulation is performed using a one-...

M. D. G. Dukes; J. P. Palutikof

1995-09-01T23:59:59.000Z

56

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, E.

1998-08-25T23:59:59.000Z

57

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-08-25T23:59:59.000Z

58

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents (OSTI)

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.

Muljadi, Eduard (Golden, CO)

1998-01-01T23:59:59.000Z

59

Long-Term Wind Speed Trends over Australia  

Science Conference Proceedings (OSTI)

Accurate estimates of long-term linear trends of wind speed provide a useful indicator for circulation changes in the atmosphere and are invaluable for the planning and financing of sectors such as wind energy. Here a large number of wind ...

Alberto Troccoli; Karl Muller; Peter Coppin; Robert Davy; Chris Russell; Annette L. Hirsch

2012-01-01T23:59:59.000Z

60

Variable speed constant frequency constant voltage alternator. Annual report  

DOE Green Energy (OSTI)

A test alternator is operated with digital control of its output frequency for variable shaft speed. The machine is a two-pole alternator with power removed through slip rings. The output frequency of the alternator is controlled by rotating the field by stepping through sixteen coils around the rotor. Usually four coils are active at one time. The rotating field in the stationary coils of the stator is controlled by microcircuits. The control circuits are constructed with available low-cost, low-power integrated circuits (ICs). The test results from the first test alternator indicate the feasibility of using this type of alternator to convert available wind power directly to usable 60 hertz power.

Grannemann, W.W.; Yang, C.E.; Seo, P.H.

1980-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

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

DOE Green Energy (OSTI)

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.

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

2012-11-01T23:59:59.000Z

62

Optimal evolutionary wind turbine placement in wind farms considering new models of shape, orography and wind speed simulation  

Science Conference Proceedings (OSTI)

In this paper we present a novel evolutionary algorithm for optimal positioning of wind turbines in wind farms. We consider a realistic model for the wind farm, which includes orography, shape of the wind farm, simulation of the wind speed and direction, ...

B. Saavedra-Moreno; S. Salcedo-Sanz; A. Paniagua-Tineo; J. Gascón-Moreno; J. A. Portilla-Figueras

2011-06-01T23:59:59.000Z

63

Scatterometer Observations at High Wind Speeds  

Science Conference Proceedings (OSTI)

Satellite scatterometer winds are commonly validated by comparing them to buoy observations and/or numerical model surface wind analyses. However, the empirical scatterometer algorithm (geophysical model function) has been calibrated against a ...

Lixin Zeng; Robert A. Brown

1998-11-01T23:59:59.000Z

64

A Short-Term Ensemble Wind Speed Forecasting System for Wind Power Applications  

Science Conference Proceedings (OSTI)

This study develops an adaptive, blended forecasting system to provide accurate wind speed forecasts 1 h ahead of time for wind power applications. The system consists of an ensemble of 21 forecasts with different configurations of the Weather ...

Justin J. Traiteur; David J. Callicutt; Maxwell Smith; Somnath Baidya Roy

2012-10-01T23:59:59.000Z

65

Echo-state-network-based real-time wind speed estimation for wind power generation  

Science Conference Proceedings (OSTI)

Wind turbine generators (WTGs) are usually equipped with one or more well-calibrated anemometers to measure wind speed for system monitoring, control, and protection. The use of these mechanical sensors increases the cost and hardware complexity and ...

Wei Qiao

2009-06-01T23:59:59.000Z

66

A Technique for Deducing Wind Direction from Satellite Microwave Measurements of Wind Speed  

Science Conference Proceedings (OSTI)

A technique is presented to deduce wind direction from satellite microwave measurements of wind speed information. The technique, based on simple Ekman boundary layer dynamics, makes use of surface pressure fields routinely analyzed at the ...

Tsann-wang Yu

1987-09-01T23:59:59.000Z

67

Wind Speeds at Heights Crucial for Wind Energy: Measurements and Verification of Forecasts  

Science Conference Proceedings (OSTI)

Wind speed measurements from one year from meteorological towers and wind turbines at heights between 20 and 250 m for various European sites are analyzed and are compared with operational short-term forecasts of the global ECMWF model. The ...

Susanne Drechsel; Georg J. Mayr; Jakob W. Messner; Reto Stauffer

2012-09-01T23:59:59.000Z

68

File:CV WindSpeed.pdf | Open Energy Information  

Open Energy Info (EERE)

WindSpeed.pdf WindSpeed.pdf Jump to: navigation, search File File history File usage Cape Verde-Map Summarizing Average Wind Speed (m/s) Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 246 KB, MIME type: application/pdf) Description Cape Verde-Map Summarizing Average Wind Speed (m/s) Sources ECOWAS Creation Date 2011/11/14 Coordinates 16.002082°, -24.013197° File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 11:43, 14 November 2011 Thumbnail for version as of 11:43, 14 November 2011 1,650 × 1,275 (246 KB) STobin (Talk | contribs) You cannot overwrite this file. Edit this file using an external application (See the setup instructions for more information)

69

Review of Weibull Statistics for Estimation of Wind Speed Distributions  

Science Conference Proceedings (OSTI)

A statistical distribution commonly used for describing measured wind speed data is the Weibull distribution. A review of the methods found in the statistical literature for the purpose of estimation of the parameters in Weibull distributions is ...

K. Conradsen; L. B. Nielsen; L. P. Prahm

1984-08-01T23:59:59.000Z

70

Weibull Statistics of Wind Speed over the Ocean  

Science Conference Proceedings (OSTI)

The probability distribution of wind speed data over the world's oceans is studied using a two-parameter Weibull distribution. The parameters are estimated following a linearized least-squares approach. The seasonal and latitudinal variation are ...

Edgar G. Pavia; James J. O'Brien

1986-10-01T23:59:59.000Z

71

Global Estimates of Extreme Wind Speed and Wave Height  

Science Conference Proceedings (OSTI)

A long-term dataset of satellite altimeter measurements of significant wave height and wind speed, spanning 23 years, is analyzed to determine extreme values corresponding to a 100-yr return period. The analysis considers the suitability of both ...

J. Vinoth; I. R. Young

2011-03-01T23:59:59.000Z

72

Hurricane Surface Wind Measurements from an Operational Stepped Frequency Microwave Radiometer  

Science Conference Proceedings (OSTI)

For the first time, the NOAA/Aircraft Operations Center (AOC) flew stepped frequency microwave radiometers (SFMRs) on both WP-3D research aircraft for operational hurricane surface wind speed measurement in 2005. An unprecedented number of major ...

Eric W. Uhlhorn; Peter G. Black; James L. Franklin; Mark Goodberlet; James Carswell; Alan S. Goldstein

2007-09-01T23:59:59.000Z

73

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

74

Development of Wind Speed Forecasting Model Based on the Weibull Probability Distribution  

Science Conference Proceedings (OSTI)

Wind is a variable energy source. The power output of a wind turbine generator (WTG) unit, therefore, fluctuates with wind speed variations. Accurate models reflecting the variability of wind speed is hence required in both reliability evaluation of ... Keywords: Wind Energy, Wind Speed Forecasting Model, Weibull Distribution, Maximum Likelihood Method, Time Series Model

Ruigang Wang; Wenyi Li; B. Bagen

2011-02-01T23:59:59.000Z

75

Modelling the Vertical Wind Speed and Turbulence Intensity Profiles at Prospective Offshore Wind Farm Sites  

E-Print Network (OSTI)

Monin-Obukhov theory predicts the well-known log-linear form of the vertical wind speed profile. A turbulence intensity profile can be estimated from this by assuming that the standard deviation of the wind speed is proportional to the friction velocity. Two parameters, namely the aerodynamic surface roughness length and the MoninObukhov length, are than needed to predict the vertical wind speed and turbulence intensity profiles from a measurement at one height. Different models to estimate these parameters for conditions important for offshore wind energy utilisation are compared and tested: Four models for the surface roughness and three methods to derive the Monin-Obukov-length from measurements. They have been tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind speed to 50 m height and comparing it with the measured 50 m wind speed.

Bernhard Lange; Sřren Larsen; Jřrgen Hřjstrup; Rebecca Barthelmie; Ulrich Focken

2002-01-01T23:59:59.000Z

76

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)

The amount of power in the wind is very dependent on the speed of the wind. Because the power in the wind is proportional to the cube of the wind speed, small differences in the wind speed make a big. This gives rise to the primary reason for wind re- source assessment. In order to more accurately predict

Massachusetts at Amherst, University of

77

Anemometer Data (Wind Speed, Direction) for Laurel, Nebraska (2001 - 2002)  

Open Energy Info (EERE)

Laurel, Nebraska (2001 - 2002) Laurel, Nebraska (2001 - 2002) Dataset Summary Description Wind data collected from Laurel, Nebraska from a 20-meter anemometer as part of the Western Area Power Administration anemometer loan program. Ten-minute average wind speed and direction is available for 2001 - 2002. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago) Keywords wind wind direction wind speed Data text/csv icon Jun 11, 2001 - Jul 1, 2001 (csv, 144 KiB)

78

Short term wind speed forecasting with evolved neural networks  

Science Conference Proceedings (OSTI)

Concerns about climate change, energy security and the volatility of the price of fossil fuels has led to an increased demand for renewable energy. With wind turbines being one of the most mature renewable energy technologies available, the global use ... Keywords: forecasting, renewable energy, wind-speed

David Corne; Alan Reynolds; Stuart Galloway; Edward Owens; Andrew Peacock

2013-07-01T23:59:59.000Z

79

The Influence of Wind Speed on Shallow Marine Cumulus Convection  

Science Conference Proceedings (OSTI)

The role of wind speed on shallow marine cumulus convection is explored using large-eddy simulations and concepts from bulk theory. Focusing on cases characteristic of the trades, the equilibrium trade wind layer is found to be deeper at stronger ...

Louise Nuijens; Bjorn Stevens

2012-01-01T23:59:59.000Z

80

Correlation of Real and Model Wind Speeds in Different Terrains  

Science Conference Proceedings (OSTI)

Wind speeds over a 6-month period from 21 surface stations, 3 upper-wind stations, and 2 different models are compared. Similar data are used for three different topographic regions of New Zealand broadly classed as having low, moderate, and high ...

Steve J. Reid; Richard Turner

2001-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Comparison of Synthetic Aperture Radar–Derived Wind Speeds with Buoy Wind Speeds along the Mountainous Alaskan Coast  

Science Conference Proceedings (OSTI)

Satellite-borne synthetic aperture radar (SAR) offers the potential for remotely sensing surface wind speed both over the open sea and in close proximity to the coast. The resolution improvement of SAR over scatterometers is of particular ...

C. M. Fisher; G. S. Young; N. S. Winstead; J. D. Haqq-Misra

2008-05-01T23:59:59.000Z

82

System and method for upwind speed based control of a wind turbine ...  

A method for controlling power output of a wind turbine generator in response to an anticipated change in wind speed is provided. The method includes sensing wind ...

83

Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) |  

Open Energy Info (EERE)

40 40 Varnish cache server Anemometer Data (Wind Speed, Direction) for Tanana, AK (2001 - 2002) Dataset Summary Description Wind data collected from Tanana Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago)

84

Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) |  

Open Energy Info (EERE)

0 0 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142278290 Varnish cache server Anemometer Data (Wind Speed, Direction) for Ugashik, AK (2001 - 2002) Dataset Summary Description Wind data collected from Ugashik Traditional Village in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2001 through 2002, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp.

85

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

E-Print Network (OSTI)

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

Richardson, John

86

Short-term wind speed forecasting based on a hybrid model  

Science Conference Proceedings (OSTI)

Wind power is currently one of the types of renewable energy with a large generation capacity. However, operation of wind power generation is very challenging because of the intermittent and stochastic nature of the wind speed. Wind speed forecasting ... Keywords: Forecasting, RBF neural networks, Seasonal adjustment, Wavelet transform, Wind speed

Wenyu Zhang, Jujie Wang, Jianzhou Wang, Zengbao Zhao, Meng Tian

2013-07-01T23:59:59.000Z

87

Variable-Speed Wind System Design : Final Report.  

SciTech Connect

Almost from the onset of the development of wind energy conversion systems (WECS), it was known that variable-speed operation of the turbine would maximize energy capture. This study was commissioned to assess the cost, efficiency gain, reduction of the cost of energy (COE), and other operating implications of converting the existing hardware of a modern fixed-speed wind energy conversion system to variable-speed operation. The purpose of this study was to develop a preliminary design for the hardware required to allow variable-speed operation using a doubly-fed generator with an existing fixed-speed wind turbine design. The turbine selected for this study is the AWT-26 designed and built by Advanced Wind Turbines Inc. of Redmond, Washington. The lowest projected COE using this variable-speed generation system is projected to be $0.0499/kWh, compared to the lowest possible COE with fixed-speed generation which is projected to be $0.0546/kWh. This translates into a 8.6% reduction of the COE using this variable-speed generation option. The preliminary system design has advanced to where the printed circuit boards can be physically laid out based on the schematics and the system software can be written based on the control flow-charts. The core of hardware and software has been proven to be successful in earlier versions of VSG systems. The body of this report presents the results of the VSWG system development. Operation under normal and fault conditions is described in detail, the system performance for variable-speed operation is estimated and compared to the original fixed-speed system performance, and specifications for all system components (generator, power electronic converter, and system controller) are given. Costs for all components are estimated, and incremental system cost is compared to incremental energy production. Finally, operational features of the VSWG which are not available in the existing FSWG system are outlined.

Lauw, Hinan K.; Weigand, Claus H.; Marckx, Dallas A.; Electronic Power Conditioning, Inc.

1993-10-01T23:59:59.000Z

88

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

E-Print Network (OSTI)

1. Wind-splash erosion 4. Relationships between rainfall intensity, wind-speed, wind direction and erosion 5. Longer term influence of wind-direction on landscape evolution 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1 of tubes at approximately two week intervals. Contour plots of rainfall intensity (mm/hr) against wind

89

Empirical-Statistical Method to Estimate the Surface Wind Speed over Complex Terrain  

Science Conference Proceedings (OSTI)

An empirical-statistical method to estimate surface wind speed over complex terrain under strong wind condition is proposed. This method is based on the postulation that the surface wind speed depends on a surface roughness parameter and a ...

Hiromi Yamazawa; Junsei Kondo

1989-09-01T23:59:59.000Z

90

Empirical Models of the Probability Distribution of Sea Surface Wind Speeds  

Science Conference Proceedings (OSTI)

This study considers the probability distribution of sea surface wind speeds, which have historically been modeled using the Weibull distribution. First, non-Weibull structure in the observed sea surface wind speeds (from SeaWinds observations) ...

Adam Hugh Monahan

2007-12-01T23:59:59.000Z

91

Simulation of wind-speed time series for wind-energy conversion analysis.  

DOE Green Energy (OSTI)

In order to investigate operating characteristics of a wind energy conversion system it is often desirable to have a sequential record of wind speeds. Sometimes a long enough actual data record is not available at the time an analysis is needed. This may be the case if, e.g., data are recorded three times a day at a candidate wind turbine site, and then the hourly performance of generated power is desired. In such cases it is often possible to use statistical characteristics of the wind speed data to calibrate a stochastic model and then generate a simulated wind speed time series. Any length of record may be simulated by this method, and desired system characteristics may be studied. A simple wind speed simulation model, WEISIM, is developed based on the Weibull probability distribution for wind speeds with a correction based on the lag-one autocorrelation value. The model can simulate at rates from one a second to one an hour, and wind speeds can represent short-term averages (e.g., 1-sec averages) or longer-term averages (e.g., 1-min or 1 hr averages). The validity of the model is verified with PNL data for both histogram characteristics and persistance characteristics.

Corotis, R.B.

1982-06-01T23:59:59.000Z

92

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

DOE Green Energy (OSTI)

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.

Robert W. Preus; DOE Project Officer - Keith Bennett

2008-04-23T23:59:59.000Z

93

Manual and Semiautomated Wind Direction Editing for Use in the Generation of Synthetic Aperture Radar Wind Speed Imagery  

Science Conference Proceedings (OSTI)

Previous studies have demonstrated that satellite synthetic aperture radar (SAR) can be used as an accurate scatterometer, yielding wind speed fields with subkilometer resolution. This wind speed generation is only possible, however, if a ...

George S. Young; Todd D. Sikora; Nathaniel S. Winstead

2007-06-01T23:59:59.000Z

94

An Optical Disdrometer for Use in High Wind Speeds  

Science Conference Proceedings (OSTI)

A new optical disdrometer has been developed that is optimized for use in high wind speeds, for example, on board ships. The minimal detectable size of droplets is 0.35 mm. Each drop is measured separately with regard to its size and residence ...

Martin Grossklaus; Klaus Uhlig; Lutz Hasse

1998-08-01T23:59:59.000Z

95

A Mechanism for the Increase of Wind Stress (Drag) Coefficient with Wind Speed over Water Surfaces: A Parametric Model  

Science Conference Proceedings (OSTI)

A mechanism is proposed for a physical explanation of the increase in wind stress (drag) coefficient with wind speed over water surfaces. The formula explicitly incorporates the contribution of both winds and waves through the parameterizations ...

S. A. Hsu

1986-01-01T23:59:59.000Z

96

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

E-Print Network (OSTI)

Wind energy is considered as the most viable renewable energy options. In a renewable energy system more energy from the wind. One of the options is to use the variable speed wind turbine-speed wind turbine system for transient studies are discussed in this paper. The performance of wind energy

97

Analysis of Wind Speed Measurements using Continuous Wave LIDAR for Wind Turbine Control ?†  

E-Print Network (OSTI)

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 accurate the incoming wind field can be measured. This study examines the accuracy of different measurement scenarios that rely on coherent continuouswave Doppler LIDAR systems to determine their applicability to feedforward 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. Nomenclature d measurement preview distance F focal distance k wind velocity wavenumber (m?1) r scan radius for spinning LIDAR RMS root mean square ?u standard deviation of u component of wind velocity TI turbulence intensity ? LIDAR measurement angle ? mean u wind speed u ? friction velocity U ? D average friction velocity over rotor disk ? angle between laser and wind velocity vector ? angle in the rotor plane ? rotational rate of spinning LIDAR

Eric Simley; Lucy Y. Pao; Rod Frehlich; Bonnie Jonkman; Neil Kelley

2011-01-01T23:59:59.000Z

98

Hi-Q Rotor - Low Wind Speed Technology  

DOE Green Energy (OSTI)

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.

Todd E. Mills; Judy Tatum

2010-01-11T23:59:59.000Z

99

The Influence of Bubbles on Ambient Noise in the Ocean at High Wind Speeds  

Science Conference Proceedings (OSTI)

Observations of ambient noise in the ocean at high wind speeds reveal significant departures in spectral shape from previously reported values at lower wind speeds. The observations were made in open ocean conditions in Queen Charlotte Sound, ...

David M. Farmer; David D. Lemon

1984-11-01T23:59:59.000Z

100

Using a new characterization of turbulent wind for accurate correlation of wind turbine response with wind speed  

SciTech Connect

The turbulence encountered by a point on a rotating wind turbine blade has characteristics that in some important respects are different from those measured by a stationary anemometer. The conventional one-peaked continuous spectrum becomes, broadly, a two-peaked spectrum that in addition contains a set of narrow-band spikes of turbulence energy, one centered on the frequency of rotor rotation and the others centered on multiples of that frequency. The rotational sampling effect on wind spectra is quantified using measurements of wind velocity by anemometers on stationary crosswind circular arrays. Characteristics of fluctuating wind are compared to measured fluctuations of bending moments of the rotor blades and power output fluctuations of a horizontal-axis wind turbine at the same site. The wind characteristics and the correlations between wind fluctuations and wind turbine fluctuations provide a basis for improving turbine design, siting, and control. 6 refs., 11 figs., 1 tab.

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

1987-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Modeling and design of control system for variable speed wind turbine in all operating region  

Science Conference Proceedings (OSTI)

In order to get the maximum power from the wind, the variable-speed wind turbine should run at different speed when wind speed changes. In this paper a control system is introduced to get this purpose base on establishing the three-mass model of the ... Keywords: doubly-fed induction generator (DFIG), feed-forward compensator, loop-shaping, pitch controller, speed controller, three-mass model, wind turbine

Wu Dingguo; Wang Zhixin

2008-05-01T23:59:59.000Z

102

A neural network control strategy for improved energy capture on a variable-speed wind turbine  

Science Conference Proceedings (OSTI)

Pitch control has so far been the dominating method for power control in modern variable speed wind turbines. This paper proposes an improved control technique for pitching the blades of a variable speed wind turbine, using Artificial Neural Networks ... Keywords: artificial neural networks, control trajectories, pitch control, variable-speed wind turbines

António F. Silva; Fernando A. Castro; José N. Fidalgo

2005-06-01T23:59:59.000Z

103

Systematic Controller Design Methodology for Variable-Speed Wind Turbines  

DOE Green Energy (OSTI)

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.

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

2002-02-01T23:59:59.000Z

104

Pitch Angle Control of Variable Low Rated Speed Wind Turbine Using Fuzzy Logic Control  

E-Print Network (OSTI)

Abstract — Pitch angle control of wind turbine has been used widely to reduce torque and output power variation in high rated wind speed areas. It is a challenge to maximize available energy in the low rated wind speed areas. In this paper, a wind turbine prototype with a pitch angle control based on fuzzy logic to maximize the output power is built and demonstrated. In the varying low rated wind speed of 4-6 m/s, the use of fuzzy logic controller can maximize the average output power of 14.5 watt compared to 14.0 watt at a fixed pitch angle of the blade. Implementation of pitch angle fuzzy logic-based control to the wind turbine is suitable for the low rated wind speed areas. Index Terms — low rated wind speed areas, pitch angle control, fuzzy logic, wind turbine. T I.

A. Musyafa; A. Harika; I. M. Y. Negara; I. Rob

2010-01-01T23:59:59.000Z

105

Model Simulations Examining the Relationship of Lake-Effect Morphology to Lake Shape, Wind Direction, and Wind Speed  

Science Conference Proceedings (OSTI)

Idealized model simulations with an isolated elliptical lake and prescribed winter lake-effect environmental conditions were used to examine the influences of lake shape, wind speed, and wind direction on the mesoscale morphology. This study ...

Neil F. Laird; John E. Walsh; David A. R. Kristovich

2003-09-01T23:59:59.000Z

106

Error Estimates for Ocean Surface Winds: Applying Desroziers Diagnostics to the Cross-Calibrated, Multiplatform Analysis of Wind Speed  

Science Conference Proceedings (OSTI)

The Desroziers diagnostics (DD) are applied to the cross-calibrated, multi-platform (CCMP) ocean surface wind data sets to estimate wind speed errors of the ECMWF background, the microwave satellite observations and the resulting CCMP analysis. ...

