Analysis And Study Of Floating Offshore Wind Turbines

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Analysis and Study of Floating Offshore Wind Turbines

Author : Mehran Ahmadi
Publisher :
ISBN 13 :
Total Pages : 99 pages
Book Rating : 4.:/5 (879 download)

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Book Synopsis Analysis and Study of Floating Offshore Wind Turbines by : Mehran Ahmadi

Download or read book Analysis and Study of Floating Offshore Wind Turbines written by Mehran Ahmadi and published by . This book was released on 2013 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floating wind turbines offer a means to vastly expand the number of possible sites for offshore wind energy plants. By using a floating support platform secured by mooring lines, a wind turbine can be installed in waters exceeding the 30m depth that limits installation of conventional bottom-fixed offshore wind turbines. However, to be economically viable advances in floating offshore wind turbine system design and deployment are necessary to significantly reduce the cost and improve the reliability of floating wind turbines. This thesis develops a model-based simulation of floating offshore wind turbines in the MATLAB/Simulink environment. When necessary, the National Renewable Energy Laboratory's FAST code is used to conduct wind turbine simulations. Methods to link FAST to Simulink are developed in this thesis to accomplish this task. Modeling the wind turbine in the Simulink environment enables an efficient system level view of the entire wind turbine system. A number of design approaches to reduce the cost of offshore turbines are proposed in this thesis and studied in this modeling environment. A doubly-fed induction generator (DFIG) is proposed for wind turbine application. The primary advantage of DFIGs for wind turbines is that they allow the amplitude and frequency of their output voltages to be maintained at a constant value, no matter the wind speed. Because of this feature, DFIGs can be directly connected to the AC power network and remain synchronized at all times with that power network. Another advantage is the ability to control the power factor while keeping the power electronic devices in the wind turbine at a moderate size. In order to link a Simulink DFIG model to FAST, the model must be expressed in time domain. This thesis develops the time-domain modeling and simulation of DFIGs. Floating offshore wind turbines encounter greatly increased loading, which decreases fatigue life. One method to reduce the cost and mitigate offshore wind turbine structural loads is the application of structural control techniques commonly used in skyscrapers and bridges. Tuned mass dampers have been used to reduce loads in simulations of offshore wind turbines. This thesis discusses expanding the structural control methods by developing a set of optimum passive and active tuned mass dampers for offshore wind turbine platforms. Additionally, a new, high-efficiency, DC/DC bidirectional converter for a power quality conditioner for floating offshore wind turbines is proposed and analyzed. The power quality conditioner is used to smooth the variable turbine power and the DC/DC bidirectional converter acts as an interface circuit between the DC bus and ultracapacitors to manage the power flow during charging and discharging modes. Simulation results and experimental results are presented to verify the operation of the converter.

Floating Offshore Wind Energy

Author : Joao Cruz
Publisher : Springer
ISBN 13 : 3319293982
Total Pages : 345 pages
Book Rating : 4.3/5 (192 download)

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Book Synopsis Floating Offshore Wind Energy by : Joao Cruz

Download or read book Floating Offshore Wind Energy written by Joao Cruz and published by Springer. This book was released on 2016-08-20 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a state-of-the-art review of floating offshore wind turbines (FOWT). It offers developers a global perspective on floating offshore wind energy conversion technology, documenting the key challenges and practical solutions that this new industry has found to date. Drawing on a wide network of experts, it reviews the conception, early design stages, load & structural analysis and the construction of FOWT. It also presents and discusses data from pioneering projects. Written by experienced professionals from a mix of academia and industry, the content is both practical and visionary. As one of the first titles dedicated to FOWT, it is a must-have for anyone interested in offshore renewable energy conversion technologies.

