Electricity Generation Using Wind Power (Second Edition)

by William Shepherd, Li Zhang

Overview

Is wind power the answer to our energy supply problems? Is there enough wind for everyone? Is offshore generation better than onshore generation? Can a roof-mounted wind turbine generate enough electricity to supply a typical domestic household? Electricity Generation Using Wind Power (2nd Edition) answers these pressing questions through its detailed coverage of the different types of electrical generator machines used, as well as the power electronic converter technologies and control principles employed. Also covered is the integration of wind farms into established electricity grid systems, plus environmental and economic aspects of wind generation.Written for technically minded readers, especially electrical engineers concerned with the possible use of wind power for generating electricity, it incorporates some global meteorological and geographical features of wind supply plus a survey of past and present wind turbines. Included is a technical assessment of the choice of turbine sites. The principles and analysis of wind power conversion, transmission and efficiency evaluation are described.This book includes worked numerical examples in some chapters, plus end of chapter problems and review questions, with answers. As a textbook it is pitched at the level of final year undergraduate engineering study but may also be useful as a textbook or reference for wider technical studies.

Product Details

ISBN-13:	9789813148659
Publisher:	World Scientific Publishing Company, Incorporated
Publication date:	03/08/2017
Pages:	300
Product dimensions:	6.10(w) x 9.70(h) x 0.80(d)

