Search for: wind-turbine
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    Reliability-based selection of wind turbines for large-scale wind farms

    , Article World Academy of Science, Engineering and Technology ; Volume 37 , 2009 , Pages 734-740 ; 2010376X (ISSN) Fotuhi Firuzabad, M ; Salehi Dobakhshari, A ; Sharif University of Technology
    This paper presents a reliability-based approach to select appropriate wind turbine types for a wind farm considering site-specific wind speed patterns. An actual wind farm in the northern region of Iran with the wind speed registration of one year is studied in this paper. An analytic approach based on total probability theorem is utilized in this paper to model the probabilistic behavior of both turbines' availability and wind speed. Well-known probabilistic reliability indices such as loss of load expectation (LOLE), expected energy not supplied (EENS) and incremental peak load carrying capability (IPLCC) for wind power integration in the Roy Billinton Test System (RBTS) are examined. The... 

    Vibration suppression of offshore wind turbine foundations using tuned liquid column dampers and tuned mass dampers

    , Article Ocean Engineering ; Volume 172 , 2019 , Pages 286-295 ; 00298018 (ISSN) Hemmati, A ; Oterkus, E ; Khorasanchi, M ; Sharif University of Technology
    Elsevier Ltd  2019
    Highly dynamic nature of the applied loads on flexible and lightly damped offshore wind turbine (OWT) foundations affects the lifetime and serviceability of the system. In this study, the excessive vibration responses of OWTs are minimized using tuned mass dampers (TMD) and tuned liquid column dampers (TLCD). Due to high efficiency of TLCDs and TMDs for certain loading conditions, a combined TLCD-TMD is also utilized to improve the overall performance in a wide range of loading conditions. First, a parametric study was performed that highlights the sensitivity of these structural control devices. The effect of two devices on fixed offshore wind turbine foundations for the benchmark 5 MW NREL... 

    Enhancement of a horizontal axis wind turbine airfoil performance using single dielectric barrier discharge plasma actuator

    , Article Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy ; 2020 Fadaei, M ; Davari, A. R ; Sabetghadam, F ; Soltani, M. R ; Sharif University of Technology
    SAGE Publications Ltd  2020
    Wind turbines are of the most promising devices to cut down carbon emissions. However, some phenomena that adversely affect their performance are inevitable. The aim of the present paper is to investigate flow separation prevention exploiting leading edge (LE) single dielectric barrier discharge plasma actuator (SDBD-PA) on an airfoil belonging to a section of a locally developed wind turbine. The numerical results of the surface pressure distribution over the airfoil were compared with the experimental measurements carried out by the authors on the same blade section, and good agreement was found between numerical and experimental data for both plasma-OFF and plasma-ON cases. An in-depth... 

    Nonlinear pitch control of a large scale wind turbine by considering aerodynamic behavior of wind

    , Article 9th International Conference on Modern Circuits and Systems Technologies, MOCAST 2020, 7 September 2020 through 9 September 2020 ; 2020 Golnary, F ; Moradi, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    In this research, nonlinear sliding mode pitch control of a wind turbine has been investigated by considering aerodynamic nonlinearities. For modeling aerodynamic interaction between the wind and the drive-train system, blade element momentum theory is used by considering Prandtl's tip loss factor and Glaurt correction. Finally, the two-degrees of freedom model of the drive-train is extracted and the sliding mode approach is examined for regulating the output power into its nominal value by controlling the pitch angle. The implementation of the above proposed control law in its related electronic circuit of the wind turbine will be considered as the future stage of the current research. ©... 

    Effects of motion and structural vibration–induced loadings on the coupled dynamic response of a mono-column tension-leg-platform floating wind turbine

    , Article Proceedings of the Institution of Mechanical Engineers Part M: Journal of Engineering for the Maritime Environment ; Volume 234, Issue 2 , 2020 , Pages 426-445 Imani, H ; Abbaspour, M ; Tabeshpour, M. R ; Karimirad, M ; Sharif University of Technology
    SAGE Publications Ltd  2020
    Floating wind turbines are subjected to highly dynamic and complicated environmental conditions leading to significant platform motions and structural vibrations during operation and survival conditions. These motions and vibrations alter the induced loading characteristics; and consequently, affect the dynamic behavior of the system. In order to better understand the influence of such motions and structural vibrations, herein elastic structural disturbance of tower, on the system behavior, the spectral and statistical characteristics of a floating wind turbine dynamic responses under operational and survival conditions are fully explored using a fully coupled... 

