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Note: This page contains sample records for the topic "measure 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

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect (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

2

Ris-R-Report LIDAR Wind Speed Measurements from a  

E-Print Network [OSTI]

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

3

MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY  

SciTech Connect (OSTI)

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

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

2009-01-20T23:59:59.000Z

4

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

E-Print Network [OSTI]

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

Ruf, Christopher

5

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

E-Print Network [OSTI]

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

Heinemann, Detlev

6

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

E-Print Network [OSTI]

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

Heinemann, Detlev

7

Estimation of Wind Speed in Connection to a Wind Turbine  

E-Print Network [OSTI]

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

8

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

E-Print Network [OSTI]

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

Peinke, Joachim

9

Wind Speed Data Analysis using Wavelet Transform  

E-Print Network [OSTI]

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

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

10

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

SciTech Connect (OSTI)

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

11

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

SciTech Connect (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

12

Forecasting wind speed financial return  

E-Print Network [OSTI]

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

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

13

VARIABLE SPEED WIND TURBINE  

E-Print Network [OSTI]

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

Chatinderpal Singh

14

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

15

Wind Speed Prediction Via Time Series Modeling.  

E-Print Network [OSTI]

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

Alexander, Daniel

2009-01-01T23:59:59.000Z

16

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...

Zhu, Xinxin

2013-07-22T23:59:59.000Z

17

Dual-speed wind turbine generation  

SciTech Connect (OSTI)

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

1996-10-01T23:59:59.000Z

18

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

E-Print Network [OSTI]

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

19

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

SciTech Connect (OSTI)

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

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

1993-03-01T23:59:59.000Z

20

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

SciTech Connect (OSTI)

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

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

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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 THE VERTICAL WIND SPEED AND TURBULENCE INTENSITY PROFILES AT PROSPECTIVE OFFSHORE WIND FARM SITES  

E-Print Network [OSTI]

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

Heinemann, Detlev

22

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

E-Print Network [OSTI]

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

Heinemann, Detlev

23

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

Open Energy Info (EERE)

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

24

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

Open Energy Info (EERE)

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

25

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

E-Print Network [OSTI]

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

26

Wind speed vertical distribution at Mt. Graham  

E-Print Network [OSTI]

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

Hagelin, S; Lascaux, F

2010-01-01T23:59:59.000Z

27

Statistical Analysis of Environment Canada's Wind Speed Data  

E-Print Network [OSTI]

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

Taylor, James H.

28

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

29

Dynamic simulation of dual-speed wind turbine generation  

SciTech Connect (OSTI)

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

30

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

E-Print Network [OSTI]

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

Stoffelen, Ad

31

Pitch-controlled variable-speed wind turbine generation  

SciTech Connect (OSTI)

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

Muljadi, E.; Butterfield, C.P.

2000-03-01T23:59:59.000Z

32

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

SciTech Connect (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

33

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

E-Print Network [OSTI]

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

34

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

E-Print Network [OSTI]

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

Ruf, Christopher

35

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

36

Wind velocity measurements using a pulsed LIDAR system: first results  

E-Print Network [OSTI]

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

Peinke, Joachim

37

QUIKSCAT MEASUREMENTS AND ECMWF WIND FORECASTS  

E-Print Network [OSTI]

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

Malmberg, Anders

38

QUIKSCAT MEASUREMENTS AND ECMWF WIND FORECASTS  

E-Print Network [OSTI]

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

Malmberg, Anders

39

Probabilistic Wind Speed Forecasting Using Ensembles and Bayesian Model Averaging  

E-Print Network [OSTI]

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

Raftery, Adrian

40

Spatial and Temporal Patterns of Global Onshore Wind Speed Distribution  

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "measure 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

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

E-Print Network [OSTI]

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

Hennon, Christopher C.

42

Hi-Q Rotor - Low Wind Speed Technology  

SciTech Connect (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

43

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

E-Print Network [OSTI]

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

Heinemann, Detlev

44

Analytical Modelling of Wind Speed Deficit in Large Offshore Wind Farms  

E-Print Network [OSTI]

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

Pryor, Sara C.

45

0 Riso-R-434 Wind Speed and Direction  

E-Print Network [OSTI]

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

46

NACA0015 Measurements in LM Wind Tunnel and Turbulence  

E-Print Network [OSTI]

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

47

Microsoft Word - idaho_wind_speed_summary.doc  

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

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

48

Probabilistic Wind Speed Forecasting using Ensembles and Bayesian Model Averaging  

E-Print Network [OSTI]

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

Washington at Seattle, University of

49

Microsoft Word - utah_wind_speed_summary.doc  

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

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

50

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

E-Print Network [OSTI]

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

Castillo, Davis

2011-08-08T23:59:59.000Z

51

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

SciTech Connect (OSTI)

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

52

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

SciTech Connect (OSTI)

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

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

1996-10-01T23:59:59.000Z

53

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

SciTech Connect (OSTI)

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

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

1996-11-01T23:59:59.000Z

54

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

55

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

56

Wind Measurement Equipment: Registration (Nebraska)  

Broader source: Energy.gov [DOE]

All wind measurement equipment associated with the development or study of wind-powered electric generation, whether owned or leased, shall be registered with the Department of Aeronautics if the...

57

SODAR Wind Resource Measurement Results at Falmouth, MA Prepared for  

E-Print Network [OSTI]

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

Massachusetts at Amherst, University of

58

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

E-Print Network [OSTI]

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

McMinn, Steven Lee

2012-06-07T23:59:59.000Z

59

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

Massachusetts at Amherst, University of

60

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

SciTech Connect (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 Energys (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

Note: This page contains sample records for the topic "measure 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

the risk issue of wind measurement for wind turbine operation  

E-Print Network [OSTI]

Sciences, National Taiwan University #12;outline Wind measurement in meteorology and wind farm design-related issues on wind turbine operation 3/31/2011 2 #12;WIND MEASUREMENT IN METEOROLOGY & WIND FARM DESIGN 3.brainybetty.com 11 wind farm at ChangHwa Coastal Industrial Park 70m wind tower 70m 50m 30m 10m #12;1 2 3 4 5 1 (70M

Leu, Tzong-Shyng "Jeremy"

62

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

E-Print Network [OSTI]

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

Vogel, Richard M.

63

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

E-Print Network [OSTI]

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

Kusiak, Andrew

64

MAPping Foehn Winds in the Austrian Alps  

E-Print Network [OSTI]

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

Gohm, Alexander

65

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

Broader source: Energy.gov [DOE]

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

66

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

E-Print Network [OSTI]

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

Pota, Himanshu Roy

67

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

E-Print Network [OSTI]

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

68

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

E-Print Network [OSTI]

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

Fitch, Dillon T; Moore, J. Keith

2007-01-01T23:59:59.000Z

69

Laboratory implementation of variable-speed wind turbine generation  

SciTech Connect (OSTI)

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

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

1996-07-01T23:59:59.000Z

70

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

E-Print Network [OSTI]

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

Zender, Charles

71

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

E-Print Network [OSTI]

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

72

Systematic Controller Design Methodology for Variable-Speed Wind Turbines  

SciTech Connect (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

73

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

E-Print Network [OSTI]

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

Sera, Dezso

74

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

SciTech Connect (OSTI)

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

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

1998-04-01T23:59:59.000Z

75

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

E-Print Network [OSTI]

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

He, Yanping

76

Ris National Laboratory DTU Wind Energy Department  

E-Print Network [OSTI]

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

77

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

E-Print Network [OSTI]

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

Gui, Lichuan

78

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

Boyer, Edmond

79

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

E-Print Network [OSTI]

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

80

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

Note: This page contains sample records for the topic "measure 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

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

82

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

83

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

SciTech Connect (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

84

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

SciTech Connect (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

85

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

86

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

E-Print Network [OSTI]

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

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

2011-01-01T23:59:59.000Z

87

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

SciTech Connect (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

88

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

SciTech Connect (OSTI)

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.

Not Available

2006-03-01T23:59:59.000Z

89

MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES  

E-Print Network [OSTI]

APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES #12;A-1 APPENDIX A MEASURING IMPACTS TO BIRDS CAUSED BY WIND TURBINES 1.0 INTRODUCTION Differential composition of wind turbines at wind energy used is the number of fatalities per wind turbine per year (Anderson et al. 1999). This metric has

90

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

SciTech Connect (OSTI)

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

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

2000-02-08T23:59:59.000Z

91

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

E-Print Network [OSTI]

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

Pryor, Sara C.

92

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

E-Print Network [OSTI]

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

Pota, Himanshu Roy

93

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

SciTech Connect (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

94

Ris0-M-2829 2 Extreme Values ofWind Speeds  

E-Print Network [OSTI]

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

95

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

E-Print Network [OSTI]

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

Kohfeld, Karen

96

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

97

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

E-Print Network [OSTI]

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

Hu, Weihao

98

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

E-Print Network [OSTI]

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

Stanford University

99

CRYOPUMP MEASUREMENTS RELATING TO SAFETY, PUMPING SPEED, AND RADIATION OUTGASSING  

E-Print Network [OSTI]

Fast Gas Pulse Typical Data for Dynamic Pumping Speed Measurements with Deuterium Plan View of Reactor

Graham, W.G.

2011-01-01T23:59:59.000Z

100

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

E-Print Network [OSTI]

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

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Measurement of turbulent wind velocities using a rotating boom apparatus  

SciTech Connect (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

102

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

E-Print Network [OSTI]

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

Chen, Zhe

103

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

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

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

104

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

105

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

E-Print Network [OSTI]

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

Dupuis, Keith Wade

2009-05-15T23:59:59.000Z

106

The feasibility of sodar wind profile measurements from an oceanographic buoy  

E-Print Network [OSTI]

This thesis explores the feasibility of making wind speed profile measurements from an oceanographic buoy using a Doppler sodar. In the fall of 2005, we deployed a Scintec SFAS sodar on an ASIS buoy. Roughly one week of ...

Berg, Allison M. (Allison May)

2006-01-01T23:59:59.000Z

107

Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise spectroscopy  

E-Print Network [OSTI]

Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise of the plasma thermal noise analysis for the Solar Orbiter, in order to get accurate measurements of the total of their small mass and therefore large thermal speed, the solar wind electrons are expected to play a major role

California at Berkeley, University of

108

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

E-Print Network [OSTI]

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

109

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

E-Print Network [OSTI]

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

Otago, University of

110

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

E-Print Network [OSTI]

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

Zender, Charles

111

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

E-Print Network [OSTI]

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

Beckman, Samuel Karl

2012-06-07T23:59:59.000Z

112

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

SciTech Connect (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

113

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

E-Print Network [OSTI]

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

Haak, Hein

114

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

115

Vermont Wind Measurement Company Still Strong | Department of...  

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

Vermont Wind Measurement Company Still Strong Vermont Wind Measurement Company Still Strong April 9, 2010 - 3:16pm Addthis NRG's new building utilizes solar power, but their...

116

Probabilistic Forecasts of Wind Speed: Ensemble Model Output Statistics  

E-Print Network [OSTI]

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

Washington at Seattle, University of

117

Measuring the Impacts of Speed Reduction Technologies  

E-Print Network [OSTI]

-Seoud, Edward Anderson #12;Background Identified as a problem area Sharp curve & excessive speed High crash;Comparison of Mean Zones - Southbound, Commercial Vehicles 45 46 47 48 49 50 51 52 53 54 55 -1300 -1100 -900-70 Speed Category Before After #12;At nearest rest area

Bertini, Robert L.

118

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

SciTech Connect (OSTI)

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

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

1996-10-01T23:59:59.000Z

119

Wind speed modeled as a semi-Markov process with memory  

E-Print Network [OSTI]

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

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

120

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

E-Print Network [OSTI]

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

Pierrard, John Martin

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

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

SciTech Connect (OSTI)

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

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

2007-07-01T23:59:59.000Z

122

Reliability measures for indexed semi-Markov chains applied to wind energy production  

E-Print Network [OSTI]

The computation of the dependability measures is a crucial point in the planning and development of a wind farm. In this paper we address the issue of energy production by wind turbine by using an indexed semi-Markov chain as a model of wind speed. We present the mathematical model, we describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10kW). We show how to compute some of the main dependability measures such as reliability, availability and maintainability functions. We compare the results of the model with real energy production obtained from data available in the Lastem station (Italy) and sampled every 10 minutes.

D'Amico, Guglielmo; Prattico, Flavio

2013-01-01T23:59:59.000Z

123

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

E-Print Network [OSTI]

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

He, Yanping

124

Measured and predicted rotor performance for the SERI advanced wind turbine blades  

SciTech Connect (OSTI)

Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction. 11 refs.

Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

1992-02-01T23:59:59.000Z

125

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

E-Print Network [OSTI]

measurements of the wind fields engulfing today's huge wind turbines. Our aim is to measure in real- time 3D velocity field, ,within the volumes that fully surround the huge wind turbines of today and tomorrow atmospheric flow that surrounds the giant wind turbines. This new knowledge we envision will accelerate

126

WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO-AND MESOSCALE MODELLING  

E-Print Network [OSTI]

sets for evaluating the potential wind power output from large electricity-producing wind turbine and accurate wind atlas data sets for evaluating the potential wind power output from large electricityWIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO- AND MESOSCALE MODELLING Niels G. Mortensen1 , Jens

127

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

SciTech Connect (OSTI)

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

128

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

E-Print Network [OSTI]

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

Monahan, Adam Hugh

129

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

E-Print Network [OSTI]

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

Pota, Himanshu Roy

130

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

E-Print Network [OSTI]

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

Hawkins, Samuel Lennon

2012-11-29T23:59:59.000Z

131

A comparison of predicted wind turbine blade loads to test measurements  

SciTech Connect (OSTI)

The accurate prediction of wind turbine blade loads and response is important in predicting the fatigue life of wind machines. At the SERI Wind Energy Research Center, a rotor code called FLAP (Force and Loads Analysis Program) is currently being validated by comparing predicted results to machine measurements. The FLAP code has been modified to allow the teetering degrees of freedom. This paper describes these modifications and comparisons of predicted blade bending moments to test measurements. Wind tunnel data for a 1/20th scale model will be used to compare FLAP predictions for the cyclic flap-bending moments at the 33% spanwise station for three different wind speeds. The comparisons will be made for both rigid and teetering hubs. Currently, the FLAP code accounts for deterministic excitations such as wind shear, tower shadow, gravity, and prescribed yawing motions. Conclusions will be made regarding the code's accuracy in predicting the cyclic bending moments.

Wright, A.D.; Thresher, R.W.