Ross N. Hoffman; Joseph V. Ardizzone; S. Mark Leidner; Deborah K. Smith; Robert Atlas

107

One-Month Ahead Prediction of Wind Speed and Output Power Based on EMD and LSSVM  

Science Conference Proceedings (OSTI)

Wind speed is a kind of non-stationary time series, it is difficult to construct the model for accurate forecast. The way improving accuracy of the model for predicting wind speed up to one-month ahead has been investigated using measured data recorded ... Keywords: wind speed forecasting, empirical mode decomposition(EMD), least square support vector machine (LSSVM), intrinsic mode function(IFM), wind power

Wang Xiaolan; Li Hui

2009-10-01T23:59:59.000Z

108

Neuroadaptive speed assistance control of wind turbine with variable ratio gearbox (VRG)  

Science Conference Proceedings (OSTI)

Wind power as a renewable energy source is irregular in occurrence. It is interesting yet challenging to maximize the energy capture from wind. Most existing control methods for wind power generation are traditionally based on wind turbine with fixed ... Keywords: PMSM, neuroadaptive control, speed regulation, wind turbine

Xue-fei Wang; Yong-duan Song; Dan-yong Li; Kai Zhang; Shan Xue; Ming Qin

2012-07-01T23:59:59.000Z

109

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

SciTech Connect

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.

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

2013-12-01T23:59:59.000Z

110

Pitch-Controlled Variable-Speed Wind Turbine Generation  

NLE Websites -- All DOE Office Websites (Extended Search)

Pitch-Controlled Variable-Speed Pitch-Controlled Variable-Speed Wind Turbine Generation February 2000 * NREL/CP-500-27143 E. Muljadi and C.P. Butterfield Presented at the 1999 IEEE Industry Applications Society Annual Meeting Phoenix, Arizona October 3-7, 1999 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute * * * * Battelle * * * * Bechtel Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes.

111

Measurement strategies for estimating long-term average wind speeds  

DOE Green Energy (OSTI)

The uncertainty and bias in estimates of long-term average wind speeds inherent in continuous and intermittent measurement strategies are examined by simulating the application of the strategies to 40 data sets. Continuous strategies have smaller uncertainties for fixed duration measurement programs, but intermittent strategies make more efficient use of instruments and have smaller uncertainties for a fixed amount of instrument use. Continuous strategies tend to give biased estimates of the long-term annual mean speed unless an integral number of years' data is collected or the measurement program exceeds 3 years in duration. Intermittent strategies with three or more month-long measurement periods per year do not show any tendency toward bias.

Ramsdell, J.V.; Houston, S.; Wegley, H.L.

1980-10-01T23:59:59.000Z

112

Simplified wind turbine model for the simulation of frequency support mode of operation  

Science Conference Proceedings (OSTI)

Nowadays, technology evolution and deregulation of the electric utility industry enable Distributed Generation (DG) to play an increasing role in satisfying locally the expanding power demand and generally provide ancillary services to the system. In ... Keywords: control, frequency support, modeling, variable speed wind turbines (VSWT)

F. D. Kanellos; G. J. Tsekouras; C. D. Tsirekis

2011-07-01T23:59:59.000Z

113

Homogenization and Trend Analysis of Canadian Near-Surface Wind Speeds  

Science Conference Proceedings (OSTI)

Near-surface wind speeds recorded at 117 stations in Canada for the period from 1953 to 2006 were analyzed in this study. First, metadata and a logarithmic wind profile were used to adjust hourly wind speeds measured at nonstandard anemometer ...

Hui Wan; Xiaolan L. Wang; Val R. Swail

2010-03-01T23:59:59.000Z

114

Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems  

E-Print Network (OSTI)

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

Brest, Université de

115

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

116

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

Open Energy Info (EERE)

from the KAMMWASP studies for Kenya.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

117

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

Open Energy Info (EERE)

for Nepal.

The KAMMWAsP methodology uses a set of windclasses to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using...

118

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

Open Energy Info (EERE)

the KAMMWASP studies for Ethiopia.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

119

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

Open Energy Info (EERE)

See supplemental information.

The KAMMWAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for...

120

Solar wind acceleration in coronal holes. [High speed solar wind streams  

SciTech Connect

Past attempts to explain the large solar wind velocities in high speed streams by theoretical models of the expansion have invoked either extended nonthermal heating of the corona, heat flux inhibition, or direct addition of momentum to the expanding coronal plasma. Several workers have shown that inhibiting the heat flux at low coronal densities is probably not adequate to explain quantitatively the observed plasma velocities in high speed streams. It stressed that, in order to account for both these large plasma velocities and the low densities found in coronal holes (from which most high speed streams are believed to emanate), extended heating by itself will not suffice. One needs a nonthermal mechanism to provide the bulk acceleration of the high wind plasma close to the sun, and the most likely candidate at present is direct addition of the momentum carried by outward-propagating waves to the expanding corona. Some form of momentum addition appears to be absolutely necessary if one hopes to build quantitatively self-consistent models of coronal holes and high speed solar wind streams.

Kopp, R.A.

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Pitch angle control in wind turbines above the rated wind speed by multi-layer perceptron and radial basis function neural networks  

Science Conference Proceedings (OSTI)

In wind energy conversion systems, one of the operational problems is the changeability and discontinuity of wind. In most cases, wind speed can fluctuate rapidly. Hence, quality of produced energy becomes an important problem in wind energy conversion ... Keywords: Neural network-based controller, Pitch control, Variable-speed wind turbine, Wind energy conversion systems

Ahmet Serdar Yilmaz; Zafer Özer

2009-08-01T23:59:59.000Z

122

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Kenya from RisoeDTU Kenya from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Kenya. The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and ii. a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the

123

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Bangladesh from RisoeDTU Bangladesh from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Bangladesh. Version 2 is an updated version of the earlier release and includes an adjustment to Weibull A and k to bring the Atlas values into better agreement with observations. See supplemental information.The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The result is i. a wind resource map, a summary of the simulated wind climate, and ii. a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to

124

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

DOE Green Energy (OSTI)

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.

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

1996-11-01T23:59:59.000Z

125

File:QuikSCAT - Annual Wind Speed at 10 m.pdf | Open Energy Information  

Open Energy Info (EERE)

QuikSCAT - Annual Wind Speed at 10 m.pdf QuikSCAT - Annual Wind Speed at 10 m.pdf Jump to: navigation, search File File history File usage QuikSCAT - Annual Wind Speed at 10 m Size of this preview: 463 × 599 pixels. Other resolution: 464 × 600 pixels. Full resolution ‎(1,275 × 1,650 pixels, file size: 1.19 MB, MIME type: application/pdf) Title Annual Wind Speed at 10 m Description QuikSCAT - Annual Wind Speed at 10 m Sources NREL, National Aeronautics and Space Administration Extent International Coordinates 0°, 0° Scatterometer measurements of the state of the ocean surface are used to estimate 10-m ocean winds in the QuikSCAT satellite data set. The QuikSCAT data are produced by Remote Sensing Systems and sponsored by the U.S. National Aeronautics and Space Administration Ocean Vector Winds Science

126

A WRF Ensemble for Improved Wind Speed Forecasts at Turbine Height  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting Model (WRF) with 10-km horizontal grid spacing was used to explore improvements in wind speed forecasts at a typical wind turbine hub height (80 m). An ensemble consisting of WRF model simulations with ...

Adam J. Deppe; William A. Gallus Jr.; Eugene S. Takle

2013-02-01T23:59:59.000Z

127

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

Science Conference Proceedings (OSTI)

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.

Mikhail, A.

2009-01-01T23:59:59.000Z

128

Comparison of Mean Wind Speeds and Turbulence at a Coastal Site and Offshore Location  

Science Conference Proceedings (OSTI)

Observations of mean wind speed and longitudinal turbulence at a height of 8 m over the Atlantic ocean, 5 km off Long Island, New York, were compared with simultaneous observations at the beach. Results were grouped into wind direction classes ...

S. SethuRaman; G. S. Raynor

1980-01-01T23:59:59.000Z

129

Spatial Predictions of Extreme Wind Speeds over Switzerland Using Generalized Additive Models  

Science Conference Proceedings (OSTI)

The purpose of this work is to present a methodology aimed at predicting extreme wind speeds over Switzerland. Generalized additive models are used to regionalize wind statistics for Swiss weather stations using a number of variables that ...

Christophe Etienne; Anthony Lehmann; Stéphane Goyette; Juan-Ignacio Lopez-Moreno; Martin Beniston

2010-09-01T23:59:59.000Z

130

An Isofactorial Change-of-Scale Model for the Wind Speed Probability Density Function  

Science Conference Proceedings (OSTI)

The wind speed probability density function (PDF) is used in a variety of applications in meteorology, oceanography, and climatology usually as a dataset comparison tool of a function of a quantity such as momentum flux or wind power density. The ...

Mark L. Morrissey; Angie Albers; J. Scott Greene; Susan Postawko

2010-02-01T23:59:59.000Z

131

A variable speed wind generator maximum power tracking based on adaptative neuro-fuzzy inference system  

Science Conference Proceedings (OSTI)

The power from wind varies depending on the environmental factors. Many methods have been proposed to locate and track the maximum power point (MPPT) of the wind, such as the fuzzy logic (FL), artificial neural network (ANN) and neuro-fuzzy. In this ... Keywords: ANFIS, MPPT, Power generation, Variable speed wind generator, Wind energy

A. Meharrar; M. Tioursi; M. Hatti; A. Boudghčne Stambouli

2011-06-01T23:59:59.000Z

132

The study of multimode power control system for MW variable-speed wind turbine  

Science Conference Proceedings (OSTI)

Wind energy is a viable option to complement other types of pollution-free generation. In the past constant-speed wind turbine is used for the limitation of the control technology and manufacturing technology. But this kind wind turbine has low efficiency ... Keywords: feed-forward compensator, loop-shaping, multimode power control system, pitch controller, speed controller, the shaft system model, wind turbine

Dingguo Wu; Zhixin Wang

2008-10-01T23:59:59.000Z

133

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

DOE Green Energy (OSTI)

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.

Genesis Partners LP

2010-08-01T23:59:59.000Z

134

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

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.

2006-03-01T23:59:59.000Z

135

Can Satellite Sampling of Offshore Wind Speeds Realistically Represent Wind Speed Distributions? Part II: Quantifying Uncertainties Associated with Distribution Fitting Methods  

Science Conference Proceedings (OSTI)

Remote sensing tools represent an attractive proposition for measuring wind speeds over the oceans because, in principle, they also offer a mechanism for determining the spatial variability of flow. Presented here is the continuation of research ...

S. C. Pryor; M. Nielsen; R. J. Barthelmie; J. Mann

2004-05-01T23:59:59.000Z

136

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Ethiopia from RisoeDTU Ethiopia from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Ethiopia. The KAMM/WAsP methodology uses a set of wind classes to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and ii.a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the mapping exercise, but it also means that verification of results has not been as complete would be ideal. There is some concern that the results may underestimate the resource. However, new measurement data is coming and revisions to the map may be made if necessary as verification is carried out.

137

Wind: wind speed and wind power density GIS data at 50m above ground and  

Open Energy Info (EERE)

Nepal from RisoeDTU Nepal from RisoeDTU Dataset Summary Description (Abstract): These data are results from the KAMM/WASP studies for Nepal. The KAMM/WAsP methodology uses a set of windclasses to represent wind conditions for the mapped region. A mesoscale simulation for each wind class, using KAMM (Karlsruhe Mesoscale Model), is performed and statistics performed on the model output. The results are a summary of the simulated wind climate, and a wind atlas, a summary of the wind climate standardized to flat, uniform roughness terrain. (Purpose): The product is intended to be used to estimate the wind resource potential in the country including the the spatial variability. This map covers regions where long term measurements are not available. In a sense this is the point of the mapping exercise, but it also means that verification of results has not been as complete would be ideal. There is some concern that the results may underestimate the resource. However, new measurement data is coming and revisions to the map may be made if necessary as verification is carried out.

138

Standard Deviations of Wind Speed and Direction from Observations over a Smooth Surface  

Science Conference Proceedings (OSTI)

Measurements of wind speed and direction made every minute on a 15 m mast sited on a large expanse of sea ice were analyzed to study the behavior of their standard deviation. The large scatter normally observed under low wind speed and/or non-...

Sylvain M. Joffre; Tuomas Laurila

1988-05-01T23:59:59.000Z

139

Observed Coherent Trends of Surface and Upper-Air Wind Speed over China since 1960  

Science Conference Proceedings (OSTI)

Previous studies indicated that surface wind speed over China declined during past decades, and several explanations exist in the literature. This study presents long-term (1960–2009) changes of both surface and upper-air wind speeds over China ...

Changgui Lin; Kun Yang; Jun Qin; Rong Fu

2013-05-01T23:59:59.000Z

140

Hydrogen Sulfide Dispersion Consequences Analysis in Different Wind Speeds: A CFD Based Approach  

Science Conference Proceedings (OSTI)

Hydrogen sulfide (h2s) leakage and dispersion from a sulfide recycle installation in different wind speeds are simulated by implementing a 3D Computational Fluid Dynamics (CFD) model. H2s concentrations of monitor points which represent dispersion contours ... Keywords: CFD, hydrogen Sulfide, dispersion, concenquences analysis, different wind speeds

Bo Zhang; Guo-ming Chen

2009-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Utilization of Automatic Weather Station Data for Forecasting High Wind Speeds at Pegasus Runway, Antarctica  

Science Conference Proceedings (OSTI)

Reduced visibility due to blowing snow can severely hinder aircraft operations in the Antarctic. Wind speeds in excess of approximately 7–13 m s?1 can result in blowing snow. The ability to forecast high wind speed events can improve the safety ...

R. E. Holmes; C. R. Stearns; G. A. Weidner; L. M. Keller

2000-04-01T23:59:59.000Z

142

Estimating Probabilities of Hurricane Wind Speeds Using a Large-Scale Empirical Model  

Science Conference Proceedings (OSTI)

A new method is presented for estimating the probability of exceeding a given wind speed in 1 year at any given location in the Atlantic tropical cyclone basin. The method is especially appropriate for wind speeds with return periods of 100 years ...

R. W. R. Darling

1991-10-01T23:59:59.000Z

143

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

E-Print Network (OSTI)

??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)

Motamed, Bardia

2013-01-01T23:59:59.000Z

144

Wind Speeds in ASCE 7 Standard Peak-Gust Map ...  

Science Conference Proceedings (OSTI)

... The second zone comprises these three states, for which ... implies that the extreme wind climate in Central ... 6 is similar to the wind climates in Central ...

2013-08-19T23:59:59.000Z

145

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

DOE Green Energy (OSTI)

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.

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

1996-11-01T23:59:59.000Z

146

Adaptive variable structure control law for a variable speed wind turbine  

Science Conference Proceedings (OSTI)

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, an adaptive robust control for a doubly feed induction generator drive for variable speed wind power generation is described. ... Keywords: modeling and simulation, variable structure control, wind turbine control

Oscar Barambones; Jose Maria Gonzalez De Durana; Patxi Alkorta; Jose Antonio Ramos; Manuel De La Sen

2011-05-01T23:59:59.000Z

147

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

E-Print Network (OSTI)

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

Hansen, René Rydhof

148

An Examination of Tropical and Extratropical Gust Factors and the Associated Wind Speed Histograms  

Science Conference Proceedings (OSTI)

A gust factor, defined as the ratio between a peak wind gust and mean wind speed over a period of time, can be used along with other statistics to examine the structure of the wind. Gust factors are heavily dependent on upstream terrain ...

B. M. Paulsen; J. L. Schroeder

2005-02-01T23:59:59.000Z

149

Wind Conditions in a Fjord-like Bay and Predictions of Wind Speed Using Neighboring Stations Employing Neural Network Models  

Science Conference Proceedings (OSTI)

This paper evaluates the applicability of neural networks to estimate wind speeds at various target locations using neighboring reference locations on the South coast of Newfoundland Canada. The stations were chosen to cover a variety of ...

Jens J. Currie; Pierre J. Goulet; Andry W. Ratsimandresy

150

The Characteristics of Wind Velocity that Favor the Fitting of a Weibull Distribution in Wind Speed Analysis  

Science Conference Proceedings (OSTI)

The derivation of the Weibull distribution from the bivariate normal distribution provides theoretical justification for its use in wind speed analysis if four conditions are met. These conditions are that the orthogonal components of horizontal ...

Stanton E. Tuller; Arthur C. Brett

1984-01-01T23:59:59.000Z

151

Maximizing Energy Capture of Fixed-Pitch Variable-Speed Wind Turbines  

DOE Green Energy (OSTI)

Field tests of a variable-speed, stall-regulated wind turbine were conducted at a US Department of Energy Laboratory. A variable-speed generating system, comprising a doubly-fed generator and series-resonant power converter, was installed on a 275-kW, downwind, two-blade wind turbine. Gearbox, generator, and converter efficiency were measured in the laboratory so that rotor aerodynamic efficiency could be determined from field measurement of generator power. The turbine was operated at several discrete rotational speeds to develop power curves for use in formulating variable-speed control strategies. Test results for fixed-speed and variable-speed operation are presented along with discussion and comparison of the variable-speed control methodologies. Where possible, comparisons between fixed-speed and variable-speed operation are shown.

Pierce, K.; Migliore, P.

2000-08-01T23:59:59.000Z

152

The Power Decoupling Control for Wind Power Converter Based on a Novel Speed Sensor-Less  

Science Conference Proceedings (OSTI)

Doubly fed induction generators based wind turbines are today one of the most widely used generation systems in wind farms. The stator is directly connected to the constant frequency three phase grid and the rotor currents are appropriately controlled ...

Zhang Jia-ming; Fu Yang

2009-10-01T23:59:59.000Z

153

Evaluation Of Models For The Vertical Extrapolation Of Wind Speed Measurements At Offshore Sites  

E-Print Network (OSTI)

Monin-Obukhov theory predicts the well-known log-linear form of the vertical wind speed profile. Two parameters, namely the aerodynamic surface roughness length and the Monin-Obukhov-length, are needed to predict the vertical wind speed profile from a measurement at one height. Different models to estimate these parameters for conditions important for offshore wind energy utilisation are discussed and tested: Four models for the surface roughness and three methods to derive the Monin-Obukov-length from measurements are compared. They have been tested with data from the offshore field measurement Rdsand by extrapolating the measured 10 m wind speed to 50 m height and comparing it with the measured 50 m wind speed. The mean

Bernhard Lange; Jřrgen Hřjstrup; Sřren Larsen; Rebecca Barthelmie

2001-01-01T23:59:59.000Z

154

Analysis of the electrical harmonic characteristics of a slip recovery variable speed generating system for wind turbine applications  

SciTech Connect

Variable speed electric generating technology can enhance the general use of wind energy in electric utility applications. This enhancement results from two characteristic properties of variable speed wind turbine generators: an improvement in drive train damping characteristics, which results in reduced structural loading on the entire wind turbine system, and an improvement in the overall efficiency by using a more sophisticated electrical generator. Electronic converter systems are the focus of this investigation -- in particular, the properties of a wound-rotor induction generator with the slip recovery system and direct-current link converter. Experience with solid-state converter systems in large wind turbines is extremely limited. This report presents measurements of electrical performances of the slip recovery system and is limited to the terminal characteristics of the system. Variable speed generating systems working effectively in utility applications will require a satisfactory interface between the turbine/generator pair and the utility network. The electrical testing described herein focuses largely on the interface characteristics of the generating system. A MOD-O wind turbine was connected to a very strong system; thus, the voltage distortion was low and the total harmonic distortion in the utility voltage was less than 3% (within the 5% limit required by most utilities). The largest voltage component of a frequency below 60 Hz was 40 dB down from the 60-Hz< component. 8 refs., 14 figs., 8 tabs.

Herrera, J.I.; Reddoch, T.W.

1988-02-01T23:59:59.000Z

155

Toward Objective, Standardized Intensity Estimates from Surface Wind Speed Observations  

Science Conference Proceedings (OSTI)

Extreme wind climatology and event-specific intensity assessments rely heavily on surface wind field observations. The most widely used platforms sited at airports are the Automated Surface Observing System (ASOS) and its predecessor, the ...

Forrest J. Masters; Peter J. Vickery; Phuong Bacon; Edward N. Rappaport

2010-12-01T23:59:59.000Z

156

Space-Time Wind Speed Forecasting for Improved Power System Dispatch  

E-Print Network (OSTI)

In order to support large scale integration of wind power, state-of-the-art wind speed forecasting methods should provide accurate and adequate information to enable efficient scheduling of wind power in electric energy systems. In this article, space-time wind forecasts are incorporated into power system economic dispatch models. First, we proposed a new space-time wind forecasting model, which generalizes and improves upon a so-called regime-switching space-time model by allowing the forecast regimes to vary with the dominant wind direction and with the seasons. Then, results from the new wind forecasting model are implemented into a power system economic dispatch model, which takes into account both spatial and temporal wind speed correlations. This, in turn, leads to an overall more cost-effective scheduling of system-wide wind generation portfolio. The potential economic benefits arise in the system-wide generation cost savings and in the ancillary service cost savings. This is illustrated in a test system in the northwest region of the U.S. Compared with persistent and autoregressive models, our proposed method could lead to annual integration cost savings on the scale of tens of millions of dollars in regions with high wind penetration, such as Texas and the Northwest. Key words: Power system economic dispatch; Power system operation; Space-time statistical model; Wind data; Wind speed forecasting.

Xinxin Zhu; Marc G. Genton; Yingzhong Gu; Le Xie

2012-01-01T23:59:59.000Z

157

Low Wind Speed Technology Phase II: LIDAR for Turbine Control  

SciTech Connect

This fact sheet describes NREL's subcontract with QinetiQ to conduct a study on LIDAR systems for wind turbines.

Not Available

2006-06-01T23:59:59.000Z

158

Anemometer Data (Wind Speed, Direction) for YKHC-Bethel, AK (2003 - 2004) |  

Open Energy Info (EERE)

YKHC-Bethel, AK (2003 - 2004) YKHC-Bethel, AK (2003 - 2004) Dataset Summary Description Wind data collected from YKHC - Bethel in Alaska from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2003 through 2004, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released November 09th, 2010 (4 years ago) Date Updated November 09th, 2010 (4 years ago) Keywords wind wind direction wind speed

159

A fuzzy logic controller to increase fault ride-through capability of variable speed wind turbines  

Science Conference Proceedings (OSTI)

A fuzzy controller for improving Fault Ride-Through (FRT) capability of Variable Speed Wind Turbines (WTs) equipped with Doubly Fed Induction Generator (DFIG) is presented. The controller is designed in order to compensate the voltage at the Point of ...

Geev Mokryani, Pierluigi Siano, Antonio Piccolo, Vito Calderaro

2012-01-01T23:59:59.000Z

160

Observed Hurricane Wind Speed Asymmetries and Relationships to Motion and Environmental Shear  

Science Conference Proceedings (OSTI)

Wavenumber-1 wind speed asymmetries in 35 hurricanes are quantified in terms of amplitude and phase, based on aircraft observations from 128 individual flights between 1998 and 2011. The impacts of motion and 850-200 mb environmental vertical ...

Eric W. Uhlhorn; Bradley W. Klotz; Tomislava Vukicevic; Paul D. Reasor; Robert F. Rogers

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

A Phenomenological Model for Wind Speed and Shear Stress Profiles in Vegetation Cover Layers  

Science Conference Proceedings (OSTI)

A phenomenological model for the mean wind speed and Reynolds shear stress profiles with height in a vegetation cover layer is derived from forms suggested by truncation of the equations of turbulent fluid motion at second order in fluctuating ...

