• Title/Summary/Keyword: WIND SPEED

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An integrator based wind speed estimator for wind turbine control

  • Elmaati, Younes Ait;El Bahir, Lhoussain;Faitah, Khalid
    • Wind and Structures
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    • v.21 no.4
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    • pp.443-460
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    • 2015
  • In this paper, an integrator based method to estimate the effective wind speed in wind turbine systems is proposed. First, the aerodynamic torque was accurately estimated through a proportional gain based observer where the generator speed is the measured output of the system. The torque signal contains not only useful frequencies of the wind, but also high frequencies and the ones due to structural vibration. The useful information of the wind signal is low frequency. A spectral analysis permitted the determination of the useful frequencies. The high frequencies were then filtered before introducing the torque signal in the wind speed observer. The desired effective wind speed was extracted through an integrator based observer using the previously estimated aerodynamic torque. The strength of the method is to avoid numerical solutions used in literature of the wind speed estimation. The effectiveness of the proposed wind speed estimator and its use to control the generator speed has been tested under turbulent situations using the FAST software (Fatigue, Aerodynamics, Structures, and Turbulence), for large scale Megawatt turbine.

Accounting for the Atmospheric Stability in Wind Resource Variations and Its Impacts on the Power Generation by Concentric Equivalent Wind Speed (동심원 등가풍속을 이용한 대기안정도에 따른 풍력자원 변화에 관한 연구)

  • Ryu, Geon-Hwa;Kim, Dong-Hyeok;Lee, Hwa-Woon;Park, Soon-Young;Yoo, Jung-Woo;Kim, Hyun-Goo
    • Journal of the Korean Solar Energy Society
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    • v.36 no.1
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    • pp.49-61
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    • 2016
  • The power production using hub height wind speed tends to be overestimated than actual power production. It is because the hub height wind speed cannot represent vertical wind shear and blade tip loss that aerodynamics characteristic on the wind turbine. The commercial CFD model WindSim is used to compare and analyze each power production. A classification of atmospheric stability is accomplished by Monin-Obukhov length. The concentric wind speed constantly represents low value than horizontal equivalent wind speed or hub height wind speed, and also relevant to power production. The difference between hub height wind speed and concentric equivalent wind speed is higher in nighttime than daytime. Under the strongly convective state, power production is lower than under the stable state, especially using the concentric equivalent wind speed. Using the concentric equivalent wind speed considering vertical wind shear and blade tip loss is well estimated to decide suitable area for constructing wind farm.

Spatial and temporal distribution of Wind Resources over Korea (한반도 바람자원의 시공간적 분포)

  • Kim, Do-Woo;Byun, Hi-Ryong
    • Atmosphere
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    • v.18 no.3
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    • pp.171-182
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    • 2008
  • In this study, we analyzed the spatial and temporal distribution of wind resources over Korea based on hourly observational data recorded over a period of 5 years from 457 stations belonging to Korea Meteorological Administration (KMA). The surface and 850 hPa wind data obtained from the Korea Local Analysis and Prediction System (KLAPS) and the Regional Data Assimilation and Prediction System (RDAPS) over a period of 1 year are used as supplementary data sources. Wind speed is generally high over seashores, mountains, and islands. In 62 (13.5%) stations, mean wind speeds for 5 years are greater than $3ms^{-1}$. The effects of seasonal wind, land-sea breeze, and mountain-valley winds on wind resources over Korea are evaluated as follows: First, wind is weak during summer, particularly over the Sobaek Mountains. However, over the coastal region of the Gyeongnam-province, strong southwesterly winds are observed during summer owing to monsoon currents. Second, the wind speed decreases during night-time, particularly over the west coast, where the direction of the land breeze is opposite to that of the large-scale westerlies. Third, winds are not always strong over seashores and highly elevated areas. The wind speed is weaker over the seashore of the Gyeonggi-province than over the other seashores. High wind speed has been observed only at 5 stations out of the 22 high-altitude stations. Detailed information on the wind resources conditions at the 21 stations (15 inland stations and 6 island stations) with high wind speed in Korea, such as the mean wind speed, frequency of wind speed available (WSA) for electricity generation, shape and scale parameters of Weibull distribution, constancy of wind direction, and wind power density (WPD), have also been provided. Among total stations in Korea, the best possible wind resources for electricity generation are available at Gosan in Jeju Island (mean wind speed: $7.77ms^{-1}$, WSA: 92.6%, WPD: $683.9Wm^{-2}$) and at Mt. Gudeok in Busan (mean wind speed: $5.66ms^{-1}$, WSA: 91.0%, WPD: $215.7Wm^{-2}$).