1987-01-01T23:59:59.000Z

132

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

E-Print Network [OSTI]

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

Manuel, Lance

133

Solar Wind Sources in the Late Declining Phase ofCycle23: Effects of the Weak Solar Polar Field onHighSpeed 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

134

An evaluation of inductance loop detectors for speed measurement accuracy  

E-Print Network [OSTI]

AN EVALUATION OF INDUCTANCE LOOP DETECTORS FOR SPEED MEASUREMENT ACCURACY A Thesis by BRIAN PATRICK CRONIN Submitted to the OfBce of Graduate Studies of Texas AJkM University in partial fulSllment of the requirements for the degree of MASTER... OF SCIENCE December 1994 Major Subject: Civil Engineering AN EVALUATION OF INDUCTANCE LOOP DETECTORS FOR SPEED MEASUREMENT ACCURACY A Thesis by BRIAN PATRICK CRONIN Submitted to Texas ~M University in partial fulfillment of the requirements...

Cronin, Brian Patrick

2012-06-07T23:59:59.000Z

135

Critical speed measurements in the Tevatron cold compressors  

SciTech Connect (OSTI)

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high energy operations. Nominal operating range for these compressors is 43,000 to 85,000 rpm. Past foil bearing failures prompted investigation to determine if critical speeds for operating compressors fall within operating range. Data acquisition hardware and software settings will be discussed for measuring liftoff, first critical and second critical speeds. Several tests provided comparisons between an optical displacement probe and accelerometer measurements. Vibration data and analysis of the 20 Tevatron ring cold compressors will be presented.

DeGraff, B.; Bossert, R.; Martinez, A.; Soyars, W.M.; /Fermilab

2006-01-01T23:59:59.000Z

136

Summary report: The shadow effect of large wind farms: measurements,  

E-Print Network [OSTI]

Summary report: The shadow effect of large wind farms: measurements, data analysis and modelling of large wind farms Department: Wind Energy Ris-R-1615(EN) July 2007 ISSN 0106-2840 ISBN 978 of the project by means of data from the demonstration wind farms Horns Rev and Nysted, analyses of these data

137

SPINNER ANEMOMETRY -AN INNOVATIVE WIND MEASUREMENT CONCEPT TF Pedersen*)  

E-Print Network [OSTI]

that it is positioned behind the rotor, and therefore measures wind that is influenced by the wakes of blade roots on a tripod. The spinner anemometer has been tested both in a large wind tunnel, and in the field. The sensors made during operation of the wind turbine. The wind tunnel tests confirm the concept ideas. Free field

138

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

SciTech Connect (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

139

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

E-Print Network [OSTI]

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

Guillermo Garcia-Segura; Jose Alberto Lopez; Jose Franco

2004-09-24T23:59:59.000Z

140

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

E-Print Network [OSTI]

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

Ringwald, F A

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind  

E-Print Network [OSTI]

upstream of the Earth?s bow shock. The WIND/WAVES thermal noise receiver was specially designed to measureSolar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind the in situ plasma thermal noise spectra, from which the electron density and temperature can be accurately

California at Berkeley, University of

142

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

E-Print Network [OSTI]

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

Wauben, Wiel

143

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

SciTech Connect (OSTI)

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

144

Measuring the Isotopic Composition of Solar Wind Noble Gases  

E-Print Network [OSTI]

noble gases. #12;Exploring the Solar Wind94 Light solar wind noble gases were directly measured by mass of the light gases are known to vary with energy, so none of these provided solar isotopic and elemental5 Measuring the Isotopic Composition of Solar Wind Noble Gases Alex Meshik, Charles Hohenberg, Olga

145

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

SciTech Connect (OSTI)

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

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

2013-08-01T23:59:59.000Z

146

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

E-Print Network [OSTI]

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

Mursula, Kalevi; Holappa, Lauri

2015-01-01T23:59:59.000Z

147

Wind Resource Assessment in Europe Using Emergy  

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

148

STANDARDS FOR MEASUREMENTS AND TESTING OF WIND TURBINE POWER QUALITY Poul Srensen, Ris National Laboratory, P.O.Box 49, DK-4000 Roskilde, Denmark.  

E-Print Network [OSTI]

STANDARDS FOR MEASUREMENTS AND TESTING OF WIND TURBINE POWER QUALITY Poul Sørensen, Risø National and verification of wind turbine power quality. The work has been organised in three major activities. The first farm summation on the power quality of wind turbines with constant rotor speed. The third activity has

Heinemann, Detlev

149

Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration  

SciTech Connect (OSTI)

New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

Rodney Frehlich

2012-10-30T23:59:59.000Z

150

Measured effect of wind generation on the fuel consumption of an isolated diesel power system  

SciTech Connect (OSTI)

The Block Island Power Company (BIPCO), on Block Island, Rhode Island, operates an isolated electric power system consisting of diesel generation and an experimental wind turbine. The 150-kW wind turbine, designated MOD-OA by the U.S. Department of Energy is typically operated in parallel with two diesel generators to serve an average winter load of 350 kW. Wind generation serves up to 60% of the system demand depending on wind speed and total system load. Results of diesel fuel consumption measurements are given for the diesel units operated in parallel with the wind turbine and again without the wind turbine. The fuel consumption data are used to calculate the amount of fuel displaced by wind energy. Results indicate that the wind turbine displaced 25,700 lbs. of the diesel fuel during the test period, representing a calculated reduction in fuel consumption of 6.7% while generating 11% of the total electrical energy. The amount of displaced fuel depends on operating conditions and system load. It is also shown that diesel engine throttle activity resulting from wind gusts which rapidly change the wind turbine output do not significantly influence fuel consumption.

Stiller, P.; Scott, G.; Shaltens, R.

1983-06-01T23:59:59.000Z

151

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

E-Print Network [OSTI]

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

F. A. Ringwald; T. Naylor

1997-10-02T23:59:59.000Z

152

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

SciTech Connect (OSTI)

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

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

2014-10-01T23:59:59.000Z

153

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

154

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

E-Print Network [OSTI]

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

Lyons, Larry

155

Offshore wind profile measurements from remote sensing instruments  

E-Print Network [OSTI]

Offshore wind profile measurements from remote sensing instruments Ioannis Antoniou (1) , Hans E) have been mounted on top of a transformer platform situated offshore close to the Nysted wind farm be used to supplement met mast measurements for offshore applications. #12;1. Introduction Exploiting

156

Methods and apparatus for reducing peak wind turbine loads  

DOE Patents [OSTI]

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

Moroz, Emilian Mieczyslaw

2007-02-13T23:59:59.000Z

157

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

E-Print Network [OSTI]

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

Mount, Glynn O., Jr

2012-06-07T23:59:59.000Z

158

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

SciTech Connect (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

159

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

E-Print Network [OSTI]

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

160

The spatial response function of SeaWinds backscatter measurements  

E-Print Network [OSTI]

regions are used to produce images of the Earth's land and ice surfaces to support climate studies in a wide variety of studies, including ocean wind retrieval, sea-ice mapping and classification, iceberg are also collected over the land and ice areas of the Earth. SeaWinds measurements over these land and ice

Long, David G.

Note: This page contains sample records for the topic "measure 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

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

SciTech Connect (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

162

Aerodynamic pressure and flow-visualization measurement from a rotating wind turbine blade  

SciTech Connect (OSTI)

Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.

Butterfield, C.P.

1988-11-01T23:59:59.000Z

163

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

164

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

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

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

165

Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact on an ocean model  

E-Print Network [OSTI]

Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact by the QuikSCAT-SeaWinds scatterometer tandem mission (April­October 2003) and their impact on ocean model simulation. The diurnal variability captured by twice-daily scatterometer wind from the tandem mission

Talley, Lynne D.

166

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

167

Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings  

SciTech Connect (OSTI)

The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

Hunt, A.; Easley, S.

2012-05-01T23:59:59.000Z

168

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

E-Print Network [OSTI]

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

Heinemann, Detlev

169

Comparison of Triton SODAR Data to Meteorological Tower Wind Measurement Data in Hebei Province, China  

SciTech Connect (OSTI)

With the increased interest in remote sensing of wind information in recent years, it is important to determine the reliability and accuracy of new wind measurement technologies if they are to replace or supplement conventional tower-based measurements. In view of this, HydroChina Corporation and the United States National Renewable Energy Laboratory (NREL) conducted a comparative test near a wind farm in Hebei Province, China. We present the results of an analysis characterizing the measurement performance of a state-of-the-art Sound Detection and Ranging (sodar) device when compared to a traditional tower measurement program. NREL performed the initial analysis of a three-month period and sent the results to HydroChina. When another month of data became available, HydroChina and their consultant Beijing Millenium Engineering Software (MLN) repeated NREL's analysis on the complete data set, also adding sensitivity analysis for temperature, humidity, and wind speed (Section 6). This report presents the results of HydroChina's final analysis of the four-month period.

Yuechun, Y.; Jixue, W.; Hongfang, W.; Guimin, L.; Bolin, Y.; Scott, G.; Elliott, D.; Kline, D.

2012-01-01T23:59:59.000Z

170

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

E-Print Network [OSTI]

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

171

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

E-Print Network [OSTI]

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

Pryor, Sara C.

172

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...

Manning, Norman Willis William

2012-06-07T23:59:59.000Z

173

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 < 700 km/s), but with a different histogram. We use this result to deduce a relation between the solar-wind speed and density, which formalizes the anti-correlation between these quantities.

Chat, G Le; Meyer-Vernet, N

2012-01-01T23:59:59.000Z

174

Reliability measures of second order semi-Markov chain in state and duration with application to wind energy production  

E-Print Network [OSTI]

In this paper we consider the problem of wind energy production using a second order semi-Markov chain in state and duration as a model of wind speed. We present the mathematical model, we describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10kW). We show how to compute some of the main dependability measures such as reliability, availability and maintainability functions. We compare the results of the model with real energy production obtained from data available in the Lastem station (Italy) and sampled every 10 minutes. The computation of the dependability measures is a crucial point in the planning and development of a wind farm.

D'Amico, Guglielmo; Prattico, Flavio

2012-01-01T23:59:59.000Z

175

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

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

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

176

Measurement of wind set-up on an open coast  

E-Print Network [OSTI]

L IB R A R Y A t i !V? COLLcic OF TEXAS MEASUREMENT OF WIND SET-UP ON AN OPEN COAST A Dissertation By William H. Clayton Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY August 1956 MAJOR SUBJECT: PHYSICAL OCEANOGRAPHY MEASUREMENT OF WIND SET-UP ON AN OPEN COAST A Dissertation By WILLIAM H. CLAYTON Approved as to style and content by: Chairman of Committee August...

Clayton, William Howard

1956-01-01T23:59:59.000Z

177

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

E-Print Network [OSTI]

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

Schwarzenbach, Jean Christophe

1942-01-01T23:59:59.000Z

178

Bachelor thesis: "Validation of an engineering model of the near wake wind field of wind turbines based on nacelle based lidar measurements"  

E-Print Network [OSTI]

Bachelor thesis: "Validation of an engineering model of the near wake wind field of wind turbines, in an early stage of wind farm layout optimisation and wind turbine loading calculation in wind farms developed/validated indirectly. Mainly, based on power measurements of downstream wind turbines, instead

Peinke, Joachim

179

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

180

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

Note: This page contains sample records for the topic "measure 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

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

182

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

183

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

184

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

185

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

186

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

187

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

188

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

189

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

190

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

E-Print Network [OSTI]

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

Robock, Alan

191

Spatial and temporal distributions of U.S. winds and wind power at 80 m derived from measurements  

E-Print Network [OSTI]

, global warming, air pollution, energy, wind speed Citation: Archer, C. L., and M. Z. Jacobson, Spatial- pollution-related mortality, urban smog, acid deposition, and visibility degradation. Coal mining also: Pollution--urban and regional (0305); 3399 Meteorology and Atmospheric Dynamics: General or miscellaneous

192

On measurement of the isotropy of the speed of light  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Three experimental concepts investigating possible anisotropy of the speed of light are presented. They are based on i) beam deflection in a 180 degree magnetic arc, ii) narrow resonance production in an electron-positron collider, and iii) the ratio of magnetic moments of an electron and a positron moving in opposite directions.

Wojtsekhowski, Bogdan B. [JLAB

2014-11-01T23:59:59.000Z

193

Speed Meter As a Quantum Nondemolition Measuring Device for Force  

E-Print Network [OSTI]

Quantum noise is an important issue for advanced LIGO. Although it is in principle possible to beat the Standard Quantum Limit (SQL), no practical recipe has been found yet. This paper dicusses quantum noise in the context of speedmeter-a devise monitoring the speed of the testmass. The scheme proposed to overcome SQL in this case might be more practical than the methods based on monitoring position of the testmass.

F. Ya. Khalili; Yu. Levin

1996-03-26T23:59:59.000Z

194

Wind pro?le assessment for wind power purposes.  

E-Print Network [OSTI]

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

Sointu, Iida

2014-01-01T23:59:59.000Z

195

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

E-Print Network [OSTI]

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

Wauben, Wiel

196

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

197

The high-speed after pulse measurement system for PMT  

E-Print Network [OSTI]

A system employing a desktop FADC has been developed to investigate the features of 8 inches Hamamatsu PMT. The system stands out for its high-speed and informative results as a consequence of adopting fast waveform sampling technology. Recording full waveforms allows us to perform digital signal processing, pulse shape analysis, and precision timing extraction. High precision after pulse time and charge distribution characteristics are presented in this manuscript. Other photomultipliers characteristics, such as dark rate and transit time spread, can also be obtained by exploiting waveform analysis using this system.

Yaping Cheng; Sen Qian; Zhe Ning; Jingkai Xia; Wenwen Wang; Yifang Wang; Jun Cao; Xiaoshan Jiang; Zheng Wang; Xiaonan Li; Ming Qi; Yuekun Heng; Shulin Liu; Xiangcui Lei; Zhi Wu

2014-04-24T23:59:59.000Z

198

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

E-Print Network [OSTI]

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

Manuel, Lance

199

Cloud Features and Zonal Wind Measurements of Saturn's Atmosphere as Observed by Cassini/VIMS  

E-Print Network [OSTI]

We present an analysis of data about Saturn's atmosphere from Cassini's Visual and Infrared Mapping Spectrometer (VIMS), focusing on the meteorology of the features seen in the 5-micron spectral window. We present VIMS mosaics and discuss the morphology and general characteristics of the features backlit by Saturn's thermal emission. We have also constructed a zonal wind profile from VIMS feature tracking observation sequences using an automated cloud feature tracker. Comparison with previously constructed profiles from Voyager and Cassini imaging data reveals broad similarities, suggesting minimal vertical shear of the zonal wind. However, areas of apparent wind shear are present in the VIMS zonal wind profile at jet stream cores. In particular, our analysis shows that the equatorial jet reaches speeds exceeding 450 m/s, similar to speeds obtained during the Voyager era. This suggests that recent inferences of relatively slower jet speeds of ~275-375 m/s are confined to the upper troposphere and that the dee...