    Improved generic model of variable speed wind turbines for dynamic studies

    , Article IEEE Transactions on Sustainable Energy ; Volume 11, Issue 4 , October , 2020 , Pages 2162-2173 Mirnezhad, H ; Ravanji, M. H ; Parniani, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Fast growth of wind power generation and its contribution in power systems dynamic performance has highlighted the importance of developing generic models for wind turbines. Following the former efforts, an enhanced version of standard generic wind turbine model is proposed in this article. The enhancements are aimed to make the model applicable for unbalanced Root Mean Square (RMS), short-Term frequency stability, and low-voltage ride-Through (LVRT) studies. Moreover, fidelity of the overall responses of the model is increased. To achieve these goals, five new blocks are designed and added to the base model and three existing blocks are modified. The new blocks are negative-sequence... 

    Robust adaptive reference model control of nonlinear wind-induced oscillations of floating offshore wind turbine blade in finite-time

    , Article Ocean Engineering ; Volume 241 , 2021 ; 00298018 (ISSN) Ghabraei, S ; Moradi, H ; Vossoughi, G ; Sharif University of Technology
    Elsevier Ltd  2021
    In this research, to overcome the challenging problem of the vibration suppression in the wind turbine blade, an active robust adaptive finite-time model reference controller is introduced. First, edgewise vibrations of the wind turbine blade, with consideration of the platform heave displacements, is modeled by Euler-Bernoulli beam theory. Then, the appropriate adaptation laws and control laws are introduced to compensate the uncertainties and guarantee the convergence to the desired reference model. The robustness and convergence of the designed adaptation and control laws are mathematically proved via finite-time Lyapunov theory. Performance of the designed robust adaptive finite-time... 

    Variable speed wind turbine power control: A comparison between multiple MPPT based methods

    , Article International Journal of Dynamics and Control ; 2021 ; 2195268X (ISSN) Nouriani, A ; Moradi, H ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Reducing the renewable energy costs is necessary for the competition with the fossil energies and control strategies have great impact on the efficiency of wind machines. In the wind turbine industry, a practical approach is to maximize the energy capture of a wind machine by optimizing the power coefficient in the under-rated situations. In this paper, with the main objective of maximizing the energy capture in the second region, four different control strategies are compared in the presence of uncertainties. The proposed control methods are compared based on their power capture and robustness against probable uncertainties in the structural and environmental parameters. A two-mass... 

    Novel sensorless fault-tolerant pitch control of a horizontal axis wind turbine with a new hybrid approach for effective wind velocity estimation

    , Article Renewable Energy ; Volume 179 , December , 2021 , Pages 1291-1315 ; 09601481 (ISSN) Golnary, F ; Tse, K. T ; Sharif University of Technology
    Elsevier Ltd  2021
    In this research, the fault-tolerant pitch angle control of a horizontal axis wind turbine in region 3 (where the wind velocity is greater than rated wind speed) is investigated. The effective wind velocity (EWV) is one of the necessary information for each control system. Wind speed is measured by the anemometers on the top of the nacelle however, the measurement is not precise and is only applicable for one point in the rotor. To address this issue, we have developed a novel hybrid approach. The approach is based on a sliding mode observer to estimate the aerodynamic torque and an adaptive neuro-fuzzy inference system (ANFIS) is introduced for obtaining the EWV. The estimated aerodynamic... 

    Linear multi-variable control technique for smart power management of wind turbines

    , Article 2012 International Conference onAdvanced Mechatronic Systems, ICAMechS 2012 ; 2012 , Pages 559-564 ; 9780955529382 (ISBN) Emami, S. A ; Banazadeh, A ; Sharif University of Technology
    Variable speed wind turbines are widely used in the modern power industry. These turbines that are usually driven by doubly fed induction generators (DFIG) contain two groups of controlling variables; mechanical variables like pitch angle, and electrical variables like rotor voltage. During the turbine operation, with variable wind speed, power must be managed in two different regimes; power optimization and power limitation. In the current research, initially a non-linear simulation, based on the general wind turbine dynamic model is presented. Then, the desired controllers for both pitch angle and generator voltage components are constructed. To validate turbine behavior and controller... 