F. A. Albini

1981-11-01T23:59:59.000Z

162

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

E-Print Network (OSTI)

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.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

163

Method for Estimation of Surface Roughness and Similarity Function of Wind Speed Vertical Profile  

Science Conference Proceedings (OSTI)

This study is aimed at identifying and refining a method suitable to estimate the surface roughness length (z0) and the universal similarity function of the wind speed profile (?M) based on ultrasonic anemometer measurements carried out at only ...

Roberto Sozzi; Maurizio Favaron; Teodoro Georgiadis

1998-05-01T23:59:59.000Z

164

Air–Sea Enthalpy and Momentum Exchange at Major Hurricane Wind Speeds Observed during CBLAST  

Science Conference Proceedings (OSTI)

Quantifying air–sea exchanges of enthalpy and momentum is important for understanding and skillfully predicting tropical cyclone intensity, but the magnitude of the corresponding wind speed–dependent bulk exchange coefficients is largely unknown ...

Michael M. Bell; Michael T. Montgomery; Kerry A. Emanuel

2012-11-01T23:59:59.000Z

165

Air–Sea Enthalpy and Momentum Exchange at Major Hurricane Wind Speeds Observed during CBLAST  

E-Print Network (OSTI)

Quantifying air–sea exchanges of enthalpy and momentum is important for understanding and skillfully predicting tropical cyclone intensity, but the magnitude of the corresponding wind speed–dependent bulk exchange coefficients ...

Bell, Michael M.

166

Tests of the Generalized Pareto Distribution for Predicting Extreme Wind Speeds  

Science Conference Proceedings (OSTI)

Extreme wind speed predictions are often based on statistical analysis of site measurements of annual maxima, using one of the Generalized Extreme Value (GEV) distributions. An alternative method applies one of the Generalized Pareto ...

B. B. Brabson; J. P. Palutikof

2000-09-01T23:59:59.000Z

167

Evaluation of the National Hurricane Center’s Tropical Cyclone Wind Speed Probability Forecast Product  

Science Conference Proceedings (OSTI)

A tropical cyclone (TC) wind speed probability forecast product developed at the Cooperative Institute for Research in the Atmosphere (CIRA) and adopted by the National Hurricane Center (NHC) is evaluated for U.S. land-threatening and landfalling ...

Michael E. Splitt; Jaclyn A. Shafer; Steven M. Lazarus; William P. Roeder

2010-04-01T23:59:59.000Z

168

Estimation of Wind Speed Distribution Using Markov Chain Monte Carlo Techniques  

Science Conference Proceedings (OSTI)

The Weibull distribution is the most commonly used statistical distribution for describing wind speed data. Maximum likelihood has traditionally been the main method of estimation for Weibull parameters. In this paper, Markov chain Monte Carlo ...

Wan-Kai Pang; Jonathan J. Forster; Marvin D. Troutt

2001-08-01T23:59:59.000Z

169

On the Accuracy of Monthly Mean Wind Speeds over the Equatorial Pacific  

Science Conference Proceedings (OSTI)

Yearlong in situ surface wind measurements at three sites along the Pacific equator (95°, 110°, 152°W) are used to estimate the required number of random observations per month for monthly mean wind speed components accurate to 1.0 and 0.5 m s?. ...

David Halpern

1988-04-01T23:59:59.000Z

170

Dynamical Downscaling of Wind Speed in Complex Terrain Prone To Bora-Type Flows  

Science Conference Proceedings (OSTI)

The results of numerically modeled wind speed climate, a primary component of wind energy resource assessment in the complex terrain of Croatia, are given. For that purpose, dynamical downscaling of 10 yr (1992–2001) of the 40-yr ECMWF Re-Analysis ...

Kristian Horvath; Alica Baji?; Stjepan Ivatek-Šahdan

2011-08-01T23:59:59.000Z

171

Tractable Analytic Expressions for the Wind Speed Probability Density Functions Using Expansions of Orthogonal Polynomials  

Science Conference Proceedings (OSTI)

The use of the two-parameter Weibull function as an estimator of the wind speed probability density function (PDF) is known to be problematic when a high accuracy of fit is required, such as in the computation of the wind power density function. ...

Mark L. Morrissey; J. Scott Greene

2012-07-01T23:59:59.000Z

172

Controlled operation of variable speed driven permanent magnet synchronous generator for wind energy conversion systems  

Science Conference Proceedings (OSTI)

The introduction of distributed generation through renewable sources of energy has opened a challenging area for power engineers. As these sources are intermittent in nature, variable speed electric generators are employed for harnessing electrical energy ... Keywords: permanent magnet synchronous generator, power conditioners, power quality, variable speed generators, wind energy

Rajveer Mittal; K. S. Sandhu; D. K. Jain

2009-02-01T23:59:59.000Z

173

Low-Speed Wind-Tunnel Investigation of the Stability and Control Characteristics  

Science Conference Proceedings (OSTI)

A wind-tunnel investigation was conducted in the Langley 12-Foot Low-Speed Tunnel to study the low-speed stability and control characteristics of a series of four flying wings over an extended range of angle of attack (-8\\deg to 48\\deg). Because of the ...

Fears Scott P.; Ross Holly M.; Moul Thomas M.

1995-06-01T23:59:59.000Z

174

Testing requirements for variable-speed generating technology for wind turbine applications. Final report  

Science Conference Proceedings (OSTI)

Guidelines for evaluating the impacts of integrating variable-speed, constant-frequency (VSCF) wind turbines into electric utility systems have been proposed based upon prior test experiences with the NASA VSCF system and the expected performance of the Westinghouse and OMNION VSCF systems. The NASA and Westinghouse VSCF generating systems use a wound rotor induction generator and a cycloconverter, while the OMNION system uses a wound rotor induction generator and a dc-current link converter. The design of VSCF/utility system interface requirements and test plans is based on utility system electrical issues such as utility system control and operation, protection, voltage/reactive power management, power quality, and reliability. A framework for testing VSCF concepts is proposed which includes a three stage process: modeling of the system to analyze design alternatives and simulate disturbances that could be harmful to the actual system; laboratory testing which involves the use of the system under controlled conditions; and field testing to collect data under actual conditions to validate models and analyze the wind turbine behavior.

Herrera, J.I.

1986-05-01T23:59:59.000Z

175

Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters  

E-Print Network (OSTI)

Abstract: This work discusses the accuracies of geophysical model functions (GMFs) for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model)4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs), the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error at both sites. All of the GMFs exhibit a negative bias in the retrieved wind speed. In order to understand the reason for this bias, all SAR-retrieved wind speeds are separated into two categories: onshore wind (blowing from sea to land) and offshore wind (blowing from land to sea). Only offshore winds were found to exhibit the large negative bias, and short fetches from the coastline may be a possible reason for this. Moreover, it is clarified that in both the unstable and stable conditions, CMOD5.N has atmospheric stability effectiveness, and can keep the same accuracy with CMOD5 in the neutral condition. In short, at the moment, CMOD5.N is thought to be the most promising GMF

Yuko Takeyama; Teruo Ohsawa; Katsutoshi Kozai; Charlotte Bay Hasager; Merete Badger

2013-01-01T23:59:59.000Z

176

High speed air pneumatic wind shield wiping design  

E-Print Network (OSTI)

In this creative design process a number of designs were constructed, implemented and tested in order to assess the feasibility of using high speed to create a curtain to repel the rain from the automobile windshield instead ...

Heyward, Moses A

2005-01-01T23:59:59.000Z

177

The effects of variable speed and drive train component efficiencies on wind turbine energy capture  

SciTech Connect

A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.

Fingersh, L.J.; Robinson, M.C.

1998-05-01T23:59:59.000Z

178

CONSTRAINING HIGH-SPEED WINDS IN EXOPLANET ATMOSPHERES THROUGH OBSERVATIONS OF ANOMALOUS DOPPLER SHIFTS DURING TRANSIT  

SciTech Connect

Three-dimensional (3D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km s{sup -1} directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blueshift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. recently observed a 2 {+-} 1 km s{sup -1} blueshift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night (substellar to anti-stellar) winds that have been predicted by 3D atmospheric dynamics modeling. Here, we present the results of a coupled 3D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the planet's atmosphere. We explore four different models for the hot Jupiter atmosphere using different prescriptions for atmospheric drag via interaction with planetary magnetic fields. We find that models with no magnetic drag produce net Doppler blueshifts in the transmission spectrum of {approx}2 km s{sup -1} and that lower Doppler shifts of {approx}1 km s{sup -1} are found for the higher drag cases, results consistent with-but not yet strongly constrained by-the Snellen et al. measurement. We additionally explore the possibility of recovering the average terminator wind speed as a function of altitude by measuring Doppler shifts of individual spectral lines and spatially resolving wind speeds across the leading and trailing terminators during ingress and egress.

Miller-Ricci Kempton, Eliza [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rauscher, Emily, E-mail: ekempton@ucolick.org [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States)

2012-06-01T23:59:59.000Z

179

Adaptive pitch control for variable speed wind turbines  

DOE Patents (OSTI)

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.

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

2012-05-08T23:59:59.000Z

180

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

Science Conference Proceedings (OSTI)

Knowledge of the diurnally varying land surface wind speed probability distribution is essential for surface flux estimation and wind power management. Global observations indicate that the surface wind speed probability density function (PDF) is ...

Yanping He; Norman A. McFarlane; Adam H. Monahan

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Secular Change in Reported Surface Wind Speeds over the Ocean  

Science Conference Proceedings (OSTI)

The Comprehensive Ocean-Atmosphere Data Set reveals that mean scalar winds decreased between 1854 and 1920 and increased since World War II. The latter increase is due to a change in estimating procedure and to the growing proportion of ships ...

C. S. Ramage

1987-04-01T23:59:59.000Z

182

The Extrapolation of Vertical Profiles of Wind Speed within the Marine Atmospheric Surface layer Using the p Formula  

Science Conference Proceedings (OSTI)

Values of p for the exponent-type wind profile formulation, used in vertical extrapolations of wind speed, were derived for the marine atmospheric surface layer. Nomograms were constructed providing p values as dependent on a single elevation ...

M. Segal; R. A. Pielke

1988-02-01T23:59:59.000Z

183

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

E-Print Network (OSTI)

amount of wind power generation that can be accommodated.ramping of generation Power and Frequency Control as itfrequency to loss of generation Power and Frequency Control

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

184

Wind Plant Capacity Credit Variations: A Comparison of Results Using Multiyear Actual and Simulated Wind-Speed Data  

DOE Green Energy (OSTI)

Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patterns. This paper calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this paper finds that the actual inter- annual variation in capacity credit is still understated by the synthetic data technique.

Milligan, Michael

1997-06-01T23:59:59.000Z

185

Power-Electronic, Variable-Speed Wind Turbine Development: 1988-1993  

Science Conference Proceedings (OSTI)

A five-year development program culminated in the 33M-VS power-electronic, variable-speed turbine, used in a number of wind power plants to offer competitively priced electricity. This report describes turbine development activities from conception through field testing, highlights design decisions that led to the new technology, and provides an overview of the turbine's electrical and mechanical design. An appendix describes technical issues relevant to building a wind power plant using 33M-VS turbines.

1995-11-16T23:59:59.000Z

186

Research on Control System of High Power DFIG Wind Power System  

Science Conference Proceedings (OSTI)

Compared with constant speed constant frequency wind turbine, variable speed constant frequency wind turbine has many advantages: higher efficiency of wind energy converting to electric power, absorbing gust energy, smoothly cutting into the network ... Keywords: wind power, DFIG, high power, LQR, variable speed constant frequency, constant power control

Li Jianlin; Xu Honghua

2008-12-01T23:59:59.000Z

187

Anemometer Data (Wind Speed, Direction) for Pascua Yaqui, AZ (2003 - 2004)  

Open Energy Info (EERE)

Pascua Yaqui, AZ (2003 - 2004) Pascua Yaqui, AZ (2003 - 2004) Dataset Summary Description Wind data collected from Pascua Yaqui Indian Reservation in Arizona from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2003 through 2004, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released December 02nd, 2010 (3 years ago) Date Updated December 02nd, 2010 (3 years ago) Keywords wind

188

Anemometer Data (Wind Speed, Direction) for Quinault #3, WA (2004 - 2005) |  

Open Energy Info (EERE)

Quinault #3, WA (2004 - 2005) Quinault #3, WA (2004 - 2005) Dataset Summary Description Wind data collected from Quinault Indian Reservation in Washington from an anemometer as part of the Native American anemometer loan program. Monthly mean wind speed is available for 2004 through 2005, as is wind direction and turbulence data. Data is reported from a height of 20 m. The data was originally made available by Wind Powering America, a DOE Office of Energy Efficiency & Renewable Energy (EERE) program. A dynamic map displaying all available data from DOE anemometer loan programs is available http://www.windpoweringamerica.gov/anemometerloans/projects.asp. Source EERE Date Released December 02nd, 2010 (4 years ago) Date Updated December 02nd, 2010 (4 years ago) Keywords wind

189

Low Wind Speed Technology Phase II: Integrated Wind Energy/Desalination System; General Electric Global Research  

SciTech Connect

This fact sheet describes a subcontract with General Electric Global Research to explore wind power as a desirable option for integration with desalination technologies.

Not Available

2006-03-01T23:59:59.000Z

190

Fluctuating wind power penetration as limited by frequency standard.  

E-Print Network (OSTI)

??Fluctuating wind power is due to wind turbulence and is the part which should be filtered out leaving behind the more predictable mean wind power… (more)

Luo, Changling, 1980-

2005-01-01T23:59:59.000Z

191

On Sudbury-Area Wind Speeds—A Tale of Forest Regeneration  

Science Conference Proceedings (OSTI)

A 34% reduction in 10-m wind speeds at Sudbury Airport in Ontario, Canada, over the period 1975–95 appears to be a result of significant changes in the surface roughness of the surrounding area that are due to land restoration and reforestation ...

Andrew J. Tanentzap; Peter A. Taylor; Norman D. Yan; James R. Salmon

2007-10-01T23:59:59.000Z

192

On the Maximum Observed Wind Speed in a Randomly Sampled Hurricane  

Science Conference Proceedings (OSTI)

There is considerable interest in detecting a long-term trend in hurricane intensity possibly related to large-scale ocean warming. This effort is complicated by the paucity of wind speed measurements for hurricanes occurring in the early part of ...

Andrew R. Solow

2010-03-01T23:59:59.000Z

193

Optimal Power-Law Description of Oceanic Whitecap Coverage Dependence on Wind Speed  

Science Conference Proceedings (OSTI)

The optimal power-law expression for the dependence of oceanic whitecap coverage fraction W on 10 m elevation wind speed U as determined by ordinary least squares fitting applied to the combined whitecap data sets of Monahan (1971) and Toba and ...

Edward C. Monahan; IognáidÓ Muircheartaigh

1980-12-01T23:59:59.000Z

194

Creating Synthetic Wind Speed Time Series for 15 New Zealand Wind Farms  

Science Conference Proceedings (OSTI)

Wind data at time scales from 10 min to 1 h are an important input for modeling the performance of wind farms and their impact on many countries’ national electricity systems. Planners need long-term realistic (i.e., meteorologically spatially and ...

Richard Turner; Xiaogu Zheng; Neil Gordon; Michael Uddstrom; Greg Pearson; Rilke de Vos; Stuart Moore

2011-12-01T23:59:59.000Z

195

Trends in Wind Speed at Wind Turbine Height of 80 m over the Contiguous United States Using the North American Regional Reanalysis (NARR)  

Science Conference Proceedings (OSTI)

The trends in wind speed at a typical wind turbine hub height (80 m) are analyzed using the North American Regional Reanalysis (NARR) dataset for 1979–2009. A method, assuming the wind profile in the lower boundary layer as power-law functions of ...

Eric Holt; Jun Wang

2012-12-01T23:59:59.000Z

196

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

SciTech Connect

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.

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

197

Angular frequency analysis of wind turbines by means of digital image processing  

Science Conference Proceedings (OSTI)

This paper proposes a method to calculate the angular frequency of a wind turbine by using Artificial Vision techniques. For a given video in which several wind turbines appear, the set of frames that compose it are taken out. Then, a certain frame is ... Keywords: angular frequency, image processing, wind turbine

R. González López; L. Sánchez; Eduardo Calvo

2010-02-01T23:59:59.000Z

198

Documenting Wind Speed and Power Deficits behind a Utility-Scale Wind Turbine  

Science Conference Proceedings (OSTI)

High-spatial-and-temporal-resolution radial velocity measurements surrounding a single utility-scale wind turbine were collected using the Texas Tech University Ka-band mobile research radars. The measurements were synthesized to construct the ...

Brian D. Hirth; John L. Schroeder

2013-01-01T23:59:59.000Z

199

SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE  

E-Print Network (OSTI)

SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE Justin C. Kasper,1 Michael L. Stevens, and Alan J. Lazarus Kavli Institute for Astrophysics of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind

Richardson, John

200

Correlated solar wind speed, density, and magnetic field changes at J. D. Richardson and C. Wang1  

E-Print Network (OSTI)

., in press, 2003. Wang, C., and J. D. Richardson, Energy partition between solar wind protons and pickup ionsCorrelated solar wind speed, density, and magnetic field changes at Voyager 2 J. D. Richardson December 2003. [1] The character of the solar wind plasma data observed by Voyager 2 recently changed

Richardson, John

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Wisconsin Low Wind Speed Turbine Project First- and Second-Year Operating Experience: 1998-2000: U.S. Department of Energy-EPRI Wind Turbine Verification Program  

Science Conference Proceedings (OSTI)

The 1.2 MW Low Wind Speed Turbine Project (LWSTP) -- installed in Glenmore, Wisconsin, in early 1998 -- was the first commercial-scale wind project in Wisconsin. This report describes the first- and second-year operating experience at the LWSTP. The lessons learned in the project will be valuable to other utilities planning similar wind power projects, particularly in cold-weather, moderate wind resource areas.

2000-12-15T23:59:59.000Z

202

Low-Frequency Variability and Remote Forcing of Gap Winds over the East Pacific Warm Pool  

Science Conference Proceedings (OSTI)

The low-frequency variability of gap winds at the Isthmuses of Tehuantepec and Papagayo is investigated using a 17-yr wind stress dataset merging the remotely sensed observations of Special Sensor Microwave Imager (SSM/I) and Quick Scatterometer (...

Kristopher B. Karnauskas; Antonio J. Busalacchi; Raghu Murtugudde

2008-10-01T23:59:59.000Z

203

Novel sensorless generator control and grid fault ride-through strategies for variable-speed wind turbines and implementation on a new real-time simulation platform.  

E-Print Network (OSTI)

??The usage of MW-size variable-speed wind turbines as sources of energy has increased significantly during the last decade. Advantages over fixed-speed wind turbines include more… (more)

Yang, Sheng

2010-01-01T23:59:59.000Z

204

Comparison of Observed 10-m Wind Speeds to Those Based on Monin–Obukhov Similarity Theory Using IHOP_2002 Aircraft and Surface Data  

Science Conference Proceedings (OSTI)

Comparisons of 10-m above ground level (AGL) wind speeds from numerical weather prediction (NWP) models to point observations consistently show that model daytime wind speeds are slow compared to observations, even after improving model physics ...

Diane Strassberg; Margaret A. LeMone; Thomas T. Warner; Joseph G. Alfieri

2008-03-01T23:59:59.000Z

205

Temporal trend analyses of alpine data using North American Regional Reanalysis and in situ data: temperature, wind speed, precipitation, and derived blowing snow  

Science Conference Proceedings (OSTI)

Across the globe wind speed trends have shown a slight decline for in situ meteorological datasets. Yet few studies have assessed long-term wind speed trends for alpine regions or how such trends could influence snow transport and distribution. ...

Jamie D. Fuller; Nolan Doesken; Kelly Elder; Melinda Laituri; Glen E. Liston

206

A Nonstationary Extreme Value Analysis for the Assessment of Changes in Extreme Annual Wind Speed over the Gulf of St. Lawrence, Canada  

Science Conference Proceedings (OSTI)

Changes in the extreme annual wind speed in and around the Gulf of St. Lawrence (Canada) were investigated through a nonstationary extreme value analysis of the annual maximum 10-m wind speed obtained from the North American Regional Reanalysis (...

Y. Hundecha; A. St-Hilaire; T. B. M. J. Ouarda; S. El Adlouni; P. Gachon

2008-11-01T23:59:59.000Z

207

Low Wind Speed Technology Phase II: Development of a 2-MW Direct-Drive Wind Turbine for Low Wind Speed Sites; Northern Power Systems  

SciTech Connect

This fact sheet describes a subcontract with Northern Power Systems (NPS) to develop and evaluate a 2-MW wind turbine that could offer significant opportunities for reducing the cost of energy (COE).

2006-03-01T23:59:59.000Z

208

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

E-Print Network (OSTI)

Steady decline of east Asian monsoon winds, 1969­2000: Evidence from direct ground measurements winter monsoon but strengthen the summer monsoon, because of stronger warming over high-latitude land with the east Asian monsoon has significantly weakened in both winter and summer in the recent three decades

Chang, Chih-Pei

209

Nonlinear Dual-Mode Control of Variable-Speed Wind Turbines with Doubly Fed Induction Generators  

E-Print Network (OSTI)

This paper presents a feedback/feedforward nonlinear controller for variable-speed wind turbines with doubly fed induction generators. By appropriately adjusting the rotor voltages and the blade pitch angle, the controller simultaneously enables: (a) control of the active power in both the maximum power tracking and power regulation modes, (b) seamless switching between the two modes, and (c) control of the reactive power so that a desirable power factor is maintained. Unlike many existing designs, the controller is developed based on original, nonlinear, electromechanically-coupled models of wind turbines, without attempting approximate linearization. Its development consists of three steps: (i) employ feedback linearization to exactly cancel some of the nonlinearities and perform arbitrary pole placement, (ii) design a speed controller that makes the rotor angular velocity track a desired reference whenever possible, and (iii) introduce a Lyapunov-like function and present a gradient-based approach for mini...

Tang, Choon Yik; Jiang, John N

2010-01-01T23:59:59.000Z

210

Solar wind iron abundance variations at solar wind speeds > 600 km s/sup -1/, 1972 to 1976  

SciTech Connect

We have analyzed the Fe/H ratios in the peaks of high speed streams (HSS) during the decline of Solar Cycle 20 and the following minimum (October 1972 to December 1976). We utilized the response of the 50 to 200 keV ion channel of the APL/JHU energetic particle experiment (EPE) onIMP-7 and 8 to solar wind iron ions at high solar wind speeds (V greater than or equal to 600 km sec/sup -1/), and compared our Fe measurements with solar wind H and He parameters from the Los Alamos National Laboratory (LANL) instruments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ration in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 10/sup -5/, abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS. There are, as well, factor of 2 variations between stream-averaged abundances for recurent HSS emanating from different coronal holes occurring on the sun on the same solar rotation. flare-related solar wind streams sometimes show Fe/H ratios enhanced by factors of 4 to 5 over coronal-hole associated, quite time streams. Over the period 1973 to 1976, a steady decrease in the average quitetime Fe/H ratio by a ractor approx. 4 is measured on both IMP-7 and 8.

Mitchell, D.G.; Roelof, E.C.; Bame, S.J.