Choi, David S; Brown, Robert H; 10.1029/2008JE003254

2013-01-01T23:59:59.000Z

200

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

DOE Patents [OSTI]

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

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

2005-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

ESTABLISHING A CONNECTION BETWEEN ACTIVE REGION OUTFLOWS AND THE SOLAR WIND: ABUNDANCE MEASUREMENTS WITH EIS/HINODE  

SciTech Connect (OSTI)

One of the most interesting discoveries from Hinode is the presence of persistent high-temperature high-speed outflows from the edges of active regions (ARs). EUV imaging spectrometer (EIS) measurements indicate that the outflows reach velocities of 50 km s{sup -1} with spectral line asymmetries approaching 200 km s{sup -1}. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. We use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a 5 day period in 2007 December. We find that Si is always enhanced over S by a factor of 3-4. This is generally consistent with the enhancement factor of low FIP elements measured in situ in the slow solar wind by non-spectroscopic methods. Plasma with a slow wind-like composition was therefore flowing from the edge of the AR for at least 5 days. Furthermore, on December 10 and 11, when the outflow from the western side was favorably oriented in the Earth direction, the Si/S ratio was found to match the value measured a few days later by the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer. These results provide strong observational evidence for a direct connection between the solar wind, and the coronal plasma in the outflow regions.

Brooks, David H. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P., E-mail: dhbrooks@ssd5.nrl.navy.mil [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2011-01-20T23:59:59.000Z

202

Synchrophasor Measurement-Based Wind Plant Inertia Estimation: Preprint  

SciTech Connect (OSTI)

The total inertia stored in all rotating masses that are connected to power systems, such as synchronous generations and induction motors, is an essential force that keeps the system stable after disturbances. To ensure bulk power system stability, there is a need to estimate the equivalent inertia available from a renewable generation plant. An equivalent inertia constant analogous to that of conventional rotating machines can be used to provide a readily understandable metric. This paper explores a method that utilizes synchrophasor measurements to estimate the equivalent inertia that a wind plant provides to the system.

Zhang, Y.; Bank, J.; Wan, Y. H.; Muljadi, E.; Corbus, D.

2013-05-01T23:59:59.000Z

203

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

204

HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS  

SciTech Connect (OSTI)

It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

Deibele, Craig Edmond [ORNL] [ORNL; Curry, Douglas E [ORNL] [ORNL; Dickson, Richard W [ORNL] [ORNL

2012-01-01T23:59:59.000Z

205

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

E-Print Network [OSTI]

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

Kohn, David Jacob

2012-06-07T23:59:59.000Z

206

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

SciTech Connect (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

207

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

208

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

209

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

210

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

211

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

212

Resolving Spacecraft Earth-Flyby Anomalies with Measured Light Speed Anisotropy  

E-Print Network [OSTI]

Doppler shift observations of spacecraft, such as Galileo, NEAR, Cassini, Rosetta and MESSENGER in earth flybys, have all revealed unexplained speed `anomalies' - that the doppler-shift determined speeds are inconsistent with expected speeds. Here it is shown that these speed anomalies are not real and are actually the result of using an incorrect relationship between the observed doppler shift and the speed of the spacecraft - a relationship based on the assumption that the speed of light is isotropic in all frames, i.e. invariant. Taking account of the repeatedly measured light-speed anisotropy the anomalies are resolved. The Pioneer 10/11 anomalies are discussed, but not resolved. The spacecraft observations demonstrate again that the speed of light is not invariant, and is isotropic only with respect to a dynamical 3-space. The existing doppler shift data also offers a resource to characterise a new form of gravitational waves, the dynamical 3-space turbulence, that has also been detected by other techniques.

Reginald T. Cahill

2008-04-30T23:59:59.000Z

213

Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic Downscaling with Doppler Lidar Wind Measurements  

SciTech Connect (OSTI)

Previous estimates of the wind resources in Uttarakhand, India, suggest minimal wind resources in this region. To explore whether or not the complex terrain in fact provides localized regions of wind resource, the authors of this study employed a dynamic down scaling method with the Weather Research and Forecasting model, providing detailed estimates of winds at approximately 1 km resolution in the finest nested simulation.

Lundquist, J. K.; Pukayastha, A.; St. Martin, C.; Newsom, R.

2014-03-01T23:59:59.000Z

214

Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"  

E-Print Network [OSTI]

The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.

Nagornyi, V D

2014-01-01T23:59:59.000Z

215

Wind Power Plant Prediction by Using Neural Networks: Preprint  

SciTech Connect (OSTI)

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

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

2012-08-01T23:59:59.000Z

216

Wind resource assessment with a mesoscale non-hydrostatic model  

E-Print Network [OSTI]

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

Boyer, Edmond

217

Measurement of Infrasound Emissions from Wind Turbines Dave Pepyne, Michael Zink and Jamyang Tenzin  

E-Print Network [OSTI]

Measurement of Infrasound Emissions from Wind Turbines Dave Pepyne, Michael Zink and Jamyang Tenzin energy has made wind turbine technology a suitable candidate for pollution-free energy. With its great that received many complaints from the residents living near the large wind turbine poles. Many scientists

Mountziaris, T. J.

218

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model  

E-Print Network [OSTI]

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model 1 dynamics, lIre performed at four diameters behind a 95 kW wind turbine. The wake 111eaeasurement technique allows esti111ation of qUClsiinstantancou~ two dimensional wind fields in an area

219

Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement  

E-Print Network [OSTI]

Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement Abstract Wind turbines (WT) are normally designed for a service life (SL) of 20 years. In Germany, over safety. 1 Introduction A wind turbine (WT) is normally designed, tested and certified for a design life

Berlin,Technische Universität

220

Final Map Draft Comparison Report WIND ENERGY RESOURCE MODELING AND MEASUREMENT PROJECT  

E-Print Network [OSTI]

II Final Map Draft Comparison Report #12;WIND ENERGY RESOURCE MODELING AND MEASUREMENT PROJECT Tel: 978-749-9591 Fax: 978-749-9713 mbrower@awstruewind.com August 10, 2004 #12;2 WIND ENERGY RESOURCE issues. 1 Background In Task 2 of the project, five promising areas of the state for wind energy

Note: This page contains sample records for the topic "measure 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

On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction  

E-Print Network [OSTI]

the accuracies of surface wind fields in the National Centers for Envi- ronmental Prediction (NCEP) and EuropeanOn the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction ocean vector winds for marine weather prediction is investigated from two Northern Hemisphere case

Kurapov, Alexander

222

Comparison of Wake Model Simulations with Offshore Wind Turbine Wake Profiles Measured by Sodar  

E-Print Network [OSTI]

a ship-mounted sodar at a small offshore wind farm. The experiments were conducted at varying distances Offshore wind farms have increased in size from the first phase of installation with up to 20 turbinesComparison of Wake Model Simulations with Offshore Wind Turbine Wake Profiles Measured by Sodar R

Pryor, Sara C.

223

Measuring Program for Wind, Waves and Current for Horns Rev and Ls; Documentation  

E-Print Network [OSTI]

REPORT Measuring Program for Wind, Waves and Current for Horns Rev and Ls; Documentation Documentation of wind sensors, data logs, etc. for Horns Rev is described in folder 2CF/EB001 supplied by ED is described in folder 2 CF/EB003 supplied by ED service centre and TW. Documentation of 3D Sonic Wind

224

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

E-Print Network [OSTI]

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

Capps, Scott B; Zender, Charles S

2010-01-01T23:59:59.000Z

225

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

E-Print Network [OSTI]

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

226

Strengths and limitations of MST radar measurements of middle-atmosphere winds  

E-Print Network [OSTI]

levels of the atmosphere. 1 Introduction Radars used for atmospheric wind measurements cover a broadStrengths and limitations of MST radar measurements of middle-atmosphere winds W. K. Hocking for many years to measure atmospheric motions over a wide range of altitudes, from ground level up

Paris-Sud XI, Université de

227

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

E-Print Network [OSTI]

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

Duffy, Ken

228

CWEX (Crop/Wind-Energy Experiment): Measurements of the interaction between crop agriculture and wind power.  

E-Print Network [OSTI]

??The current expansion of wind farms in the U.S. Midwest promotes an alternative renewable energy portfolio to conventional energy sources derived from fossil fuels. The (more)

Rajewski, Daniel Andrew

2013-01-01T23:59:59.000Z

229

Distributed Compression for Condition Monitoring of Wind Farms  

E-Print Network [OSTI]

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

Cheng, Samuel

230

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

E-Print Network [OSTI]

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

McCalley, James D.

231

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

E-Print Network [OSTI]

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

Pryor, Sara C.

232

Specification of >2 MeV geosynchronous electrons based on solar wind measurements  

E-Print Network [OSTI]

affected by the solar wind. Statistical asynchronous regression (SAR), a statistical method recently use measurements directly from the solar wind, instead of the Kp index, and the SAR method when they pass through these local times. We cross calibrate the electron measurements from the five

Li, Xinlin

233

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

SciTech Connect (OSTI)

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

234

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

E-Print Network [OSTI]

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

235

20% Wind Energy 20% Wind Energy  

E-Print Network [OSTI]

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

Powell, Warren B.

236

DEWEK Wind Energy Conference 2012 Category: 4. Simulation models BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND  

E-Print Network [OSTI]

DEWEK Wind Energy Conference 2012 Category: 4. Simulation models 1 BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND TURBINES Dipl.-Ing. René Kamieth, Prof. Dr, Germany, Tel.: +49-(0)30-314-23603, Fax: +49-(0)30-314-26131 Summary Wind turbines built in the last

Berlin,Technische Universität

237

Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control (Poster)  

SciTech Connect (OSTI)

Integrating Lidar to improve wind turbine controls is a potential breakthrough for reducing the cost of wind energy. By providing undisturbed wind measurements up to 400m in front of the rotor, Lidar may provide an accurate update of the turbine inflow with a preview time of several seconds. Focusing on loads, several studies have evaluated potential reductions using integrated Lidar, either by simulation or full scale field testing.

Scholbrock, F. A.; Fleming, P.; Wright, A.; Davoust, S.; Jehu, A.; Bouillet, M.; Bardon M.; Vercherin, B.

2014-02-01T23:59:59.000Z

238

High temperature measurement using very high shutter speed to avoid image saturation  

SciTech Connect (OSTI)

This paper explores the adaptation of the two-colour principle to develop a high-speed colour temperature correlation system, which is able to cover a range of temperature that is challenging to achieve before. A colour digital camera has built in RGB filters. It is possible to measure the temperature from the ratio of intensity of the green and red pixels using the two-colour principle based on the expansion of the Planks radiation law. In this study, experiments were carried out using a temperature calibrated tungsten ribbon lamp which can be tuned to vary from 1300 to 2200C. Using very high shutter speed and small aperture, the high-speed camera successfully captured the tungsten ribbon without image saturation at the full temperature scale. Tests have been carried out at different temperature and camera settings. The sensitivity and errors have been analysed, and experiment results demonstrate the potential of using very high shutter speed is available for measuring the temperature even beyond 2200C.

Ma, Zhen; Zhang, Yang [Department of Mechanical Engineering, Sir Frederick Mappin Building, University of Sheffield, Sheffield, S1 3JD (United Kingdom)

2014-04-11T23:59:59.000Z

239

European Wind Energy Conference 2007 Milan Measurement based analysis of active and reactive power  

E-Print Network [OSTI]

of the electricity is produced by wind turbines and combined heat and power plants (CHPs). Most of them are connected heat and power plants. The investigation is based on 15 min average power measurements and load flow power losses in a distribution network with wind farms and CHPs 1 Introduction In Denmark, a large part

240

American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure-Correlate-Predict Analyses  

E-Print Network [OSTI]

American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure Wind Energy Association, Denver, May 2005 Statistical models are then investigated that estimate-Correlate-Predict Analyses Anthony L. Rogers, Ph. D.* John W. Rogers, M.S.** James F. Manwell, Ph. D.* *Renewable Energy

Massachusetts at Amherst, University of

Note: This page contains sample records for the topic "measure 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

Energy analysis of substorms based on remote sensing techniques, solar wind measurements, and geomagnetic indices  

E-Print Network [OSTI]

Energy analysis of substorms based on remote sensing techniques, solar wind measurements wind Citation: ?stgaard, N., G. Germany, J. Stadsnes, and R. R. Vondrak, Energy analysis of substorms satellite have been used to examine the energy deposition in the Northern Hemisphere by precipitating

?stgaard, Nikolai

242

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

243

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

244

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

245

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

246

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

247

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

248

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

249

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

250

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

251

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

252

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

253

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

254

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

255

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

256

Measuring M dwarf Winds with DAZ White Dwarfs  

E-Print Network [OSTI]

Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, show evidence for ongoing accretion of material onto their surfaces. Some DAZs are known to have unresolved M dwarf companions, which could account for the observed accretion through a stellar wind. I combine observed Ca abundances of the DAZs with information on the orbital separation of their M dwarf companions to infer the mass loss rate of the M dwarfs. I find that for three of the six known DAZs with M dwarf companions, a stellar wind can plausibly explain the observed accretion on the white dwarfs assuming Bondi-Hoyle accretion of solar abundance stellar winds on the order of 10$^{-14}-10^{-16}\\Msun$ yr$^{-1}$. The rest of the sample have companions with orbits $\\gtorder$ 1~AU, and require companion mass loss rates of $> 10^{-11}\\Msun$ yr$^{-1}$. I conclude that there must be an alternative explanation for accretion of material onto DAZs with widely separated companions. The inferred winds for two of the close binaries are orders of magnitude smaller than typically assumed for the angular momentum loss of red dwarf-white dwarf pairs due to magnetic braking from a stellar wind and may seriously affect predictions for the formation rate of CVs with low mass companions.

J. H. Debes

2006-08-01T23:59:59.000Z

257

Abstract--Resolvers are absolute angle transducers that are usually used for position and speed measurement in  

E-Print Network [OSTI]

measurement in permanent magnet motors. An observer that uses the sinusoidal signals of the resolver is fixed on the rotor, and therefore, it rotates jointly with the shaft passing the output windings. Two on the reference winding Uref and along with the angular movement of the motor shaft , the respective voltages

Sontag, Eduardo

258

Analysis of Alongwind Tall Building Response to Transient Nonstationary Winds  

E-Print Network [OSTI]

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

Chen, Xinzhong

259

Wind power resource assessment in complex urban environments: MIT campus case-study using CFD Analysis  

E-Print Network [OSTI]

around buildings. The software model has been used to evaluate the wind energy potential on the campus-site. Comparisons between the measurements and the predicted wind speeds allowed validation of the software results of Technology, 2Meteodyn Objectives Conclusions References [1] TopoWind software, User Manual [2] Wind Resource

260

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

E-Print Network [OSTI]

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

Hering, Amanda S.