Global Distribution of Surface Layer Wind Speed for the years 2000-2009 Based on the NCEP Reanalysis (NCEP 재분석 자료를 이용한 전지구 지표층의 2000-2009년 풍속 분포)

  • Byon, Jae-Young;Choi, Young-Jean;Lee, Jae-Won
    • Atmosphere
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    • v.21 no.4
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    • pp.439-446
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    • 2011
  • NCEP reanalysis data were analyzed in order to provide distribution of global wind resource and wind speed in the surface layer for the years 2000-2009. Wind speed at 10 m above ground level (AGL) was converted to wind speed at 80 m above the ground level using the power law. The global average 80 m wind speed shows a maximum value of $13ms^{-1}$ at the storm track region. High wind speed over the land exists in Tibet, Mongolia, Central North America, South Africa, Australia, and Argentina. Wind speed over the ocean increased with a large value in the South China Sea, Southeast Asia, East Sea of the Korea. Sea surface wind in Western Europe and Scandinavia are suitable for wind farm with a value of $7-8ms^{-1}$. Areas with great potential for wind farm are also found in Eastern and Western coastal region of North America. Sea surface wind in Southern Hemisphere shows larger values in the high latitude of South America, South Africa and Australia. The distribution of low-resolution reanalysis data represents general potential areas for wind power and can be used to provide information for high-resolution wind resource mapping.

A design of vertical axis wind power generating system combined with Darrieus-Savonius for adaptation of variable wind speed (다변풍속 적응형 Darrieus-Sauonius 초합 수직푹 풍력발전 시스템의 설계)

  • 서영택;오철수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.2
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    • pp.185-192
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    • 1996
  • This paper presents a design of vertical axis Darrieus wind turbine combine with Savonius for wind-power generating system to be adapted for variable wind speed. The wind turbine consists of two troposkien- and four Savonius-blades. Darrieus turbine is designed with diameter 9.4[m], chord length 380[mm], tip speed ratio 5. Savonius turbine is designed with diameter 1.8[m], height 2[m], tip speed ratio 0.95. The design of turbine is laid for the main data of rated wind speed 10[m/s], turbine speed 101.4[rpm]. The generating power is estimated to maximum power 20[kW], and this is converted to commercial power line by means of three phase synchronous generator-inverter system. Generating system is designed for operation on VSVF(variable speed variable frequency) condition and constant voltage system.

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Wind Turbine Simulator for Comparative Study of MPPT Controls

  • Putri, Adinda Ihsani;Ahn, Minho;Choi, Jaeho
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.128-129
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    • 2012
  • This paper proposed the wind turbine simulator for comparative study of the MPPT controls. The development of this wind turbine simulator is based on the torque controlled induction motor. The torque reference is obtained from a mathematical model of wind turbine whereas the inputs are rotor speed, wind speed and fixed-value of pitch angle. By using this wind turbine simulator, the real wind is not needed. Wind speed information can be stored and regenerated anytime. Hence it is possible to apply the same wind speed condition to different MPPT controls. With the same wind speed condition, it can fairly compare the advantages and disadvantages of the MPPT controls. The proposed wind turbine simulator is verified through PSIM simulation.

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Output Power Control of Wind Generation System using Estimated Wind Speed by Support Vector Regression

  • Abo-Khalil Ahmed G.;Lee Dong-Choon
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.345-347
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    • 2006
  • In this paper, a novel method for wind speed estimation in wind power generation systems is presented. The proposed algorithm is based on estimating the wind speed using Support-Vector-Machines for regression (SVR). The wind speed is estimated using the generator power-speed characteristics as a set of training vectors. SVR is trained off-line to predict a continuos-valued function between the system's inputs and wind speed value. The predicted off-line function as well as the instantaneous generator power and speed are then used to determine the unknown winds speed on-line. The simulation results show that SVR can define the corresponding wind speed rapidly and accurately to determine the optimum generator speed reference for maximum power point tracking.

