Wind Power Technology: An Introduction

Preface
Acknowledgements
Contents
Editor and Contributors
The History of Wind Energy
	1 Introduction
	2 The First Windmills: 600–1890
	3 Electricity Generation by Windmills: Wind Turbines 1890–1930
	4 The First Innovation Period: 1930–1960
	5 The Second Innovation Period and Full Commercialisation: From 1960 Until Today
	Literatures
The International Development of Wind Energy
	1 The Beginning of the Modern Energy Debate
	2 On the Renewal of Energy Markets
	3 On the Importance of Electricity Grids
	4 The Renewed Value Chain
	5 International Perspectives
	6 Expansion in Selected Countries
	7 The Role of the EU
	8 International Institutions and Organizations
	9 Global Wind Energy Outlook 2010—The Global View into the Future
	10 Update on the Basis of 2015
	Literatures
The Wind—From Theory to Practice
	1 Atmospheric Scales in Time and Space
		1.1 Introduction
		1.2 Global Scales—Formation of Global Wind Systems
		1.3 Mesoscale Phenomena—Formation of Local Wind Systems
		1.4 Microscale Phenomena—Turbulence
	2 The Atmospheric Boundary Layer (ABL)
		2.1 The Vertical Wind Profile
		2.2 Influence of Roughness on the Wind Profile
		2.3 Influence of Atmospheric Stability on the Wind Profile
		2.4 Influence of the Orography on the Wind Profile
		2.5 Influence of Obstacles on the Wind Profile
	3 Statistical Representation of the Wind
		3.1 The Power Spectrum
		3.2 Frequency Distribution of the Wind Speed
		3.3 Wind Direction Distribution
	4 Flow Models
		4.1 Reanalysis Models
		4.2 Mesoscale Models
		4.3 Microscale Models
	5 The First Step: Site Identification
	6 The Second Step: Measuring the Wind Climate
		6.1 Introduction
		6.2 Anemometer
		6.3 Remote Sensing Systems
		6.4 Production Data
		6.5 Measurement Period and Averaging Time
	7 The Third Step: Data Analysis
		7.1 Quality Control
		7.2 Data Corrections
		7.3 Long-Term Correction
	8 The Fourth Step: Spatial Extrapolation
	9 The Fifth Step: Choosing the Wind Turbine
		9.1 Turbulence
		9.2 Vertical Gradient (Shear)
		9.3 Inflow Angle
		9.4 Extreme Winds
	10 The Sixth Step: Energy Yield
		10.1 Energy Yield of the Individual Wind Turbine
		10.2 Energy Yield of the Wind Farm
		10.3 Further Production Losses
		10.4 Uncertainty Analysis
	Literatures
Aerodynamics and Blade Design
	1 Summary
	2 Introduction
	3 Wind Turbines with Horizontal Axis of Rotation
		3.1 General
		3.2 Basic Aerodynamic Principles
	4 Integral Momentum Methods
		4.1 Momentum Theory of Wind Turbines: Betz' Limit
		4.2 Change in Air Density Due to Temperature and Altitude
		4.3 Loss in Performance Due to Finite Number of Blades
		4.4 Swirl Losses and Local Optimization of the Wing According to Glauert
		4.5 Aerodynamic Loss Due to Profile Drag
	5 Momentum Theory of Blade Elements
		5.1 Formulation
		5.2 Specific Implementations: Wt-Perf, CCBlade and FAST
		5.3 Optimization and Blade Design
		5.4 Extensions, Differential Formulations, Actuator-Line Method
		5.5 3D Flow Simulation—CFD—RANS
		5.6 Summary: Horizontal Axis Wind Turbines
	6 Vertical Axis Wind Turbines
		6.1 General
		6.2 Aerodynamics of H-Rotors
		6.3 Aero-Elastics of VAWTs
		6.4 A 50kW Sample-Rotor
		6.5 Design Rules for Small Wind Turbines of H-Darieus Type
		6.6 Summary: VAWT
	7 Wind Driven Vehicles with Rotor
		7.1 Introduction
		7.2 On the Theory of Wind-Driven Vehicles
		7.3 Numerical Example
		7.4 The Kiel Design Method
		7.5 Evaluation
		7.6 Completed Vehicles