2010-10-12T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Measuring M dwarf Winds with DAZ White Dwarfs  

E-Print Network [OSTI]

Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, show evidence for ongoing accretion of material onto their surfaces. Some DAZs are known to have unresolved M dwarf companions, which could account for the observed accretion through a stellar wind. I combine observed Ca abundances of the DAZs with information on the orbital separation of their M dwarf companions to infer the mass loss rate of the M dwarfs. I find that for three of the six known DAZs with M dwarf companions, a stellar wind can plausibly explain the observed accretion on the white dwarfs assuming Bondi-Hoyle accretion of solar abundance stellar winds on the order of 10$^{-14}-10^{-16}\\Msun$ yr$^{-1}$. The rest of the sample have companions with orbits $\\gtorder$ 1~AU, and require companion mass loss rates of $> 10^{-11}\\Msun$ yr$^{-1}$. I conclude that there must be an alternative explanation for accretion of material onto DAZs with widely separated companions. The inferred winds for two of the close binaries are orders of magn...

Debes, J H

2006-01-01T23:59:59.000Z

262

Ris-PhD-Report Complex Terrain and Wind Lidars  

E-Print Network [OSTI]

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

263

Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control: Preprint  

SciTech Connect (OSTI)

Turbine-mounted lidars provide preview measurements of the incoming wind field. By reducing loads on critical components and increasing the potential power extracted from the wind, the performance of wind turbine controllers can be improved [2]. As a result, integrating a light detection and ranging (lidar) system has the potential to lower the cost of wind energy. This paper presents an evaluation of turbine-mounted lidar availability. Availability is a metric which measures the proportion of time the lidar is producing controller-usable data, and is essential when a wind turbine controller relies on a lidar. To accomplish this, researchers from Avent Lidar Technology and the National Renewable Energy Laboratory first assessed and modeled the effect of extreme atmospheric events. This shows how a multirange lidar delivers measurements for a wide variety of conditions. Second, by using a theoretical approach and conducting an analysis of field feedback, we investigated the effects of the lidar setup on the wind turbine. This helps determine the optimal lidar mounting position at the back of the nacelle, and establishes a relationship between availability, turbine rpm, and lidar sampling time. Lastly, we considered the role of the wind field reconstruction strategies and the turbine controller on the definition and performance of a lidar's measurement availability.

Davoust, S.; Jehu, A.; Bouillet, M.; Bardon, M.; Vercherin, B.; Scholbrock, A.; Fleming, P.; Wright, A.

2014-05-01T23:59:59.000Z

264

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

SciTech Connect (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. Traditional controller design generally consists of linearizing a model about an operating point. This step was taken for two different operating points, and the systematic design approach was used. A comparison of the optimal regions selected using the n on-linear model and the two linear models shows similarities. The linearization point selection does, however, affect the turbine performance slightly. Exploitation of the simplicity of the model allows surfaces consisting of operation under a wide range of gain values to be created. This methodology provides a means of visually observing turbine performance based upon the two metrics chosen for this study. Design of a PID controller is simplified, and it is possible to ascertain the best possible combination of controller parameters. The wide, flat surfaces indicate that a PID controller is very robust in this variable-speed wind turbine application.

Hand, M. M.

1999-07-30T23:59:59.000Z

265

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

SciTech Connect (OSTI)

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

266

Determination of the pressure at the gas-liquid interface using acoustic speed measurements  

E-Print Network [OSTI]

. The density can be expressed with the use of the real gas law. This yields BP = ? (g/gc) *dz*P*M/(144*Z*R*T) BP = ? (g/gc) *dz*P*SG*MAIR/(144*Z*R*T) (26) 21 where: SG MAIR specific gravity of gas. (air= 1. 0), Molecular weight of air, 28. 966...DETERMINATION OF THE PRESSURE AT THE GAS-LIQUID INTERFACE USING ACOUSTIC SPEED MEASUREMENTS A Thesis by DAG GUSTAV HEGGELUND Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree...

Heggelund, Dag Gustav

1988-01-01T23:59:59.000Z

267

Estimating long-term mean winds from short-term wind data  

SciTech Connect (OSTI)

The estimation of long-term mean winds from short-term data is especially important in the area of wind energy. It is desirable to obtain reliable estimates of the long-term wind speed from as short a period of on-site measurements as possible. This study examined seven different methods of estimating the long-term average wind speed and compared the performance of these techniques. Three linear, three weather pattern, and one eigenvector methods were compared for measurement periods ranging from 3 months to 36 months. Average errors, both relative and absolute, and the rms errors in the techniques were determined. The best technique for less than 12 months of measurement was the eigenvector method using weekly mean wind speeds. However, this method was only slightly better than the linear adjusted method. When 12 or more months of data were used, the difference in errors between techniques was found to be slight.

Barchet, W.R.; Davis, W.E.

1983-08-01T23:59:59.000Z

268

Comparison of the Performance of Four Measure-Correlate-Predict Algorithms Anthony L. Rogers, Ph. D., Senior Research Fellow*  

E-Print Network [OSTI]

at the target site, assuming a sample wind turbine power curve, and 4) the correct wind direction distribution between wind data (speed and direction) measured at the target site, usually over a period of up to a year site to predict the long-term wind speed and direction distributions at the target site. Defining

Massachusetts at Amherst, University of

269

Sandia National Laboratories: measure 3-D wind flow  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbine bladelifetime is the cumulative timemaximize energy3-D wind flow

270

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

271

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

E-Print Network [OSTI]

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

Yang, Cher-Chiang

2008-05-05T23:59:59.000Z

272

Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements  

SciTech Connect (OSTI)

A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields.

Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

2007-05-20T23:59:59.000Z

273

Determination of volume fractions in two-phase flows from sound speed measurement  

SciTech Connect (OSTI)

Accurate measurement of the composition of oil-water emulsions within the process environment is a challenging problem in the oil industry. Ultrasonic techniques are promising because they are non-invasive and can penetrate optically opaque mixtures. This paper presents a method of determining the volume fractions of two immiscible fluids in a homogenized two-phase flow by measuring the speed of sound through the composite fluid along with the instantaneous temperature. Two separate algorithms are developed by representing the composite density as (i) a linear combination of the two densities, and (ii) a non-linear fractional formulation. Both methods lead to a quadratic equation with temperature dependent coefficients, the root of which yields the volume fraction. The densities and sound speeds are calibrated at various temperatures for each fluid component, and the fitted polynomial is used in the final algorithm. We present results when the new algorithm is applied to mixtures of crude oil and process water from two different oil fields, and a comparison of our results with a Coriolis meter; the difference between mean values is less than 1%. Analytical and numerical studies of sensitivity of the calculated volume fraction to temperature changes and calibration errors are also presented.

Chaudhuri, Anirban [Los Alamos National Laboratory; Sinha, Dipen N. [Los Alamos National Laboratory; Osterhoudt, Curtis F. [University of Alaska

2012-08-15T23:59:59.000Z

274

Photoacoustically Measured Speeds of Sound of Liquid HBO2: On Unlocking the Fuel Potential of Boron  

SciTech Connect (OSTI)

Elucidation of geodynamic, geochemical, and shock induced processes is often limited by challenges to accurately determine molecular fluid equations of state (EOS). High pressure liquid state reactions of carbon species underlie physiochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. Here we introduce a versatile photoacoustic technique developed to measure accurate and precise speeds of sound (SoS) of high pressure molecular fluids and fluid mixtures. SoS of an intermediate boron oxide, HBO{sub 2} are measured up to 0.5 GPa along the 277 C isotherm. A polarized Exponential-6 interatomic potential form, parameterized using our SoS data, enables EOS determinations and corresponding semi-empirical evaluations of > 2000 C thermodynamic states including energy release from bororganic formulations. Our thermochemical model propitiously predicts boronated hydrocarbon shock Hugoniot results.

Bastea, S; Crowhurst, J; Armstrong, M; ., N T

2010-03-24T23:59:59.000Z

275

Relationship between speed distribution measures and rural two-lane highway characteristics  

E-Print Network [OSTI]

mandated 55 mph (88. 5 km/h) speed limit, the original design speed of a roadway does not always meet the desired operating speeds of today's drivers. Thus, a design consistency approach has been suggested as an alternative means for ensuring driver... STATISTICS PRELIMINARY ANALYSIS MEAN SPEED REDUCTION ANALYSIS STANDARD DEVIATION DIFFERENCE ANALYSIS . . 80 . 88 . . 91 VII SUMMARY AND CONCLUSIONS 93 CONCLUSIONS . RECOMMENDATIONS 95 97 REFERENCES APPENDIX . . VITA 100 I04 117 LIST...

Collins, Jon Michael

2012-06-07T23:59:59.000Z

276

Experimental Investigation of Wind-Forced Drop Stability  

E-Print Network [OSTI]

aluminum (RA = 3.26 micrometers) floor of a tiltable wind tunnel and brought to critical conditions, when the drop begins to run downstream. Various combinations of drop size, inclination angle, and flow speed were employed. A measurement technique capable...

Schmucker, Jason

2012-10-19T23:59:59.000Z

277

The influence of Earth rotation in neutrino speed measurements between CERN and the OPERA detector  

E-Print Network [OSTI]

The OPERA neutrino experiment at the underground Gran Sasso Laboratory recently reported, in arXiv:1109.4897v1, high-accuracy velocity measurements of neutrinos from the CERN CNGS beam over the 730 km distance between the two laboratories. This raised significant interest, as the observed neutrinos appeared to arrive at the OPERA detector about 60 ns (or equivalently 18 m) earlier than would have been expected if they had traveled at the speed of light, with high statistical significance. As the authors did not indicate whether and how they took into account the Coriolis or Sagnac effect that Earth's rotation has on the (southeastwards traveling) neutrinos, this brief note quantifies this effect. It would explain a 2.2 ns later arrival time.

Markus G. Kuhn

2011-10-20T23:59:59.000Z

278

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

E-Print Network [OSTI]

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

Lantz, Eric

2014-01-01T23:59:59.000Z

279

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

E-Print Network [OSTI]

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

Lantz, Eric

2014-01-01T23:59:59.000Z

280

NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)  

SciTech Connect (OSTI)

Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive-responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

Not Available

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

NREL Develops New Controls that Proactively Adapt to the Wind (Fact Sheet)  

SciTech Connect (OSTI)

Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive -- responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

Not Available

2012-10-01T23:59:59.000Z

282

High speed measurements of neutral beam turn-on and impact of beam modulation on measurements of ion density  

SciTech Connect (OSTI)

Modulation of neutral beams on tokamaks is performed routinely, enabling background rejection for active spectroscopic diagnostics, and control of injected power and torque. We find that there exists an anomalous initial transient in the beam neutrals delivered to the tokamak that is not accounted for by the accelerator voltage and power supply current. Measurements of the charge-exchange and beam photoemission on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] at high speed (200 ?s) reveal that the energy of the beam neutrals is constant, but the density of beam neutrals displays dramatic variation in the first 23 ms following beam turn-on. The impact of this beam density variation on inferred ion densities and impurity transport is presented, with suggested means to correct for the anomalous transient.

Grierson, B. A., E-mail: bgriers@pppl.gov; Grisham, L. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Crowley, B.; Scoville, J. T. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2014-10-15T23:59:59.000Z

283

Subhourly wind forecasting techniques for wind turbine operations  

SciTech Connect (OSTI)

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

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

1984-08-01T23:59:59.000Z

284

Temporal variability of the trade wind inversion: Measured with a boundary layer vertical profiler. Master's thesis  

SciTech Connect (OSTI)

This study uses Hawaiian Rainband Project (HaRP) data, from the summer of 1991, to show a boundary layer wind profiler can be used to measure the trade wind inversion. An algorithm has been developed for the profiler that objectively measures the depth of the moist oceanic boundary layer. The Hilo inversion, measured by radiosonde, is highly correlated with the moist oceanic boundary layer measured by the profiler at Paradise Park. The inversion height on windward Hawaii is typically 2253 + or - 514 m. The inversion height varies not only on a daily basis, but on less than an hourly basis. It has a diurnal, as well as a three to four day cycle. There appears to be no consistent relationship between inversion height and precipitation. Currently, this profiler is capable of making high frequency (12 minute) measurements of the inversion base variation, as well as other features.

Grindinger, C.M.

1992-05-01T23:59:59.000Z

285

ISET-Wind-Index Assessment of the Annual Available Wind Energy  

E-Print Network [OSTI]

Particularly in years with wind speeds that are clearly below average, dissatisfaction of operators and even liquidity problems are sparked through the unexpected low annual power production. An objective standard for the evaluation of the respective wind year is required for the internal estimation of the performance of wind farms, and for justification to share owners and banks. The annual wind conditions are composed from such a multitude of meteorological situations, differing from location to location, that the available wind energy at every individual location develops totally differently. A single code is therefore not sufficient to describe the wind year in Germany and, moreover, the evaluation of annual available wind energy must be carried out separately for the smallest areas possible. With the support of the Gothaer Rckversicherungen AG, a procedure has been developed at ISET which provides the proportion of the respective annual available wind energy, in relation to the long-term average available wind energy, for each 10 km x 10 km sized plan area in Germany. This amount, the ISET-Wind-Index, is founded on wind measurements at locations that are typical for wind energy use and therefore presents an objective standard. The measurement grid is part of the Scientific Measurement and Evaluation Programme (WMEP), which accompanies the 250 MW Wind project of the German Federal Ministry for Economy and Labour. The ISET-Wind-Index, which will be regularly updated, provides an objective standard for the estimation of annual available

Berthold Hahn; Kurt Rohrig

2003-01-01T23:59:59.000Z

286

Cloud features and zonal wind measurements of Saturn's atmosphere as observed by Cassini/VIMS  

E-Print Network [OSTI]

Cloud features and zonal wind measurements of Saturn's atmosphere as observed by Cassini/VIMS D. S Cassini's Visual and Infrared Mapping Spectrometer (VIMS), focusing on the meteorology of the features seen in the 5 mm spectral window. We present VIMS mosaics and discuss the morphology and general

Choi, David S.

287

Preprint submitted to the Proceedings of the European Wind Energy Conference EWEC in Madrid, Spain June 2003 PREVIENTO meets HORNS REV  

E-Print Network [OSTI]

of future offshore wind farms. Surprisingly, in all possible thermal conditions measured speeds of westerly Horns Rev offshore wind farm has to be considered as a step to new dimensions in wind power production June 2003 1 PREVIENTO meets HORNS REV Short-Term Wind-Power Prediction ­ adaptation to Offshore Sites

Heinemann, Detlev

288

Recovery of a source term or a speed with one measurement and  

E-Print Network [OSTI]

Apr 3, 2013 ... version, of the problem of recovery a sound speed, given the source. It has applications to thermoacoustic tomography. We are also inspired by...