1982-01-01T23:59:59.000Z

211

Design of State-Space-Based Control Algorithms for Wind Turbine Speed Regulation: Preprint  

DOE Green Energy (OSTI)

Control can improve the performance of wind turbines by enhancing energy capture and reducing dynamic loads.At the National Renewable Energy Laboratory, we are beginning to design control algorithms for regulation of turbine speed and power using state-space control designs. In this paper, we describe the design of such a control algorithm for regulation of rotor speed in full-load operation (region 3) for a two-bladed wind turbine. We base our control design on simple linear models of a turbine, which contain rotor and generator rotation, drivetrain torsion, and rotor flap degrees of freedom (first mode only). We account for wind-speed fluctuations using disturbance-accommodating control. We show the capability of these control schemes to stabilize the modeled turbine modes via pole placement while using state estimation to reduce the number of turbine measurements that are needed for these control algorithms. We incorporate these controllers into the FAST-AD code and show simulation results for various conditions. Finally, we report conclusions to this work and outline future studies.

Wright, A.; Balas, M.

2002-01-01T23:59:59.000Z

212

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)

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

2009-01-01T23:59:59.000Z

213

Low Wind Speed Technologies Annual Turbine Technology Update (ATTU) Process for Land-Based, Utility-Class Technologies  

SciTech Connect

The Low Wind Speed Technologies (LWST) Project comprises a diverse, balanced portfolio of industry-government partnerships structured to achieve ambitious cost of energy reductions. The LWST Project goal is: ''By 2012, reduce the cost of energy (COE) for large wind systems in Class 4 winds (average wind speed of 5.8 m/s at 10 m height) to 3 cents/kWh (in levelized 2002 dollars) for onshore systems.'' The Annual Turbine Technology Update (ATTU) has been developed to quantify performance-based progress toward these goals, in response to OMB reporting requirements and to meet internal DOE program needs for advisory data.

Schreck, S.; Laxson, A.

2005-06-01T23:59:59.000Z

214

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

DOE Green Energy (OSTI)

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.

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

215

Wisconsin Low Wind Speed Turbine Project Third-Year Operating Experience: 2000-2001: U.S. Department of Energy - EPRI Wind Turbine V erification Program  

Science Conference Proceedings (OSTI)

This report describes the third-year operating experience at the 1.2-MW Low Wind Speed Turbine Project (LWSTP) in Glenmore, Wisconsin. The lessons learned in the project will be valuable to other utilities planning similar wind power projects.

2001-12-06T23:59:59.000Z

216

The Impact of Radar Data on Short-Term Forecasts of Surface Temperature, Dewpoint Depression, and Wind Speed  

Science Conference Proceedings (OSTI)

A statistical system that uses surface observations and radar data to provide 1-, 3-, and 6-h forecasts of temperature, dewpoint depression, and wind speed is developed. Application of the system to independent data demonstrates that the radar ...

Emily K. Grover-Kopec; J. Michael Fritsch

2003-12-01T23:59:59.000Z

217

Low Wind Speed Technology Phase II: Development of an Operations and Maintenance Cost Model for LWST; Global Energy Concepts  

SciTech Connect

This fact sheet describes a subcontract with Global Energy Concepts to evaluate real-world data on O&M costs and to develop a working model to describe these costs for low wind speed sites.

Not Available

2006-03-01T23:59:59.000Z

218

The Determination of Surface-Layer Stability and Eddy Fluxes Using Wind Speed and Vertical Temperature Gradient Measurements  

Science Conference Proceedings (OSTI)

Analytical relations are developed that relate the Monin-Obukhov parameter to a modified bulk Richardson number expressed in terms of measured wind speed and vertical temperature difference. Measured Monin-Obukhov parameters and Richardson ...

I. T. Wang

1981-10-01T23:59:59.000Z

219

Retrieval of Surface Wind Speed and Aerosol Optical Depth over the Oceans from AVHRR Images of Sun Glint  

Science Conference Proceedings (OSTI)

This paper investigates the feasibility of recovering both the tropospheric aerosol loading and the surface wind speed from satellite measurements of the radiance within cloud free regions of sun glint over the ocean surface. The method relies on ...

D. M. O'Brien; R. M. Mitchell

1988-12-01T23:59:59.000Z

220

An Empirical Model for Predicting the Decay of Tropical Cyclone Wind Speed after Landfall over the Indian Region  

Science Conference Proceedings (OSTI)

An empirical model for predicting the maximum surface wind speed associated with a tropical cyclone after crossing the east coast of India is described. The model parameters are determined from the database of 19 recent cyclones. The model is ...

S. K. Roy Bhowmik; S. D. Kotal; S. R. Kalsi

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

A doubly-fed permanent magnet generator for wind turbines  

E-Print Network (OSTI)

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 ...

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

2004-01-01T23:59:59.000Z

222

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  

DOE Green Energy (OSTI)

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.

Erdman, W.; Behnke, M.

2005-11-01T23:59:59.000Z

223

The Vibration Frequencies of Wind Turbine Steel Tower by Transfer Matrix Method  

Science Conference Proceedings (OSTI)

Large-scale wind turbine structure is simplified as a slender cantilever beam with variable sections subject to complex loads configuration. An analytical procedure to estimate not only natural frequencies but also vibration mode shapes of thin-walled ... Keywords: horizontal axis wind turbine tower, natural frequency, transfer matrix method, free vibration

Wang Meng; Wang Zhangqi

2011-01-01T23:59:59.000Z

224

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

DOE Green Energy (OSTI)

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 the 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)

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

1982-08-01T23:59:59.000Z

225

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

DOE Green Energy (OSTI)

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)

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

1983-03-01T23:59:59.000Z

226

Spatial variation of iron abundance in the high speed solar wind, 1972 to 1976  

SciTech Connect

The Fe/H ratios in the peaks of high speed streams (HSS) during the decline of Solar Cycle 20 and the following minimum (October 1972-December 1976) were analyzed. The response of the 50-200 keV ion channel of the APL/JHU energetic particle experiment (EPE) on IMP-7 and 8 to solar wind iron ions at high solar wind speeds and Fe measurements were compared with solar wind H and He parameters from the Los Alamos National Laboratory (LANL) instrments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ratio in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 10(-5), abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS. Over the period 1973-1976, a steady decrease in the average quiet-time Fe/H ratio by a factor of about 4 is measured on both IMP-7 and 8.

Mitchell, D.G.; Roelof, E.C.; Bame, S.J.

1983-11-01T23:59:59.000Z

227

Analysis of SWADE Discus N Wind Speed and Wave Height Time Series. Part I: Discrete Wavelet Packet Representations  

Science Conference Proceedings (OSTI)

Discus N denotes a single buoy employed during the SWADE experiment, equipped to record wave amplitude and wind speed time series at a rate of 1 Hz. Over the course of approximately 4.5 days, two clear-cut examples of sea response to wind ...

Jorge E. Willemsen

1995-12-01T23:59:59.000Z

228

Distrubance Tracking and Blade Load Control of Wind Turbines in Variable-Speed Operation: Preprint  

DOE Green Energy (OSTI)

A composite state-space controller was developed for a multi-objective problem in the variable-speed operation of wind turbines. Disturbance Tracking Control theory was applied to the design of a torque controller to optimize energy capture under the influence of persistent wind disturbances. A limitation in the theory for common multi-state models is described, which led to the design of a complementary pitch controller. The goal of the independent blade pitch design was to minimize blade root fatigue loads. Simulation results indicate an 11% reduction in fatigue damage using the proposed controllers, compared to a conventional torque-only design. Meanwhile, energy capture is almost identical, partly because of nonlinear effects.

Stol, K. A.

2003-01-01T23:59:59.000Z

229

Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains  

E-Print Network (OSTI)

We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \\Alfven (fast MHD) waves and acoustic (slow MHD) waves travelling upwardly along with a magnetic field line eventually form fast switch-on shock trains and hydrodynamical shock trains (N-waves) respectively to heat and accelerate the plasma. We determine one dimensional structure of the corona from the bottom of the transition region (TR) to 1AU under the steady-state condition by solving evolutionary equations for the shock amplitudes simultaneously with the momentum and proton/electron energy equations. Our model reproduces the overall trend of the high-speed wind from the polar holes and the low-speed wind from the mid- to low-latitude streamer except the observed hot corona in the streamer. The heating from the slow waves is effective in the low corona to increase the density there, and plays an important role in the formation of the dense low-speed wind. On the other hand, the fast waves can carry a sizable energy to the upper level to heat the outer corona and accelerate the high-speed wind effectively. We also study dependency on field strength, $B_0$, at the bottom of the TR and non-radial expansion of a flow tube, $f_{\\rm max}$, to find that large $B_0/f_{\\rm max}\\gtrsim 2$ but small $B_0\\simeq 2$G are favorable for the high-speed wind and that small $B_0/f_{\\rm max}\\simeq 1$ is required for the low-speed wind.

Takeru K. Suzuki

2003-12-22T23:59:59.000Z

230

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

DOE Green Energy (OSTI)

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.

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

2012-03-01T23:59:59.000Z

231

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

SciTech Connect

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.

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

2012-03-01T23:59:59.000Z

232

Alongshore Wind Forcing of Coastal Sea Level as a Function of Frequency  

Science Conference Proceedings (OSTI)

The amplitude of the frequency response function between coastal alongshore wind stress and adjusted sea level anomalies along the west coast of the United States increases linearly as a function of the logarithm (log10) of the period for time ...

Holly F. Ryan; Marlene A. Noble

2006-11-01T23:59:59.000Z

233

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

SciTech Connect

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.

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

2011-10-01T23:59:59.000Z

234

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

E-Print Network (OSTI)

High-quality short-term forecasts of wind speed are vital to making wind power a more reliable energy source. Gneiting et al. (2006) have introduced a model for the average wind speed two hours ahead based on both spatial and temporal information. The forecasts produced by this model are accurate, and subject to accuracy, the predictive distribution is sharp, i.e., highly concentrated around its center. However, this model is split into nonunique regimes based on the wind direction at an off-site location. This work both generalizes and improves upon this model by treating wind direction as a circular variable and including it in the model. It is robust in many experiments, such as predicting at new locations. This is compared with the more common approach of modeling wind speeds and directions in the Cartesian space and use a skew-t distribution for the errors. The quality of the predictions from all of these models can be more realistically assessed with a loss measure that depends upon the power curve relating wind speed to power output. This proposed loss measure yields more insight into the true value of each model's predictions. One method of evaluating time series forecasts, such as wind speed forecasts, is to test the null hypothesis of no difference in the accuracy of two competing sets of forecasts. Diebold and Mariano (1995) proposed a test in this setting that has been extended and widely applied. It allows the researcher to specify a wide variety of loss functions, and the forecast errors can be non-Gaussian, nonzero mean, serially correlated, and contemporaneously correlated. In this work, a similar unconditional test of forecast accuracy for spatial data is proposed. The forecast errors are no longer potentially serially correlated but spatially correlated. Simulations will illustrate the properties of this test, and an example with daily average wind speeds measured at over 100 locations in Oklahoma will demonstrate its use. This test is compared with a wavelet-based method introduced by Shen et al. (2002) in which the presence of a spatial signal at each location in the dataset is tested.

Hering, Amanda S.

2009-08-01T23:59:59.000Z

235

Analysis of SWADE Discus N Wind Speed and Wave Height Time Series. Part II: Quantitative Growth Rates during a Storm  

Science Conference Proceedings (OSTI)

In Part I, wind speed and wave height time series obtained from the Discus N buoy during two storm events recorded in the SWADE experiment were analyzed using discrete wavelet packet transforms. One result of the analysis is that distinct tightly ...

Jorge F. Willemsen

1997-06-01T23:59:59.000Z

236

Joint Calibration of Multiplatform Altimeter Measurements of Wind Speed and Wave Height over the Past 20 Years  

Science Conference Proceedings (OSTI)

Since 1985, for a period of more than 23 yr, seven altimeter missions have provided global coverage of significant wave height and wind speed. This study undertakes a long-term analysis of the accuracy and stability of altimeter-derived values of ...

S. Zieger; J. Vinoth; I. R. Young

2009-12-01T23:59:59.000Z

237

Consistency of Geosat, SSM/I, and ERS-1 Global Surface Wind Speeds—Comparison with In Situ Data  

Science Conference Proceedings (OSTI)

The authors compare wind speed retrieved from the Geosat altimeter, from two Special Sensor Microwave/Imager (SSM/I) microwave radiometers. The SSM/I F08 and SSM/I F10, and from the European Space Agency ERS-1 scatterometer. As ground truth, ship ...

J. Boutin; J. Etcheto

1996-02-01T23:59:59.000Z

238

A Test of a Lapse Rate/Wind Speed Model for Estimating Heat Island Magnitude in an Urban Airshed  

Science Conference Proceedings (OSTI)

In the winter of 1975/76 a helicopter was used to obtain temperature profiles across the city of Calgary. This operation was supported by airborne measurements of wind speed and lapse rate at the edge of the city, upwind. Regression analysis ...

Lawrence C. Nkemdirim

1980-06-01T23:59:59.000Z

239

A study on nocturnal surface wind speed over-prediction by the WRF-ARW model in Southeastern Texas  

Science Conference Proceedings (OSTI)

The over-prediction of surface wind speed during nighttime by the WRF-ARW model was investigated for a period of the Second Texas Air Quality Study (May 28 – July 3, 2006). In coastal regions of southeastern Texas, the model had significant ...

Fong Ngan; Hyuncheol Kim; Pius Lee; Khalid Al-Wali; Bright Dornblaser

240

The Effects of the Variations In Sea Surface Temperature and Atmospheric Stability in the Estimation of Average Wind Speed by SEASAT-SASS  

Science Conference Proceedings (OSTI)

Wind speeds from the scatterometer (SASS) on the ocean observing satellite SEASAT averaged over 2° latitude by 2° longitude and a 92-day period are compared with wind speeds from ship reports in the western North Atlantic and the eastern North ...

W. Timothy Liu

1984-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Low-Frequency Variability in the Wind-Driven Circulation  

Science Conference Proceedings (OSTI)

The origins of low-frequency variability in a simple homogenous ocean model, forced by a double gyre Ekman suction, are examined numerically. It is found that irregular, large amplitude vacillations in the structure of the circulation typify the ...

S. P. Meacham

2000-02-01T23:59:59.000Z

242

Factors Affecting Surface Wind Speeds in Gravity Waves and Wake Lows  

Science Conference Proceedings (OSTI)

Ducted gravity waves and wake lows have been associated with numerous documented cases of “severe” winds (>25 m s?1) and wind damage. These winds are associated with the pressure perturbations and transient mesoscale pressure gradients occurring ...

Timothy A. Coleman; Kevin R. Knupp

2009-12-01T23:59:59.000Z

243

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

DOE Green Energy (OSTI)

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.

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

2007-09-01T23:59:59.000Z

244

Numerical Simulation of Along-Wind Loading on Small ...  

Science Conference Proceedings (OSTI)

... This means that the energy of the missing low-frequency fluctuations is supplied, in the simplified flow, by the increment in mean wind speed, which ...

2013-09-27T23:59:59.000Z

245

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

DOE Green Energy (OSTI)

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.

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

2012-08-01T23:59:59.000Z

246

Wind characteristics for agricultural wind energy applications  

SciTech Connect

Wind energy utilization in agriculture can provide a potentially significant savings in fuel oil consumption and ultimately a cost savings to the farmer. A knowledge of the wind characteristics within a region and at a location can contribute greatly to a more efficient and cost-effective use of this resource. Current research indicates that the important wind characteristics include mean annual wind speed and the frequency distribution of the wind, seasonal and diurnal variations in wind speed and direction, and the turbulent and gustiness characteristics of the wind. Further research is underway to provide a better definition of the total wind resource available, improved methods for siting WECS and an improved understanding of the environment to which the WECS respond.

Renne, D. S.

1979-01-01T23:59:59.000Z

247

Low Wind Speed Technology Phase II: Offshore Floating Wind Turbine Concepts: Fully Coupled Dynamic Response Simulations; Massachusetts Institute of Technology  

SciTech Connect

This fact sheet describes a subcontract with Massachusetts Institute of Technology to study dynamic response simulations to evaluate floating platform concepts for offshore wind turbines.

2006-03-01T23:59:59.000Z

248

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

DOE Green Energy (OSTI)

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.

Milligan, M.R.; Artig, R.

1999-07-08T23:59:59.000Z

249

An Intercomparison of TOPEX, NSCAT, and ECMWF Wind Speeds: Illustrating and Understanding Systematic Discrepancies  

Science Conference Proceedings (OSTI)

The availability of multiple satellite missions with wind measuring capacity has made it more desirable than ever before to integrate wind data from various sources in order to achieve an improved accuracy, resolution, and duration. A clear ...

Ge Chen

2004-03-01T23:59:59.000Z

250

Resolving Nonstationary Spectral Information in Wind Speed Time Series Using the Hilbert–Huang Transform  

Science Conference Proceedings (OSTI)

This work is motivated by the observation that large-amplitude wind fluctuations on temporal scales of 1–10 h present challenges for the power management of large offshore wind farms. Wind fluctuations on these scales are analyzed at a ...

Claire Vincent; Gregor Giebel; Pierre Pinson; Henrik Madsen

2010-02-01T23:59:59.000Z

251

Evaporation-Wind Feedback and Low-Frequency Variability in the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

A mechanism by which feedback between zonal wind perturbations and evaporation can create unstable, low-frequency modes in a simple two-layer model of the tropical troposphere is presented. The modes resemble the 30–50 day oscillation. A series ...

J. David Neelin; Isaac M. Held; Kerry H. Cook

1987-08-01T23:59:59.000Z

252

Wind Speed Technology Phase II: Semisubmersible Platform and Anchor Foundation Systems for Wind Turbine Support; Concept Marine Associates, Inc.  

SciTech Connect

This fact sheet describes a subcontract with Concept Marine Associates, Inc. to evaluate and optimize a semisubmersible platform and anchor foundation system that can support a 5-MW wind turbine.

2006-03-01T23:59:59.000Z

253

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

DOE Green Energy (OSTI)

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.

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

2011-12-01T23:59:59.000Z

254

Determination of the Mean Wind Speed and Momentum Diffusivity Profiles above Tall Vegetation and Forest Canopies Using a Mass Conservation Assumption  

Science Conference Proceedings (OSTI)

A semianalytical method based on a mass conservation principle is presented for describing the transition- layer profiles of mean wind speed and momentum diffusivity and for estimating the aerodynamic characteristics of forest and tall vegetation ...

N. M. Zoumakis

1994-02-01T23:59:59.000Z

255

An Experimental Field Dataset with Buoyant, Neutral, and Dense Gas Atmospheric Releases and Model Comparisons in Low–Wind Speed (Diffusion) Conditions  

Science Conference Proceedings (OSTI)

A unique field dataset from a series of low–wind speed experiments, modeling efforts using three commonly used models to replicate these releases, and statistical analysis of how well these models were able to predict the plume concentrations is ...

Veronica E. Wannberg; Gustavious Williams; Patrick Sawyer; Richard Venedam

2010-09-01T23:59:59.000Z

256

A Comparative Assessment of Surface Wind Speed and Sea Surface Temperature over the Indian Ocean by TMI, MSMR, and ERA-40  

Science Conference Proceedings (OSTI)

A 2-yr (June 1999–June 2001) observation of ocean surface wind speed (SWS) and sea surface temperature (SST) derived from microwave radiometer measurements made by a multifrequency scanning microwave radiometer (MSMR) and the Tropical Rainfall ...

Anant Parekh; Rashmi Sharma; Abhijit Sarkar

2007-06-01T23:59:59.000Z

257

Frequency-Domain Synthesis Of The Fatigue Load Spectrum For The Nps 100-Kw Wind Turbine  

E-Print Network (OSTI)

* The LIFE2 code is a fatigue/fracture mechanics code that is specialized to the analysis of wind turbine components. Two frequency-domain stress spectra techniques contained in this code are used to analyze the measured frequency loads spectra from the Northern Power Systems 100-kW turbine. Results of the two techniques are compared to cycle counts obtained directly from time series data. These results provide the wind turbine designer with two techniques for determining the cycle-counts from frequency data and illustrate the accuracy that the designer can expect from various cycle-counting techniques. INTRODUCTION The LIFE2 code is a fatigue/fracture mechanics code that is specialized to the analysis of wind turbine components. 1 This code permits the analysis of both time series 2 and frequency domain data. 3 In the case of the former, a "rainflow counting" algorithm is used to convert time series data into a cycle count matrix suitable for fatigue analysis. For the latter,...

Herbert J. Sutherland; Richard M. Osgood

1992-01-01T23:59:59.000Z

258

HEXOS—Humidity Exchange Over the Sea A Program for Research on Water-Vapor and Droplet Fluxes from Sea of Air at Moderate to High Wind Speeds  

Science Conference Proceedings (OSTI)

HEXOS is an international program for the study of evaporation and spray-droplet flux from sea to air. The program includes measurements in the field at moderate-to-high wind speeds, wind-tunnel studies, instrument development, boundary-layer ...

Kristina B. Katsaros; Stuart D. Smith; Wiebe A. Oost

1987-05-01T23:59:59.000Z

259

Wind Resources in Alaska | OpenEI  

Open Energy Info (EERE)

Resources in Alaska Resources in Alaska Dataset Summary Description Wind resource data for Alaska and southeast Alaska, both high resolution wind resource maps and gridded wind parameters. The two high resolution wind maps are comprised of a grid of cells each containing a single value of average wind speed (m/s) at a hub height of 30, 50, 70, and 100 meters and wind power density (W/m^2) at a hub height of 50 meters for a 40,000 square meter area. The additional gridded wind parameter data includes data for points spaced 2 kilometers apart, and include: predicted wind speed frequency distribution as well as speed and energy in 16 directions (the information needed to produce a wind rose image at a given point). Data included here as .kml files (for viewing in Google Earth). GIS shape files available for the gridded wind parameters datasets from AEDI (http://akenergyinventory.org/data.shtml).

260

Acoustic ranging technique with application to assessment of low-frequency acoustic noise of wind turbines  

DOE Green Energy (OSTI)

Impulsive low-frequency noise from wind turbines can cause annoyance particularly when a residential structure is involved. Such noise is typically generated in some spatially restricted region of a turbine rotor swept area. Low-frequency impulsive noise of the MOD-1 turbine was generated when the rotor blades passed downwind of the tower legs encountering the complex unsteady flows there. An acoustic ranging technique that aids assessment of the degree of concentration of acoustic generation within the turbine swept area and which determines the time-average spatial source region of such concentration is described. Practical applications and limitations of the process are discussed.

Hemphill, R.

1983-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Modeling Coastally Trapped Wind Surges over Southeastern Australia. Part I: Timing and Speed of Propagation  

Science Conference Proceedings (OSTI)

During the spring and summer months, the southeast coast of Australia often experiences abrupt southerly wind changes, the leading edge being known locally as a “southerly buster.” The main characteristic of this phenomenon is the sudden shift in ...

