Download or read book Mitigation of Wind Turbine Vortex Interaction Using Disturbance Accommodating Control written by and published by DIANE Publishing. This book was released on with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mitigation of Wind Turbine vortex Interaction Using Disturbance Accommodating Control written by M. Maureen Hand and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mitigation of Wind Turbine vortex Interaction Using Disturbance Accommodating Control written by and published by . This book was released on 2003 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mitigation of Wind Turbine vortex Interaction Using Distribance Accommodating Control written by M. Maureen Hand and published by . This book was released on 2003 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Load Mitigation Control Design for a Wind Turbine Operating in the Path of Vortices written by Maureen M. Hand and published by . This book was released on 2004 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances of Science and Technology written by Mulugeta Admasu Delele and published by Springer Nature. This book was released on 2021 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set constitutes the refereed post-conference proceedings of the 8th International Conference on Advancement of Science and Technology, ICAST 2020, which took place in Bahir Dar, Ethiopia, in October 2020. The 74 revised full papers were carefully reviewed and selected from more than 200 submissions of which 157 were sent out for peer review. The papers present economic and technologic developments in modern societies in 6 tracks: Chemical, food and bio-process engineering; Electrical and computer engineering; IT, computer science and software engineering; Civil, water resources, and environmental engineering; Mechanical and industrial engineering; Material science and engineering.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Turbine Aerodynamics and Vorticity Based Methods written by Emmanuel Branlard and published by Springer. This book was released on 2017-04-05 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces the fundamentals of fluid-mechanics, momentum theories, vortex theories and vortex methods necessary for the study of rotors aerodynamics and wind-turbines aerodynamics in particular. Rotor theories are presented in a great level of details at the beginning of the book. These theories include: the blade element theory, the Kutta-Joukowski theory, the momentum theory and the blade element momentum method. A part of the book is dedicated to the description and implementation of vortex methods. The remaining of the book focuses on the study of wind turbine aerodynamics using vortex-theory analyses or vortex-methods. Examples of vortex-theory applications are: optimal rotor design, tip-loss corrections, yaw-models and dynamic inflow models. Historical derivations and recent extensions of the models are presented. The cylindrical vortex model is another example of a simple analytical vortex model presented in this book. This model leads to the development of different BEM models and it is also used to provide the analytical velocity field upstream of a turbine or a wind farm under aligned or yawed conditions. Different applications of numerical vortex methods are presented. Numerical methods are used for instance to investigate the influence of a wind turbine on the incoming turbulence. Sheared inflows and aero-elastic simulations are investigated using vortex methods for the first time. Many analytical flows are derived in details: vortex rings, vortex cylinders, Hill's vortex, vortex blobs etc. They are used throughout the book to devise simple rotor models or to validate the implementation of numerical methods. Several Matlab programs are provided to ease some of the most complex implementations.
Download or read book Wind Turbines written by Abdel Ghani Aissaoui and published by BoD – Books on Demand. This book was released on 2016-07-27 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Renewable energies constitute excellent solutions to both the increase of energy consumption and environment problems. Among these energies, wind energy is very interesting. Wind energy is the subject of advanced research. In the development of wind turbine, the design of its different structures is very important. It will ensure: the robustness of the system, the energy efficiency, the optimal cost and the high reliability. The use of advanced control technology and new technology products allows bringing the wind energy conversion system in its optimal operating mode. Different strategies of control can be applied on generators, systems relating to blades, etc. in order to extract maximal power from the wind. The goal of this book is to present recent works on design, control and applications in wind energy conversion systems.
Download or read book Wind Energy Handbook written by Tony Burton and published by John Wiley & Sons. This book was released on 2001-12-12 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: As environmental concerns have focused attention on the generation of electricity from clean and renewable sources wind energy has become the world's fastest growing energy source. The Wind Energy Handbook draws on the authors' collective industrial and academic experience to highlight the interdisciplinary nature of wind energy research and provide a comprehensive treatment of wind energy for electricity generation. Features include: An authoritative overview of wind turbine technology and wind farm design and development In-depth examination of the aerodynamics and performance of land-based horizontal axis wind turbines A survey of alternative machine architectures and an introduction to the design of the key components Description of the wind resource in terms of wind speed frequency distribution and the structure of turbulence Coverage of site wind speed prediction techniques Discussions of wind farm siting constraints and the assessment of environmental impact The integration of wind farms into the electrical power system, including power quality and system stability Functions of wind turbine controllers and design and analysis techniques With coverage ranging from practical concerns about component design to the economic importance of sustainable power sources, the Wind Energy Handbook will be an asset to engineers, turbine designers, wind energy consultants and graduate engineering students.