		7.7 Summary: Wind Vehicles
	8 Homework Problems
	References
Rotor Blade Structure
	1 Introduction
	2 Normative Requirements
		2.1 Certification
		2.2 Safety Concept
		2.3 Development Cycle of the Rotor Blade
	3 Loads
		3.1 Types of Load
		3.2 Load Calculation
		3.3 Design Load Cases
		3.4 Effects of Scaling
	4 Materials
		4.1 Fibre-Reinforced Polymers
		4.2 Semi-Finished Textile Products
		4.3 Materials Testing
		4.4 Elasticities of the Unidirectional Single Ply
		4.5 Core Materials
		4.6 Adhesives
		4.7 Coating
		4.8 Metals
	5 Structural Models
		5.1 Geometry and Structure
		5.2 Cross-Sectional Properties
		5.3 Beam Models
		5.4 Models for Thin-Walled Structures
		5.5 Full-Blade and Detailed Models
	6 Blade Root Connection Concepts
	7 Structural Design Verifications
		7.1 Strength Verifications for Fibre-Reinforced Polymers
		7.2 Stability Verifications
		7.3 Verifications of the Adhesive Joint
		7.4 Verifications of the Sandwich Core
		7.5 Verifications of the Expansion Bolt
		7.6 Serviceability Verifications
	8 Manufacturing
		8.1 Methods
		8.2 Deviations
	9 Topology Optimisation
		9.1 Optimisation Targets
		9.2 Aero-Elastic Properties
		9.3 Design for Manufacturing
		9.4 Blade Root Connection
		9.5 Blade Segmentation
	10 Sustainability
	Literatures
The Drivetrain
	1 Introduction
	2 Blade Pitch Systems
	3 Rotor Hub
	4 Drivetrain Components
		4.1 Rotor Locks and Rotor Turning Devices
		4.2 Rotor Shaft
		4.3 Rotor Bearing Assembly
		4.4 Gearbox
		4.5 Brake and Coupling
		4.6 Generator
		4.7 Yaw System
	5 Drivetrain Concepts
		5.1 Direct Drive—Two-Point Mount
		5.2 Direct Drive—Moment Bearing
		5.3 1–2 Stage Gearboxes—Two-Point Mount
		5.4 1–2 Stage Gearbox—Moment Bearing
		5.5 3–4 Stage Gearbox—Two-Point Mount
		5.6 3–4 Stage Gearbox—Three-Point Mount
		5.7 3–4 Stage Gearbox—Moment Bearing
	6 Damage and Causes of Damage
	7 Design of Drivetrain Components
	8 Validation
	9 Intellectual Property Rights in Wind Energy
	Literatures
Tower and Foundation
	1 Introduction
	2 Guidelines and Standards
	3 Stresses on Towers
		3.1 Fatigue Loads
		3.2 Extreme Loads
	4 Verification for the Tower
		4.1 Ultimate Limit State Capacity
		4.2 Serviceability Limit States
		4.3 Frequencies Calculations (Natural Frequencies)
	5 Construction Details
		5.1 Openings in the Wall of Tubular Steel Towers
		5.2 Ring Flange Connections
		5.3 Welded Joints
	6 Materials for Towers
		6.1 Steel
		6.2 Concrete
		6.3 Wood
		6.4 Glass Fibre Reinforced Plastic
	7 Designs of Towers
		7.1 Tubular Towers
		7.2 Lattice Towers
		7.3 Guyed Towers
		7.4 Comparison of Different Tower Concepts
	8 Foundations of Onshore Wind Turbines
		8.1 Foundations and Construction Types
		8.2 Transition Between Tower and Foundation
		8.3 Verification of the Foundation
	Literatures
Power Electronic Generator Systems for Wind Turbines
	1 Introduction
	2 Single Phase AC Voltage and Three Phase AC Voltage Systems
	3 Transformer
		3.1 Principle, Equations
		3.2 Equivalent Circuit Diagram, Phasor Diagram
		3.3 Simplified Equivalent Circuit Diagram
		3.4 Three-Phase Transformers
	4 Generators for Wind Turbines
		4.1 Asynchronous Machine with Squirrel Cage Rotor
		4.2 Asynchronous Machine with Slip Ring Rotor
	5 Synchronous Machines
		5.1 General Function
		5.2 Voltage Equations and Equivalent Circuit
		5.3 Power and Torque
		5.4 Embodiment of Separately Excited Synchronous Machines
		5.5 Permanently Excited Synchronous Machines
		5.6 Variable Speed Operation of the Synchronous Machine