Helen J. Reid; Lance M. Leslie

1999-02-01T23:59:59.000Z

262

Prediction of Wind Speed, Direction and Diffusivity under Neutral Conditions for Tall Stacks  

Science Conference Proceedings (OSTI)

A one dimensional model of the neutral planetary boundary layer is used to predict the wind velocity and coefficient of eddy diffusivity throughout the 2-km planetary boundary layer. Comparison with routine radiosonde observations show that at ...

Nirupama Raghavan; Swati Basu

1988-03-01T23:59:59.000Z

263

Rotor Speed Dependent Yaw Control of Wind Turbines Based on Empirical Data  

Science Conference Proceedings (OSTI)

When extracting energy from the wind using horizontal-axis upwind wind turbines, a primary condition for maximum power yield is the ability to align the rotor axis with the dominating wind direction. Attempts have been made to improve yaw alignment by applying advanced measurement techniques such as LIDARs. This study is focused at assessing the current performance of an operating turbine and exploring how the yaw alignment can be improved using existing measurements. By analyzing available turbine and met mast data a correction scheme for the original yaw alignment system is synthesized. The correction scheme is applied and it is seen that with the correction scheme in place, the power yield below rated is raised 1-5 percent. Furthermore, results indicate that blade load variations are decreased when the correction scheme is applied. The results are associated with uncertainties due to the amount of available data and the wind site climate. Further work should be focused at gathering more experimental data.

Kragh, K. A.; Fleming, P. A.

2012-01-01T23:59:59.000Z

264

Profiles of Wind Speed Variances within Nocturnal Low-Level Jets Observed with a Sodar  

Science Conference Proceedings (OSTI)

Continuous sodar measurements of wind profiles have been carried out at the Zvenigorod Scientific Station of the Obukhov Institute of Atmospheric Physics since 2008. The station is located in a slightly inhomogeneous rural area about 45 km west of ...

Margarita A. Kallistratova; Rostislav D. Kouznetsov; Valerii F. Kramar; Dmitrii D. Kuznetsov

265

Estimating Maximum Surface Winds from Hurricane Reconnaissance Measurements  

Science Conference Proceedings (OSTI)

Radial profiles of surface winds measured by the Stepped Frequency Microwave Radiometer (SFMR) are compared to radial profiles of flight-level winds to determine the slant ratio of the maximum surface wind speed to the maximum flight-level wind ...

Mark D. Powell; Eric W. Uhlhorn; Jeffrey D. Kepert

2009-06-01T23:59:59.000Z

266

WIND ENERGY Wind Energ. (2012)  

E-Print Network (OSTI)

WIND ENERGY Wind Energ. (2012) Published online in Wiley Online Library (wileyonlinelibrary since energy production depends non-linearly on wind speed (U ), and wind speed observa- tions for the assessment of future long-term wind supply A. M. R. Bakker1 , B. J. J. M. Van den Hurk1 and J. P. Coelingh2 1

Haak, Hein

267

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

268

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

269

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

270

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

271

WIND DATA REPORT FALMOUTH, MA  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

272

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

273

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

274

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

275

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

276

WIND DATA REPORT Presque Isle  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

277

WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

278

A Similarity Hypothesis for Air–Sea Exchange at Extreme Wind Speeds  

Science Conference Proceedings (OSTI)

Hurricane intensity is sensitive to fluxes of enthalpy and momentum between the ocean and atmosphere in the high wind core of the storm. It has come to be recognized that much of this exchange is likely mediated by sea spray. A number of ...

Kerry Emanuel

2003-06-01T23:59:59.000Z

279

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

E-Print Network (OSTI)

, China mcheng@seu.edu.cn Abstract-- Grid connected wind turbines are the sources of power fluctuations and the individual pitch controller is designed. The simulations are performed on the NREL (National Renewable Energy shortage, great efforts have been taken around the world to implement renewable energy projects

Chen, Zhe

280

Stability Dependence of the Ratio of Wind Speeds at Two Levels over Agriculture Land  

Science Conference Proceedings (OSTI)

Hourly averaged winds are computed from a one-year record taken atop five 10 m towers and four 30 m towers distributed over 4000 km2 of typical agricultural land. Vertical temperature differences are available from three of the 30 m towers. The ...

Jack H. Shreffler

1980-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

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

E-Print Network (OSTI)

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

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

282

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

Science Conference Proceedings (OSTI)

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

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

2010-02-21T23:59:59.000Z

283

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

DOE Green Energy (OSTI)

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

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

2010-02-21T23:59:59.000Z

284

Processing of turbulence-layer wind speed with Generalized SCIDAR through wavelet analysis  

E-Print Network (OSTI)

We describe a new method involving wavelet transforms for deriving the wind velocity associated with atmospheric turbulence layers from Generalized SCIDAR measurements. The algorithm analyses the cross-correlation of a series of scintillation patterns separated by lapses of Dt, 2Dt, 3Dt, 4Dt and 5Dt using wavelet transforms. Wavelet analysis provides the position, direction and altitude of the different turbulence layers detected in each cross-correlation. The comparison and consistency of the turbulent layer displacements in consecutive cross-correlations allow the determination of their velocities and avoid misidentifications associated with noise and/or overlapping layers. To validate the algorithm, we have compared the velocity of turbulence layers derived on four nights with the wind vertical profile provided by balloon measurements. The software is fully automated and is able to analyse huge amounts of Generalized SCIDAR measurements.

B. Garcia-Lorenzo; J. J. Fuensalida

2006-08-28T23:59:59.000Z

285

Note on the Use of the Inverse Gaussian Distribution for Wind Energy Applications  

Science Conference Proceedings (OSTI)

The inverse Gaussian distribution is suggested as an alternative to the three-parameter Weibull distribution for the description of wind speed data with low frequencies of low speeds. A comparison of the two distributions indicates a region of ...

W. E. Bardsley

1980-09-01T23:59:59.000Z

286

A proposed metric for assessing the potential of community annoyance from wind turbine low-frequency noise emissions  

SciTech Connect

Given our initial experience with the low-frequency, impulsive noise emissions from the MOD-1 wind turbine and their impact on the surrounding community, the ability to assess the potential of interior low-frequency annoyance in homes located near wind turbine installations may be important. Since there are currently no universally accepted metrics or descriptors for low-frequency community annoyance, we performed a limited program using volunteers to see if we could identify a method suitable for wind turbine noise applications. We electronically simulated three interior environments resulting from low-frequency acoustical loads radiated from both individual turbines and groups of upwind and downwind turbines. The written comments of the volunteers exposed to these interior stimuli were correlated with a number of descriptors which have been proposed for predicting low-frequency annoyance. The results are presented in this paper. We discuss our modifications of the highest correlated predictor to include the internal dynamic pressure effects associated with the response of residential structures to low-frequency acoustic loads. Finally, we outline a proposed procedure for establishing both a low-frequency ''figure of merit'' for a particular wind turbine design and, using actual measurements, estimate the potential for annoyance to nearby communities. 10 refs., 13 figs., 7 tabs.

Kelley, N.D.

1987-10-05T23:59:59.000Z

287

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

DOE Green Energy (OSTI)

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.

George, R.L.

1984-02-01T23:59:59.000Z

288

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

E-Print Network (OSTI)

??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)

Solberg, Olov

2012-01-01T23:59:59.000Z

289

The estimation of wind pressures at ventilation inlets and outlets on buildings  

Science Conference Proceedings (OSTI)

Two example calculations illustrate the application of information provided in chapter 14 of the 1989 ASHRAE Fundamentals to the estimation of wind pressures at ventilation inlets and outlets on the exteriors of buildings. Wind pressures are calculated using the local estimated reference mean wind speeds at the building site and pressure coefficients selected from figures provided in Chapter 14 of the handbook. Calculations include estimation of wind speeds at building sites located significant distance from airport weather data recording stations in a variety of terrains using the power law mean wind speed profile equation. Wind frequency data are used to calculate the relative probability of occurrence of wind speed and direction events. Wind tunnel studies are recommended as the best source of wind pressure coefficients for applications where consequences of wind effects could be critical.

Aynsley, R.M (Georgia Inst. of Technology, Atlanta, GA (US))

1989-01-01T23:59:59.000Z

290

WIND DATA REPORT January -March, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

291

WIND DATA REPORT Deer Island Outfall  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

292

ANNUAL WIND DATA REPORT Thompson Island  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

293

WIND DATA REPORT Deer Island Parking Lot  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

294

WIND DATA REPORT January -December, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

295

Frequency-Wavenumber Spectra of Sea Surface Temperature and Wind-Stress Curl in the Eastern North Pacific  

Science Conference Proceedings (OSTI)

Frequency-wavenumber spectra of sea surface temperature and wind-stress curl are computed from 11 years of surface marine observations taken in the eastern North Pacific. These data were averaged by month and 2° quadrangles to yield spectra with ...

Artemio Gallegos-Garcia; William J. Emery; Robert O. Reid; Lorenz Magaard

1981-08-01T23:59:59.000Z

296

Did the Beaufort Scale or the Wind Climate Change?  

Science Conference Proceedings (OSTI)

Possible long-term variations of the Beaufort scale of wind speeds are investigated from frequency distributions of about 300 000 ship observations. Records from the western entrance to the English Channel are taken as representative for ...

E. W. Peterson; L. Hasse

1987-07-01T23:59:59.000Z

297

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

E-Print Network (OSTI)

of doubly fed induction machine (DFIG) and PMSG based wind turbines have been proposed [7-10]. In this paper

Hu, Weihao

298

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

E-Print Network (OSTI)

turbine power if the wind is favorable at the moment and response provided by borrowing energy from the rotors

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

299

Partial CO2 Column-Averaged Dry-Air Mixing Ratio from Measurements by Coherent 2-?m Differential Absorption and Wind Lidar with Laser Frequency Offset Locking  

Science Conference Proceedings (OSTI)

A coherent 2-?m differential absorption and wind lidar (Co2DiaWiL) with a 2-?m single-frequency Q-switched laser with laser frequency offset locking was used for long-range CO2 measurement. The frequency stabilization of the single-frequency ? on ...

Shoken Ishii; Kohei Mizutani; Philippe Baron; Hironori Iwai; Ryoko Oda; Toshikazu Itabe; Hirotake Fukuoka; Takayoshi Ishikawa; Mizuki Koyama; Tomoaki Tanaka; Isamu Morino; Osamu Uchino; Atsushi Sato; Kazuhiro Asai

2012-09-01T23:59:59.000Z

300

Estimating Downburst-Related Maximum Surface Wind Speeds by Means of Proximity Soundings in New South Wales, Australia  

Science Conference Proceedings (OSTI)

A regional climatology of strong wind gusts associated with thunderstorms is presented, and the ability to estimate gust strength from ambient conditions is tested. Strong wind events were selected for 10 stations in New South Wales, Australia, ...

Bart Geerts

2001-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
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301

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

E-Print Network (OSTI)

The work described in this report was funded by the Federal Energy Regulatory Commission, Office of Electric Reliability through a subcontract administered by the Lawrence Berkeley National Laboratory, which is operated by the University of California for the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Disclaimer This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. Power and Frequency Control as it Relates to Wind-Powered Generation

Ernest Orlando Lawrence; John Undrill; John Undrill Llc; John Undrill; John Undrill Llc

2010-01-01T23:59:59.000Z

302

Very short-term wind speed forecasting with Bayesian structural break model , Zhe Song a,*, Andrew Kusiak b  

E-Print Network (OSTI)

reserved. 1. Introduction Wind is one of the most promising green energy sources. The world's installed-1527, Iowa City, United States a r t i c l e i n f o Article history: Received 27 November 2011 Accepted 31 wind power capacity is exponentially increasing in recent years and wind industry is expanding

Kusiak, Andrew

303

Definition: Wind rose | Open Energy Information  

Open Energy Info (EERE)

rose rose Jump to: navigation, search Dictionary.png Wind rose A diagram that shows the average percentage of time that the wind blows from different directions, typically on a monthly or annual basis.[1][2] View on Wikipedia Wikipedia Definition A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location. Historically, wind roses were predecessors of the compass rose, as there was no differentiation between a cardinal direction and the wind which blew from such a direction. Using a polar coordinate system of gridding, the frequency of winds over a long time period are plotted by wind direction, with color bands showing wind ranges. The directions of the rose with the longest spoke show the wind direction with

304

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

E-Print Network (OSTI)

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) for typical fan and pump loads. It also discusses advantages and disadvantages of using mechanical MC-ASD versus VFDs and it provides field experience with VFDs in refrigerated warehouses as well as the fixed magnet MC-ASD in wastewater and other field applications. Laboratory tests for a 50 hp fan retrofit showed electronic VFD savings at 62%, the MagnaDrive Coupling at 39% and PAYBACK Drive at 46%. At $0.06/kWh and list prices, the simple payback for the VFD is 2.4 years, the MagnaDrive is 4.6 years and the PAYBACK is 1.9 years. MagnaDrive has models from 25 to 500 hp while PAYBACK has models from 3 to 200 hp. Contractors to the Northwest Energy Efficiency Alliance have helped to install VFDs for about 300 evaporator fans in over two dozen refrigerated warehouses and to install fixed-magnet MC-ASDs in about 50 applications with about half of these controlling wastewater pumps. The Alliance has no particular field experience with the electcromagnetic coupling. The primary advantages of magnetically coupled adjustable speed drives (MC-ASD) over VFDs come from reduced maintenance, resistance to dirty environments, separation of load vibration from the motor, and less stringent requirements for precise shaft alignment. Field experience indicates reductions in noise and repairs from vibration loads, tolerance of poor electrical power quality, and ease of installation are often more important than energy savings. The MC-ASDs are being used where VFDs have not survived or are considered too complicated.

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

2003-05-01T23:59:59.000Z

305

NREL: Wind Research - Offshore Wind Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Options Site Map Printable Version Offshore Standards and Testing NREL's Offshore Wind Testing Capabilities 35 years of wind turbine testing experience Custom high speed data...

306

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

DOE Green Energy (OSTI)

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.

Not Available

2006-03-01T23:59:59.000Z

307

High Range Resolution Radar Measurements of the Speed Distribution of Breaking Events in Wind-Generated Ocean Waves: Surface Impulse and Wave Energy Dissipation Rates  

Science Conference Proceedings (OSTI)

A set of X-band radar measurements, backscattered from the sea surface at near grazing incidence with very high spatial and temporal resolution (30 cm in range and 2000-Hz pulse repetition frequency) in moderate wind conditions, are dominated by ...

O. M. Phillips; F. L. Posner; J. P. Hansen

2001-02-01T23:59:59.000Z

308

ON THE LOW-FREQUENCY BOUNDARY OF SUN-GENERATED MAGNETOHYDRODYNAMIC TURBULENCE IN THE SLOW SOLAR WIND  

Science Conference Proceedings (OSTI)

New aspects of the slow solar wind turbulent heating and acceleration are investigated. A physical meaning of the lower boundary of the Alfven wave turbulent spectra in the solar atmosphere and the solar wind is studied and the significance of this natural parameter is demonstrated. Via an analytical and quantitative treatment of the problem we show that a truncation of the wave spectra from the lower frequency side, which is a consequence of the solar magnetic field structure and its cyclic changes, results in a significant reduction of the heat production and acceleration rates. An appropriate analysis is presented regarding the link of the considered problem with existing observational data and slow solar wind initiation scenarios.

Shergelashvili, Bidzina M.; Fichtner, Horst [Institut fuer Theoretische Physik IV, Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

2012-06-20T23:59:59.000Z

309

Effect of generalized wind characteristics on annual power estimates from wind turbine generators  

SciTech Connect

A technique is presented for estimating the average power output of a wind turbine using, as the wind characteristic input, only the mean annual wind magnitude. Hourly wind speeds are assumed to have a Rayleigh frequency distribution which requires a single parameter input (e.g., the mean value, variance or higher moment values). Based upon a general shape, for the wind speed versus machine output, a generic set of curves is developed to estimate the average power output of wind turbines. Also, estimates of the percent of time the wind turbine would not produce power (percent down time) and the percent of time the wind turbine would be operating at its rated power are presented.

Cliff, W.C.

1977-10-01T23:59:59.000Z

310

Low Wind Speed Technology Phase II: Reducing Cost of Energy Through Rotor Aerodynamics Control; Global Energy Concepts, LLC  

DOE Green Energy (OSTI)

This fact sheet describes a subcontract with Global Energy Concepts to evaluate a wide range of wind turbine configurations and their impact on overall cost of energy (COE).

Not Available

2006-03-01T23:59:59.000Z

311

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

SciTech Connect

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.

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

2010-12-20T23:59:59.000Z

312

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

SciTech Connect

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.

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

2010-12-20T23:59:59.000Z

313

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

Science Conference Proceedings (OSTI)

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.

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

314

A simple method to downscale daily wind statistics to hourly wind data  

E-Print Network (OSTI)

Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the overall agreement between observed and simulated cumulative wind speed probability distributions appears excellent, especially for the wind speeds greater than 5 m s-1 range (erosive wind speed). The results further revealed that the values of daily average erosive wind power density (AWPD) calculated from generated wind speeds fit the counterparts computed from measured wind speeds well with high models' efficiency (Nash-Sutcliffe coefficient). So that the hourly wind speed data can be predicted from daily average and maximu...

Guo, Zhongling

2013-01-01T23:59:59.000Z

315

NREL GIS Data: Global Offshore Wind GIS data for offshore wind...  

Open Energy Info (EERE)

Global Offshore Wind GIS data for offshore wind speed (meterssecond).  Specified to Exclusive Economic Zones (EEZ).

Wind resource based on NOAA blended sea winds and...

316

A Resonance Mechanism Leading to Wind-Forced Motions with a 2f Frequency  

Science Conference Proceedings (OSTI)

This study revisits the mechanisms that spatially reorganize wind-forced inertial motions embedded in an oceanic mesoscale eddy field. Inertial motions are known to be affected by the eddy relative vorticity, being expelled from cyclonic ...

Eric Danioux; Patrice Klein

2008-10-01T23:59:59.000Z

317

The Application of Diode-Clamped Cascaded Inverter in the Direct-Driven Wind Power System  

Science Conference Proceedings (OSTI)

Power inverter is widely used in direct-driven variable speed constant frequency (VSVF) wind power system. With the level of wind power jumping from the kilowatt to megawatt, topologies and control of inverter have a corresponding change. Considering ... Keywords: direct-driven wind power, multi-level inverter, diode-clamped cascaded inverter, PD-SPWM and CPS-SPWM

Xianglian Xu; Pingting Xu; Zilin Tang; Gang Tang; Xiaole Ye

2012-04-01T23:59:59.000Z

318

A three-phase three-winding core-type transformer model for low-frequency transient studies  

Science Conference Proceedings (OSTI)

A topology-based and duality-derived three-phase, three-winding, core-type transformer model is presented. The model treats the leakage inductances and the coupling effects of the core in a straightforward and integrated way. The long-established positive- and zero-sequence star equivalent circuits of a three-phase three-winding transformer are derived from the original equivalent magnetic circuit of the transformer by applying duality. Formulations for determining the values of the leakage inductances and the core loss resistances from transformer open- and short-circuit test data are presented. A supporting routine is written to generate the {lambda}-i curves for each segment of the core and the other input data for EMTP. Since the duality-derived model consists of only RLC elements, no device-specific code to EMTP time-step code is needed. Winding capacitances are lumped to the terminals. The model is suitable for simulation of power system low-frequency transients such as inrush currents and ferroresonance, short circuits, and abnormalities including transformer winding faults.

Chen, X. [Seattle Univ., WA (United States). Dept. of Electrical Engineering; Venkata, S.S. [Univ. of Washington, Seattle, WA (United States). Dept. of Electrical Engineering

1997-04-01T23:59:59.000Z

319

A Climatological Study of Boundary Layer Wind Speed Using a Meso-?-Scale Higher-Order Closure Model  

Science Conference Proceedings (OSTI)

A mesoscale higher-order closure atmospheric boundary layer model has been used to get more detailed information than is possible from observations regarding horizontal and vertical variations of the wind in an area in southeastern Sweden. To ...

Hans Bergström

1996-08-01T23:59:59.000Z

320

A First-Guess Feature-Based Algorithm for Estimating Wind Speed in Clear-Air Doppler Radar Spectra  

Science Conference Proceedings (OSTI)

Algorithms for deriving winds from profiler range-gated spectra currently rely on consensus averaging to remove outliers from the subhourly velocity estimates. For persistent ground clutter in the echo return that is stronger than the atmospheric ...

E. E. Clothiaux; R. S. Penc; D. W. Thomson; T. P. Ackerman; S. R. Williams

1994-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

The Probability Distribution of Sea Surface Wind Speeds: Effects of Variable Surface Stratification and Boundary Layer Thickness  

Science Conference Proceedings (OSTI)

Air–sea exchanges of momentum, energy, and material substances of fundamental importance to the variability of the climate system are mediated by the character of the turbulence in the atmospheric and oceanic boundary layers. Sea surface winds ...

Adam Hugh Monahan

2010-10-01T23:59:59.000Z

322

WIND DATA REPORT December 1 2003 February 29 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

323

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

324

WIND DATA REPORT September 1 2003 November 30 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

325

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

326

WIND DATA REPORT March 1, 2004 May 31, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

327

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

328

WIND DATA REPORT December 1, 2003 February 29, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

329

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

330

Validation of HRDI MLT winds with meteor radars  

Science Conference Proceedings (OSTI)

applied to determine whether the wind speed has been overestimated by HRDI ... wind vector components as well as wind speeds, and two nonparametric tests ...

331

WIND DATA REPORT Camden Hills Regional High School, ME  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

332

WIND DATA REPORT December, 2003 February 29, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

333

WIND DATA REPORT October 27, 2003 November 31, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

334

WIND DATA REPORT January 1, 2004 December 31, 2004  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

335

WIND DATA REPORT September 1, 2003 November 31, 2003  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

336

WIND DATA REPORT August 28 -December 31, 2002  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

337

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

E-Print Network (OSTI)

2009. “North America Dynamic Wind Generator Modeling Update,work performed by the WECC Wind Generator Modeling Group andIEEE Dynamic Performance of Wind Power Generation Working

Mackin, Peter

2011-01-01T23:59:59.000Z

338

Sea-Tower Measurements of Wind-Wave Spectra in the Caspian Sea  

Science Conference Proceedings (OSTI)

High frequency spectra of wind generated waves corresponding to mean wind speeds from 3.5 to 13.5 m s?1 were measured at the research tower in the Caspian Sea. The techniques used made it possible to evaluate spectra S(?) in the frequency range ...

I. A. Leykin; A. D. Rozenberg

1984-01-01T23:59:59.000Z

339

Low Speed Technology for Small Turbine Development Reaction Injection Molded 7.5 Meter Wind Turbine Blade  

Science Conference Proceedings (OSTI)

An optimized small turbine blade (7.5m radius) was designed and a partial section molded with the RIM (reaction-injection molded polymer) process for mass production. The intended market is for generic three-bladed wind turbines, 100 kilowatts or less, for grid-assist end users with rural and semi-rural sites, such as the farm/ranch market, having low to moderate IEC Class 3-4 wind regimes. This blade will have substantial performance improvements over, and be cheaper than, present-day 7.5m blades. This is made possible by the injection-molding process, which yields high repeatability, accurate geometry and weights, and low cost in production quantities. No wind turbine blade in the 7.5m or greater size has used this process. The blade design chosen uses a RIM skin bonded to a braided infused carbon fiber/epoxy spar. This approach is attractive to present users of wind turbine blades in the 5-10m sizes. These include rebladeing California wind farms, refurbishing used turbines for the Midwest farm market, and other manufacturers introducing new turbines in this size range.