Floating Offshore Wind Farms

Author : Laura Castro-Santos
Publisher : Springer
ISBN 13 : 3319279726
Total Pages : 204 pages
Book Rating : 4.3/5 (192 download)

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Book Synopsis Floating Offshore Wind Farms by : Laura Castro-Santos

Download or read book Floating Offshore Wind Farms written by Laura Castro-Santos and published by Springer. This book was released on 2016-03-05 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of floating offshore wind farms and focuses on the economic aspects of this renewable-energy technology. It presents economic maps demonstrating the main costs, and explores various important aspects of floating offshore wind farms. It examines topics including offshore wind turbines, floating offshore wind platforms, mooring and anchoring, as well as offshore electrical systems. It is a particularly useful resource in light of the fact that most water masses are deep and therefore not suitable for fixed offshore wind farms. A valuable reference work for students and researchers interested in naval and ocean engineering and economics, this book provides a new perspective on floating offshore wind farms, and makes a useful contribution to the existing literature.

Offshore Mechanics

Author : Madjid Karimirad
Publisher : John Wiley & Sons
ISBN 13 : 1119216621
Total Pages : 305 pages
Book Rating : 4.1/5 (192 download)

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Book Synopsis Offshore Mechanics by : Madjid Karimirad

Download or read book Offshore Mechanics written by Madjid Karimirad and published by John Wiley & Sons. This book was released on 2018-05-07 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers theoretical concepts in offshore mechanics with consideration to new applications, including offshore wind farms, ocean energy devices, aquaculture, floating bridges, and submerged tunnels This comprehensive book covers important aspects of the required analysis and design of offshore structures and systems and the fundamental background material for offshore engineering. Whereas most of the books currently available in the field use traditional oil, gas, and ship industry examples in order to explain the fundamentals in offshore mechanics, this book uses more recent applications, including recent fixed-bottom and floating offshore platforms, ocean energy structures and systems such as wind turbines, wave energy converters, tidal turbines and hybrid marine platforms. Offshore Mechanics covers traditional and more recent methodologies used in offshore structure modelling (including SPH and hydroelasticity models). It also examines numerical techniques, including computational fluid dynamics and finite element method. Additionally, the book features easy-to-understand exercises and examples. Provides a comprehensive treatment for the case of recent applications in offshore mechanics for researchers and engineers Presents the subject of computational fluid dynamics (CFD) and finite element methods (FEM) along with the high fidelity numerical analysis of recent applications in offshore mechanics Offers insight into the philosophy and power of numerical simulations and an understanding of the mathematical nature of the fluid and structural dynamics with focus on offshore mechanic applications Offshore Mechanics: Structural and Fluid Dynamics for Recent Applications is an important book for graduate and senior undergraduate students in offshore engineering and for offshore engineers and researchers in the offshore industry.

Coupled Dynamic Analysis of Floating Offshore Wind Farms

Author : Sangyun Shim
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (69 download)

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Book Synopsis Coupled Dynamic Analysis of Floating Offshore Wind Farms by : Sangyun Shim

Download or read book Coupled Dynamic Analysis of Floating Offshore Wind Farms written by Sangyun Shim and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past decade, the demand for clean renewable energy continues to rise drastically in Europe, the US, and other countries. Wind energy in the ocean can possibly be one of those future renewable clean energy sources as long it is economically feasible and technologically manageable. So far, most of the offshore wind farm research has been limited to fixed platforms in shallow-water areas. In the water depth deeper than 30m, however, floating-type wind farms tend to be more feasible. Then, the overall design and engineering becomes more complicated than fixed platforms including the coupled dynamics of platforms, mooring lines, and blades. In the present study, a numerical time-domain model has been developed for the fully coupled dynamic analysis of an offshore floating wind turbine system including blade-rotor dynamics and platform motions. As a test case, the TLP-type floater system with 3 blades of 70-m diameter designed by the National Renewable Energy Laboratory (NREL) is selected to analyze the dynamic coupling effects among floating system, mooring lines, and wind turbine. The performance of the selected system in a typical wind-wave-current condition has been simulated and analyzed. A similar study for the floater and rotor coupled dynamic analysis was conducted by MIT and NREL. However, in the present case, the dynamic coupling between platform and mooring lines are also considered in addition to the rotor-floater dynamic coupling. It is seen that the rotor-floater coupling effects increase with wind velocity and blade size. The increased coupling effects tend to increase the dynamic tension of TLP tethers. The developed technology and numerical tool are applicable to the new offshore floating wind farms planned in the future.