2013-04-03T23:59:59.000Z

289

Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON  

E-Print Network [OSTI]

Powering Up With Space-Time Wind Forecasting Amanda S. HERING and Marc G. GENTON The technology to harvest electricity from wind energy is now advanced enough to make entire cities powered by it a reality be more realistically assessed with a loss measure that depends upon the power curve relating wind speed

Genton, Marc G.

290

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

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

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

291

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

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

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

292

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

E-Print Network [OSTI]

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

Neichel, Benoit; Guesalaga, Andrs R; Lascaux, Franck; Bchet, Clmentine

2014-01-01T23:59:59.000Z

293

Stellar Winds on the Main-Sequence I: Wind Model  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

294

Methods and apparatus for twist bend coupled (TCB) wind turbine blades  

DOE Patents [OSTI]

A method for controlling a wind turbine having twist bend coupled rotor blades on a rotor mechanically coupled to a generator includes determining a speed of a rotor blade tip of the wind turbine, measuring a current twist distribution and current blade loading, and adjusting a torque of a generator to change the speed of the rotor blade tip to thereby increase an energy capture power coefficient of the wind turbine.

Moroz, Emilian Mieczyslaw; LeMieux, David Lawrence; Pierce, Kirk Gee

2006-10-10T23:59:59.000Z

295

Performance Indicators of Wind Energy Production  

E-Print Network [OSTI]

Modeling wind speed is one of the key element when dealing with the production of energy through wind turbines. A good model can be used for forecasting, site evaluation, turbines design and many other purposes. In this work we are interested in the analysis of the future financial cash flows generated by selling the electrical energy produced. We apply an indexed semi-Markov model of wind speed that has been shown, in previous investigation, to reproduce accurately the statistical behavior of wind speed. The model is applied to the evaluation of financial indicators like the Internal Rate of Return, semi-Elasticity and relative Convexity that are widely used for the assessment of the profitability of an investment and for the measurement and analysis of interest rate risk. We compare the computation of these indicators for real and synthetic data. Moreover, we propose a new indicator that can be used to compare the degree of utilization of different power plants.

D'Amico, G; Prattico, F

2015-01-01T23:59:59.000Z

296

Comparison of optically measured and radar-derived horizontal neutral winds. Master's thesis  

SciTech Connect (OSTI)

Nighttime thermospheric winds for Sondrestrom, Greenland from 11 nights between 1983 and 1988, have been compared to learn about the O(+)-O collision cross section and the high-latitude atomic oxygen density. The horizontal winds in the magnetic meridian were derived indirectly from incoherent-scatter radar (ISR) measurements on ion velocities antiparallel to the magnetic field and directly from Fabry-Perot interferometer (FPI) measurements of Doppler shifts of the (6300-A) emission of atomic oxygen. In deriving the radar winds, the O(+)-O collision cross section, was scaled by a factor of f what was varied from 0.5 to 5.1. On the basis of several arguments the altitude of the 6300-A emission was assumed to be 230 km. The best agreement between the ISR and FPI winds was obtained when f was increased substantially, to between 1.7 and 3.4. If the average peak emission altitude were higher, these factors would be larger; if it were lower, they would be somewhat smaller. However, if the average altitude were substantially lower it would have been more difficult to have obtained agreement between the two techniques.

Christie, M.S.

1990-01-01T23:59:59.000Z

297

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

E-Print Network [OSTI]

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

Cunningham, Newton William

2012-06-07T23:59:59.000Z

298

Amplitude modulation of wind turbine noise  

E-Print Network [OSTI]

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

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

299

Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves  

E-Print Network [OSTI]

Price, Attenuation of acoustic waves in glacial ice and saltacoustics, South Pole, sound speed, pressure waves,shear waves PACS: 47.35.De, 47.35.Rs, 62.65. +k, 92.40.Vq,

Klein, Spencer

2010-01-01T23:59:59.000Z

300

A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors  

E-Print Network [OSTI]

A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors

Lawrence, C B

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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.


301

Indirect Measurement Of Nitrogen In A Multi-Component Gas By Measuring The Speed Of Sound At Two States Of The Gas.  

DOE Patents [OSTI]

A methods of indirectly measuring the nitrogen concentration in a gas mixture. The molecular weight of the gas is modeled as a function of the speed of sound in the gas, the diluent concentrations in the gas, and constant values, resulting in a model equation. Regression analysis is used to calculate the constant values, which can then be substituted into the model equation. If the speed of sound in the gas is measured at two states and diluent concentrations other than nitrogen (typically carbon dioxide) are known, two equations for molecular weight can be equated and solved for the nitrogen concentration in the gas mixture.

Morrow, Thomas B. (San Antonio, TX); Behring, II, Kendricks A. (Torrance, CA)

2004-10-12T23:59:59.000Z

302

Vertical axis wind turbine  

SciTech Connect (OSTI)

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

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

1981-01-27T23:59:59.000Z

303

RELIABILITY OF WIND POWER FROM DISPERSED SITES: A PRELIMINARY ASSESSMENT  

E-Print Network [OSTI]

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

Kahn, E.

2011-01-01T23:59:59.000Z

304

Power Performance Test Report for the SWIFT Wind Turbine  

SciTech Connect (OSTI)

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

Mendoza, I.; Hur, J.

2012-12-01T23:59:59.000Z

305

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

306

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

SciTech Connect (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

307

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

308

Development of a New Flame Speed Vessel to Measure the Effect of Steam Dilution on Laminar Flame Speeds of Syngas Fuel Blends at Elevated Pressures and Temperatures  

E-Print Network [OSTI]

/s to 16.7 cm/s. The amount of carbon monoxide dilution in the fuel was shown to be the most influential factor on the laminar flame speed from fuel lean to fuel rich. This is verified by comparing the laminar flame speed of the atmospheric mixtures. Also...

Krejci, Michael

2012-07-16T23:59:59.000Z

309

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

E-Print Network [OSTI]

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

Peinke, Joachim

310

Upper Air Wind Measurements by Weather Radar Iwan Holleman, Henk Benschop, and Jitze van der Meulen  

E-Print Network [OSTI]

or assimilated into numerical weather prediction (NWP) models. Un- der the assumption of a linear wind field background statistics of the weather radar wind profiles against the Hirlam NWP model are at least as good of the VVP wind profiles against the Hirlam NWP model demonstrate the high quality of weather radar wind

Stoffelen, Ad

311

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

E-Print Network [OSTI]

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

Sweetman, Bert

312

Hurricane Katrina Wind Investigation Report  

SciTech Connect (OSTI)

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

Desjarlais, A. O.

2007-08-15T23:59:59.000Z

313

A Stochastic DEVS Wind Turbine Component Model for Wind Farm Simulation  

E-Print Network [OSTI]

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

Ding, Yu

314

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

E-Print Network [OSTI]

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

Schwarz, Katherine; Patzek, Tad; Silin, Dmitriy

2008-01-01T23:59:59.000Z

315

Error analysis of pose measurement from sonic sensors without using speed of sound information  

E-Print Network [OSTI]

and Microphones for Testing Mike Box Location. 60 4. 9 Initial Positions of Microphones. 64 4. 10 Information for Testing Effect of Distance between Transmitters on System. . 66 4. 11 Speed of Sound in Various Substances. . . 69 4. 12 Information for Testing... Transmitter c range from mike a ange frotn mike b dg, plane ab normal vector n of pl ab Microphone a poltlt 0 Microphone b Figure 3. 1: Diagram of Generation of Plane Equation. Table 3. 1: Defirdtion of Variables. tac, tb =? soundtimeof...

Lai, Chih-Chien

1999-01-01T23:59:59.000Z

316

Wind energy conversion system  

SciTech Connect (OSTI)

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

Longrigg, P.

1987-03-17T23:59:59.000Z

317

Eddy correlation measurements of the air/sea flux of dimethylsulfide over the North Pacific Ocean  

E-Print Network [OSTI]

the fluctuations in vertical wind speed and the fluctuationslabeled DMS standard and vertical wind speed. The isotope is

Marandino, C. A; De Bruyn, W. J; Miller, S. D; Saltzman, E. S

2007-01-01T23:59:59.000Z

318

Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine  

SciTech Connect (OSTI)

Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research and Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally, the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D Computational Fluid Dynamics (CFD) results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the non-dimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Medina, P.; Singh, M.; Johansen, J.; Jove, A. R.; Fingersh, L.; Schreck, S.

2012-01-01T23:59:59.000Z

319

Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine: Preprint  

SciTech Connect (OSTI)

Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3-101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research And Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D CFD results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the nondimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Medina, P.; Singh, M.; Johansen, J.; Jove, A.; Fingersh, L.; Schreck, S.

2012-01-01T23:59:59.000Z

320

Experimental and numerical study of the accuracy of flame-speed measurements for methane/air combustion in a slot burner  

SciTech Connect (OSTI)

Measuring the velocities of premixed laminar flames with precision remains a controversial issue in the combustion community. This paper studies the accuracy of such measurements in two-dimensional slot burners and shows that while methane/air flame speeds can be measured with reasonable accuracy, the method may lack precision for other mixtures such as hydrogen/air. Curvature at the flame tip, strain on the flame sides and local quenching at the flame base can modify local flame speeds and require corrections which are studied using two-dimensional DNS. Numerical simulations also provide stretch, displacement and consumption flame speeds along the flame front. For methane/air flames, DNS show that the local stretch remains small so that the local consumption speed is very close to the unstretched premixed flame speed. The only correction needed to correctly predict flame speeds in this case is due to the finite aspect ratio of the slot used to inject the premixed gases which induces a flow acceleration in the measurement region (this correction can be evaluated from velocity measurement in the slot section or from an analytical solution). The method is applied to methane/air flames with and without water addition and results are compared to experimental data found in the literature. The paper then discusses the limitations of the slot-burner method to measure flame speeds for other mixtures and shows that it is not well adapted to mixtures with a Lewis number far from unity, such as hydrogen/air flames. (author)

Selle, L.; Ferret, B. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); Poinsot, T. [Universite de Toulouse, INPT, UPS, IMFT, Institut de Mecanique des Fluides de Toulouse (France); CNRS, IMFT, Toulouse (France); CERFACS, Toulouse (France)

2011-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Vertical axis wind turbine  

SciTech Connect (OSTI)

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

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

1981-01-27T23:59:59.000Z

322

Development and Validation of an Aeroelastic Model of a Small Furling Wind Turbine: Preprint  

SciTech Connect (OSTI)

Small wind turbines often use some form of furling (yawing and/or tilting out of the wind) to protect against excessive power generation and rotor speeds in high winds.The verification study demonstrated the correct implementation of FAST's furling dynamics. During validation, the model tends to predict mean rotor speeds higher than measured in spite of the fact that the mean furl motion and rotor thrust are predicted quite accurately. This work has culminated with an enhanced version of FAST that should prove to be a valuable asset to designers of small wind turbines.

Jonkman, J. M.; Hansen, A. C.

2004-12-01T23:59:59.000Z

323

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

SciTech Connect (OSTI)

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

Fripp, Matthias; Wiser, Ryan

2006-05-31T23:59:59.000Z

324

An evaluation of operating speed reduction as a surrogate measure for accident experience on horizontal curves on two-lane rural highways  

E-Print Network [OSTI]

AN EVALUATION OF OPERATING SPEED REDUCTION AS A SURROGATE MEASURE FOR ACCIDENT EXPERIENCE ON HORIZONTAL CURVES ON TWO-LANE RURAL HIGHWAYS A Thesis by INGRID BERNICE ANDERSON Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1993 Major Subject: Civil Engineering AN EVALUATION OF OPERATING SPEED REDUCTION AS A SURROGATE MEASURE OF ACCIDENT EXPERIENCE ON HORIZONTAL CURVES ON TWO-LANE RURAL...

Anderson, Ingrid Bernice

1993-01-01T23:59:59.000Z

325

Surface-Layer Wind and Turbulence Profiling from LIDAR: Theory and Measurements  

E-Print Network [OSTI]

turbines become taller wind energy assessment and also turbine control require knowledge of the detailed calibrated cup anemometers in tall met-towers, wind data from remote-sensing instrumentation, such as SODARS, in particular for use in connection with power curve reference and wind turbine certification purposes. However

326

WIND ENERGY Wind Energ. 2013; 00:112  

E-Print Network [OSTI]

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

327

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

SciTech Connect (OSTI)

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

328

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

SciTech Connect (OSTI)

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

329

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

SciTech Connect (OSTI)

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

Robichaud, R.

2014-09-01T23:59:59.000Z

330

Reading profiles for adults with low-literacy: Cluster analysis with power and speeded measures  

E-Print Network [OSTI]

adult literacy services. We selected seven measures from a batery of asesments administered in this study to test our hypothesis. Next, we applied Morris, Stuebing, Fletcher, Shaywitz, Lyon, Shankweiler, et al.s (1998) clasification research...

Mellard, Daryl; Fall, Emily C.; Mark, Caroline Ann

2009-01-01T23:59:59.000Z

331

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

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

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

332

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

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

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

Coulter, Richard; Ritsche, Michael

333

Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO.206) Track: Technical  

E-Print Network [OSTI]

Session: Poster Session + Poster Award + Scientific Award + Excellent young wind doctor award (PO the erection of masts equipped with calibrated cup or sonic anemometers. In order to reduce costs associated, the mean horizontal wind speed measured with a LiDAR shows very good comparison to cup anemometers. However

334

The effect of imbalance distribution and measurement locations on critical speeds in a turboprop engine rotor  

E-Print Network [OSTI]

Imbalance Response at RY aud RX. imbalance Mass at tbe Coupling) 35 6 a. d 5 CL E 0 1IXXI 2000 3000 ?XXI SXm 6000 7OIXI SXXI 9000 10000111XXI12000 IXXXI1400016000 Spddd &rpm& TX 6 d N 'E 5 Ol 4 O. E 3 D 1000 2CCO 3000 4XXI SOXI 6000 7000.... 000- sa 0. 500? N "O. 00O E 0 0 Z 41 500 -' 2 4 8 10 12 14 16 18 20 24 26 Axial Location measured from the coupling (in) Figure 6. Measured Free-Free Vibration Frequency Spectrum and Mode Shape for Gas Generator Spool - 16 Maae Oot Date A CHI...

Marin, Manuel

2012-06-07T23:59:59.000Z

335

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

E-Print Network [OSTI]

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

Mansbach, David K.

