نتایج جستجو برای: wind speed

تعداد نتایج: 276062  

2016
Carlos D. Zuluaga Mauricio A. Álvarez Eduardo Giraldo

The use of wind energy for power electric systems attempts to reduce the dependence on fuel-based energy. With the aim of generating electrical power based on wind energy, it becomes necessary to model and predict wind speed. Wind speed observations are packed with outliers what makes it difficult to propose accurate predictors. This paper presents an experimental comparison of three different ...

2015
Shuting Wan Lifeng Cheng Xiaoling Sheng Chi-Ming Lai

Natural wind is stochastic, being characterized by its speed and direction which change randomly and frequently. Because of the certain lag in control systems and the yaw body itself, wind turbines cannot be accurately aligned toward the wind direction when the wind speed and wind direction change frequently. Thus, wind turbines often suffer from a series of engineering issues during operation,...

2014
Jujie Wang

It is important to improve the accuracy of wind speed forecasting for wind parks management and wind power utilization. In this paper, a novel hybrid approach known as WTT-TNN is proposed for wind speed forecasting. In the first step of the approach, a wavelet transform technique (WTT) is used to decompose wind speed into an approximate scale and several detailed scales. In the second step, a t...

2008
Mohammad Monfared Hasan Rastegar Hossein Madadi Kojabadi

A new strategy in wind speed prediction based on fuzzy logic and artificial neural networks was proposed. The new strategy for fuzzy logic not only provides significantly less rule base but also has increased estimated wind speed accuracy when compared to traditional one. Meanwhile, applying the proposed approach to artificial neural network leads to less neuron numbers and less learning time p...

2012
David Schlipf

LIDAR systems are able to provide preview information of wind speed, direction and shears at various distances in front of the wind turbines. This technology paves the way for new control concepts such as feedforward control and model predictive control to increase the energy production and to reduce loads of wind turbines. This paper describes how the necessary information can be obtained from...

2015
Annalisa Appice Sonja Pravilovic Antonietta Lanza Donato Malerba

A wind speed forecast corresponds to an estimate of the upcoming production of a wind farm. The paper illustrates a variant of the Nearest Neighbor algorithm that yields wind speed forecasts, with a fast time resolution, for a (very) short time horizon. The proposed algorithm allows us to monitor a grid of wind farms, which collaborate by sharing information (i.e. wind speed measurements). It a...

The most common controller in wind turbine is the blade pitch angle control in order to get the desired power. Controlling the pitch angle in wind turbines has a direct impact on the dynamic performance of the machine and fluct­uat­io­ns in the power systems. Due to constant changes in wind speed, the wind turbines are of nonlinear and multivariate system. The design of a controller that can ad...

2008
T. Laubrich F. Ghasemi J. Peinke H. Kantz

We study the statistics of the horizontal component of atmospheric boundary layer wind speed. Motivated by its non-stationarity, we investigate which parameters remain constant or can be regarded as being piece-wise constant and explain how to estimate them. We will verify the picture of natural atmospheric boundary layer turbulence to be composed of successively occurring close to ideal turbul...

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 ...

2007
Y. Quilfen C. Prigent B. Chapron A. A. Mouche N. Houti

The physics of remote sensing sea surface measurements is still poorly understood under severe weather conditions. Wind vector algorithms are usually developed for non-precipitating atmospheres and for wind speeds less than 20 m/s. In this study, we analyze observations from the QuikSCAT Kuband scatterometer collocated with the WindSat full polarimetric microwave radiometer to estimate the pote...

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