Design Load Analysis of Two Floating Offshore Wind Turbine Concepts

Author : Gordon M. Stewart
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (945 download)

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Book Synopsis Design Load Analysis of Two Floating Offshore Wind Turbine Concepts by : Gordon M. Stewart

Download or read book Design Load Analysis of Two Floating Offshore Wind Turbine Concepts written by Gordon M. Stewart and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of the United States' wind resource is located over deep water where fixed-bottom offshore wind turbines are cost-prohibitive. To capture this energy, floating offshore wind turbines are being developed. However, current design standards do not explicitly cover issues relating to floating offshore wind turbines, which leads to risk and uncertainty in the design process. Two important issues that this dissertation investigates are the effect of simulation length and wind and wave misalignment on fatigue and ultimate loads. Experience in the offshore floating oil and gas industry has recommended simulation lengths of 3-6 hours, but the wind industry typically simulates between 10 minutes and one hour. The reasons for these simulation lengths is explored and recommendations for floating offshore wind turbines are made. The current offshore wind turbine design standard states that co-aligned wind and waves are a conservative ``worst-case'' scenario for loads, but this assertion may only hold true for fixed-bottom offshore turbines. A large operational design-space set of simulations are run to determine the impact of wind and wave misalignment on floating offshore turbines. Using results from both the simulation length and wind/wave misalignment study, probabilistic methods are used to determine a minimum set of simulations that is able to accurately characterize the loads response of floating platforms. Reduction of avian impacts have long been an important concern for the installation of wind farms. There is large uncertainty in the impacts of offshore wind farms on seabirds in the United States, as no offshore wind farms are currently operating. In this dissertation, experience from Europe is used to create a model of seabirds' interaction with fixed-bottom offshore wind farms. This model is used in a multi-objective optimization of the layout of a generic fixed-bottom offshore wind farm, considering both impacts on birds as well as power production. To simulate a farm comprised of floating offshore wind turbines, uncertainty in the positions of the turbines in the farm is introduced, and the layout is once again subjected to a multi-objective optimization.

Offshore Wind Energy Technology

Author : Olimpo Anaya-Lara
Publisher : John Wiley & Sons
ISBN 13 : 1119097789
Total Pages : 459 pages
Book Rating : 4.1/5 (19 download)

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Book Synopsis Offshore Wind Energy Technology by : Olimpo Anaya-Lara

Download or read book Offshore Wind Energy Technology written by Olimpo Anaya-Lara and published by John Wiley & Sons. This book was released on 2018-05-11 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: A COMPREHENSIVE REFERENCE TO THE MOST RECENT ADVANCEMENTS IN OFFSHORE WIND TECHNOLOGY Offshore Wind Energy Technology offers a reference based on the research material developed by the acclaimed Norwegian Research Centre for Offshore Wind Technology (NOWITECH) and material developed by the expert authors over the last 20 years. This comprehensive text covers critical topics such as wind energy conversion systems technology, control systems, grid connection and system integration, and novel structures including bottom-fixed and floating. The text also reviews the most current operation and maintenance strategies as well as technologies and design tools for novel offshore wind energy concepts. The text contains a wealth of mathematical derivations, tables, graphs, worked examples, and illustrative case studies. Authoritative and accessible, Offshore Wind Energy Technology: Contains coverage of electricity markets for offshore wind energy and then discusses the challenges posed by the cost and limited opportunities Discusses novel offshore wind turbine structures and floaters Features an analysis of the stochastic dynamics of offshore/marine structures Describes the logistics of planning, designing, building, and connecting an offshore wind farm Written for students and professionals in the field, Offshore Wind Energy Technology is a definitive resource that reviews all facets of offshore wind energy technology and grid connection.