2010-01-01T23:59:59.000Z

336

Large Area Divertor Temperature Measurements Using A High-speed Camera With Near-infrared FiIters in NSTX  

SciTech Connect (OSTI)

Fast cameras already installed on the National Spherical Torus Experiment (NSTX) have be equipped with near-infrared (NIR) filters in order to measure the surface temperature in the lower divertor region. Such a system provides a unique combination of high speed (> 50 kHz) and wide fi eld-of-view (> 50% of the divertor). Benchtop calibrations demonstrated the system's ability to measure thermal emission down to 330 oC. There is also, however, signi cant plasma light background in NSTX. Without improvements in background reduction, the current system is incapable of measuring signals below the background equivalent temperature (600 - 700 oC). Thermal signatures have been detected in cases of extreme divertor heating. It is observed that the divertor can reach temperatures around 800 oC when high harmonic fast wave (HHFW) heating is used. These temperature profiles were fi t using a simple heat diffusion code, providing a measurement of the heat flux to the divertor. Comparisons to other infrared thermography systems on NSTX are made.

Lyons, B C; Zweben, S J; Gray, T K; Hosea, J; Kaita, R; Kugel, H W; Maqueda, R J; McLean, A G; Roquemore, A L; Soukhanovskii, V A

2011-04-05T23:59:59.000Z

337

A13G-0330: Evaluation of 3-dimensional winds measured by the Aircraft Integrated Meteorological Measurement System (AIMMS) Christopher G Kruse, David J Delene, and Cedric Grainger, University of North Dakota (christopher.kruse@und.edu)  

E-Print Network [OSTI]

A13G-0330: Evaluation of 3-dimensional winds measured by the Aircraft Integrated Meteorological, and IMU to derive the winds. The IMU and CPU were mounted in the cabin, the ADP was mounted under The time intervals and mean magnitude of vertical wind during the straight and level and porpoise maneuvers

Delene, David J.

338

X-ray Spectral Measurements of the Most Massive Stars: Stellar Wind Mass-Loss Rates and Shock Physics  

E-Print Network [OSTI]

X-ray Spectral Measurements of the Most Massive Stars: Stellar Wind Mass-Loss Rates and Shock/Themes: Significant technological advances in X-ray astronomy have driven discovery over the last few decades. New. The priorities at Swarthmore have allowed me to do careful work on the small number of X-ray spectral datasets

Cohen, David

339

Proposed method for high-speed plasma density measurement in proton-driven plasma wakefield acceleration  

SciTech Connect (OSTI)

Recently a proton-bunch-driven plasma wakefield acceleration experiment using the CERN-SPS beam was proposed. Different types of plasma cells are under study, especially laser ionization, plasma discharge, and helicon sources. One of the key parameters is the spatial uniformity of the plasma density profile along the cell that has to be within < 1% of the nominal density (6 Multiplication-Sign 10{sup 14} cm{sup -3}). Here a setup based on a photomixing concept is proposed to measure the plasma cut-off frequency and determine the plasma density.

Tarkeshian, R.; Reimann, O.; Muggli, P. [Max-Planck-Institut fuer Physik, 80805 Munich (Germany)

2012-12-21T23:59:59.000Z

340

Measurements of air-sea gas exchange at high wind speeds in the Southern Ocean: Implications for global parameterizations  

E-Print Network [OSTI]

August 2006. [1] The SOLAS Air-Sea Gas Exchange (SAGE) Experiment was conducted in the western Pacific of air-sea gas exchange. Globally, the dominant control of air-sea gas exchange is turbulent energy as the primary source of energy for the atmospheric and oceanic molecular boundary layers have been derived from

Ho, David

Note: This page contains sample records for the topic "measure 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

Low-noise, high-speed detector development for optical turbulence fluctuation measurements for NSTX  

SciTech Connect (OSTI)

A new beam emission spectroscopy (BES) diagnostic is under development. Photon-noise limited measurements of neutral beam emissions are achieved using photoconductive photodiodes with a novel frequency-compensated broadband preamplifier. The new BES system includes a next-generation preamplifier and upgraded optical coupling system. Notable features of the design are surface-mount components, minimized stray capacitance, a wide angular acceptance photodiode, a differential output line driver, reduced input capacitance, doubling of the frequency range, net reduced electronic noise, and elimination of the need for a cryogenic cooling system. The irreducible photon noise dominates the noise up to 800 kHz for a typical input power of 60 nW. This new assembly is being integrated into an upgraded multichannel optical detector assembly for a new BES system on the NSTX experiment.

Schoenbeck, N. L.; Fonck, R. J.; McKee, G. R.; Smith, D.; Uzun-Kaymak, I. U.; Winz, G. [Department of Engineering Physics, University of Wisconsin-Madison, Wisconsin 53706 (United States); Ellington, S. D. [Space Science and Engineering Center, University of Wisconsin-Madison, Wisconsin 53706 (United States); Jaehnig, K. [Department of Astronomy, University of Wisconsin-Madison, Wisconsin 53706 (United States)

2010-10-15T23:59:59.000Z

342

Modeling of wind farm controllers Poul Srensen1  

E-Print Network [OSTI]

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

343

A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.  

SciTech Connect (OSTI)

The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

Lu, Louise [University of Michigan, Ann Arbor, MI; Sick, Volker [University of Michigan, Ann Arbor, MI; Frank, Jonathan H.

2013-09-01T23:59:59.000Z

344

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

E-Print Network [OSTI]

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

Genton, Marc G.

2012-01-01T23:59:59.000Z

345

Aerodynamic and Performance Measurements on a SWT-2.3-101 Wind Turbine  

SciTech Connect (OSTI)

This paper provides an overview of a detailed wind turbine field experiment being conducted at NREL under U.S. Department of Energy sponsorship. The purpose of the experiment is to obtain knowledge about the aerodynamics, performance, noise emission and structural characteristics of the Siemens SWT-2.3-101 wind turbine.

Medina, P.; Singh, M.; Johansen, J.; Jove, A.R.; Machefaux, E.; Fingersh, L. J.; Schreck, S.

2011-10-01T23:59:59.000Z

346

accretion disk winds: Topics by E-print Network  

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

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

347

accretion disk wind: Topics by E-print Network  

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

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

348

Design of PM generator for avertical axis wind turbine.  

E-Print Network [OSTI]

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

Rynkiewicz, Mateusz

2012-01-01T23:59:59.000Z

349

Description of the Columbia Basin Wind Energy Study (CBWES)  

SciTech Connect (OSTI)

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

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

2012-10-01T23:59:59.000Z

350

Sound speed and thermal property measurements of inert materials: laser spectroscopy and the diamond-anvil cell  

SciTech Connect (OSTI)

An indispensable companion to dynamical physics experimentation, static high-pressure diamond-anvil cell research continues to evolve, with laser diagnostic, as an accurate and versatile experimental deep planetary properties have bootstrapped each other in a process that has produced even higher pressures; consistently improved calibrations of temperature and pressure under static and dynamic conditions; and unprecedented data and understanding of materials, their elasticity, equations of state (EOS), and transport properties under extreme conditions. A collection of recent pressure and/or temperature dependent acoustic and thermal measurements and deduced mechanical properties and EOS data are summarized for a wide range of materials including H2, H2O, H2S, D2S, CO2, CH4, N2O, CH3OH,, SiO2, synthetic lubricants, PMMA, single crystal silicates, and ceramic superconductors. Room P&T sound speed measurements are presented for the first time on single crystals of beta-HMX. New high-pressure and temperature diamond cell designed and pressure calibrant materials are reviewed.

Zaug, J.M.

1997-07-01T23:59:59.000Z

351

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

352

agb stellar winds: Topics by E-print Network  

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

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

353

Wind motor applications for transportation  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

354

Turbine Inflow Characterization at the National Wind Technology Center: Preprint  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

355

Turbine Inflow Characterization at the National Wind Technology Center  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

356

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

SciTech Connect (OSTI)

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

Simms, D A; Butterfield, C P

1991-10-01T23:59:59.000Z

357

Wind Resource Assessment of Gujarat (India)  

SciTech Connect (OSTI)

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

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

2014-07-01T23:59:59.000Z

358

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

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

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

359

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

360

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

E-Print Network [OSTI]

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

Mansbach, David K.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Ris R 1068EN Extreme Winds  

E-Print Network [OSTI]

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

362

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

363

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

364

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

E-Print Network [OSTI]

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

365

Using satellite data for mapping offshore wind resources and wakes  

E-Print Network [OSTI]

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

366

SAT-WIND project Final report  

E-Print Network [OSTI]

-2840 ISBN 87-550-3570-1 The SAT-WIND project `Winds from satellites for offshore and coastal wind energy) technologies for wind energy tools for wind resources and wind-indexing. The study area was the Danish Seas microwave polarimetric 223.3.1 History 3.3.2 Measurement principle 22 223.3.3 WindSat (passive microwave

367

Measurement and Numerical Simulation of Wind Environment for One Residential District  

E-Print Network [OSTI]

A residential quarter in the west of Changsha has a nearby main transport corridor to the east,and Tianma Hill is to the west. The circumference of this residential quarter is open to the outside; therefore, the wind environment is special...

Li, C.; Li, N.

2006-01-01T23:59:59.000Z

368

Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel  

E-Print Network [OSTI]

rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results...

Meng, Q.; Zhang, Y.; Zhang, L.

2006-01-01T23:59:59.000Z

369

Natural Ventilation in Buildings: Measurement in a Wind Tunnel and Numerical Simulation with Large Eddy Simulation  

E-Print Network [OSTI]

save energy compared to mechanical ventilation systems. In building design the prediction save energy consumed by the heating, ventilating, and air- conditioning systems in a building. In a naturally ventilated building, air is driven in and out due to pressure differences produced by wind

Chen, Qingyan "Yan"

370

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

SciTech Connect (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

371

Dynamic analysis of a 5 megawatt offshore floating wind turbine  

E-Print Network [OSTI]

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

Harriger, Evan Michael

2011-01-01T23:59:59.000Z

372

Global ocean wind power sensitivity to surface layer stability  

E-Print Network [OSTI]

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

Capps, Scott B; Zender, Charles S

2009-01-01T23:59:59.000Z

373

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

E-Print Network [OSTI]

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

Cameron, Iain Dickson

2008-01-01T23:59:59.000Z

374

Characterizing Inflow Conditions Across the Rotor Disk of a Utility-Scale Wind Turbine (Poster)  

SciTech Connect (OSTI)

Multi-megawatt utility-scale wind turbines operate in a turbulent, thermally-driven atmosphere where wind speed and air temperature vary with height. Turbines convert the wind's momentum into electrical power, and so changes in the atmosphere across the rotor disk influence the power produced by the turbine. To characterize the inflow into utility scale turbines at the National Wind Technology Center (NWTC) near Boulder, Colorado, NREL recently built two 135-meter inflow monitoring towers. This poster introduces the towers and the measurements that are made, showing some of the data obtained in the first few months of operation in 2011.

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

2012-01-01T23:59:59.000Z

375

Wind farm electrical system  

DOE Patents [OSTI]

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

Erdman, William L.; Lettenmaier, Terry M.

2006-07-04T23:59:59.000Z

376

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

377

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

378

Effect of Blending on High-Pressure Laminar Flame Speed Measurements, Markstein Lengths, and Flame Stability of Hydrocarbons  

E-Print Network [OSTI]

for pure fuels and their blends for laminar flame speed and high-temperature shock-tube and low-temperature RCM ignition target data (Lowry et al., 2010a; Petersen et al., 2007; Healy et al., 2008a, 2008b), for the laminar flame speed of pure DME... enthalpy (KJ/kg) Le Lewis Number g1865g4662 " Mass burning rate per unit area (kg/m2-s) g1839g3050 Molecular weight (kg/kmol) X Mole fraction (kmol/kmol) g1851 Mass fraction (kg/kg) Subscripts b Burned condition i For species i L Laminar flame u...

Lowry, William Baugh

2012-02-14T23:59:59.000Z

379

CALIBRATION OF AND ATTITUDE ERROR ESTIMATION FOR A SPACEBORNE SCATTEROMETER USING MEASUREMENTS OVER LAND  

E-Print Network [OSTI]

of ocean wind speed and direction. Scatterometers must be calibrated before their measurements are scienti in the long-term, thus propelling them out of the crowded valley of the common and up the inclines

Long, David G.

380

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

E-Print Network [OSTI]

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

Kay, J.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Sensitivity of the wind stress and storm surges to surface drag  

E-Print Network [OSTI]

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

Vries, Hans de

382

Distributed Wind Energy in Idaho  

SciTech Connect (OSTI)

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. â?¢ 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. â?¢ 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. â?¢ 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 windâ??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

383

Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity  

E-Print Network [OSTI]

mixing ratios and vertical wind speed plotted as a functionPanel: De-trended vertical wind speed (blue) and toluene (between toluene and vertical wind speed. Dashed curve

Karl, T.; Apel, E.; Hodzic, A.; Riemer, D. D; Blake, D. R; Wiedinmyer, C.

2009-01-01T23:59:59.000Z

384

Aleutian Pribilof Islands Wind Energy Feasibility Study  

SciTech Connect (OSTI)

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

Bruce A. Wright

2012-03-27T23:59:59.000Z

385

In situ measurements of Krypton in Xenon gas with a quadrupole mass spectrometer following a cold-trap at a temporarily reduced pumping speed  

E-Print Network [OSTI]

A new method for measuring trace amounts of krypton in xenon using a cold trap with a residual gas analyzer has been developed, which achieves an increased sensitivity by temporarily reducing the pumping speed while expending a minimal amount of xenon. By partially closing a custom built butterfly valve between the measurement chamber and the turbomolecular pump, a sensitivity of 40 ppt has been reached. This method has been tested on an ultra-pure gas sample from Air Liquide with an unknown intrinsic krypton concentration, yielding a krypton concentration of $330 \\pm 200$ ppt.

Ethan Brown; Stephan Rosendahl; Christian Huhmann; Christian Weinheimer; Hans Kettling

2012-12-20T23:59:59.000Z

386

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

E-Print Network [OSTI]

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

387

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

E-Print Network [OSTI]

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

Drobinski, Philippe

2012-01-01T23:59:59.000Z

388

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

E-Print Network [OSTI]

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

Pryor, Sara C.

389

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

390

PSO (FU 2101) Ensemble-forecasts for wind power  

E-Print Network [OSTI]

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

391

Wind Farm Power Prediction: A Data-Mining Approach  

E-Print Network [OSTI]

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

Kusiak, Andrew

392

RisR1238(EN) Extreme Winds over Denmark  

E-Print Network [OSTI]

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

393

A study of clear-air turbulence from detailed wind profiles over Cape Kennedy, Florida  

E-Print Network [OSTI]

versus lapse rate of temperature for obser- vations of CAT (rms-r a 0. 85 mps) over the 250-m, 500-m, and 1000-m layers. . . . . . . . . . . . 31 Profile of wind speed measured by the FPS-16 radar/Jimsphere system over Cape Kennedy, Florida. LIST... profiles to mean meteorological para- meters. Detailed wind profiles, measured by the FPS-16 radar/ Jimsphere system, and rawinsonde profiles are the main sources of data. The Jimsphere balloon was developed to furnish a wind sensor that would give...