	6 Converter Systems for Wind Turbines
		6.1 General Function
		6.2 Frequency Converter in Two-Level Topology
		6.3 Frequency Converter with Multi-level Circuitry
	7 Control of Variable Speed Converter-Generator Systems
		7.1 Control of the Converter-Fed Asynchronous Generator with Squirrel-Cage Rotor
		7.2 Control of the Doubly-Fed Asynchronous Machine
		7.3 Control of the Synchronous Machine
		7.4 Control of the Grid-Side Part Converter
		7.5 Design of the Control
	8 Grid Integration
	9 Further Electrotechnical Components
	10 Characteristics of the Power Electronics Generator Systems in Overview
	11 Exercises
	Literatures
Control and Automation of Wind Energy Systems
	1 Fundamental Relationships
		1.1 Classification of WT Automation
		1.2 System Properties of Energy Conversion in WTs
		1.3 Energy Conversion at the Rotor
		1.4 Energy Conversion at the Drive Train
		1.5 Energy Conversion at the Generator-Converter System
		1.6 Idealised Operating Characteristic Curves of WTs
	2 Control Systems of the WT
		2.1 Yaw Angle Control
		2.2 Pitch Angle Control
		2.3 Active Power Control
		2.4 Reactive Power Control
		2.5 Summary of the Control Behaviour and Extended Operating Ranges of the WT
	3 Operation Control Systems for WTs
		3.1 Control of the Operating Sequence of WTs
		3.2 Safety Systems
	4 WPP Control and Automation Systems
	5 Remote Control and Monitoring
	6 Communication Systems for WES
	Literatures
Grid Integration of Wind Turbines
	1 Introduction to Grid Integration of Wind Turbines
		1.1 Introduction to Electric Power Systems
		1.2 Introduction of the Different WT Types
		1.3 Traditional Aspects of Grid Integration
		1.4 Overview of Current Challenges of Grid Integration
	2 Power System Voltage
		2.1 Equivalent Circuits of Power System Components
		2.2 Power System Stiffness and Short-Circuit Power
		2.3 Voltage Stability
		2.4 Transient Voltage Drops
	3 Voltage Stability with Wind Turbines
		3.1 Voltage Support with Wind Turbines
		3.2 Low Voltage Ride Through with Wind Turbines
	4 Power System Frequency
		4.1 Frequency Control
		4.2 System Inertia
		4.3 Damping Sub-synchronous Oscillations
		4.4 Frequency Stability
	5 Frequency Stability with Wind Turbines
		5.1 Inertial Response of Wind Turbines
		5.2 Fast Frequency Response with Wind Turbines
		5.3 Power System Stabilization with Wind Turbines
	Literatures
Offshore Wind Energy
	1 Introduction
		1.1 History and Development Trends
		1.2 Differences Between Onshore and Offshore Wind Turbines
		1.3 Design Basis for Offshore Wind Farms
		1.4 Environmental Protection and Safety Requirements
	2 Essential Components of an Offshore Wind Farm
		2.1 Turbines for Offshore Wind Farms
		2.2 Support Structures for Offshore Wind Turbines
		2.3 Bottom-Fixed Foundations for Offshore Wind Turbines
		2.4 Floating Structures for Offshore Wind Turbines
		2.5 Offshore Stations
		2.6 Power Cables
		2.7 Research Platforms
	3 Load Actions for Offshore Wind Turbines
		3.1 Permanent Loads
		3.2 Aerodynamic Loads
		3.3 Hydrostatic Loads
		3.4 Hydrodynamic Loads
		3.5 Effects Due to Temperature
		3.6 Effects Due to Ice
		3.7 Functional Loads
		3.8 Accidental Loads
	4 Design of Offshore Structures for Wind Energy
		4.1 Design Basis
		4.2 Site Conditions
		4.3 Semi-Probabilistic Safety Concept
		4.4 Design Load Cases and Load Case Combinations
		4.5 Analysis Methods for Structural Design
		4.6 Limit States of Structrual Design
	Literatures
Index