نتایج جستجو برای: high speed wind tunnels

تعداد نتایج: 2246726  

2011
Ch Rambabu M Sunil Kumar Sri Harish Sri Vasavi

The wind energy conversion system can deliver the maximum power when the load impedance matches with the source impedance under a given wind speed. Since the load and wind speed are varying dynamically, the maximum power point tracking (MPPT) becomes more complex. A wind-generator (WG) maximum-power-point tracking (MPPT) system is presented in the present work, consisting of a high efficiency b...

This paper describes a new method for harvesting maximum electrical energy in wind farms. In proposing technique, the stochastic process principles are applied for detecting fault measurements of sensors. On the other hand, the wind farm is modeled by using fuzzy concept. Thereby the turbines are controlled against continuous changes in speed, direction and eddy currents of the blowing wind. To...

2008
Y. Hu

Global satellite observations of lidar backscatter measurements acquired by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission and collocated sea surface wind speed data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), are used to investigate the relation between wind driven wave slope variance and sea surface wind spe...

2013
Ronay Ak Yanfu Li Valeria Vitelli Enrico Zio

— In this work, the non-dominated sorting genetic algorithm–II (NSGA-II) is applied to determine the weights of a neural network trained for short-term forecasting of wind speed. More precisely, the neural network is trained to produce the lower and upper bounds of the prediction intervals of wind speed. The objectives driving the search for the optimal values of the neural network weights are ...

2016
Kenneth W Corscadden Allan Thomson Behrang Yoonesi Josiah McNutt

Estimation of wind speed at proposed hub heights is typically achieved using a wind shear exponent or wind shear coefficient (WSC), variation in wind speed as a function of height. The WSC is subject to temporal variation at low and high frequencies, ranging from diurnal and seasonal variations to disturbance caused by weather patterns; however, in many cases, it is assumed that the WSC remains...

2009
Ghanim PUTRUS Mahinsasa NARAYANA Milutin JOVANOVIC Pak Sing LEUNG

Variable-speed, fixed-pitch wind turbines are required to optimize power output performance without the aerodynamic controls. A wind turbine generator system is operated such that the optimum points of wind rotor curve and electrical generator curve coincide. In order to obtain maximum power output of a wind turbine generator system, it is necessary to drive the wind turbine at an optimal rotor...

2009
Fatih O. Hocaoğlu Mehmet Fidan Ömer N. Gerek

Wind speed modeling and prediction plays a critical role in wind related engineering studies. However, since the data have random behavior, it is difficult to apply statistical approaches with apriori and deterministic parameters. On the other hand, wind speed data have an important feature; extreme transitions from a wind state to a far different one are rare. Therefore, behavioral modeling is...

Ali ajami, Shirmohammadi ramin

This paper provides a review of OTC and P&O; MPPT controllers used for extracting maximum power from the wind energy systems using permanent magnet synchronous generators. Hence, the output power of wind energy system varies continually as wind speed changes, it is desirable to determine the one optimal generator speed that ensures maximum energy yield. Thus, it is important to include a con...

2007
J. D. Richardson C. Wang

The ow of solar wind from the Sun is bimodal. High speed, low density plasma comes from high magnetic latitude regions and low speed, high density ow from near the heliospheric current sheet (HCS). We investigate whether this bimodal ow combined with the HCS tilt controls the solar wind velocities in the outer heliosphere near solar minimum when the Sun's magnetic eld is roughly dipolar. We pre...

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