Offshore Wind Energy Technology

Author : Olimpo Anaya-Lara
Publisher : John Wiley & Sons
ISBN 13 : 1119097762
Total Pages : 455 pages
Book Rating : 4.1/5 (19 download)

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Book Synopsis Offshore Wind Energy Technology by : Olimpo Anaya-Lara

Download or read book Offshore Wind Energy Technology written by Olimpo Anaya-Lara and published by John Wiley & Sons. This book was released on 2018-05-29 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: A COMPREHENSIVE REFERENCE TO THE MOST RECENT ADVANCEMENTS IN OFFSHORE WIND TECHNOLOGY Offshore Wind Energy Technology offers a reference based on the research material developed by the acclaimed Norwegian Research Centre for Offshore Wind Technology (NOWITECH) and material developed by the expert authors over the last 20 years. This comprehensive text covers critical topics such as wind energy conversion systems technology, control systems, grid connection and system integration, and novel structures including bottom-fixed and floating. The text also reviews the most current operation and maintenance strategies as well as technologies and design tools for novel offshore wind energy concepts. The text contains a wealth of mathematical derivations, tables, graphs, worked examples, and illustrative case studies. Authoritative and accessible, Offshore Wind Energy Technology: Contains coverage of electricity markets for offshore wind energy and then discusses the challenges posed by the cost and limited opportunities Discusses novel offshore wind turbine structures and floaters Features an analysis of the stochastic dynamics of offshore/marine structures Describes the logistics of planning, designing, building, and connecting an offshore wind farm Written for students and professionals in the field, Offshore Wind Energy Technology is a definitive resource that reviews all facets of offshore wind energy technology and grid connection.

Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine

Author : Yoon Hyeok Bae
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (868 download)

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Book Synopsis Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine by : Yoon Hyeok Bae

Download or read book Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine written by Yoon Hyeok Bae and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present study, a numerical simulation tool has been developed for the rotor-floater-tether coupled dynamic analysis of Multiple Unit Floating Offshore Wind Turbine (MUFOWT) in the time domain including aero-blade-tower dynamics and control, mooring dynamics and platform motion. In particular, the numerical tool developed in this study is based on the single turbine analysis tool FAST, which was developed by National Renewable Energy Laboratory (NREL). For linear or nonlinear hydrodynamics of floating platform and generalized-coordinate-based FEM mooring line dynamics, CHARM3D program, hull-riser-mooring coupled dynamics program developed by Prof. M.H. Kim's research group during the past two decades, is incorporated. So, the entire dynamic behavior of floating offshore wind turbine can be obtained by coupled FAST-CHARM3D in the time domain. During the coupling procedure, FAST calculates all the dynamics and control of tower and wind turbine including the platform itself, and CHARM3D feeds all the relevant forces on the platform into FAST. Then FAST computes the whole dynamics of wind turbine using the forces from CHARM3D and return the updated displacements and velocities of the platform to CHARM3D. To analyze the dynamics of MUFOWT, the coupled FAST-CHARM3D is expanded more and re-designed. The global matrix that includes one floating platform and a number of turbines is built at each time step of the simulation, and solved to obtain the entire degrees of freedom of the system. The developed MUFOWT analysis tool is able to compute any type of floating platform with various kinds of horizontal axis wind turbines (HAWT). Individual control of each turbine is also available and the different structural properties of tower and blades can be applied. The coupled dynamic analysis for the three-turbine MUFOWT and five-turbine MUFOWT are carried out and the performances of each turbine and floating platform in normal operational condition are assessed. To investigate the coupling effect between platform and each turbine, one turbine failure event is simulated and checked. The analysis shows that some of the mal-function of one turbine in MUFOWT may induce significant changes in the performance of other turbines or floating platform. The present approach can directly be applied to the development of the remote structural health monitoring system of MUFOWT in detecting partial turbine failure by measuring tower or platform responses in the future. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149465