Blackburn, James Harvey

2012-06-07T23:59:59.000Z

394

Optimum propeller wind turbines  

SciTech Connect (OSTI)

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

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

1983-11-01T23:59:59.000Z

395

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

396

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

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

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

397

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

398

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

Energy Savers [EERE]

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

399

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

E-Print Network [OSTI]

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

Stanford University

400

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

Note: This page contains sample records for the topic "measure 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

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

402

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

E-Print Network [OSTI]

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

Mark, Pinsky

403

Real-time solar wind prediction based on SDO/AIA coronal hole data  

E-Print Network [OSTI]

We present an empirical model based on the visible area covered by coronal holes close to the central meridian in order to predict the solar wind speed at 1 AU with a lead time up to four days in advance with a 1hr time resolution. Linear prediction functions are used to relate coronal hole areas to solar wind speed. The function parameters are automatically adapted by using the information from the previous 3 Carrington Rotations. Thus the algorithm automatically reacts on the changes of the solar wind speed during different phases of the solar cycle. The adaptive algorithm has been applied to and tested on SDO/AIA-193A observations and ACE measurements during the years 2011-2013, covering 41 Carrington Rotations. The solar wind speed arrival time is delayed and needs on average 4.02 +/- 0.5 days to reach Earth. The algorithm produces good predictions for the 156 solar wind high speed streams peak amplitudes with correlation coefficients of cc~0.60. For 80% of the peaks, the predicted arrival matches within ...

Rotter, T; Temmer, M; Vrsnak, B

2015-01-01T23:59:59.000Z

404

Wind derivatives: hedging wind risk:.  

E-Print Network [OSTI]

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

Hoyer, S.A.

2013-01-01T23:59:59.000Z

405

Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic...  

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

Estimating the Wind Resource in Uttarakhand: Comparison of Dynamic Downscaling with Doppler Lidar Wind Measurements Estimating the Wind Resource in Uttarakhand: Comparison of...

406

Convective heat transfer on leeward building walls in an urban environment: Measurements in an outdoor scale model  

E-Print Network [OSTI]

layer wind speed (height 2H) and the vertical velocity nearthe horizontal wind speed at 2H and the average verticalvertical error bars indicate the magnitude of the UC wind speed

Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.

2011-01-01T23:59:59.000Z

407

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

E-Print Network [OSTI]

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

2011-01-01T23:59:59.000Z

408

Determining Wind Turbine Gearbox Model Complexity Using Measurement Validation and Cost Comparison: Preprint  

SciTech Connect (OSTI)

The Gearbox Reliability Collaborative (GRC) has conducted extensive field and dynamometer test campaigns on two heavily instrumented wind turbine gearboxes. In this paper, data from the planetary stage is used to evaluate the accuracy and computation time of numerical models of the gearbox. First, planet-bearing load and motion data is analyzed to characterize planetary stage behavior in different environments and to derive requirements for gearbox models and life calculations. Second, a set of models are constructed that represent different levels of fidelity. Simulations of the test conditions are compared to the test data and the computational cost of the models are compared. The test data suggests that the planet-bearing life calculations should be made separately for each bearing on a row due to unequal load distribution. It also shows that tilting of the gear axes is related to planet load share. The modeling study concluded that fully flexible models were needed to predict planet-bearing loading in some cases, although less complex models were able to achieve good correlation in the field-loading case. Significant differences in planet load share were found in simulation and were dependent on the scope of the model and the bearing stiffness model used.

LaCava, W.; Xing, Y.; Guo, Y.; Moan, T.

2012-04-01T23:59:59.000Z

409

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

E-Print Network [OSTI]

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

Yanikoglu, Berrin

410

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

411

Measurements and computations of second-mode instability waves in three hypersonic wind tunnels.  

SciTech Connect (OSTI)

High-frequency pressure-fluctuation measurements were made in AEDC Tunnel 9 at Mach 10 and the NASA Langley 15-Inch Mach 6 and 31-Inch Mach 10 tunnels. Measurements were made on a 7{sup o}-half-angle cone model. Pitot measurements of freestream pressure fluctuations were also made in Tunnel 9 and the Langley Mach-6 tunnel. For the first time, second-mode waves were measured in all of these tunnels, using 1-MHz-response pressure sensors. In Tunnel 9, second-mode waves could be seen in power spectra computed from records as short as 80 {micro}s. The second-mode wave amplitudes were observed to saturate and then begin to decrease in the Langley tunnels, indicating wave breakdown. Breakdown was estimated to occur near N {approx} 5 in the Langley Mach-10 tunnel. The unit-Reynolds-number variations in the data from Tunnel 9 were too large to see the same processes.

Lewis, Daniel R. (Aerospace Testing Alliance, Silver Spring, MD); Alba, Christopher R. (Air Force Research Laboratory, Wright-Patterson AFB, OH); Rufer, Shann J. (NASA Langley Research Center, Hampton, VA); Beresh, Steven Jay; Casper, Katya M.; Berridge, Dennis C. (Purdue University, West Lafayette, IN); Schneider, Steven P. (Purdue University, West Lafayette, IN)

2010-06-01T23:59:59.000Z

412

Offshore wind resource assessment through satellite images  

E-Print Network [OSTI]

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

413

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

E-Print Network [OSTI]

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

Pota, Himanshu Roy

414

Inverse Load Calculation of Wind Turbine Support Structures - A Numerical Verification Using the Comprehensive Simulation Code FAST: Preprint (Revised)  

SciTech Connect (OSTI)

Physically measuring the dynamic responses of wind turbine support structures enables the calculation of the applied loads using an inverse procedure. In this process, inverse means deriving the inputs/forces from the outputs/responses. This paper presents results of a numerical verification of such an inverse load calculation. For this verification, the comprehensive simulation code FAST is used. FAST accounts for the coupled dynamics of wind inflow, aerodynamics, elasticity and turbine controls. Simulations are run using a 5-MW onshore wind turbine model with a tubular tower. Both the applied loads due to the instantaneous wind field and the resulting system responses are known from the simulations. Using the system responses as inputs to the inverse calculation, the applied loads are calculated, which in this case are the rotor thrust forces. These forces are compared to the rotor thrust forces known from the FAST simulations. The results of these comparisons are presented to assess the accuracy of the inverse calculation. To study the influences of turbine controls, load cases in normal operation between cut-in and rated wind speed, near rated wind speed and between rated and cut-out wind speed are chosen. The presented study shows that the inverse load calculation is capable of computing very good estimates of the rotor thrust. The accuracy of the inverse calculation does not depend on the control activity of the wind turbine.

Pahn, T.; Jonkman, J.; Rolges, R.; Robertson, A.

2012-11-01T23:59:59.000Z

415

Wind power generating system  

SciTech Connect (OSTI)

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

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

1985-03-12T23:59:59.000Z

416

Acoustic Noise Test Report for the Viryd CS8 Wind Turbine  

SciTech Connect (OSTI)

This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the Viryd CS8 is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and binning by wind speed instead of regression analysis.

Roadman, J.; Huskey, A.

2013-07-01T23:59:59.000Z

417

Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO  

SciTech Connect (OSTI)

This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the SWIFT is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and utilized binning by wind speed instead of regression analysis.

Roadman, J.; Huskey, A.

2013-04-01T23:59:59.000Z

418

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

E-Print Network [OSTI]

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

Beard, Daniel Walker

1984-01-01T23:59:59.000Z

419

Solar Wind Forecasting with Coronal Holes  

E-Print Network [OSTI]

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

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

2007-01-09T23:59:59.000Z

420

Characterization of condenser microphones under different environmental conditions for accurate speed of sound measurements with acoustic resonators  

SciTech Connect (OSTI)

Condenser microphones are more commonly used and have been extensively modeled and characterized in air at ambient temperature and static pressure. However, several applications of interest for metrology and physical acoustics require to use these transducers in significantly different environmental conditions. Particularly, the extremely accurate determination of the speed of sound in monoatomic gases, which is pursued for a determination of the Boltzmann constant k by an acoustic method, entails the use of condenser microphones mounted within a spherical cavity, over a wide range of static pressures, at the temperature of the triple point of water (273.16 K). To further increase the accuracy achievable in this application, the microphone frequency response and its acoustic input impedance need to be precisely determined over the same static pressure and temperature range. Few previous works examined the influence of static pressure, temperature, and gas composition on the microphone's sensitivity. In this work, the results of relative calibrations of 1/4 in. condenser microphones obtained using an electrostatic actuator technique are presented. The calibrations are performed in pure helium and argon gas at temperatures near 273 K and in the pressure range between 10 and 600 kPa. These experimental results are compared with the predictions of a realistic model available in the literature, finding a remarkable good agreement. The model provides an estimate of the acoustic impedance of 1/4 in. condenser microphones as a function of frequency and static pressure and is used to calculate the corresponding frequency perturbations induced on the normal modes of a spherical cavity when this is filled with helium or argon gas.

Guianvarc'h, Cecile; Pitre, Laurent [Laboratoire Commun de Metrologie LNE/Cnam, 61 rue du Landy, 93210 La Plaine Saint Denis (France); Gavioso, Roberto M.; Benedetto, Giuliana [Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Turin (Italy); Bruneau, Michel [Laboratoire d'Acoustique de l'Universite du Maine UMR CNRS 6613, av. Olivier Messiaen, 72085 Le Mans Cedex 9 (France)

2009-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

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

SciTech Connect (OSTI)

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

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

1982-06-01T23:59:59.000Z

422

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

E-Print Network [OSTI]

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

Belanger, David P.

423

Simulated performance of an airborne lidar wind shear detection system  

E-Print Network [OSTI]

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

Griffith, Kenneth Scott

2012-06-07T23:59:59.000Z

424

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

SciTech Connect (OSTI)

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

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

2014-04-09T23:59:59.000Z

425

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

E-Print Network [OSTI]

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

Boyer, Edmond

426

Pitfalls of modeling wind power using Markov chains  

E-Print Network [OSTI]

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

Kirtley, James L., Jr.

427

Simulation and Optimization of Wind Farm Operations under Stochastic Conditions  

E-Print Network [OSTI]

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

Byon, Eunshin

2011-08-08T23:59:59.000Z

428

Ris National Laboratory Satellite SAR applied in offshore wind  

E-Print Network [OSTI]

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

429

Dynamic Simulation of DFIG Wind Turbines on FPGA Boards  

E-Print Network [OSTI]

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

Zambreno, Joseph A.

430

Cambridge Danehy Park Wind Turbine Preliminary Project Assessment  

E-Print Network [OSTI]

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

431

WIND ENERGY Wind Energ. (2014)  

E-Print Network [OSTI]

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

Peinke, Joachim

432

Final Project Report, Bristol Bay Native Corporation Wind and Hydroelectric Feasibility Study  

SciTech Connect (OSTI)

The Bristol Bay Native Corporation (BBNC) grant project focused on conducting nine wind resource studies in eight communities in the Bristol Bay region of southwest Alaska and was administered as a collaborative effort between BBNC, the Alaska Energy Authority, Alaska Village Electric Cooperative, Nushagak Electric Cooperative (NEC), Naknek Electric Association (NEA), and several individual village utilities in the region. BBNCs technical contact and the project manager for this study was Douglas Vaught, P.E., of V3 Energy, LLC, in Eagle River, Alaska. The Bristol Bay region of Alaska is comprised of 29 communities ranging in size from the hub community of Dillingham with a population of approximately 3,000 people, to a few Native Alaska villages that have a few tens of residents. Communities chosen for inclusion in this project were Dillingham, Naknek, Togiak, New Stuyahok, Kokhanok, Perryville, Clarks Point, and Koliganek. Selection criteria for conduction of wind resource assessments in these communities included population and commercial activity, utility interest, predicted Class 3 or better wind resource, absence of other sources of renewable energy, and geographical coverage of the region. Beginning with the first meteorological tower installation in October 2003, wind resource studies were completed at all sites with at least one year, and as much as two and a half years, of data. In general, the study results are very promising for wind power development in the region with Class 6 winds measured in Kokhanok; Class 4 winds in New Stuyahok, Clarks Point, and Koliganek; Class 3 winds in Dillingham, Naknek, and Togiak; and Class 2 winds in Perryville. Measured annual average wind speeds and wind power densities at the 30 meter level varied from a high of 7.87 meters per second and 702 watts per square meter in Kokhanok (Class 6 winds), to a low of 4.60 meters per second and 185 watts per square meter in Perryville (Class 2 winds).

Vaught, Douglas J.

2007-03-31T23:59:59.000Z

433

Analysis of wind turbine vibrations based on SCADA data  

E-Print Network [OSTI]

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

Andrew Kusiak; Zijun Zhang

2010-01-01T23:59:59.000Z

434

Wind Spires as an Alternative Energy Source  

SciTech Connect (OSTI)

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

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

2012-10-30T23:59:59.000Z

435

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

E-Print Network [OSTI]

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

Hu, Weihao

436

Concept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D sonic anemometer  

E-Print Network [OSTI]

comparable potential. Wind measurements on wind turbines in undisturbed wind, relative to nacelle anemometryConcept tests: Wind tunnel tests in controlled wind Comparison tests: Free field comparison to 3D" by CFD calculations Spinner AnemometrySpinner Anemometry -- An Innovative Wind Measurement Concept

437

Stability Improvement of Wind Farms using Shunt and Series Compensation  

E-Print Network [OSTI]

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

Pota, Himanshu Roy

438

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

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

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

439

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

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

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

440

Wind Power Plant Voltage Stability Evaluation: Preprint  

SciTech Connect (OSTI)

Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

Muljadi, E.; Zhang, Y. C.

2014-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Review of Wind Energy Forecasting Methods for Modeling Ramping Events  

SciTech Connect (OSTI)

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

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

2011-03-28T23:59:59.000Z

442

ARM - Measurement - Horizontal wind  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Related InformationAciddroplet size

443

915-MHz Radar Wind Profiler (915RWP) Handbook  

SciTech Connect (OSTI)

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

Coulter, R

2005-01-01T23:59:59.000Z

444

The dominant X-ray wind in massive star binaries  

E-Print Network [OSTI]

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

J. M. Pittard; I. R. Stevens

2002-04-15T23:59:59.000Z

445

WIND ENERGY Wind Energ. (2014)  

E-Print Network [OSTI]

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

2014-01-01T23:59:59.000Z

446

SPRING 2014 wind energy's impact  

E-Print Network [OSTI]

SPRING 2014 wind energy's impact on birds, bats......... 2-3 school news........... 4-5 alumni news measurable benefits reaped by the use of wind energy. But, it is a fact: all energy sources, alternative Interactions with Offshore Wind Energy Facilities," involves the design, deployment and testing

Tullos, Desiree

447

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

448

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

E-Print Network [OSTI]

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

Pota, Himanshu Roy

449

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

450

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

E-Print Network [OSTI]

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

Kusiak, Andrew

451

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

E-Print Network [OSTI]

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

Long, David G.