Download or read book Individual Blade Pitch and Disturbance Accommodating Control of Floating Offshore Wind Turbines written by Hazim Namik and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floating wind turbines offer a feasible solution for going further offshore into deep waters. However, using a floating platform introduces additional motions that must be taken into account actively or passively. Therefore, the control system becomes an important component in controlling these motions. In this work, the development, implementation, and simulation of multi-objective state feedback and disturbance accommodating controllers applied on the three main floating concepts are described. The three concepts are the barge, tension leg, and spar-buoy floating platforms. These controllers utilise individual blade pitching to create asymmetric aerodynamic loads in addition to the symmetric loads created by collective blade pitching to increase the platform restoring moments. Simulation results, according to design load case 1.2 of the IEC 61400-3 standard for offshore wind turbines, show that state feedback controllers improve the performance relative to a collective blade pitch gain scheduled proportional-integral controller in terms of power and rotor speed regulation as well as reducing tower fore-aft and side-side bending loads. However, the magnitude of the improvements depends on the dynamics of each platform, its responsiveness to individual blade pitching and sensitivities to external wind and wave disturbances. Furthermore, interesting physical phenomena, such as the platform roll to pitch coupling caused by the controller, are identified. Disturbance accommodating controllers for rejecting wind speed perturbations further improve rotor speed regulation and reduce tower fore-aft bending loads except on the barge platform; the barge platform motion is dominated by incident waves and therefore rejecting wind speed perturbations has no noticeable impact. Wave moment disturbance rejection is also investigated but in a limited case study. While the approach taken can theoretically cancel the effects of incident wave moments, practically, the required actuation force cannot be generated by the wind turbine blades. Furthermore, using the blades for rejecting wave moments increases the tower bending due to the load path of the restoring moment through the tower. Out of the three investigated platforms, the tension leg platform with a disturbance accommodating controller has the best overall performance with fatigue loads close or less than that of an onshore wind turbine. The other two platforms, in their current design form, experience large tower fore-aft bending loads that would prevent them from being deployed in rough sea conditions.
Download or read book Manipulating the Flow Through Wind Farms to Increase Their Efficiency written by Daniel Houck and published by . This book was released on 2020 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind farms are adversely affected by the very wakes that are a necessary by-product of their energy extraction process. While turbines that are most upstream produce at or near their maximum power production, those downstream suffer from the reduction in available energy and increase in turbulence created by the upstream turbines. Methods to combat these effects generally either attempt to increase the available energy to the downstream turbines or mitigate the effects of the upstream turbines' wakes. Wake dissipation also requires entrainment of energy from the ambient flow into the wake, so, in fact, wake mitigation and increasing available energy are two sides of the same coin. To explore methods that would improve wind farm efficiency, we performed model-scale wind turbine experiments while recording their power production and measuring the flow. Accurately measuring power production is the subject of the first paper in which a high-accuracy torque transducer was designed and validated to facilitate mechanical power measurements with very low uncertainty. This transducer was necessary to obtain non-intrusive measurements of torque via a calibration to a turbine's current output. In the second paper, a wake mitigation technique, called dynamic induction control, was studied. With this technique, the set point of the turbine is periodically varied in an effort to trigger or accelerate instabilities in its wake. Contrary to existing literature that indicated that the oscillation frequency would be critical, results showed that the amplitude of oscillation, which corresponds to the turbine's rotation rate, had the largest effect. We theorize that switching to higher rotation rates reduces the pitch of the tip vortex helices promoting more destructive interactions among them. Accelerating the decay of the tip vortices allows for greater mixing with the ambient flow and ultimately accelerated wake decay compared to conventional steady operation. Finally, in the last paper, static axial induction control was studied with an array of five turbines while measuring the flow and turbine power in an effort to understand the fluid dynamics associated with the increase in power. In static axial induction control (AIC), upstream turbines are derated in an effort to maximize the total power production of the array, though not all turbines operate at their individual optima. While data from the power production of individual turbines and flow measurements are difficult to interpret, the total power production of the treatment using AIC was successfully increased. Flow measurements indicate that unharvested energy in the array was redistributed to the edges of the wakes as hypothesized.