David M. Wright; DOE Project Officer - Keith Bennett

2007-07-31T23:59:59.000Z

340

Wind Power as an Electrical Energy Source in Illinois  

Science Conference Proceedings (OSTI)

Using 3 h wind data (1970–74) from nine first-order NWS stations in and around Illinois, monthly frequency histograms of wind speeds for each station, and for each half-day (0700–1800 and 1900–0600 LST) were constructed. The histogram class ...

Wayne M. Wendland

1982-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

The Estimation of Wind Turbine Pitch Angle Based on ANN  

Science Conference Proceedings (OSTI)

Variable-speed and constant-frequency (VSCF) pitch-controlled wind turbine is believed to be superior to other types of wind turbine due to its features such as high efficiency and ideal starting and braking performance, Artificial Neural Networks (ANN) ... Keywords: VSCF, ANN, pitch angle, Pitch-controlled system

Yanping Liu; Shuhong Liu; Hongmei Guo; Huajun Wang

2009-11-01T23:59:59.000Z

342

Model-based fault detection and isolation of a liquid-cooled frequency converter on a wind turbine  

Science Conference Proceedings (OSTI)

With the rapid development of wind energy technologies and growth of installed wind turbine capacity in the world, the reliability of the wind turbine becomes an important issue for wind turbine manufactures, owners, and operators. The reliability of ...

Peng Li, Peter Fogh Odgaard, Jakob Stoustrup, Alexander Larsen, Kim Mřrk

2012-01-01T23:59:59.000Z

343

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

E-Print Network (OSTI)

to manipulate the electrical power delivered to the grid 2 .turbine pitch and of electrical power output can be used torelationship between electrical power and frequency, or to

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

344

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

E-Print Network (OSTI)

2   1.4   Modes of Power Plant32   4.3   Power Plant Controls (Plant Operation by24. Effect of frequency bias in power plant preselected load

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

345

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

SciTech Connect

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.

Lacommare, Kristina S H

2010-12-20T23:59:59.000Z

346

On the Heating of the Solar Corona and the Acceleration of the Low-Speed Solar Wind by Acoustic Waves Generated in Corona  

E-Print Network (OSTI)

We investigate possibilities of solar coronal heating by acoustic waves generated not at the photosphere but in the corona, aiming at heating in the mid- to low-latitude corona where the low-speed wind is expected to come from. Acoustic waves of period tau ~ 100s are triggered by chromospheric reconnection, one model of small scale magnetic reconnection events recently proposed by Sturrock. These waves having a finite amplitude eventually form shocks to shape sawtooth waves (N-waves), and directly heat the surrounding corona by dissipation of their wave energy. Outward propagation of the N-waves is treated based on the weak shock theory, so that the heating rate can be evaluated consistently with physical properties of the background coronal plasma without setting a dissipation length in an ad hoc manner. We construct coronal structures from the upper chromosphere to the outside of 1AU for various inputs of the acoustic waves having a range of energy flux of F_{w,0} = (1-20) times 10^5 erg cm^{-2} s^{-1} and a period of tau = 60-300s. The heating by the N-wave dissipation effectively works in the inner corona and we find that the waves of F_{w,0} >= 2 times 10^5 erg cm^{-2} s^{-1} and tau >= 60s could maintain peak coronal temperature, T_{max} > 10^6 K. The model could also reproduce the density profile observed in the streamer region. However, due to its short dissipation length, the location of T_{max} is closer to the surface than the observation, and the resultant flow velocity of the solar wind is lower than the observed profile of the low-speed wind. The cooperations with other heating and acceleration sources with the larger dissipation length are inevitable to reproduce the real solar corona.

Takeru Ken Suzuki

2002-06-14T23:59:59.000Z

347

The InterHourly-Variability (IHV) Index of Geomagnetic Activity and its Use in Deriving the Long-term Variation of Solar Wind Speed  

E-Print Network (OSTI)

We describe the derivation of the InterHourly Variability (IHV) index of geomagnetic activity. The IHV-index for a geomagnetic element is mechanically derived from hourly values as the sum of the unsigned differences between adjacent hours over a seven-hour interval centered on local midnight. The index is derived separately for stations in both hemispheres within six longitude sectors using only local night hours. It is intended as a long-term index. Available data allows derivation of the index back well into the 19th century. On a time scale of a 27-day Bartels rotation, IHV averages for stations with corrected geomagnetic latitude less than 55 degrees are strongly correlated with midlatitude range indices. Assuming a constant calibration of the aa-index we find that observed yearly values of aa before the year 1957 are 2.9 nT too small compared to values calculated from IHV using the regression constants based on 1980-2004. We interpret this discrepancy as an indication that the calibration of the aa index is in error before 1957. There is no such problem with the ap index. Rotation averages of IHV are also strongly correlated with solar wind parameters (BV^2). On a time scale of a year combining the IHV-index and the recently-developed Inter-Diurnal Variability (IDV) index (giving B) allows determination of solar wind speed, V, from 1890-present. Over the ~120-year series, the yearly mean solar wind speed varied from a low of 303 km/s in 1902 to a high value of 545 km/s in 2003. The calculated yearly values of the product BV using B and V separately derived from IDV and IHV agree quantitatively with (completely independent) BV derived from the amplitude of the diurnal variation of the H component in the polar caps since 1926 and sporadically beyond.

Leif Svalgaard; Edward W. Cliver

2007-06-07T23:59:59.000Z

348

Very Low Frequency (VLF) Hipot Testing of Rotating Machine Stator Winding Insulation  

Science Conference Proceedings (OSTI)

High-potential (hipot) tests are performed to determine whether winding insulation in rotating electrical machinery has a minimum level of electrical strength to successfully survive electrical stresses in normal service for the expected life of the machine. In recent years, the Electric Power Research Institute (EPRI) has been engaged in helping to clarify industry practices and investigate questions about specific aspects of hipot testing. One topic of interest to the industry is the use of very-low-fr...

2011-12-23T23:59:59.000Z

349

Wind energy resource atlas. Volume 3. Great Lakes Region  

DOE Green Energy (OSTI)

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.

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

1981-02-01T23:59:59.000Z

350

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

SciTech Connect

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.

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

1981-02-01T23:59:59.000Z

351

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

DOE Green Energy (OSTI)

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.

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

1981-03-01T23:59:59.000Z

352

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

SciTech Connect

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.

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

1984-09-01T23:59:59.000Z

353

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

E-Print Network (OSTI)

LFC) commands issued by BAs. In this regard they are verya power system in which two BAs are interconnected by aControl Error (ACE) of the BAs. Power and Frequency Control

Lacommare, Kristina S H

2011-01-01T23:59:59.000Z

354

Low-Frequency Free Wave and Wind-Driven Motions Over a Submarine Bank  

Science Conference Proceedings (OSTI)

This study attempts to isolate the physics peculiar to a submarine bank. The particular model is barotropic and contains an infinitely long straight bank within an unbounded ocean basin. The low-frequency, free wave solutions consist of two ...

K. H. Brink

1983-01-01T23:59:59.000Z

355

Low Wind Speed Turbine Project Conceptual Design Study: Advanced Independent Pitch Control; July 30, 2002--July 31, 2004 (Revised)  

DOE Green Energy (OSTI)

AES conducted a conceptual study of independent pitch control using inflow angle sensors. The control strategy combined input from turbine states (rotor speed, rotor azimuth, each blade pitch) with inflow angle measurements (each blade angle of attack at station 11 of 15) to derive blade pitch demand signals. The controller reduced loads sufficiently to allow a 10% rotor extension and reduce COE by 6.3%.

Olsen, T.; Lang, E.; Hansen, A.C.; Cheney, M. C.; Quandt, G.; VandenBosche, J.; Meyer, T.

2004-12-01T23:59:59.000Z

356

Strong wind forcing of the ocean  

E-Print Network (OSTI)

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 .

Zedler, Sarah E.

2007-01-01T23:59:59.000Z

357

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

NLE Websites -- All DOE Office Websites (Extended Search)

Technology Improvement Technology Improvement Opportunities for Low Wind Speed Turbines and Implications for Cost of Energy Reduction July 9, 2005 - July 8, 2006 J. Cohen and T. Schweizer Princeton Energy Resources International (PERI) Rockville, Maryland A. Laxson, S. Butterfield, S. Schreck, and L. Fingersh National Renewable Energy Laboratory Golden, Colorado P. Veers and T. Ashwill Sandia National Laboratories Albuquerque, New Mexico Technical Report NREL/TP-500-41036 February 2008 NREL is operated by Midwest Research Institute â—Ź Battelle Contract No. DE-AC36-99-GO10337 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy

358

Perpendicular Ion Heating by Low-Frequency Alfven-Wave Turbulence in the Solar Wind  

E-Print Network (OSTI)

We consider ion heating by turbulent Alfven waves (AWs) and kinetic Alfven waves (KAWs) with perpendicular wavelengths comparable to the ion gyroradius and frequencies smaller than the ion cyclotron frequency. When the turbulence amplitude exceeds a certain threshold, an ion's orbit becomes chaotic. The ion then interacts stochastically with the time-varying electrostatic potential, and the ion's energy undergoes a random walk. Using phenomenological arguments, we derive an analytic expression for the rates at which different ion species are heated, which we test by simulating test particles interacting with a spectrum of randomly phased AWs and KAWs. We find that the stochastic heating rate depends sensitively on the quantity epsilon = dv/vperp, where vperp is the component of the ion velocity perpendicular to the background magnetic field B0, and dv (dB) is the rms amplitude of the velocity (magnetic-field) fluctuations at the gyroradius scale. In the case of thermal protons, when epsilon eps1, the proton ...

Chandran, Benjamin D G; Rogers, Barrett N; Quataert, Eliot; Germaschewski, Kai

2010-01-01T23:59:59.000Z

359

Grid Operation and Coordination with Wind -2 1.0 Introduction  

E-Print Network (OSTI)

(DFIGs) also produce power that varies with wind speed, although the torque- speed controller provides

McCalley, James D.

360

Analysis on Control Method VSCF Wind Power System  

Science Conference Proceedings (OSTI)

By analyzing the operation behavior of an A.C. excited variable-speed constant-frequency (VSCF) wind-power generator, the field-oriented vector control technique and and the internal model controller (IMC) are transplanted into the voltage control of ... Keywords: Doubly-fed induction generator, pitch control, field oriented vector control, internal model controller, fuzzy-PD controller, Variable-speed constant frequency

Wang Yulong; Shao Guiping

2008-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

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

E-Print Network (OSTI)

based on the wind farm single phase equivalent circuit. The stability analysis is carried out, phase margin, and vector gain margin calculated for different number of wind turbines in operation. The interaction between the wind turbine control system and the wind farm structure in wind farms is deeply

Paris-Sud XI, Université de

362

Low-Frequency Variability, Coherence Resonance, and Phase Selection in a Low-Order Model of the Wind-Driven Ocean Circulation  

Science Conference Proceedings (OSTI)

In this paper, a low-order spectral quasigeostrophic (QG) model of the wind-driven ocean circulation is derived and used to analyze the low-order character of the intrinsic low-frequency variability of the midlatitude double-gyre ocean circulation ...

Stefano Pierini

2011-09-01T23:59:59.000Z

363

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

DOE Green Energy (OSTI)

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.

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

2013-06-01T23:59:59.000Z

364

Large Scale, Low Frequency Variability of the 1979 FGGE Surface Buoy Drifts and Winds over the Southern Hemisphere  

Science Conference Proceedings (OSTI)

The surface response of the Southern Hemisphere's oceans to the large spatial scale, interseasonal changes in wind forcing during the FGGE year of 1979 is investigated. The primary data are the analyzed daily wind fields, and the trajectories of ...

W. G. Large; H. Van Loon

1989-02-01T23:59:59.000Z

365

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

E-Print Network (OSTI)

factor. Type 2 Wind Turbine Generator (Wound Rotor InductionTurbine Generator (Doubly-fed Induction (Asynchronous) Generator: The rotor

Mackin, Peter

2011-01-01T23:59:59.000Z

366

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)

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 is used to restrict the application of the geophysical retrieval algorithms which are developed to handle specific atmospheric absorptive situations. An improved semi-empirical sea surface emissivity model is integrated into this refined D-matrix procedure that is being developed for the Advanced Microwave Sounding Radiometer (AMSR). The purpose of this work is to test the refined geophysical parameter retrieval methods using data from the Special Sensor Microwave / Imager (SSM/I). When comparing the statistical performance of the TIWV, WS, and CLW retrieval methods presented to the statistical performance of published retrieval methods for each geophysical parameter, the retrieval methods developed for this study perform only slightly better. However, it is demonstrated that the new retrieval methods are more physically valid than the comparison retrieval methods. The utilization of the polarization difference of the 85 GHZ channels to restrict the application of specifically-derived retrieval algorithms proves to be a valuable and reliable geophysical parameter retrieval tool.

Manning, Norman Willis William

1997-01-01T23:59:59.000Z

367

Wind Derivatives: Modeling and Pricing  

Science Conference Proceedings (OSTI)

Wind is considered to be a free, renewable and environmentally friendly source of energy. However, wind farms are exposed to excessive weather risk since the power production depends on the wind speed, the wind direction and the wind duration. This risk ... Keywords: Forecasting, Pricing, Wavelet networks, Weather derivatives, Wind derivatives

A. Alexandridis; A. Zapranis

2013-03-01T23:59:59.000Z

368

An Improved Method for Estimating the Wind Power Density Distribution Function  

Science Conference Proceedings (OSTI)

The wind power density (WPD) distribution curve is essential for wind power assessment and wind turbine engineering. The usual practice of estimating this curve from wind speed data is to first estimate the wind speed probability density function ...

Mark L. Morrissey; Werner E. Cook; J. Scott Greene

2010-07-01T23:59:59.000Z

369

Wind energy resource atlas. Volume 8. The southern Rocky Mountain region  

DOE Green Energy (OSTI)

The Southern Rocky Mountain atlas assimilates five collections of wind resource data: one for the region and one for each of the four states that compose the Southern Rocky Mountain region (Arizona, Colorado, New Mexico, and Utah). 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 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.

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

1981-03-01T23:59:59.000Z

370

Wind energy resource atlas. Volume 12. Puerto Rico and US Virgin Islands  

DOE Green Energy (OSTI)

The Puerto Rico/US Virgin Island atlas assimilates three collections of wind resource data: one for the region as a whole and one each for both the Commonwealth of Puerto Rico and the US Virgin Islands. For the two subregions, features of the climate, topography and wind resource are discussed in greater detail than is 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 both subregions 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.

Wegley, H.L.; Elliott, D.L.; Barchet, W.R.; George, R.L.

1981-01-01T23:59:59.000Z

371

Wind Energy Technologies  

Science Conference Proceedings (OSTI)

... Avg Wind Speed 7.5 m/s 8.74 m/s GE 2.x turbine family ... 1 to 48 Hour Wind Forecasting ... Danish Transmission Grid w/ Interconnects & Offshore Sites ...

2012-08-31T23:59:59.000Z

372

INCORPORATING KINETIC PHYSICS INTO A TWO-FLUID SOLAR-WIND MODEL WITH TEMPERATURE ANISOTROPY AND LOW-FREQUENCY ALFVEN-WAVE TURBULENCE  

Science Conference Proceedings (OSTI)

We develop a one-dimensional solar-wind model that includes separate energy equations for the electrons and protons, proton temperature anisotropy, collisional and collisionless heat flux, and an analytical treatment of low-frequency, reflection-driven, Alfven-wave (AW) turbulence. To partition the turbulent heating between electron heating, parallel proton heating, and perpendicular proton heating, we employ results from the theories of linear wave damping and nonlinear stochastic heating. We account for mirror and oblique firehose instabilities by increasing the proton pitch-angle scattering rate when the proton temperature anisotropy exceeds the threshold for either instability. We numerically integrate the equations of the model forward in time until a steady state is reached, focusing on two fast-solar-wind-like solutions. These solutions are consistent with a number of observations, supporting the idea that AW turbulence plays an important role in the origin of the solar wind.

Chandran, Benjamin D. G.; Dennis, Timothy J. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Quataert, Eliot [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Bale, Stuart D., E-mail: benjamin.chandran@unh.edu, E-mail: tim.dennis@unh.edu, E-mail: eliot@astro.berkeley.edu, E-mail: bale@ssl.berkeley.edu [Physics Department and Space Sciences Laboratory, 311 Old LeConte Hall, University of California, Berkeley, CA 94720 (United States)

2011-12-20T23:59:59.000Z

373

New England Wind Forum: Wind Power Economics  

Wind Powering America (EERE)

State Activities Projects in New England Building Wind Energy in New England Wind Resource Wind Power Technology Economics Cost Components Determining Factors Influencing Wind Economics in New England How does wind compare to the cost of other electricity options? Markets Siting Policy Technical Challenges Issues Small Wind Large Wind Newsletter Perspectives Events Quick Links to States CT MA ME NH RI VT Bookmark and Share Wind Power Economics Long-Term Cost Trends Since the first major installations of commercial-scale wind turbines in the 1980s, the cost of energy from wind power projects has decreased substantially due to larger turbine generators, towers, and rotor lengths; scale economies associated with larger projects; improvements in manufacturing efficiency, and technological advances in turbine generator and blade design. These technological advances have allowed for higher generating capacities per turbine and more efficient capture of wind, especially at lower wind speeds.

374

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

DOE Green Energy (OSTI)

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.

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

2008-02-01T23:59:59.000Z

375

Global ocean wind power sensitivity to surface layer stability  

E-Print Network (OSTI)

2005), Evaluation of global wind power, J. Geophys. Res. ,Pryor (2003), Can satellite sampling of offshore wind speedsrealistically represent wind speed distributions? , J. Appl.

Capps, Scott B; Zender, Charles S

2009-01-01T23:59:59.000Z

376

Methods and apparatus for reducing peak wind turbine loads ...  

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 ...

377

DOE provides detailed offshore wind resource maps - Today in ...  

U.S. Energy Information Administration (EIA)

Includes hydropower, solar, wind, geothermal, biomass and ethanol. ... Wind energy potential is broken down by wind speed, water depth, and distance from shore.

378

Studies on Spatial Structure of Wind Gust  

Science Conference Proceedings (OSTI)

The peak gust speed is often used to evaluate the maximum wind tome acting on the structure in wind engineering. To evaluate this peak gust speed, the ratio of the peak gust speed over the mean wind speed (called gust factor) is defined. The peak ...

Yasushi Mitsuta; Osamu Tsukamoto

1989-11-01T23:59:59.000Z

379

Zoning for Small Wind: The Importance of Tower Height  

Wind Powering America (EERE)

1 1 Zoning for Small Wind: The Importance of Tower Height An ASES Small Wind Webinar Mick Sagrillo-Wisconsin's Focus on Energy © 2008 by Mick Sagrillo 2 Definitions: rotor L&S Tech. Assoc., Inc. Rotor = "collector" for a wind system 3 Definitions: wind * Wind = the 'fuel' * Wind has two 'components' - Quantity = wind speed (velocity or V) - Quality = 'clean' flowing wind 4 Quantity * = average annual wind speed * Climate, not weather * Akin to annual average sun hours for PV or head and flow for hydro * Wind speed increases with height above ground... * ...Due to diminished ground drag (friction) 5 Power in the wind V³ * Wind speed = V * Power available is proportional to wind speed x wind speed x wind speed - or P ~ V x V x V - or P ~ V ³ * Therefore, 10% V = 33% P * Lesson !

380

The Temporal Autocorrelation Structure of Sea Surface Winds  

Science Conference Proceedings (OSTI)

The temporal autocorrelation structures of sea surface vector winds and wind speeds are considered. Analyses of scatterometer and reanalysis wind data demonstrate that the autocorrelation functions (acf) of surface zonal wind, meridional wind, and ...

Adam H. Monahan

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Low Wind Speed Technology Phase II: Developing Techniques to Evaluate the Designs and Operating Environments of Offshore Wind Turbines in the Mid-Atlantic and Lower Great Lakes Region; AWS Truewind, LLC  

DOE Green Energy (OSTI)

This fact sheet describes a subcontract with AWS Truewind, LLC to study offshore wind and wave environments of the Atlantic and lower Great Lakes regions by estimating available wind power resource.

Not Available

2006-03-01T23:59:59.000Z

382

Wind turbine  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

383

Wind energy conversion system  

DOE Patents (OSTI)

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.

Longrigg, Paul (Golden, CO)

1987-01-01T23:59:59.000Z

384

Application of Radar Wind Observations for Low-Level NWP Wind Forecast Validation  

Science Conference Proceedings (OSTI)

The Finnish Meteorological Institute has produced a new numerical weather prediction model–based wind atlas of Finland. The wind atlas provides information on local wind conditions in terms of annual and monthly wind speed and direction averages. ...

Kirsti Salonen; Sami Niemelä; Carl Fortelius

2011-06-01T23:59:59.000Z

385

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

E-Print Network (OSTI)

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 ...

Abdelhalim, Hussein Mohamed

2012-01-01T23:59:59.000Z

386

Low Wind Speed Technology Phase II: Design and Demonstration of On-Site Fabrication of Fluted-Steel Towers Using LITS-Form(TM) Process  

DOE Green Energy (OSTI)

This fact sheet describes NREL's subcontract with Native American Technologies to develop a new method of metal plate forming to produce wind turbine towers.

Not Available

2006-06-01T23:59:59.000Z

387

Geographical Variations of the Influence of Low-Frequency Variability on Lower-Tropospheric Extreme Westerly Wind Events  

Science Conference Proceedings (OSTI)

A conceptual framework is developed for quantifying the relationship between low-frequency variability and extreme events. In this framework, variability is decomposed into low-frequency and synoptic components using complementary 10-day low-pass ...

Jeffrey H. Yin; Grant W. Branstator

2008-09-01T23:59:59.000Z

388

Wavelet Analysis on Solar Wind Parameters and Geomagnetic Indices  

E-Print Network (OSTI)

The sun as an oscillator produces frequencies which propagate in the heliosphere, via solar wind, to the terrestrial magnetosphere. We searched for those frequencies in the parameters of the near Earth solar plasma and the geomagnetic indices for the past four solar cycles. The solar wind parameters used in this work are the interplanetary magnetic field, plasma beta, Alfven Mach number, solar wind speed, plasma temperature, plasma pressure, plasma density and the geomagnetic indices DST, AE, Ap and Kp. We found out that each parameter of the solar wind exhibit certain periodicities which di?erentiate in each cycle. Our results indicate intermittent periodicities in our data, some of them shared between the solar wind parameters and geomagnetic indices.