    Failure Modes and Effects Analysis (FMEA) for wind turbines

    , Article International Journal of Electrical Power and Energy Systems ; Volume 32, Issue 7 , 2010 , Pages 817-824 ; 01420615 (ISSN) Arabian Hoseynabadi, H ; Oraee, H ; Tavner, P. J ; Sharif University of Technology
    The Failure Modes and Effects Analysis (FMEA) method has been used to study the reliability of many different power generation systems. This paper now applies that method to a wind turbine (WT) system using a proprietary software reliability analysis tool. Comparison is made between the quantitative results of an FMEA and reliability field data from real wind turbine systems and their assemblies. These results are discussed to establish relationships which are useful for future wind turbine designs. The main system studied is an existing design 2 MW wind turbine with a Doubly Fed Induction Generator (DFIG), which is then compared with a hypothetical wind turbine system using the Brushless... 

    Design and comparison of quasi continuous sliding mode control with feedback linearization for a large scale wind turbine with wind speed estimation

    , Article Renewable Energy ; Volume 127 , 2018 , Pages 495-508 ; 09601481 (ISSN) Golnary, F ; Moradi, H ; Sharif University of Technology
    In this paper, dynamic modelling and control of WindPACT 1.5 MW wind turbine in Region 2 for extracting the maximum energy from wind is investigated (where the wind velocity is greater than ‘cut in’ and below ‘rated’ wind speeds). In this region, the generator torque must regulate the rotor speed in its optimal value while the blade pitch angle is considered constant in its optimal value. To achieve a more accurate model, wind turbine is modeled as an electromechanical system with two masses dynamics. A new method based on adaptive neuro fuzzy inference system (ANFIS) is considered for wind speed estimation; where rotor speed, output power and pitch angle are inputs of such system and... 

    The comparison of form drag and profile drag of a wind turbine blade section in pitching oscillation

    , Article World Academy of Science, Engineering and Technology ; Volume 40 , 2009 , Pages 294-301 ; 2010376X (ISSN) Soltani, M. R ; Seddighi, M ; Mahmoudi, M ; Sharif University of Technology
    Extensive wind tunnel tests have been conducted to investigate the unsteady flow field over and behind a 2D model of a 660 kW wind turbine blade section in pitching motion. The surface pressure and wake dynamic pressure variation at a distance of 1.5 chord length from trailing edge were measured by pressure transducers during several oscillating cycles at 3 reduced frequencies and oscillating amplitudes. Moreover, form drag and linear momentum deficit are extracted and compared at various conditions. The results show that the wake velocity field and surface pressure of the model have similar behavior before and after the airfoil beyond the static stall angle of attack. In addition, the... 

    Enhancement the economical and environmental aspects of plus-zero energy buildings integrated with INVELOX turbines

    , Article Renewable Energy ; Volume 153 , 2020 , Pages 1355-1367 Shaterabadi, M ; Jirdehi, M. A ; Amiri, N ; Omidi, S ; Sharif University of Technology
    Elsevier Ltd  2020
    A multi-objective energy management strategy for a plus-zero energy building during a year, incorporating renewable resources, air to water heat pump, micro-CHP, ventilation, energy storage systems and thermal-cooling-electrical loads have been proposed in this paper. In this strategy, a novel technology of wind turbine that has been known as INVELOX has been investigated and collaborated in ZEB planning to reach efficient plus-ZEB at lower cost and pollution. As well the building can sell and buy power to/from the upstream network. The total cost and pollution of the building have been considered as objective functions. Also, the effect of objective function priority on the planning of the... 

    Estimation of Wind turbine’s Produced Energy in Different Regions

    , M.Sc. Thesis Sharif University of Technology Jafarian, Mohammad (Author) ; Ranjbar, Ali Mohammad (Supervisor)
    One of the most important problems in using wind energy is the estimation of wind energy potential of a region with acceptable accuracy. To use wind energy and convert it to electrical energy it is necessary to study the economical aspects of wind farm installation, and to choose an appropriate wind turbine to be installed in a region. To do such a study and to choose approperiate wind turbine, annual energy output of different wind turbines should be estimated in that region. The porpuse of this thesis is to develop new methods to estimate annual energy production of a wind turbine by using some of the parameters of wind speed pattern of a region such as wind speed average, wind speed... 

