Wind Turbines: Theory and Practice

Description

In the multi-disciplinary field of wind energy, students and professionals can often be uncomfortable outside their own specialist areas. This essential textbook explains the key aspects of wind turbine technology and its application in a single readable text. Covering a broad range of multi-disciplinary topics, including everything from aerodynamics through to electrical and control theory, to structures, planning, economics, and policy, this reference is an excellent toolkit for undergraduate students, postgraduate students, and professionals in the field of wind energy. Key concepts, including more challenging ones such as rotational sampling of turbulence, vortex wake structures, and reactive power management, are explained using clear language and simplifying illustrations including experimental graphs, photos, and line drawings. Contents Acknowledgements Preface Chapter Overview 1 Introduction 1.1 A Wake-Up Call 1.2 Early History 1.3 The First Wind Turbines 1.4 The Wind Revolution 1.5 Scaling Up 1.6 Some Definitions 2 The Wind and Its Characteristics 2.1 Introduction 2.1.1 The Geostrophic and Gradient Winds 2.2 Wind Shear and Turbulence 2.2.1 Shear Profiles 2.2.2 Turbulence 2.3 Time and Space Scales 2.4 Gust and Extreme Wind Speeds 2.5 The Weibull Wind Distribution 2.6 Topographic Factors 2.7 Exercises 3 Aerodynamic Theory 3.1 Introduction 3.2 The Actuator Disc 3.3 Multiple Streamtube Theory 3.4 Blade Element (2D Wing) Theory 3.5 BEM: The Combined Theory 3.6 Modifications to BEM Theory 3.6.1 Inclusion of Drag 3.6.2 Tangential Induction Factor 3.6.3 Momentum Theory Correction 3.6.4 Radial Flow and Stall Delay 3.6.5 Tip Loss Correction 3.7.2 Vortex Wake Analysis 3.7.3 Near-Wake Measurements 3.8 Operation in Yaw 3.9 Unsteady Aerodynamic Influences 3.9.1 Stall Effects 3.9.2 Dynamic Inflow 3.10 Exercises 4 Rotor Design and Performance 4.1 Introduction 4.2 Power, Thrust, and Torque 4.3 The Cp, λ Curve 4.4 Tip Speed Ratio and Solidity 4.5 Blade Twist and Pitch 4.6 Blade Number 4.7 Rotor Aerodynamic Control 4.7.1 Stall Regulation: Fixed Pitch 4.7.2 Pitch Control 4.7.3 Other Aerodynamic Control Devices 4.8 Downwind Rotors 4.9 Exercises 5 Electrical Aspects 5.1 Introduction 5.2 Fundamentals 5.3 Measurement and Metering 5.4 Generators 5.4.1 Introduction 5.4.2 Characteristics of Different Generator Types 5.4.3 Variable-Speed Generators 5.4.4 Geared and Gearless (Direct Drive) Generators 5.4.5 Historic Developments 5.5 Power Quality 5.5.1 Network Characteristics 5.5.2 Steady-State Voltage 5.5.3 Flicker 5.5.4 Statcoms and SVCs 5.5.5 Fault Protection 5.5.6 Harmonics 5.7 Lightning Protection 5.8 Exercises 6 Control 6.1 Introduction: Levels of Control 6.2 Yaw Control 6.3 Power Limiting 6.3.1 Stall Regulation 6.3.2 Constant Speed, Variable Pitch (CSVP) 6.3.3 Variable Speed, Variable Pitch (VSVP) 6.4 Starting and Stopping 6.5 Sector Management 6.6 Exercises 7 Structural Loading and Response 7.1 Introduction 7.2 Fundamentals 7.2.1 Static and Dynamic Loads 7.2.2 Dynamic Response of a Simple System 7.2.3 Modal Analysis 7.2.4 Deterministic and Stochastic Loads 7.3 Aerodynamic Loads 7.3.1 Reference Frames 7.3.2 Steady Loads 7.3.3 Deterministic Loads 7.3.4 Stochastic Loads 7.4 Gravitational Loads 7.5 Gyroscopic and Centrifugal Loads 7.6 Electromechanical Loads 7.7 Vibration and Resonance 7.7.1 Aerodynamic Damping 7.7.2 Tower Resonance 7.7.3 Blade Edgewise Vibration 7.8 Dynamic Response Measurements 7.8.1 Introduction 7.8.2 Mean Loads 7.8.3 Load Spectra 7.8.4 Stochastic and Deterministic Loads 7.9 Complete Load Prediction 7.10 Exercises 8 Rotor Blade Technology 8.1 Introduction 8.2 Properties of Fibre-Reinforced Composites 8.3 Blade Structure 8.3.1 Cantilever Beam Model 8.3.2 Compressive Buckling 8.3.3 Shear 8.3.4 Elements of a Composite Blade 8.3.5 Bending Analysis 8.4 Root Attachment Methods 8.5 Blade Manufacture 8.5.1 GFRP Blade Manufacture (VRIM) 8.5.2 Wood-Epoxy Blades 8.5.3 Blade Balancing 8.6 Blade Testing 8.7 Weight Trends 8.8 Exercises 9 Siting and Installation 9.1 Introduction 9.2 Site Wind Assessment 9.2.1 Wind Resource 9.2.2 Site Measurements 9.2.3 MCP Analysis 9.2.4 Turbulence and Shear 9.3 Array Interactions 9.3.1 Array Losses 9.3.2 Wake Turbulence 9.4 Construction 9.4.1 Introduction 9.4.2 Foundations 9.4.3 Transport and Access 9.4.4 Crane Operations 9.4.5 Electrical Infrastructure 9.5 Exercises 10 Planning and Environment 10.1 Introduction 10.2.2 Mammals 10.3 Public Safety and Acceptance 10.3.1 Public Safety 10.3.2 Visual Impact 10.3.3 Shadow Flicker 10.3.4 Pollution Risk 10.4 Noise 10.4.1 Origin of Wind Turbine Noise 10.4.2 Noise Prediction 10.4.3 Planning Limits 10.5 Aviation 10.5.1 Collision Risk 10.5.2 Radar 10.6 Radio and Microwave Communications 10.6.1 Microwaves 10.6.2 Television 10.7 Exercises 11 Economic and Political Considerations 11.1 Introduction 11.2 The Cost of Wind Energy 11.2.1 Installation Costs 11.2.2 Operational Costs 11.2.3 Intermittency 11.2.4 Total Generation Costs 11.3 The Price of Wind Energy 11.4 Matching Supply and Demand 11.4.1 Background 11.4.2 On-Site Generation Example 11.4.3 Extrapolating to Wider Scale 11.5 Ownership 11.5.1 Overview 11.5.2 The Gigha Community Windfarm 11.6 UK Renewables Policy 11.7 Exercises References Index