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Design of Nonlinear Controller for Variable Speed Wind Turbines based on Kalman Filter and Artificial Neural Network (칼만필터 및 인공신경망에 기반한 가변속 풍력발전 시스템을 위한 비선형 제어기 설계)

  • Moon, Dae-Sun;Kim, Sung-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.2
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    • pp.243-250
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    • 2010
  • As the wind has become one of the fastest growing renewable energy sources, the key issue of wind energy conversion systems is how to efficiently operate the wind turbines in a wide range of wind speeds. Compared to fixed speed turbines, variable speed wind turbines feature higher energy yields, lower component stress and fewer grid connection power peaks. Generally, measurement of wind speed is required for the control of variable speed wind turbine system. However, wind speed measured by anemometers is not accurate owing to various reasons. In this work, a new control algorithm for variable speed wind turbine system based on Kalman filter which can be used for the estimation of wind speed and artificial neural network which can generate optimum rotor speed is proposed. Also, to verify the feasibility of the proposed scheme, various simulation studies are carried out by using Simulink in Matlab.

Heat Transfer Analysis for Asphalt Mixture Temperature Variation due to Wind Speed (풍속에 따른 포설 아스팔트 혼합물의 온도변화에 대한 열전달 해석)

  • Yun, Tae Young;Yoo, Pyeong Jun
    • International Journal of Highway Engineering
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    • v.17 no.4
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    • pp.33-40
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    • 2015
  • PURPOSES: Evaluation of the wind speed effect on the temperature drop of an asphalt mixture during construction, by using the transient heat transfer theory and dominant convective heat transfer coefficient model. METHODS: Finite difference method (FDM) is used to solve the transient heat transfer difference equation numerically for various wind speeds and initial temperature conditions. The Blasius convective heat transfer coefficient model is adapted to account for the effect of wind speed in the temperature predictions of the asphalt mixture, and the Beaufort number is used to select a reasonable wind speed for the analysis. As a function of time and depth, the temperature of the pavement structure is predicted and analyzed for the given initial conditions. RESULTS : The effect of wind speed on the temperature drop of asphalt mixture is found to be significant. It seems that wind speed is another parameter to be accounted for in the construction specifications for obtaining a better quality of the asphalt mixture. CONCLUSIONS: It is concluded that wind speed has a significant effect on the temperature drop of the asphalt layer. Although additional field observations have to be made to reflect the effect of wind speed on the construction specifications, it appears that wind speed is a dominant variable to be considered, in addition to the atmospheric temperature.

Maximum Power Tracking Control for parallel-operated DFIG Based on Fuzzy-PID Controller

  • Gao, Yang;Ai, Qian
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2268-2277
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    • 2017
  • As constantly increasing wind power penetrates power grid, wind power plants (WPPs) are exerting a direct influence on the traditional power system. Most of WPPs are using variable speed constant frequency (VSCF) wind turbines equipped with doubly fed induction generators (DFIGs) due to their high efficiency over other wind turbine generators (WTGs). Therefore, the analysis of DFIG has attracted considerable attention. Precisely measuring optimum reference speed is basis of utilized maximum wind power in electric power generation. If the measurement of wind speed can be easily taken, the reference of rotation speed can be easily calculated by known system's parameters. However, considering the varying wind speed at different locations of blade, the turbulence and tower shadow also increase the difficulty of its measurement. The aim of this study is to design fuzzy controllers to replace the wind speedometer to track the optimum generator speed based on the errors of generator output power and rotation speed in varying wind speed. Besides, this paper proposes the fuzzy adaptive PID control to replace traditional PID control under rated wind speed in variable-pitch wind turbine, which can detect and analyze important aspects, such as unforeseeable conditions, parameters delay and interference in the control process, and conducts online optimal adjustment of PID parameters to fulfill the requirement of variable pitch control system.