Katsavrias, Ch; Moussas, X

2012-01-01T23:59:59.000Z

389

Wind Energy Resource Assessment of the Caribbean and Central America  

DOE Green Energy (OSTI)

A wind energy resource assessment of the Caribbean and Central America has identified many areas with good to outstanding wind resource potential for wind turbine applications. Annual average wind resource maps and summary tables have been developed for 35 island/country areas throughout the Caribbean and Central America region. The wind resource maps highlight the locations of major resource areas and provide estimates of the wind energy resource potential for typical well-exposed sites in these areas. The average energy in the wind flowing in the layer near the ground is expressed as a wind power class: the greater the average wind energy, the higher the wind power class. The summary tables that are included with each of the 35 island/country wind energy maps provide information on the frequency distribution of the wind speeds (expressed as estimates of the Weibull shape factor, k) and seasonal variations in the wind resource for the major wind resource areas identified on the maps. A new wind power class legend has been developed for relating the wind power classes to values of mean wind power density, mean wind speed, and Weibull k. Guidelines are presented on how to adjust these values to various heights above ground for different roughness and terrain characteristics. Information evaluated in preparing the assessment included existing meteorological data from airports and other weather stations, and from ships and buoys in offshore and coastal areas. In addition, new data from recent measurement sites established for wind energy siting studies were obtained for a few areas of the Caribbean. Other types of information evaluated in the assessment were climatological data and maps on winds aloft, surface pressure, air flow, and topography. The various data were screened and evaluated for their usefulness in preparing the wind resource assessment. Much of the surface data from airports and other land-based weather stations were determined to be from sheltered sites and were thus not very useful in assessing the wind resource at locations that are well exposed to the winds. Ship data were determined to be the most useful for estimating the large-scale wind flow and assessing the spatial distribution of the wind resource throughout the region. Techniques were developed for analyzing and correcting ship wind data and extrapolating these data to coastal and inland areas by considering terrain influences on the large-scale wind flow. In areas where extrapolation of ship wind data was not entirely feasible, such as interior areas of Central America, other techniques were developed for estimating the wind flow and distribution of the wind resource. Through the application of the various innovative techniques developed for assessing the wind resource throughout the Caribbean and Central America region, many areas with potentially good to outstanding wind resource were identified that had not been previously recognized. In areas where existing site data were available from exposed locations, the measured wind resource was compared with the estimated wind resource that was derived using the assessment techniques. In most cases, there was good agreement between the measured wind resource and the estimated wind resource. This assessment project supported activities being pursued by the U.S. Committee for Renewable Energy Commerce and Trade (CORECT), the U.S. government's interagency program to assist in overseas marketing and promote renewable energy exports. An overall goal of the program is to improve U.S. competitiveness in the world renewable energy market. The Caribbean and Central America assessment, which is the first of several possible follow-on international wind energy resource assessments, provides valuable information needed by the U.S. wind energy industry to identify suitable wind resource areas and concentrate their efforts on these areas.

DL Elliott; CI Aspliden; GL Gower; CG Holladay, MN Schwartz

1987-04-01T23:59:59.000Z

390

NREL: Wind Research - NREL's Wind Technology Patents Boost Efficiency and  

NLE Websites -- All DOE Office Websites (Extended Search)

NREL's Wind Technology Patents Boost Efficiency and Lower Costs NREL's Wind Technology Patents Boost Efficiency and Lower Costs March 22, 2013 Wind energy research conducted at the National Wind Technology Center (NWTC) at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) during the last decade has earned the lab two patents, one for adaptive pitch control and one for a resonance blade test system that will ultimately help its industry partners increase the efficiency of wind technologies and reduce the cost of wind energy. The most recent patent for adaptive pitch control for variable-speed wind turbines was granted in May 2012. Variable-speed wind turbines use rotor blade pitch control to regulate rotor speed at the high wind speed limit. Although manufacturers and operators have been interested in developing a nominal pitch to improve

391

Doppler Lidar–Based Wind-Profile Measurement System for Offshore Wind-Energy and Other Marine Boundary Layer Applications  

Science Conference Proceedings (OSTI)

Accurate measurement of wind speed profiles aloft in the marine boundary layer is a difficult challenge. The development of offshore wind energy requires accurate information on wind speeds above the surface at least at the levels occupied by ...

Yelena L. Pichugina; Robert M. Banta; W. Alan Brewer; Scott P. Sandberg; R. Michael Hardesty

2012-02-01T23:59:59.000Z

392

WIND DATA REPORT Wellfleet, MA  

E-Print Network (OSTI)

/RERL_Fact_Sheet_6_Wind_resource_interpretation.pdf * 1 m/s = 2.237 mph. July 10, 2007 Renewable Energy Research Distributions Figure 3 - Wind Speed Distribution, March 1, 2007 ­ May 31, 2007 July 10, 2007 Renewable Energy Figure 5 - Diurnal Average Wind Speed, March 1, 2007 ­ May 31, 2007 July 10, 2007 Renewable Energy

Massachusetts at Amherst, University of

393

WIND DATA REPORT Wellfleet, MA  

E-Print Network (OSTI)

from a given direction and the average wind speed in that May 2, 2007 Renewable Energy Research Wind Speed, December 1, 2006 ­ February 28, 2007 May 2, 2007 Renewable Energy Research Laboratory PageWIND DATA REPORT Wellfleet, MA December 1st , 2006 ­ February 28th , 2007 Prepared

Massachusetts at Amherst, University of

394

Turbulence in the sub-Alfv\\'enic solar wind driven by reflection of low-frequency Alfv\\'en waves  

E-Print Network (OSTI)

We study the formation and evolution of a turbulent spectrum of Alfv\\'en waves driven by reflection off the solar wind density gradients, starting from the coronal base up to 17 solar radii, well beyond the Alfv\\'enic critical point. The background solar wind is assigned and 2D shell models are used to describe nonlinear interactions. We find that the turbulent spectra are influenced by the nature of reflected waves. Close to the base, these give rise to a flatter and steeper spectrum for the outgoing and reflected waves respectively. At higher heliocentric distance both spectra evolve toward an asymptotic Kolmogorov spectrum. The turbulent dissipation is found to account for at least half of the heating required to sustain the background imposed solar wind and its shape is found to be determined by the reflection-determined turbulent heating below 1.5 solar radii. Therefore reflection and reflection-driven turbulence are shown to play a key role in the accelerationof the fast solar wind and origin of the tur...

Verdini, A; Buchlin, E

2009-01-01T23:59:59.000Z

395

Energy Analysis Department Analyzing the Effects of Temporal Wind Patterns  

E-Print Network (OSTI)

Energy Analysis Department Analyzing the Effects of Temporal Wind Patterns on the Value of Wind;Methods Summary Energy Analysis Department Wind Speed Data ­ TrueWind modeled wind-speed estimates (main;Summary of Key Findings (1) Energy Analysis Department Temporal patterns of wind production have

396

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

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.

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

2005-11-01T23:59:59.000Z

397

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

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.

Lipo, T. A.; Tenca, P.

2006-07-01T23:59:59.000Z

398

Development of an Operations and Maintenance Cost Model to Identify Cost of Energy Savings for Low Wind Speed Turbines: July 2, 2004 -- June 30, 2008  

SciTech Connect

The report describes the operatons and maintenance cost model developed by Global Energy Concepts under contract to NREL to estimate the O&M costs for commercial wind turbine generator facilities.

Poore, R.

2008-01-01T23:59:59.000Z

399

8, 27712793, 2008 Sea surface wind  

E-Print Network (OSTI)

ACPD 8, 2771­2793, 2008 Sea surface wind speed estimation from space-based lidar Y. Hu et al. Title.0 License. Atmospheric Chemistry and Physics Discussions Sea surface wind speed estimation from space;ACPD 8, 2771­2793, 2008 Sea surface wind speed estimation from space-based lidar Y. Hu et al. Title

Paris-Sud XI, Université de

400

Definition: Wind power | Open Energy Information  

Open Energy Info (EERE)

Wind power Wind power Jump to: navigation, search Dictionary.png Wind power The amount of power available to a wind turbine depends on: air density, wind speed and the swept area of the rotor. While the power is proportional to air density and swept area, it varies with the cube of wind speed, so small changes in wind speed can have a relatively large impact on wind power.[1] View on Wikipedia Wikipedia Definition Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electrical power, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships. Large wind farms consist of hundreds of individual wind turbines which are connected to the electric power transmission network. Offshore wind is steadier and stronger than on land, and offshore farms

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Missing wind data forecasting with adaptive neuro-fuzzy inference system  

Science Conference Proceedings (OSTI)

In any region, to begin generating electricity from wind energy, it is necessary to determine the 1-year distribution characteristics of wind speed. For this aim, a wind observation station must be constructed and 1-year wind speed and direction data ... Keywords: ANFIS, Back-propagation, Forecasting, Missing data, Wind energy, Wind speed

Fatih O. Hocaoglu; Yusuf Oysal; Mehmet Kurban

2009-02-01T23:59:59.000Z

402

Statistics on Vertical Wind Shear over Oceans  

Science Conference Proceedings (OSTI)

Statistics on boundary layer vertical wind shear were gathered from rawinsonde soundings taken from three small islands and one weather ship. These soundings show a high correlation between surface and 1829 m altitude wind directions. Wind speeds ...

Donald P. Wylie; Barry B. Hinton; Kellie M. Millett

1984-06-01T23:59:59.000Z

403

Low frequency geomagnetic eld uctuations at low latitude during the passage of a higher pressure solar wind region  

E-Print Network (OSTI)

Low frequency geomagnetic ®eld ¯uctuations at low latitude during the passage of a higher pressure ¯uctuations in the frequency range (0.8±5.5 mHz) for both the horizontal geomagnetic ®eld components. Spectral of the geomagnetic ®eld components at L'Aquila (Italy, v 1X6, Francia and Villante, 1997) we found statistical

Paris-Sud XI, Université de

404

The Solar Wind Energy Flux  

E-Print Network (OSTI)

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 solar-wind speed and density, which formalizes the anti-correlation between these quantities.

Chat, G Le; Meyer-Vernet, N

2012-01-01T23:59:59.000Z

405

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

E-Print Network (OSTI)

3.4.2 Wind roses . . . . . . . .Figure 5.5: Downscaled wind speed changes and componentin?uences on California’s wind energy resource. Part 1:

Mansbach, David K

2010-01-01T23:59:59.000Z

406

NREL: Wind Research - Offshore Wind Resource Characterization  

NLE Websites -- All DOE Office Websites (Extended Search)

Offshore Wind Resource Characterization Offshore Wind Resource Characterization Map of the United States, showing the wind potential of offshore areas across the country. Enlarge image US offshore wind speed estimates at 90-m height NREL scientists and engineers are leading efforts in resource mapping, remote sensor measurement and development, and forecasting that are essential for the development of offshore wind. Resource Mapping For more than 15 years, NREL's meteorologists, engineers, and Geographic Information System experts have led the production of wind resource characterization maps and reports used by policy makers, private industry, and other government organizations to inform and accelerate the development of wind energy in the United States. Offshore wind resource data and mapping has strategic uses. As with terrestrial developments, traditional

407

Wind Prediction Based on Improved BP Artificial Neural Network in Wind Farm  

Science Conference Proceedings (OSTI)

Wind power prediction is important to the operation of power system with comparatively large mount of wind power. It can relieve or avoid the disadvantageous impact of wind farm on power systems. Because the traditional neural network may fall into local ... Keywords: wind farm, wind power generation, wind speed prediction, BP neural networks

Keyuan Huang; Lang Dai; Shoudao Huang

2010-06-01T23:59:59.000Z

408

Measurement of turbulent wind velocities using a rotating boom apparatus  

DOE Green Energy (OSTI)

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.

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

1984-04-01T23:59:59.000Z

409

The Probability Distribution of Wind Power From a Dispersed Array of Wind Turbine Generators  

Science Conference Proceedings (OSTI)

A method is presented for estimating the probability distribution of wind power from a dispersed array of wind turbine sites where the correlation between wind speeds at distinct sites is less than unity. The distribution is obtained from a model ...

John Carlin; John Haslett

1982-03-01T23:59:59.000Z

410

Wind Power | Open Energy Information  

Open Energy Info (EERE)

Wind Power Wind Power Jump to: navigation, search Wind Power WIndfarm.Sunset.jpg Wind power is a form of solar energy.[1] Wind is caused by the uneven heating of the atmosphere by the sun, variations in the earth's surface, and rotation of the earth. Mountains, bodies of water, and vegetation all influence wind flow patterns[2], [3]. Wind energy (or wind power) describes the process by which wind is used to generate electricity. Wind turbines convert the energy in wind to electricity by rotating propeller-like blades around a rotor. The rotor turns the drive shaft, which turns an electric generator.[2] Three key factors affect the amount of energy a turbine can harness from the wind: wind speed, air density, and swept area.[4] Mechanical power can also be utilized directly for specific tasks such as

411

Nonlinear Control of a Wind Turbine Sven Creutz Thomsen  

E-Print Network (OSTI)

. This quantity is denoted the point wind. However, the turbine is not subject to a single wind speed, but ratherNonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12;Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind

412

Analysis of Temporal and Spatial Characteristics on Output of Wind Farms with Doubly Fed Induction Generator Wind Turbines  

Science Conference Proceedings (OSTI)

Due to the large number of wind turbines and covering too large area in a large wind farm, wake effects among wind turbines and wind speed time delays will have a greater impact of wind farms models. Taking wind farms with doubly fed induction generator(DFIG) ... Keywords: wind farm, modeling, temporal and spatial characteristics, DFIG, output characteristics

Shupo Bu, Xunwen Su

2012-12-01T23:59:59.000Z

413

Detection of Breaking Events in a Wind-Generated Wave Field  

Science Conference Proceedings (OSTI)

Measurements were made of the surface elevation of a fetch-limited wave field (fetch 7 km, wind speed about 6 m s?1). Good high-frequency response was attained by the use of a very thin, bare wire probe of diameter 0.13 mm. Breaking waves were ...

M. A. Weissman; S. S. Ataktürk; K. B. Katsaros

1984-10-01T23:59:59.000Z

414

Relation between Saffir–Simpson Hurricane Scale Wind ...  

Science Conference Proceedings (OSTI)

... verifying the results based on the power law as ... of the open-sea roughness in winds greater than ... continue to increase at mean wind speeds beyond ...

2013-07-24T23:59:59.000Z

415

Multi-winding Homopolar Electric Machine Offers Variable Voltage ...  

Wind Energy Industrial Technologies Multi-winding Homopolar Electric Machine Offers Variable Voltage at Low Rotational Speed Oak Ridge National Laboratory. Contact ...

416

Simulation of doubly-fed machine with improved wind turbine  

Science Conference Proceedings (OSTI)

Most of wind turbines use induction generators that are very reliable with low costs [2], but when it is straightly connected to the grid, maximum power is not accessible [1] and only a few change of speed between maximum speed and synchronous speed ... Keywords: doubly-fed machine, gearbox ratio, high speed shaft, low speed shaft, wind turbine

Hengameh Kojooyan Jafari

2009-02-01T23:59:59.000Z

417

Wind Energy Forecasting Technology Update: 2004  

Science Conference Proceedings (OSTI)

This report describes the status of wind energy forecasting technology for predicting wind speed and energy generation of wind energy facilities short-term (minutes to hours), intermediate-term (hours to days), and long-term (months to years) average wind speed and energy generation. The information should be useful to companies that are evaluating or planning to incorporate wind energy forecasting into their operations.

2005-04-26T23:59:59.000Z

418

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

E-Print Network (OSTI)

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 ...

Reddy, Sivananda Kumjula

2005-01-01T23:59:59.000Z

419

A Simple Empirical Model for Predicting the Decay of Tropical Cyclone Winds after Landfall  

Science Conference Proceedings (OSTI)

An empirical model for predicting the maximum wind of landfalling tropical cyclones is developed. The model is based upon the observation that the wind speed decay rate after landfall is proportional to the wind speed. Observations also indicate ...

John Kaplan; Mark DeMaria

1995-11-01T23:59:59.000Z

420

Analytical expressions for maximum wind turbine average power in a Rayleigh wind regime  

DOE Green Energy (OSTI)

Average or expectation values for annual power of a wind turbine in a Rayleigh wind regime are calculated and plotted as a function of cut-out wind speed. This wind speed is expressed in multiples of the annual average wind speed at the turbine installation site. To provide a common basis for comparison of all real and imagined turbines, the Rayleigh-Betz wind machine is postulated. This machine is an ideal wind machine operating with the ideal Betz power coefficient of 0.593 in a Rayleigh probability wind regime. All other average annual powers are expressed in fractions of that power. Cases considered include: (1) an ideal machine with finite power and finite cutout speed, (2) real machines operating in variable speed mode at their maximum power coefficient, and (3) real machines operating at constant speed.

Carlin, P.W.

1996-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

WIND DATA REPORT Rockport School Complex  

E-Print Network (OSTI)

speed. Figure 4 shows that the wind speeds ranged January 4, 2007 Renewable Energy Research Laboratory Renewable Energy Research Laboratory Page 12 University of Massachusetts, Amherst Amherst, MA 01003 #12;Wind ­ Wind Rose, November 1, 2006 through November 30, 2006 January 4, 2007 Renewable Energy Research

Massachusetts at Amherst, University of

422

WIND DATA REPORT Ragged Mt Maine  

E-Print Network (OSTI)

Energy Research Laboratory (RERL) at the University of Massachusetts, Amherst. This report covers wind Average Wind Speeds, September 1, 2007 ­ November 30, 2007. January 22, 2008 Renewable Energy Research ­ Turbulence Intensity vs. Wind Speed, September 1, 2007 ­ November 30, 2007. January 22, 2008 Renewable Energy

Massachusetts at Amherst, University of

423

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

E-Print Network (OSTI)

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 ...

Nikandrou, Paul

2009-01-01T23:59:59.000Z

424

WIND DATA REPORT Gardner NCCI  

E-Print Network (OSTI)

/RERL_Fact_Sheet_6_Wind_resource_interpretation.pdf * 1 m/s = 2.237 mph. SECTION 1 January 30, 2008 Renewable Energy, and wind roses are included in APPENDIX B. January 30, 2008 Renewable Energy Research Laboratory Page 8 ­ Turbulent Intensity vs. Wind Speed, March 1, 2007 ­ May 31, 2007 January 30, 2008 Renewable Energy Research

Massachusetts at Amherst, University of

425

WIND DATA REPORT Gardner NCCI  

E-Print Network (OSTI)

­ Diurnal Average Wind Speed, September 1, 2007 ­ November 30, 2007 February 7, 2008 Renewable Energy 2520151050 Figure 7 ­ Wind Rose, September 1, 2007 ­ November 30, 2007 February 7, 2008 Renewable Energy. A wind direction standard February 7, 2008 Renewable Energy Research Laboratory Page 13 University

Massachusetts at Amherst, University of

426

WIND DATA REPORT Chester, MA  

E-Print Network (OSTI)

/RERL_Fact_Sheet_6_Wind_resource_interpretation.pdf * 1 m/s = 2.237 mph. July 14, 2007 Renewable Energy Research square. Figure 1 - Map of Chester wind tower site July 14, 2007 Renewable Energy Research Laboratory Page average wind speeds are plotted against time. July 14, 2007 Renewable Energy Research Laboratory Page 8

Massachusetts at Amherst, University of

427

Fitting of Weibull distribution to study wind energy potential in Kuala Terengganu, Malaysia  

Science Conference Proceedings (OSTI)

A feasibility study on the wind energy potential of Kuala Terengganu, Malaysia was carried out. The most commonly used distribution to fit wind speed data is the Weibull distribution. This distribution was applied to wind speed data for the year 2008. ... Keywords: beaufort scale, weibull distribution, wind data, wind distribution pattern, wind energy potential

A. M. Razali; M. S. Sapuan; K. Ibrahim; A. R. Ismail; A. Zaharim; K. Sopian

2009-12-01T23:59:59.000Z

428

Wind News | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wind News Wind News Wind News RSS February 7, 2011 Salazar, Chu Announce Major Offshore Wind Initiatives Strategic plan, $50 million in R&D funding, identified Wind Energy Areas will speed offshore wind energy development December 16, 2010 Department of Energy Finalizes Loan Guarantee to Support World's Largest Wind Project 845-Megawatt Wind Facility Will Create Hundreds of Jobs and Avoid Over 1.2 Million Tons of Carbon Dioxide Annually October 29, 2010 Statement by Energy Secretary Steven Chu on Today's Grand Opening of the Nordex Manufacturing Facility in Jonesboro, Arkansas Recovery Act investment creates jobs, helps lay the foundation for a clean energy economy September 13, 2010 DOE Announces More than $5 Million to Support Wind Energy Development Funds to Enhance Short-Term Wind Forecasting and Accelerate Midsize Wind

429

Wind Power Today and Tomorrow  

DOE Green Energy (OSTI)

Wind Power Today and Tomorrow is an annual publication that provides an overview of the wind research conducted under the U.S. Department of Energy's Wind and Hydropower Technologies Program. The purpose of Wind Power Today and Tomorrow is to show how DOE supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describe the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry. This 2003 edition of the program overview also includes discussions about wind industry growth in 2003, how DOE is taking advantage of low wind speed region s through advancing technology, and distributed applications for small wind turbines.

Not Available

2004-03-01T23:59:59.000Z

430

NREL: Wind Research - Gaia-Wind's 11 Kilowatt Wind Turbine Testing and  

NLE Websites -- All DOE Office Websites (Extended Search)

Gaia-Wind's 11 Kilowatt Wind Turbine Testing and Results Gaia-Wind's 11 Kilowatt Wind Turbine Testing and Results A video of Gaia-Wind's 11-kW wind turbine. Text Version As part of the National Renewable Energy Laboratory and U.S. Department of Energy (NREL/DOE) Independent Testing project, NREL tested Gaia-Wind's 11-kilowatt (kW) small wind turbine at the National Wind Technology Center (NWTC). Gaia-Wind's turbine is a three-phase induction generator that operates at 480 volts. The turbine's downwind rotor has a 13-meter diameter, and its tower is 18 meters tall. The two-bladed, oversized rotor is designed for low to moderate wind speeds. Testing Summary The summary of the tests is below with the final reports. Cumulative Energy Production 6/11/2008: 210; 6/13/2008: 528; 6/16/2008: 716; 6/18/2008: 731; 6/19/2008:

431

WIND DATA REPORT Scituate Waste Water Treatment Plant, MA  

E-Print Network (OSTI)

Distributions Figure 3 ­ Wind Speed Distribution, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Figure 5 ­ Diurnal Wind Speeds, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Research ­ Turbulence Intensity vs. Wind Speed, March 1, 2007 ­ May 31, 2007 July 16, 2007 Renewable Energy Research

Massachusetts at Amherst, University of

432

WIND DATA REPORT Upper Cape Cod Regional Technical School  

E-Print Network (OSTI)

difference between the two wind speeds is greater than Factor 1. At high August 29, 2005 Renewable Energy average wind speed of 5.87 m/s (13.15 mph) in December 2004. August 29, 2005 Renewable Energy Research - Wind Speed Time Series, December 2004 ­ February 2005 August 29, 2005 Renewable Energy Research

Massachusetts at Amherst, University of

433

Abstract--Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind  

E-Print Network (OSTI)

of the wind turbine when wind speed is above rated speed and various controlling variables may be chosen Terms--Blade aerodynamic, Fatigue load, Fuzzy logic control, Pitch angle, Wind turbine I. INTRODUCTION of 40 GW. Pitch-adjusting variable-speed wind turbines have become the dominating type of yearly

Hansen, René Rydhof

434

A New Approach to an Accurate Wind Chill Factor  

Science Conference Proceedings (OSTI)

Winter weather often shows a severity marked by low dry-bulb temperature combined with high wind speed. The wind chill factor is now a standard meteorological term to express this severity. This factor, or more appropriately the wind chill ...