The Elements of Aerofoil and Airscrew Theory

Author : Hermann Glauert
Publisher :
ISBN 13 :
Total Pages : 246 pages
Book Rating : 4.:/5 (89 download)

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Book Synopsis The Elements of Aerofoil and Airscrew Theory by : Hermann Glauert

Download or read book The Elements of Aerofoil and Airscrew Theory written by Hermann Glauert and published by . This book was released on 1926 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Wave and Tidal Energy

Author : Deborah Greaves
Publisher : John Wiley & Sons
ISBN 13 : 1119014476
Total Pages : 761 pages
Book Rating : 4.1/5 (19 download)

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Book Synopsis Wave and Tidal Energy by : Deborah Greaves

Download or read book Wave and Tidal Energy written by Deborah Greaves and published by John Wiley & Sons. This book was released on 2018-03-28 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eine umfassende Publikation zu sämtlichen Aspekten der Wellen- und Gezeitenenergie. Wave and Tidal Energy gibt einen ausführlichen Überblick über die Entwicklung erneuerbarer Energie aus dem Meer, bezieht sich auf die neueste Forschung und Erfahrungen aus Anlagentests. Das Buch verfolgt zwei Ziele, zum einen vermittelt es Einsteigern in das Fachgebiet eine Überblick über die Wellen- und Gezeitenenergie, zum anderen ist es ein Referenzwerk für komplexere Studien und die Praxis. Es vermittelt Detailwissen zu wichtigen Themen wie Ressourcencharakterisierung, Technologie für Wellen- und Gezeitenanlagen, Stromversorgungssysteme, numerische und physikalische Modellierung, Umwelteffekte und Politik. Zusätzlich enthält es eine aktuelle Übersicht über Entwicklungen in der ganzen Welt sowie Fallstudien zu ausgewählten Projekten. Hauptmerkmale: - Ausführliches Referenzwerk zu allen Aspekten der interdisziplinären Fachrichten Wellen- und Gezeitenenergie. - Greift auf die neuesten Forschungsergebnisse und die Erfahrung führender Experten in der numerischen und laborgestützten Modellierung zurück. - Gibt einen Überblick über regionale Entwicklungen in aller Welt, repräsentative Projekte werden in Fallstudien vorgestellt. Wave and Tidal Energy ist ein wertvolles Referenzwerk für eine breite Leserschaft, von Studenten der Ingenieurwissenschaften und technischen Managern über politische Entscheidungsträger bis hin zu Studienabsolventen und Forschern.

Station Keeping Analysis and Design for New Floating Offshore Wind Turbines

Author : Pau Trubat Casal
Publisher :
ISBN 13 :
Total Pages : 166 pages
Book Rating : 4.:/5 (122 download)

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Book Synopsis Station Keeping Analysis and Design for New Floating Offshore Wind Turbines by : Pau Trubat Casal