Download or read book Load Mitigation Control Design for a Wind Turbine Operating in the Path of Vortices written by Maureen M. Hand and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility Studies on Disturbance Feedforward Techniques to Improve Load Mitigation Performance January 2009 January 2010 written by Jason H. Laks and published by . This book was released on 2011 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light detection and ranging systems can measure conditions at a distance in front of wind turbines, and therefore are well suited to providing preview information of wind disturbances before they impact the turbine blades. As such, this technology makes available measurements of wind speed for use in disturbance feedforward control techniques. This study investigates disturbance feedforward and preview control to better understand the best possible improvement in load mitigation using advanced wind measurement techniques.
Download or read book Independent Blade Pitch Controller Design for a Three Bladed Turbine Using Disturbance Accommodating Control Preprint written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two independent pitch controllers (IPCs) based on the disturbance accommodating control (DAC) algorithm are designed for the three-bladed Controls Advanced Research Turbine to regulate rotor speed and to mitigate blade root flapwise bending loads in above-rated wind speed. One of the DAC-based IPCs is designed based on a transformed symmetrical-asymmetrical (TSA) turbine model, with wind disturbances being modeled as a collective horizontal component and an asymmetrical linear shear component. Another DAC-based IPC is designed based on a multiblade coordinate (MBC) transformed turbine model, with a horizontal component and a vertical shear component being modeled as step waveform disturbance. Both of the DAC-based IPCs are found via a regulation equation solved by Kronecker product. Actuator dynamics are considered in the design processes to compensate for actuator phase delay. The simulation study shows the effectiveness of the proposed DAC-based IPCs compared to a proportional-integral (PI) collective pitch controller (CPC). Improvement on rotor speed regulation and once-per-revolution and twice-per-revolution load reductions has been observed in the proposed IPC designs.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Nonlinear Control Schemes for Extremum Power Seeking and Torsional Vibration Mitigation in Variable Speed Wind Turbine Systems written by Fariba Fateh and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents nonlinear control schemes to improve the productivity and lifespan of doubly fed induction generator (DFIG)-based and permanent magnet generator (PMG)-based variable speed wind turbines. To improve the productivity, a nonlinear adaptive control scheme is developed to maximize power capture. This controller consists of three feedback loops. The first loop controls electrical torque of the generator in order to cancel the nonlinear term of the turbine equation of motion using the feedback linearization concept. The nonlinearity cancelation requires a real-time estimation of aerodynamic torque. This is achieved through a second loop which estimates the ratio of the wind turbine power capture versus the available wind power. A third loop utilizes this estimate to identify the shaft speed at which the wind turbine operates at a greater power output. Contrary to existing techniques in literature, this innovative technique does not require any prior knowledge of the optimum tip speed ratio. The presented technique does not need a dither or perturbation signal to track the optimum shaft speed at the maximum power capture. These features make this technique superior to existing methods. Furthermore, the lifespan of variable speed wind turbines is improved by reducing stress on the wind turbine drivetrain. This is achieved via developing a novel vibration mitigation technique using sliding-mode control theory. The technique measures only generator speed as the input signal and then passes it through a high-pass filter in order to extract the speed variations. The filtered signal and its integral are then passed through identical band-pass filters centered at the dominant natural frequency of the drivetrain. These two signals formulate a sliding surface and consequently a control law to damp the drivetrain torsional stress oscillations caused by electrical and mechanical disturbances. This technique provides a robust mitigation approach compared with existing techniques. These control schemes are verified through holistic models of DFIG- and PMG-based wind turbines. Except for wind turbine aerodynamics, for which an existing simulator is used, the developed models of all components including DFIG, PMG, converters, multi-mass drivetrain, and power line are presented in this dissertation.