452

NIST BUILDING SCIENCE SERIES 180 Database-Assisted Design for Wind  

E-Print Network [OSTI]

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

453

MEASUREMENT AND CORRECTION OF ULTRASONIC ANEMOMETER ERRORS  

E-Print Network [OSTI]

commonly show systematic errors depending on wind speed due to inaccurate ultrasonic transducer mounting three- dimensional wind speed time series. Results for the variance and power spectra are shown. 1 wind speeds with ultrasonic anemometers: The measu- red flow is distorted by the probe head

Heinemann, Detlev

454

Measurement of Turbulent Flame Speeds of Hydrogen and Natural Gas Blends (C1-C5 Alkanes) using a Newly Developed Fan-Stirred Vessel  

E-Print Network [OSTI]

in displacement speeds were observed for blends of NG2/H_(2) and CH_(4)/H_(2), thus validating the newly established experimental technique. Additionally, turbulent flame speeds of hydrogen and a generic, high-hydrogen-content syngas blend (50:50 H_(2):CO) were...

Ravi, Sankaranarayana

2014-05-06T23:59:59.000Z

455

The solar wind in the outer heliosphere  

E-Print Network [OSTI]

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

Richardson, John D.

456

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

SciTech Connect (OSTI)

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

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

1981-05-01T23:59:59.000Z

457

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

E-Print Network [OSTI]

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

Hoen, Ben

2010-01-01T23:59:59.000Z

458

High-Speed Shaft Bearing Loads Testing and Modeling in the NREL Gearbox Reliability Collaborative: Preprint  

SciTech Connect (OSTI)

Bearing failures in the high speed output stage of the gearbox are plaguing the wind turbine industry. Accordingly, the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) has performed an experimental and theoretical investigation of loads within these bearings. The purpose of this paper is to describe the instrumentation, calibrations, data post-processing and initial results from this testing and modeling effort. Measured HSS torque, bending, and bearing loads are related to model predictions. Of additional interest is examining if the shaft measurements can be simply related to bearing load measurements, eliminating the need for invasive modifications of the bearing races for such instrumentation.

McNiff, B.; Guo, Y.; Keller, J.; Sethuraman, L.

2014-12-01T23:59:59.000Z

459

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

E-Print Network [OSTI]

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

Reading, University of

460

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

E-Print Network [OSTI]

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

Haak, Hein

Note: This page contains sample records for the topic "measure 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

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

462

Interfacial temperature measurements, high-speed visualization and finite-element simulations of droplet impact and evaporation on a solid surface  

E-Print Network [OSTI]

The objective of this work is to investigate the coupling of fluid dynamics, heat transfer and mass transfer during the impact and evaporation of droplets on a heated solid substrate. A laser-based thermoreflectance method is used to measure the temperature at the solid-liquid interface, with a time and space resolution of 100 {\\mu}s and 20 {\\mu}m, respectively. Isopropanol droplets with micro- and nanoliter volumes are considered. A finite-element model is used to simulate the transient fluid dynamics and heat transfer during the droplet deposition process, considering the dynamics of wetting as well as Laplace and Marangoni stresses on the liquid-gas boundary. For cases involving evaporation, the diffusion of vapor in the atmosphere is solved numerically, providing an exact boundary condition for the evaporative flux at the droplet-air interface. High-speed visualizations are performed to provide matching parameters for the wetting model used in the simulations. Numerical and experimental results are compar...

Bhardwaj, Rajneesh; Attinger, Daniel

2010-01-01T23:59:59.000Z

463

WindTurbineGenerator Introduction of the Renewable Micro-Grid Test-Bed  

E-Print Network [OSTI]

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

Johnson, Eric E.

464

Understanding Inertial and Frequency Response of Wind Power Plants: Preprint  

SciTech Connect (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

465

Economic Impacts of Wind Turbine Development in U.S. Counties  

E-Print Network [OSTI]

15 percent)). Cumulative wind turbine capacity installed inper capita income of wind turbine development (measured inour sample, cumulative wind turbine capacity on a per person

J., Brown

2012-01-01T23:59:59.000Z

466

Wind Farm  

Office of Energy Efficiency and Renewable Energy (EERE)

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

467

Wasted Wind  

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

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

468

Wind Energy  

Broader source: Energy.gov [DOE]

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

469

Wind resource and site assessment in the German Bight: Extreme Winds at Meso-to Microscale  

E-Print Network [OSTI]

in the offshore wind farms. In the following, the validated Weather Research and Forecast (WRF) model simulations resolution which resolves sites of the individual offshore wind farms. In addition, the FINO-1 measurements of offshore wind farms, where in-situ measurements are scarce and expensive, the validated mesoscale wind

Heinemann, Detlev

470

Riso-M-2546 g Wind Turbine Test  

E-Print Network [OSTI]

Riso-M-2546 g Wind Turbine Test Wind Matic WM 17S Troels Friis Pedersen The Test Station for Windmills Riso National Laboratory, DK-4000 Roskilde Denmark April 1986 #12;#12;RIS0-M-2546 WIND TURBINE describes standard measurements performed on a Wind-Matic WM 17S, 75 kW wind turbine. The measurements

471

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

E-Print Network [OSTI]

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

Saltzman, Eric

472

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

E-Print Network [OSTI]

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

473

Quality Control and Verification of Weather Radar Wind Profiles IWAN HOLLEMAN  

E-Print Network [OSTI]

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

Stoffelen, Ad

474

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

E-Print Network [OSTI]

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

Shay, Lynn K. "Nick"

475

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

E-Print Network [OSTI]

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

Zhao, Xuepu

476

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

SciTech Connect (OSTI)

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

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

1998-07-01T23:59:59.000Z

477

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

SciTech Connect (OSTI)

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

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

1998-07-01T23:59:59.000Z

478

Guide to Using the WIND Toolkit Validation Code  

SciTech Connect (OSTI)

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

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

2014-12-01T23:59:59.000Z

479

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

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

Mena Lopez, Hugo Eduardo

2008-10-10T23:59:59.000Z

480

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

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

Mena, Hugo Eduardo

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "measure 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

Space-Time Prediction of Ocean Winds Anders Malmberg  

E-Print Network [OSTI]

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

Malmberg, Anders

482

Control of Wind Turbines for Power Regulation and  

E-Print Network [OSTI]

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

483

Taming Hurricanes With Arrays of Offshore Wind Turbines  

E-Print Network [OSTI]

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

Firestone, Jeremy

484

The Solar Wind, CMEs and the Origins of Heliospheric Activity  

E-Print Network [OSTI]

release o Coronal holes o Source of high-speed solar wind #12;peter.gallagher@tcd.ie #12;#12;peter Parker => Parker Spiral: r - r0 = -(v/ )( - 0) o Winding angle: o Inclined at ~45 at 1 AU and ~90 by 10The Solar Wind, CMEs and the Origins of Heliospheric Activity Peter T. Gallagher School of Physics

485

Wind Power Resource Assessment in Ohio and Puerto Rico  

E-Print Network [OSTI]

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

Womeldorf, Carole

486

IMPLEMENTATION OF WIND TURBINE CONTROLLERS W.E.Leithead  

E-Print Network [OSTI]

IMPLEMENTATION OF WIND TURBINE CONTROLLERS D.J.Leith W.E.Leithead Department of Electronic-speed wind turbines are considered, namely, (1) accommodation of the strongly nonlinear rotor aerodynamics derived and extended to cater for all wind turbine configurations. A rigorous stability analysis

Duffy, Ken

487

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

SciTech Connect (OSTI)

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

Clifton, A.

2012-12-01T23:59:59.000Z

488

A Disturbance Margin For Quantifying Limits on Power Smoothing by Wind Turbines  

E-Print Network [OSTI]

wind variation a wind turbine can absorb in variable speed mode while still being guaranteed to operate speed and generator torque to store and release energy. This ability must be constrained by turbine speed and generator torque limits. To date, work in the literature is conceptual and does not indicate

Maggiore, Manfredi

489

Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11-kW Wind Turbine  

SciTech Connect (OSTI)

This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems -- Part 11 Acoustic Noise Measurement Techniques.

Huskey, A.

2011-11-01T23:59:59.000Z

490

Eddy-resolving Lidar Measurements and Numerical Simulations of the Convective Internal Boundary Layer  

E-Print Network [OSTI]

in speed. The vertical gradient of wind-speed decreases offshore because of strong vertical mixing caused correlation functions and winds derived from horizontal (PPI) and vertical (RHI) scans of the VIL during Lake.4 0.5 0.6 0.7 DOWNSTREAM WIND SPEEDS FROM RHI SCANS ON 13 JANUARY 1998 SPATIALLY RESOLVED 5-m WINDS

Eloranta, Edwin W.

491

PowerJet Wind Turbine Project  

SciTech Connect (OSTI)

PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energyâ??s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJetâ??s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assemblyâ??including the electronic and mechanical controls designed, manufactured and field tested during the course of this projectâ??proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOEâ??s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec

Bartlett, Raymond J

2008-11-30T23:59:59.000Z

492

Wind Issues in Solar Thermal Performance Ratings: Preprint  

SciTech Connect (OSTI)

We suggest that wind bias against unglazed solar water heaters be mitigated by using a calibrated collector model to derive a wind correction to the measured efficiency curve.

Burch, J.; Casey, R.

2009-04-01T23:59:59.000Z

493

Isotopic Composition of Solar Wind Calcium: First in Situ Measurement by CELIAS/MTOF on Board SOHO  

E-Print Network [OSTI]

We present first results on the Ca isotopic abundances derived from the high resolution Mass Time-of-Flight (MTOF) spectrometer of the charge, element, and isotope analysis system (CELIAS) experiment on board the Solar and Heliospheric Observatory (SOHO). We obtain isotopic ratios 40Ca/42Ca = (128+-47) and 40Ca/44Ca = (50+-8), consistent with terrestrial values. This is the first in situ determination of the solar wind calcium isotopic composition and is important for studies of stellar modeling and solar system formation since the present-day solar Ca isotopic abundances are unchanged from their original isotopic composition in the solar nebula.

R. Kallenbach; F. M. Ipavich; P. Bochsler; S. Hefti; P. Wurz; M. R. Aellig; A. B. Galvin; J. Geiss; F. Gliem; G. Gloeckler; H. Grunwaldt; M. Hilchenbach; D. Hovestadt; B. Klecker

1998-02-07T23:59:59.000Z

494

Effectiveness of speed trailers on low-speed urban roadways  

E-Print Network [OSTI]

Efforts are being made to use speed management methods to match operating speeds to posted speeds and to reduce the variability in vehicle speeds. The effectiveness of many different methods of speed management has not been documented. This thesis...

Perrillo, Kerry Victoria

1997-01-01T23:59:59.000Z

495

756 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 3, JULY 2013 Minimization of Wind Farm Operational  

E-Print Network [OSTI]

756 IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, VOL. 4, NO. 3, JULY 2013 Minimization of Wind Farm) of wind turbine at time , denoted as 0 or 1. Energy consumed by an idle wind turbine. Electricity spot, and Guanglin Xu Abstract--Scheduling a wind farm in the presence of uncertain wind speed conditions

Kusiak, Andrew

496

Method and apparatus for reducing rotor blade deflections, loads, and/or peak rotational speed  

DOE Patents [OSTI]

A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

Moroz, Emilian Mieczyslaw; Pierce, Kirk Gee

2006-10-17T23:59:59.000Z

497

Abstract--In this paper, we present the voltage build up process and the terminal voltage control of an isolated wind  

E-Print Network [OSTI]

of an isolated wind powered induction generator driven by a variable speed wind turbine using rotor flux oriented, but they can be set to operate within a given variation of speed. Unlike a grid connected induction generator and the speed, torque and fluxes as its outputs. Key words-- Wind energy system, Induction generator, Saturation

Paris-Sud XI, Université de

498

Testing of the Pole Face Winding crimpings Measurements carried out on the 100 PS main units before start up of the PS machine in 2007  

E-Print Network [OSTI]

The crimpings of the Pole Face Windings (PFW), used to connect the rectangular copper conductor of the main windings with its supply cable, could have defects due to the manufacture process. They could lead to an extensive high electrical resistance. To locate these defects, the PFW are powered with 80 Ampere DC and the voltage drop over the electrical resistances of the crimping is measured. The measurements are done between the PFW current leads and the corresponding pick-up. By subtracting the resistance of the supply cable and the interconnection cable the crimping resistance is calculated. During the long shutdown 2005 and the annual shutdown 2006/2007 a total of 34 main units, and their PFWs, have been refurbished [1]. The refurbished main units are equipped with new PFW. On this PFW the crimping technique was improved and the defect of high crimping contact resistance should not appear. Nevertheless to have complete picture of the situation the 34 refurbished main units and the 66 none refurbished unit...

Hans, O

2007-01-01T23:59:59.000Z

499

NREL National Wind Technology Center (NWTC): M2 Tower; Boulder, Colorado (Data)  

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

The National Wind Technology Center (NWTC), located at the foot of the Rocky Mountains near Boulder, Colorado, is a world-class research facility managed by NREL for the U.S. Department of Energy. NWTC researchers work with members of the wind energy industry to advance wind power technologies that lower the cost of wind energy through research and development of state-of-the-art wind turbine designs. NREL's Measurement and Instrument Data Center provides data from NWTC's M2 tower which are derived from instruments mounted on or near an 82 meter (270 foot) meteorological tower located at the western edge of the NWTC site and about 11 km (7 miles) west of Broomfield, and approximately 8 km (5 miles) south of Boulder, Colorado. The data represent the mean value of readings taken every two seconds and averaged over one minute. The wind speed and direction are measured at six heights on the tower and air temperature is measured at three heights. The dew point temperature, relative humidity, barometric pressure, totalized liquid precipitation, and global solar radiation are also available.

Jager, D.; Andreas, A.

500

Wind turbine  

SciTech Connect (OSTI)

The improvement in a wind turbine comprises providing a tower with a freely liftable mount and adapting a nacelle which is fitted with a propeller windwheel consisting of a plurality of rotor blades and provided therein with means for conversion of wind energy to be shifted onto said mount attached to the tower. In case of a violent wind storm, the nacelle can be lowered down to the ground to protect the rotor blades from breakage due to the force of the wind. Required maintenance and inspection of the nacelle and replacement of rotor blades can be safely carried out on the ground.

Abe, M.

1982-01-19T23:59:59.000Z