Download or read book Station Keeping Analysis and Design for New Floating Offshore Wind Turbines written by Pau Trubat Casal and published by . This book was released on 2020 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the framework of the reduction of the emissions of greenhouse gases, FOWT will be the technology that will exploit the wind resources in deep seas. In order to achieve a commercial deployment of this technology, a cost reduction is necessary through the optimization of the wind turbine by detailed studies to reduce its design uncertainties. One important aspect is the mooring system, which commonly represents between a 10 to 15 % of the capex. The present research aims to increase the knowledge of the design and analysis of the station keeping systems for floating offshore wind turbines. One of the most important aspects for a correct analysis and design of the mooring system is the simulation of the lines coupled with the floating structure and the wind turbine.In this dissertation, two different mooring line models coupled to a finite element model for the analysis of floating platforms are presented. The first model is a finite element model based on a slender rod approach. The model is extended to consider the rheological damping in the axial and bending direction within the constitutive equations of the problem. The second model is a new approach named quasi-dynamic model. The model assesses the static solution of the catenary equation but updates the line tension based on the external hydrodynamic forces and the inertial forces from the theoretical motion of the mooring line.In the design of mooring lines is important to consider and foresee the different phenomena and loads that can act along on the life span of these elements. Within these phenomena, the effects of the waves forces over the mooring lines o have been studied. The study analyzes the contribution of the wave forces over the mooring lines to determine when it is an important source of damage for the fatigue strength. Finally, new floating platform concepts need to be tested and analyzed in controlled conditions in order to validate the models used for the final designs. It is common that pool and flume basins do not present enough size for the catenary shape mooring systems because they cover a large extension. In this area, an optimization model for a truncated mooring system is presented. The truncated mooring system is formed by two types of chains to emulate the actual prototype mooring system of a scale spar platform in a narrow flume.

Offshore Energy Structures

Author : Madjid Karimirad
Publisher : Springer
ISBN 13 : 3319121758
Total Pages : 307 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis Offshore Energy Structures by : Madjid Karimirad

Download or read book Offshore Energy Structures written by Madjid Karimirad and published by Springer. This book was released on 2014-12-05 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides all the key information needed to design offshore structures for renewable energy applications successfully. Suitable for practicing engineers and students, the author conveys design principles and best practices in a clear, concise manner, focusing on underlying physics while eschewing complicated mathematical detail. The text connects underlying scientific theory with industry standards and practical implementation issues for offshore wind turbines, wave energy converters and current turbines. Combined concepts such as wave-wind energy platforms are discussed, as well. Coverage of design codes and numerical tools ensures the usefulness of this resource for all those studying and working in the rapidly expanding field of offshore renewable energy.

Scale Model Experiments on Floating Offshore Wind Turbines

Author : Syed Kazim Naqvi
Publisher :
ISBN 13 :
Total Pages : 216 pages
Book Rating : 4.:/5 (833 download)

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Book Synopsis Scale Model Experiments on Floating Offshore Wind Turbines by : Syed Kazim Naqvi

Download or read book Scale Model Experiments on Floating Offshore Wind Turbines written by Syed Kazim Naqvi and published by . This book was released on 2012 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This research focuses on studying the feasibility of placing large wind turbines on deep-ocean platforms. Water tank studies have been conducted using the facilities at Alden Research Laboratories (ARL) on 100:1 scale Tension Leg Platform (TLP) and Spar Buoy (SB) models. Froude scaling was used for modeling the offshore wind turbine designs. Primary components of the platform turbine, tower, and cable attachments were fabricated in ABS plastic using rapid prototyping. A wireless data acquisition system was installed to prevent umbilical data cables from affecting the behavior of the platform when exposed to wave loading. In Phase I testing, Froude-scaled TLP and Spar Buoy models at a 100:1 scale were placed in a water flume and exposed to periodic waves at amplitudes ranging from 0.5 cm - 7.5 cm and frequencies ranging from 0.25 Hz - 1.5 Hz. The testing was conducted on simple tower and turbine models that only accounted for turbine weight at the nacelle. In Phase II testing, emphasis was placed on further testing of the tension leg platform as a more viable design for floating offshore wind turbines. The tension leg platform scale model was improved by adding a disc to simulate drag force incident at the top of the tower, as well as a rotor and blades to simulate the gyroscopic force due to turbine blade rotation at the top of the tower. Periodic wave motions of known amplitude and frequency were imposed on the model to study pitch, heave, roll, surge, sway motions and mooring cable tensions (in Phase II only) using accelerometers, inclinometers, capacitance wave gage, and load cells. Signal analysis and filtering techniques were used to refine the obtained data, and a Fourier analysis was conducted to study the dominant frequencies. Finally, Response Amplitude Operators (RAO's) were plotted for each data set to standardize the results and study the overall trend with respect to changes in wave amplitude and frequency. For Phase I testing, it is shown that surge motion of the platform dominates other motions for both the tension leg platform and spar buoy, and varying tether pretension has little effect on response amplitude operator values. For phase II testing, it was found that the introduction of thrust and gyroscopic forces increases sway and pitch motions as well as upstream tether forces. Coupling effects of pitch motion with roll and sway due to the presence of gyroscopic forces were also seen. The present experimental results can be used to validate the hydrodynamic kernels of linear frequency-domain models, time-domain dynamics models, and computational simulations on floating wind turbines. Numerical analysis and simulations have been conducted in a separate study at WPI. These simulations are comparable to the experimental results.

