Wind Energy Handbook. Michael Barton Graham
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Название: Wind Energy Handbook
Автор: Michael Barton Graham
Издательство: John Wiley & Sons Limited
Жанр: Физика
isbn: 9781119451167
isbn:
Consideration of wave loading leads to a survey of the different types of support structure deployed to date. Monopile, gravity bases, jacket structures, tripods, and tripiles are described in turn. In view of their popularity, monopiles are accorded the most space and, after an outline of the key design considerations, monopile fatigue analysis in the frequency domain is explained.
Another major cost element offshore is the undersea cable system needed to transmit power to land. This subject is considered in depth in the section on the power collection and transmission cable network. Machine reliability is also of much greater importance offshore, so developments in turbine condition monitoring and other means of increasing reliability are discussed. The chapter is completed by sections covering the assessment of environmental impacts, maintenance and access, and optimum machine size.
The existing chapters in the first edition have all been revised and brought up to date, with the addition of new material in some areas. The main changes are as follows:
Chapter 1: Introduction This chapter has been brought up to date and expanded.
Chapter 2: The wind resource Descriptions of the high frequency asymptotic behaviour of turbulence spectra and the Mann turbulence model have been added.
Chapters 3 and 4: Aerodynamics of horizontal axis wind turbines The contents of Chapters 3 and 4 of the first edition have been rearranged so that the fundamentals are covered in Chapter 3 and more advanced subjects are explored in Chapter 4. Some material on field testing and performance measurement has been omitted to make space for a survey of wind turbine aerofoils and new sections on dynamic stall and computational fluid dynamics.
Chapter 5: Design loads for horizontal axis wind turbines The description of IEC load cases has been brought up to date and a new section on the extrapolation of extreme loads from simulations added. The size of the ‘example’ wind turbine has been doubled to 80 m, in order to be more representative of the current generation of turbines.
Chapter 6: Conceptual design of horizontal axis wind turbines The initial sections on choice of machine size, rating, and number of blades have been substantially revised, making use of the NREL cost model. Variable speed operation is considered in greater depth. The section on tower stiffness has been expanded to compare tower excitation at rotational frequency and blade passing frequency.
Chapter 7: Component design New rules for designing towers against buckling are described and a section on foundation rotational stiffness has been added.
Chapter 8: The controller Individual blade pitch control is examined in greater depth.
Chapter 9: Wind turbine installations and wind farms A survey of recent research on the impact of turbines on birds has been added.
Chapter 10: Electrical systems New sections covering (a) Grid Code requirements for the connection of large wind farms to transmission networks and (b) the impact of wind farms on generation systems have been added.
Preface to Third Edition
The 10 years since the preparation of the second edition of the Wind Energy Handbook have seen further innovation in many areas of turbine design, and these form the basis for the changes in this new edition. Refinements to blade design, together with improved and better‐understood material properties, have enabled the trend to larger machines to continue. Upwind, three bladed, pitch‐regulated, variable‐speed machines are still firmly established as the norm, despite the scope for the deployment of two bladed downwind machines offshore. However, the one‐time monopoly of high‐speed gearboxes continues to be eroded, thanks to the rise of direct drive turbines and the increased use of medium‐speed gearboxes with permanent magnet generators. The design of fixed offshore support structures continues to evolve, but the most exciting development has been the successful deployment of floating wind turbines.
The third edition retains most of the material of the previous edition, as the fundamental theory underpinning wind turbine design has not changed, but many chapters have been expanded to cover recent developments. In view of the significant effects of wakes on wind farm energy yield and turbine loadings, the opportunity has been taken to add a completely new chapter (Chapter 9) entitled ‘Wake Effects and Wind Farm Control’. This includes a detailed treatment of engineering models of the wake and their implications for wind farm control, which is emerging as a way to both increase wind farm energy production and reduce turbine fatigue loading by mitigating wake interaction effects. There is also a section on wind farm control and the grid system, recognising the increasing importance of using wind farms to provide ancillary services to the grid.
The main changes to the existing chapters are as follows:
Chapter 1: Introduction This chapter has been brought up to date to reflect the continuing increase in the size of wind turbines and wind farms.
Chapter 2: The Wind Resource Updated to include edition 4 of the IEC standard. An illustrative example of the Gumbel method for extreme winds has been added. The description of turbulence in wakes and wind farms has been replaced by a more comprehensive treatment in the new Chapter 9.
Chapters 3 and 4: Aerodynamics of Horizontal Axis Wind Turbines, and Further Aerodynamic Topics for Wind Turbines Chapters 3 and 4 continue the split, as in the second edition, between fundamentals in Chapter 3 and more advanced topics in Chapter 4. In Chapter 3, minor changes have been made to Section 3.8 dealing with the tip‐loss factor, and additions have been inserted on flat‐back aerofoils and low noise designs in Sections 3.17 and 3.19 with new sections on ‘add‐on’ devices to control separation, lift, and drag (3.18) and on aerodynamic noise and blade design (3.19). The appendix to chapter 3 has been shortened by abbreviating the section on drag. In Chapter 4, Section 4.3, the mathematical analysis of the Kinner circular wing, has been abbreviated, retaining the final results, the Section 4.6 on dynamic stall has been extended and a new Section 4.7 on applications of computational fluid dynamics to rotor aerodynamics and wakes has been added.
Chapter 5: Design Loads for HAWTs The changes are mainly minor. The description of IEC load cases СКАЧАТЬ