    Experimental Investigation of Reduced Frequency Effects on the Boundary-Layer Profile of an Oscillating Airfoil in Pitching Motion

    , M.Sc. Thesis Sharif University of Technology Ghorbani Shohrat, Faegheh (Author) ; Soltani, Mohammad Reza (Supervisor)
    Application of wind energy and specially wind turbines as a green source of energy is getting more popular and as a result, the knowledge of wind energy has been improved dramatically. The purpose of this research is to determine the flow characteristics in the boundary layer profile over an airfoil which is used in a wind turbine blade. The model is sinusoidally oscillated in pitch. For the present study, the critical cross section of the wind turbine blade has been selected and the boundary layer velocity profiles over its airfoil have been investigated experimentally. Dynamic motion is produced with sinusoidal oscillator and the reduced frequency is varied in the range of 0.054 to 0.1.... 

    Cost Effective and Optimum Strategy for Gride Connected Small Wind Turbine

    , M.Sc. Thesis Sharif University of Technology Hajbabaei, Amirhosein (Author) ; Oraei, Hashem (Supervisor)
    Regarding the range of power in small wind turbine ,the manufacturing cost is very important to produce it feasible . so cost factors should be considered in control strategy. small wind turbine operate at lower wind speed because they are located where the energy is needed rather than where the wind is high for example in residential or rural area in lower height. In these condition wind speed are changing more because of lower height .so the maximum power point tracking algorithm should have a fast dynamic. In order to have lower number of device there are no sensor for wind or generator’s speed .only the voltage and current of different part of the system is measured.
    here the aim... 

    Investigation of Performance and Aeroelastic Characteristics of Wind Turbine Blades Based on Flexible Multibody Dynamics Model

    , M.Sc. Thesis Sharif University of Technology Sekandari, Mahmoud (Author) ; Ebrahimi, Abbas (Supervisor)
    Aeroelasticity analysis and prediction of wind turbines sturcture deformations are fundamental parts in their design. Increasing the size of wind turbine blades and development of Mega-watt sized wind turbines have enhanced the importance of these studies. In this study, the aeroelasticity analysis of a wind turbine blade has been done based on flexible multibody dynamics method. For this purpose, the modal approach has been used for modeling blade structure which has been considered as a flexible beam with bending and torsion degrees of freedom. The unsteady vortex lattice method has been used to calculate aerodynamic loads in order to combine with wind turbine blade structure model. Using... 

    Vibration Modeling and Analysis of a Wind Turbine Blade based on Third-Order Structural Nonliearities

    , Ph.D. Dissertation Sharif University of Technology Rezaei, Mohammad Mahdi (Author) ; Behzad, Mehdi (Supervisor) ; Haddadpour, Hassan (Co-Advisor) ; Moradi, Hamed (Co-Advisor)
    Aiming to improve the extraction performance of wind energy has led to the noticeable increase of the structural dimensions in the modern wind turbines. The larger blade with more flexibility experiences large structural deformation even under nominal operational loading, so the nonlinear modeling and analysis of these structures have become as important subject of the recent wind turbine researches. In this dissertation, the geometrical exact model of the rotating wind turbine blade under the effects of the tower tip's motion, and also the operational loading comprising the aerodynamic and gravitational loadings is presented. In this way, the geometrical exact beam formulation is developed... 

    Experimental Investigation of Reduced Frequency Effects on the Aerodynamic Efficiency of a New Wind Turbine Blade Section in Pitching Motion

    , M.Sc. Thesis Sharif University of Technology Khorshidian, Nima (Author) ; Soltani, Mohammad Reza (Supervisor)
    In recent years, renewable energy equipments such as wind turbines has become more common for electric power generation. Due to the complexity of the aerodynamics of wind turbines,experimental studies in this field are very important. The purpose of this study is to investigate the aerodynamic performance of a new wind turbine airfoil in static mode and pitching motion.The airfoil is a section of 2 MW wind turbine blade, pitching around its quarter-chord axis .All experiments are carried out in a subsonic wind tunnel. In these experiments, the reynolds number is 140,000 and the reduced frequency varies from 0.034 to 0.126. Pressure transducers have been used to determine the pressure...