Technical-economic Analysis, Modeling and Optimization of Floating Offshore Wind Farms

Author : Markus Lerch
Publisher :
ISBN 13 :
Total Pages : 245 pages
Book Rating : 4.:/5 (122 download)

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Book Synopsis Technical-economic Analysis, Modeling and Optimization of Floating Offshore Wind Farms by : Markus Lerch

Download or read book Technical-economic Analysis, Modeling and Optimization of Floating Offshore Wind Farms written by Markus Lerch and published by . This book was released on 2020 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: The offshore wind sector has grown significantly during the last decades driven by the increasing demand for clean energy and to reach defined energy targets based on renewable energies. As the wind speeds tend to be faster and steadier offshore, wind farms at sea can reach higher capacity factors compared to their onshore counterparts. Furthermore, fewer restrictions regarding land use, visual impact, and noise favors the application of this technology. However, most of today's offshore wind farms use bottom-fixed foundations that limit their feasible application to shallow water depths.Floating substructures for offshore wind turbines are a suitable solution to harness the full potential of offshore wind as they have less constraints to water depths and soil conditions and can be applied from shallow to deep waters. As several floating offshore wind turbine (FOWT) concepts have been successfully tested in wave tanks and prototypes have been proven in open seas, floating offshore wind is now moving towards the commercial phase with the first floating offshore wind farm (FOWF) commissioned in 2017 and several more are projected to be constructed in 2020. This transition increases the need for comprehensive tools that allow to model the complete system and to predict its behavior as well as to assess the performance for different locations. The aim of this thesis is to analyze from a technical and economic perspective commercial scale FOWFs. This includes the modeling of FOWTs and the study of their dynamic behavior as well as the economic assessment of different FOWT concepts. The optimization of the electrical layout is also addressed in this thesis.The first model developed is applied to analyze the performance of a Spar type FOWT. The model is tested with different load cases and compared to a reference model. The results of both models show an overall good agreement. Afterwards, the developed model is applied to study the behavior of the FOWT with respect to three different offshore sites. Even at the site with the harshest conditions and largest motions, no significant loss in energy generation is measured, which demonstrates the good performance of this concept. The second model is used to perform a technical-economic assessment of commercial scale FOWFs. It includes a comprehensive LCOE methodology based on a life cycle cost estimation as well as the computation of the energy yield. The model is applied to three FOWT concepts located at three different sites and considering a 500MW wind farm configuration. The findings indicate that FOWTs are a high competitive solution and energy can be produced at an equal or lower LCOE compared to bottom-fixed offshore wind or ocean energy technologies. Furthermore, a sensitivity analysis is performed to identify the key parameters that have a significant influence on the LCOE and which can be essential for further cost reductions.The last model is aimed to optimize the electrical layout of FOWFs based on the particle swarm optimization theory. The model is validated against a reference model at first and is then used to optimize the inter-array cable routing of a 500MW FOWF. The obtained electrical layout results in a reduction of the power cable costs and a decrease of the energy losses. Finally, the use of different power cable configurations is studied and it is shown that the use of solely dynamic power cables in comparison to combined dynamic and static cables results in decreased acquisition and installation costs due to the avoidance of cost-intensive submarine joints and additional installation activities.