Maurice Bluestein; Jack Zecher

1999-09-01T23:59:59.000Z

435

Mesoscale Influences of Wind Farms throughout a Diurnal Cycle  

Science Conference Proceedings (OSTI)

Large wind farms are expected to influence local and regional atmospheric circulations. Using a mesoscale parameterization of the effects of wind farms that includes a momentum sink and a wind speed–dependent source of turbulent kinetic energy, ...

Anna C. Fitch; Julie K. Lundquist; Joseph B. Olson

2013-07-01T23:59:59.000Z

436

A Sensitive Fast-Response Manometric Wind Sensor  

Science Conference Proceedings (OSTI)

A manometric type of wind sensor has been developed. This sensor convert the dynamic pressure of the wind into a modulated dynamic pressure signal which can then be sensed using microphones. This permits wind speed measurements to be made with ...

K. E. Kunkel; C. W. Bruce

1983-11-01T23:59:59.000Z

437

Understanding the unbalanced-voltage problem in wind turbine generation  

DOE Green Energy (OSTI)

Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operated with a small range of slips with respect to synchronous speed. Compared to a synchronous generator, an induction generator provides lower stiffness, thus alleviating the mechanical stress. In a weak power system network, an unbalanced load at the distribution lines can cause unbalanced voltage conditions. If an induction generator is connected to an unbalanced voltage, the resulting stator current will be unbalanced. The unbalanced current creates unequal heating (hot spots) on the stator winding. The heat may increase the winding temperature, which degrades the insulation of the winding, i.e., the life expectancy of the winding. Unbalanced currents also create torque pulsation on the shaft resulting in audible noise and extra mechanical stress. This paper explores the unbalanced voltage problem in induction generators. The levels of unbalance and the loads are varied. Experimental and predicted results are presented in this paper.

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

2000-02-28T23:59:59.000Z

438

On spatial estimation of wind energy potential in Malaysia  

Science Conference Proceedings (OSTI)

Statistical distribution for describing the wind speed at a particular location provides information about the wind energy potential which is available. In this paper, five different statistical distributions are fitted to the data of average hourly ... Keywords: inverse distance weighting method, kriging, semivariogram, spatial estimation, wind energy, wind speed distribution

Nurulkamal Masseran; Ahmad Mahir Razali; Kamarulzaman Ibrahim; Wan Zawiah Wan Zin; Azami Zaharim

2011-07-01T23:59:59.000Z

439

Nonlinear Control of a Wind Turbine Sven Creutz Thomsen  

E-Print Network (OSTI)

Nonlinear Control of a Wind Turbine Sven Creutz Thomsen Kongens Lyngby 2006 #12; Technical describes analysis of various nonlinear control methods for controlling a wind turbine. High speed wind Modeling and analysis 5 2 Model descriptions 7 2.1 Variable speed wind turbine

440

WIND DATA REPORT December 01, 2007 February 29, 2008  

E-Print Network (OSTI)

01003 #12;Wind Roses Figure 7 ­ Wind Rose, December 2007 ­ February 2008 April 2, 2008 Renewable Energy 22.5 0 23.5 0 24.5 0 Table 3 - Wind Speed Distribution, 49 m April 2, 2008 Renewable Energy Research - Diurnal Average Wind Speeds, 49 m April 2, 2008 Renewable Energy Research Laboratory Page 20 University

Massachusetts at Amherst, University of

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Can We See the Wind? Statistical Downscaling of Historical Sea Surface Winds in the Subarctic Northeast Pacific  

Science Conference Proceedings (OSTI)

The statistical predictability of wintertime (December–February) monthly-mean sea surface winds (both vector wind components and wind speed) in the subarctic northeast Pacific off the west coast of Canada is considered, in the context of surface ...

Adam H. Monahan

2012-03-01T23:59:59.000Z

442

Gust Factors Applied to Hurricane Winds  

Science Conference Proceedings (OSTI)

An important consideration in the design of structures is their response to extreme winds. This is especially true in regions affected by hurricanes. In this research, gust factors derived from hurricane wind-speed records are compared with those ...

William R. Krayer; Richard D. Marshall

1992-05-01T23:59:59.000Z

443

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

E-Print Network (OSTI)

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 ...

Nnadili, Christopher Dozie, 1978-

2009-01-01T23:59:59.000Z

444

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

E-Print Network (OSTI)

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 ...

Jaworsky, Christina A

2013-01-01T23:59:59.000Z

445

A Correction for the Errors in Ship Reports of Light Winds  

Science Conference Proceedings (OSTI)

The errors in ship wind reports of light winds tend to significantly bias their mean. This occurs because wind speed is a scalar quantity that is constrained to zero or positive values. Therefore, observations tend to overestimate the light winds ...

Barry B. Hinton; Donald P. Wylie

1985-09-01T23:59:59.000Z

446

Flow in Complex Terrain: Observations by Radar Wind Profilers and Anemometers near Juneau, Alaska  

Science Conference Proceedings (OSTI)

Four years of data from three radar wind profilers and collocated anemometers are used to examine the airflow regimes near Juneau, Alaska. Wind direction probability density functions and wind rose histograms show the dominant wind speeds and ...

Stephen A. Cohn

2004-04-01T23:59:59.000Z

447

European Union Wind Energy Forecasting Model Development and Testing: U.S. Department of Energy -- EPRI Wind Turbine Verification Pr ogram  

Science Conference Proceedings (OSTI)

Wind forecasting can increase the strategic and market values of wind power from large wind facilities. This report summarizes the results of the European Union (EU) wind energy forecasting project and performance testing of the EU wind forecasting model. The testing compared forecast and observed wind speed and generation data from U.S. wind facilities.

1999-12-15T23:59:59.000Z

448

The Economic Optimization of Wind Turbine Design .  

E-Print Network (OSTI)

??This thesis studies the optimization of a variable speed, three blade, horizontal-axis wind turbine. The design parameters considered are the rotor diameter, hub height and… (more)

Schmidt, Michael Frank

2007-01-01T23:59:59.000Z

449

Strong wind forcing of the ocean  

E-Print Network (OSTI)

high wind speeds in tropical cyclones. Nature, 422, 279-283.response of the tropical cyclone and the ocean. Journal ofinteraction theory for tropical cyclones: Part i : steady-

Zedler, Sarah E.

2007-01-01T23:59:59.000Z

450

Evaluation of Wind Shear Patterns at Midwest Wind Energy Facilities: Preprint  

DOE Green Energy (OSTI)

The U.S. Department of Energy-Electric Power Research Institute (DOE-EPRI) Wind Turbine Verification Program (TVP) has included several wind energy facilities in the Midwestern United States. At several of these projects, a strong diurnal shear pattern has been observed. During the day, low and sometimes negative shear has been measured. During night hours, very high positive shear is frequently observed. These high nighttime shear values are of concern due to the potential for high stresses across the rotor. The resulting loads on turbine components could result in failures. Conversely, the effects of high nighttime wind shear could benefit wind generated energy production in the Midwest by providing a source of greater hub-height wind speeds, particularly for multi-megawatt turbines that utilize tall towers. This paper presents an overview of the observed wind shear at each of the Midwest TVP projects, focusing on diurnal patterns and the frequency of very high nighttime shear at the sites. Turbine fault incidence is examined to determine the presence or absence of a correlation to periods of high shear. Implications of shear-related failures are discussed for other Midwest projects that use megawatt-scale turbines. In addition, this paper discusses the importance of accurate shear estimates for project development.

Smith, K.; Randall, G.; Malcolm, D.; Kelley, N.; Smith, B.

2002-05-01T23:59:59.000Z

451

Active control system for high speed windmills  

DOE Patents (OSTI)

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.

Avery, D.E.

1988-01-12T23:59:59.000Z

452

Active control system for high speed windmills  

DOE Patents (OSTI)

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.

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

1988-01-01T23:59:59.000Z

453

Definition of Wind Profiles in ASCE 7 Yin Zhou, M.ASCE,1  

E-Print Network (OSTI)

as the reference wind speed. The three-second gust speed is derived using Durst's model in terms of the mean wind s gust as the reference wind speed. The 3 s gust speed is derived using Durst's model in com- bination

Kareem, Ahsan

454

Distributed Wind Energy in Idaho  

SciTech Connect

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.

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

2009-01-31T23:59:59.000Z

455

Data Analytics Methods in Wind Turbine Design and Operations  

E-Print Network (OSTI)

This dissertation develops sophisticated data analytic methods to analyze structural loads on, and power generation of, wind turbines. Wind turbines, which convert the kinetic energy in wind into electrical power, are operated within stochastic environments. To account for the influence of environmental factors, we employ a conditional approach by modeling the expectation or distribution of response of interest, be it the structural load or power output, conditional on a set of environmental factors. Because of the different nature associated with the two types of responses, our methods also come in different forms, conducted through two studies. The first study presents a Bayesian parametric model for the purpose of estimating the extreme load on a wind turbine. The extreme load is the highest stress level that the turbine structure would experience during its service lifetime. A wind turbine should be designed to resist such a high load to avoid catastrophic structural failures. To assess the extreme load, turbine structural responses are evaluated by conducting field measurement campaigns or performing aeroelastic simulation studies. In general, data obtained in either case are not sufficient to represent various loading responses under all possible weather conditions. An appropriate extrapolation is necessary to characterize the structural loads in a turbine’s service life. This study devises a Bayesian spline method for this extrapolation purpose and applies the method to three sets of load response data to estimate the corresponding extreme loads at the roots of the turbine blades. In the second study, we propose an additive multivariate kernel method as a new power curve model, which is able to incorporate a variety of environmental factors in addition to merely the wind speed. In the wind industry, a power curve refers to the functional relationship between the power output generated by a wind turbine and the wind speed at the time of power generation. Power curves are used in practice for a number of important tasks including predicting wind power production and assessing a turbine’s energy production efficiency. Nevertheless, actual wind power data indicate that the power output is affected by more than just wind speed. Several other environmental factors, such as wind direction, air density, humidity, turbulence intensity, and wind shears, have potential impact. Yet, in industry practice, as well as in the literature, current power curve models primarily consider wind speed and, with comparatively less frequency, wind speed and direction. Our model provides, conditional on a given environmental condition, both the point estimation and density estimation of the power output. It is able to capture the nonlinear relationships between environmental factors and wind power output, as well as the high-order inter- action effects among some of the environmental factors. To illustrate the application of the new power curve model, we conduct case studies that demonstrate how the new method can help with quantifying the benefit of vortex generator installation, advising pitch control adjustment, and facilitating the diagnosis of faults.

Lee, Giwhyun

2013-08-01T23:59:59.000Z

456

Eastern Frequency Response Study  

Science Conference Proceedings (OSTI)

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.

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

2013-05-01T23:59:59.000Z

457

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

E-Print Network (OSTI)

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.

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

2012-01-01T23:59:59.000Z

458

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

E-Print Network (OSTI)

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

Haak, Hein

459

Altimeter Estimation of Sea Surface Wind Stress for Light to Moderate Winds  

Science Conference Proceedings (OSTI)

Aircraft altimeter and in situ measurements are used to examine relationships between altimeter backscatter and the magnitude of near-surface wind and friction velocities. Comparison of altimeter radar cross section with wind speed is made ...

Douglas Vandemark; James B. Edson; Bertrand Chapron

1997-06-01T23:59:59.000Z

460

Wind: monthly and annual average wind GIS data at one-degree...  

Open Energy Info (EERE)

monthly and annual average wind GIS data at one-degree resolution of the World from NASASSE

(Abstract):   Wind Speed At 50 m Above The Surface Of The Earth (m...

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

An Analysis of Wind Direction and Horizontal Wind Component Fluctuations over Complex Terrain  

Science Conference Proceedings (OSTI)

Based on an extensive wind dataset over complex terrain, the commonly used small-angle approximation ?v ? ??V is studied and found to overestimate over all wind speeds and ?? values observed. This should be anticipated due to the assumptions ...

K. H. Papadopoulos; C. G. Helmis; G. T. Amanatidis

1992-09-01T23:59:59.000Z

462

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

E-Print Network (OSTI)

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

Dyer, Bill

463

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

464

Low-Frequency Variability in Shallow-Water Models of the Wind-Driven Ocean Circulation. Part I: Steady-State Solution  

Science Conference Proceedings (OSTI)

Successive bifurcations—from steady states through periodic to aperiodic solutions—are studied in a shallow-water, reduced-gravity, 2˝-layer model of the midlatitude ocean circulation subject to time-independent wind stress. The bifurcation ...

Eric Simonnet; Michael Ghil; Kayo Ide; Roger Temam; Shouhong Wang

2003-04-01T23:59:59.000Z

465

Wind Electrolysis: Hydrogen Cost Optimization  

NLE Websites -- All DOE Office Websites (Extended Search)

which needs to be 44% or better along with relatively high wind speeds. Along with low production costs, however, delivery and storage costs will also factor into the final cost...

466

Figure 4.16 Offshore Wind Resources - U.S. Energy Information ...  

U.S. Energy Information Administration (EIA)

Figure 4.16 Offshore Wind Resources U.S. Energy Information Administration / Annual Energy Review 2011 123 Notes: • Data are annual average wind speed at 90 meters.

467

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

E-Print Network (OSTI)

??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)

Issaeva, Natalia

2009-01-01T23:59:59.000Z

468

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

469

Estimation of Hurricane Wind Speed Probabilities: Application ...  

Science Conference Proceedings (OSTI)

... for the design of Liquid Natural Gas (LNG) facilities, required by Federal regulations to be designed for MRIs of at least ...

2013-07-26T23:59:59.000Z

470

Estimation of Hurricane Wind Speed Probabilities: Application ...  

Science Conference Proceedings (OSTI)

... of experienc- ing nonlinear behavior under exceptionally strong windstorm events, or for the design of Liquid Natural Gas (LNG) facilities, required ...

2013-07-26T23:59:59.000Z

471

Short Circuit Analysis of Induction Machines Wind Power Application  

Science Conference Proceedings (OSTI)

he short circuit behavior of Type I (fixed speed) wind turbine-generators is analyzed in this paper to aid in the protection coordination of wind plants of this type. A simple network consisting of one wind turbine-generator is analyzed for two network faults: a three phase short circuit and a phase A to ground fault. Electromagnetic transient simulations and sequence network calculations are compared for the two fault scenarios. It is found that traditional sequence network calculations give accurate results for the short circuit currents in the balanced fault case, but are inaccurate for the un-faulted phases in the unbalanced fault case. The time-current behavior of the fundamental frequency component of the short circuit currents for both fault cases are described, and found to differ significantly in the unbalanced and balanced fault cases

Starke, Michael R [ORNL; Smith, Travis M [ORNL; Howard, Dustin [Georgia Institute of Technology; Harley, Ronald [Georgia Institute of Technology

2012-01-01T23:59:59.000Z

472

Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint  

DOE Green Energy (OSTI)

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.

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

2006-03-01T23:59:59.000Z

473

Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint  

SciTech Connect

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.

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

2006-03-01T23:59:59.000Z

474

The Solar Wind and Its Interaction with the Interstellar Medium  

E-Print Network (OSTI)

to the solar wind speed and have an initial temperature equal to the solar wind energy, about 1 keV. Figure 7 and their subsequent acceleration to the solar wind speed at the expense of the flow energy in the thermal solar wind that the slowdown is about 17% near the TS (Richardson et al. 2008a), so roughly 30% of the solar wind flow energy

Richardson, John

475

Intercomparison of Wind Measurements from Two Acoustic Doppler Sodars, a Laser Doppler Lidar, and In Situ Sensors  

Science Conference Proceedings (OSTI)

Intercomparative measurements of wind speed, wind direction, wind direction standard deviation, and vertical wind standard deviation from two acoustic Doppler sodars and a laser Doppler lidar are studied, using the BAO tower to provide reference ...

Prasan Chintawongvanich; Robert Olsen; Christopher A. Biltoft

1989-10-01T23:59:59.000Z

476

A Multisodar Approach to Wind Profiling  

Science Conference Proceedings (OSTI)

This paper presents the development of a multisodar mode from a five-beam sodar whereby a wind speed vector is found for sets of three acoustic beams. If the vertical beam is used, this mode enables the profiling of four wind speed measurements ...

Paul Behrens; Stuart Bradley; Travis Wiens

2010-07-01T23:59:59.000Z

477

Energy Savings of Variable Speed Motors  

E-Print Network (OSTI)

This paper investigates the energy savings available by utilizing variable speed motors on pump and fan applications. Conventional control of flow or pressure in process plants is normally accomplished by throttling the various streams with control valves. Depending on the system and the actual operating conditions, this throttling may consume a considerable amount of energy. The hydraulics of different systems are investigated to generalize high energy saving applications. Typical pump characteristics at varying speeds are investigated since most performance curves are only available at a constant speed. The various types of variable speed electric motors are discussed. However, the primary variable speed system recommended is a variable frequency speed system which utilizes standard induction motors. Specific cases of centrifugal pump applications and cooling tower fan service are presented. Turndown frequencies, stream factors, and electric rates are included in the evaluation. The energy savings of a variable speed system becomes significant when flow rates vary widely and the electrical rates are high.

Fishel, F. D.

1979-01-01T23:59:59.000Z

478

Can Wind Lidars Measure Turbulence?  

Science Conference Proceedings (OSTI)

Modeling of the systematic errors in the second-order moments of wind speeds measured by continuous-wave (ZephIR) and pulsed (WindCube) lidars is presented. These lidars use the conical scanning technique to measure the velocity field. The model ...

A. Sathe; J. Mann; J. Gottschall; M. S. Courtney

2011-07-01T23:59:59.000Z

479

A Hurricane Boundary Layer and Wind Field Model for Use in Engineering Applications  

Science Conference Proceedings (OSTI)

This article examines the radial dependence of the height of the maximum wind speed in a hurricane, which is found to lower with increasing inertial stability (which in turn depends on increasing wind speed and decreasing radius) near the ...

Peter J. Vickery; Dhiraj Wadhera; Mark D. Powell; Yingzhao Chen

2009-02-01T23:59:59.000Z

480

Market penetration of wind turbine concepts over the years Anca D. Hansen1  

E-Print Network (OSTI)

speed wind turbine concept with partial-scale power converter (DFIG) This configuration denotes the variable speed controlled wind turbine with doubly fed induction generator (DFIG) and pitch control

Note: This page contains sample records for the topic "frequency wind speed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Rectified Wind Forcing and Latent Heat Flux Produced by the Madden–Julian Oscillation  

Science Conference Proceedings (OSTI)

Rectification of (Madden–Julian oscillation) MJO-induced wind speed and latent heat flux variations across the tropical Indian and western Pacific Oceans is estimated using 51 yr of NCEP–NCAR reanalysis. The rectified wind speed anomaly is ...

Toshiaki Shinoda; Harry H. Hendon

2002-12-01T23:59:59.000Z

482

Mesoscale Correlation Length Scales from NSCAT and Minimet Surface Wind Retrievals in the Labrador Sea  

Science Conference Proceedings (OSTI)

Observations of the surface wind speed and direction in the Labrador Sea for the period October 1996–May 1997 were obtained by the NASA scatterometer (NSCAT), and by 21 newly developed Minimet drifting buoys. Minimet wind speeds are inferred, ...

R. F. Milliff; P. P. Niiler; J. Morzel; A. E. Sybrandy; D. Nychka; W. G. Large

2003-04-01T23:59:59.000Z

483

Distribution of Extreme Winds in the Bonneville Power Administration Service Area  

Science Conference Proceedings (OSTI)

Annual extreme 1 min wind speeds at 78 Pacific Northwest locations were analyzed using the Fisher-Tippet type II extreme value function. From computed mean recurrence intervals, we could easily determine the wind speed likely to recur in a ...

J. William Wantz; Robert E. Sinclair

1981-12-01T23:59:59.000Z

484

Observed and CAM3 GCM Sea Surface Wind  

E-Print Network (OSTI)

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

Zender, Charles

485

On the Decay of Tropical Cyclone Winds Crossing Narrow Landmasses  

Science Conference Proceedings (OSTI)

A method is developed to adjust the Kaplan and DeMaria tropical cyclone inland wind decay model for storms that move over narrow landmasses. The basic assumption that the wind speed decay rate after landfall is proportional to the wind speed is ...

Mark DeMaria; John A. Knaff; John Kaplan

2006-03-01T23:59:59.000Z

486

WIND DATA REPORT Upper Cape Cod Regional Technical School  

E-Print Network (OSTI)

wind speed of 5.06 m/s (11.33 mph). June 28, 2005 Renewable Energy Research Laboratory Page 9 Renewable Energy Research Laboratory Page 10 University of Massachusetts, Amherst Amherst, MA 01003 #12;Wind Figure 4 - Diurnal Average Wind Speed, March 2005 ­ May 2005 June 28, 2005 Renewable Energy Research

Massachusetts at Amherst, University of

487

Lidar measurement of wind velocity turbulence spectra encountered by a rotating turbine blade  

DOE Green Energy (OSTI)

A homodyne CO/sub 2/ lidar system beam was conically scanned around a horizontal axis to measure the wind speed and turbulence characteristics encountered by a rotating turbine blade. Turbulence spectra obtained from the scanning lidar differed considerably from those calculated from fixed-point anemometer measurements, showing a redistribution of energy from lower to higher frequencies. The differences appeared more pronounced during periods when the atmosphere was stable.

Hardesty, R.M.; Korrell, J.A.; Hall, F.F. Jr.

1982-01-01T23:59:59.000Z

488

Low-Frequency Variability in Shallow-Water Models of the Wind-Driven Ocean Circulation. Part II: Time-Dependent Solutions  

Science Conference Proceedings (OSTI)

The time-dependent wind-driven ocean circulation is investigated for both a rectangular and a North Atlantic–shaped basin. Multiple steady states in a 2˝-layer shallow-water model and their dependence on various parameters and other model ...

Eric Simonnet; Michael Ghil; Kayo Ide; Roger Temam; Shouhong Wang

2003-04-01T23:59:59.000Z

489

Subinertial Frequency Response of Wind-Driven Currents in the Mixed layer Measured by Drifting Buoys in the Midlatitude North Pacific  

Science Conference Proceedings (OSTI)

Previous analyses of satellite-tracked drifting buoy data (30 m drogue depth) and Fleet Numerical Ocean Center (FNOC) surface wind stress in the midlatitude North Pacific during autumn/winter have shown near-surface current vectors 25° to the ...

Gerard J. McNally; Douglas S. Luther; Warren B. White

1989-03-01T23:59:59.000Z

490

WIND DATA REPORT WBZ Tower, Hull, MA  

E-Print Network (OSTI)

WIND DATA REPORT WBZ Tower, Hull, MA 9/1/06-11/30/06 Prepared for Department of Energy (DOE) Golden the closest tower leg The data from the SecondWind Nomad2 logger is emailed to the Renewable Energy Research Energy Research Laboratory Page 10 University of Massachusetts, Amherst Amherst, MA 01003 #12;Wind Speed

Massachusetts at Amherst, University of

491