Advanced Wind Turbine Technology

Author : Weifei Hu
Publisher : Springer
ISBN 13 : 3319781669
Total Pages : 351 pages
Book Rating : 4.3/5 (197 download)

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Book Synopsis Advanced Wind Turbine Technology by : Weifei Hu

Download or read book Advanced Wind Turbine Technology written by Weifei Hu and published by Springer. This book was released on 2018-05-07 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the current challenges in modern wind turbine analysis, design and development, and provides a comprehensive examination of state-of-the-art technologies from both academia and industry. The twelve information-rich chapters cover a wide range of topics including reliability-based design, computational fluid dynamics, gearbox and bearing analyses, lightning analysis, structural dynamics, health condition monitoring, advanced techniques for field repair, offshore floating wind turbines, advanced turbine control and grid integration, and other emerging technologies. Each chapter begins with the current status of technology in a lucid, is easy-to-follow treatment, then elaborates on the corresponding advanced technology using detailed methodologies, graphs, mathematical models, computational simulations, and experimental instrumentation. Relevant to a broad audience from students and faculty to researchers, manufacturers, and wind energy engineers and designers, the book is ideal for both educational and research needs. Presents the latest developments in reliability-based design optimization, CFD of wind turbines, structural dynamics for wind turbine blades, off-shore floating wind turbines, advanced wind turbine control, and wind power and ramp forecasting for grid integration; Includes techniques for wind turbine gearboxes and bearings, evaluation of lightning strike damage, health condition monitoring and reparation techniques; Illustrates theories and operational considerations using graphics, tables, computational algorithms, simulation models, and experimental instrumentation; Examines unique, innovative technologies for wind energy.

Dynamic Analysis of a Spar-type Offshore Floating Wind Turbine and Its Mooring System

Author : Xue Xu
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

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Book Synopsis Dynamic Analysis of a Spar-type Offshore Floating Wind Turbine and Its Mooring System by : Xue Xu

Download or read book Dynamic Analysis of a Spar-type Offshore Floating Wind Turbine and Its Mooring System written by Xue Xu and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for developing sustainable and renewable energy is increasing due to the greenhouse gas effect and the reducing availability of fossil fuels. Wind energy is one of the cleanest and most sustainable renewable resources. People mainly use two types of wind turbines - onshore and offshore, to harvest the wind energy. Compared with onshore wind, offshore wind resources allow more reliable generation of electricity. In shallow water, bottom-fixed turbines may be used. However, as water depths increase it becomes increasingly difficult to build suitable fixed foundations, and floating offshore wind turbines become attractive. The OC3-Hywind is an offshore floating wind turbine (OFWT) supported by a spar platform and held in place with three mooring lines. It is important to study the dynamic responses of the floating platform and the mooring system behaviour so that the OFWT can be designed and constructed safely and economically and generate electricity with reliability. However, there are not many studies which have validated the numerical simulation results for floating offshore wind turbines with physical experiments while published studies rarely show the details of the mooring line motion behaviour for OFWTs. This thesis investigates the dynamic behaviour of a spar-type OFWT including its mooring systems, analysed under various environmental loads both by using state-of-the-art numerical software and conducting an experiment campaign at the Kelvin Hydrodynamics Laboratory. The free decay test has been carried out first to get the spar platform's motions natural frequencies and damping characteristics. A range of regular and irregular waves has been applied to the platform (both with and without realistic mooring lines) to obtain the platform motion RAO (response amplitude operator) - which can be used to predict the platform dynamic responses under other wave conditions - and to examine the reliability of the numerical predictions under realistic sea conditions. For the mooring line tensions and motion, the software shows its limitations in the calculation. A non-linear snatching phenomenon has been observed at the tank for some wave frequencies, which has rarely been discussed in published research. It is very important to study this non-linear behaviour as it is shown that snatching leads to the high instantaneous mooring line loads and platform accelerations, which could cause the failure of the mooring lines in the real structure.