Table of Contents

Foreword and Acknowledgements for the Second Edition v

Foreword and Acknowledgement for the First Edition vii

About the Authors ix

1 The Development of Wind Converters 1

1.1 Nature and Origin of the Wind 1

1.1.1 Atmospheric pressure 1

1.1.2 The Coriolis effect 1

1.2 Development of Wind Converters 3

References 6

2 Theory of Wind Converters 7

2.1 Power and Energy Basis of Wind Converters 7

2.1.1 Origin and properties of the wind 7

2.1.2 Power and energy 8

2.2 Theoretical Power Available in the Wind 9

2.3 Theoretical Maximum Power Extractable from the Wind 11

2.4 Practical Power Extractable from the Wind 15

2.4.1 Power coefficient 15

2.4.2 Torque versus rotational speed 16

2.4.3 Shaft power versus rotational speed 17

2.4.4 Tip-speed ratio (TSR) and torque coefficient (C_t) 17

2.5 Mechanical and Aeronautical Features of Wind Machines 20

2.5.1 Aeronautical forces on the turbine rotor blades 20

2.5.2 Axial thrust (pressure) 24

2.5.3 The "Yaw" effect 24

2.5.4 Gyroscopic forces and vibrations 25

2.5.5 Centrifugal forces 25

2.5.6 Solidity factor 26

2.5.7 Two rotor blades or three rotor blades? 27

2.5.8 Shaft torque and power 27

2.6 Fixed Rotational Speed or Variable Rotational Speed? 29

2.6.1 Constant speed operation 30

2.6.2 Variable speed operation 31

2.7 Efficiency Considerations of Wind-Powered Electricity Generation 32

2.8 Worked Numerical Examples on Wind-Turbine Operation 34

2.9 Problems and Review Questions 39

References 42

3 Past and Present Wind-Energy Turbines 43

3.1 Nineteenth-Century Windmills 43

3.2 Early Twentieth-Century Wind-Energy Turbines 45

3.3 Later Twentieth-Century Wind-Energy Turbines 49

3.4 Modern Large Wind Power Installations 60

3.5 Worked Numerical Example 62

3.6 Vertical Axis Wind Machines 62

3.6.1 The Savonius design 63

3.6.2 The Darrieus design 64

3.6.3 Other forms of vertical axis machine 65

References 66

4 The Location and Siting of Wind Turbines 69

4.1 The Availability of Wind Supply 69

4.1.1 Global survey 69

4.1.2 Energy content of the wind 70

4.1.3 Wind-energy supply in Europe 72

4.1.4 Wind-energy supply in the USA 77

4.2 Statistical Representation of Wind Speed 80

4.3 Choice of Wind Turbine Sites 87

4.3.1 Identification of suitable areas 89

4.3.2 Selection of possible sites within the chosen area 89

4.4 Effects of the Site Terrain 89

4.5 Spacing Effects of Wind Farm Arrays 91

4.6 Problems and Review Questions 95

References 96

5 Electrical Generator Machines in Wind-Energy Systems 97

5.1 DC Generators 97

5.2 AC Generators 97

5.3 Synchronous Machine Generators 98

5.3.1 Synchronous generator power control 102

5.3.2 Synchronous machine acting as a motor 104

5.4 Three-Phase Induction Machine 105

5.4.1 Three-phase induction motor 106

5.4.2 Three-phase induction generator 112

5.4.2.1 Power versus speed for a large induction generator 116

5.4.2.2 Different induction generator connections 116

(A) Constant speed constant frequency (CSCF) 116

(B) Variable speed constant frequency (YSCF) 117

5.4.3 Doubly-Fed, wound rotor induction generator (DFIG) 117

5.4.3.1 Principles of DFIG operation 119

5.4.3.2 Power flow for the DFIG 121

5.4.3.3 Optimal power tracking for a wind-driven DFIG 122

5.5 Analysis of Induction Generator in Terms of Complex Vector Representation 125

5.5.1 Basic theory 125

5.5.2 Dynamic modelling of an induction machine using the space vector concept 128

5.5.2.1 Space vector transformation of three-phase systems 128

5.5.2.2 Three-phase to d-q-0 space vector transformation 129

5.6 Switched Reluctance Machines 132

5.6.1 Switched reluctance motor 132

5.6.2 Switched reluctance generator 134

5.7 What Form of Generator is the Best Choice for Wind Generation Systems? 135

5.8 Worked Numerical Examples 135

5.9 Problems and Review Questions 140

References 141

6 Three-Phase Power Electronic Converters in Wind-Energy Systems 143

6.1 Types of Semiconductor Switching Converters 143

6.2 Three-Phase Controlled Bridge Rectifier 145

6.3 Three-Phase Controlled Bridge Inverter Feeding an Infinite Bus 151

6.3.1 Output voltage 151

6.3.2 Real power output 156

6.3.3 Reactive power 157

6.3.4 RMS output current 158

6.3.5 Inverter power factor 159

6.4 The Effect of A.C. System Reactance on Inverter Operation 161

6.5 Three-Phase Cycloconverter Feeding an Infinite Bus 162

6.6 Matrix Converter Feeding an Infinite Bus 163

6.7 Worked Numerical Examples 167

6.7.1 Three-phase bridge rectifier 167

6.7.2 Three-phase bridge inverter feeding on infinite bus 168

6.8 Problems and Review Questions 174

6.8.1 Three-phase controlled bridge rectifier, with ideal supply, feeding a highly inductive load 174

6.8.2 Three-phase, full-wave, and controlled bridge inverter feeding an infinite bus 174

References 176

7 Operation and Control of Wind Energy Generation Schemes 177

7.1 General Principles 177

7.2 Basic Control Schemes (1) 177

7.3 Wind Speed Ranges (2) 178

7.4 Supervisory Control 180

7.5 Closed-loop Control of the Wind Turbine 181

7.6 Commonly Used Forms of Power Electronic Drive in Wind Energy Systems (3) 181

7.6.1 Fixed-speed, directly-coupled, cage induction generator 181

7.6.2 Variable-speed, doubly-fed induction generator 183

7.6.3 Variable-speed, direct drive synchronous generator 185

7.7 Voltage Source AC-DC Converter and Switching Schemes 187

7.7.1 Single-phase full-bridge converter circuit and operating principle 187

7.7.2 Sine-Triangle Pulse-Width-Modulation (PWM) Technique 189

7.7.3 Harmonics in the output waveform 191

7.7.4 Single-Phase PWM 192

7.7.5 Three-phase PWM 192

7.7.6 Selective harmonic elimination 194

7.8 Power Flow Analysis for the Grid-Converter 197

7.8.1 General principle 197

7.8.2 DC-link power and current 200

7.8.3 Power calculation using space vectors 201

7.9 Turbine Control Strategies (1) 202

7.9.1 Turbine control with a grid-coupled induction (asynchronous) generator (1) 202

7.9.2 Turbine control with a grid-coupled synchronous generator (1) 202

References 203

8 Integrating Wind Power Generation into an Electrical Power System 205

8.1 Electricity Distribution Systems 205

8.2 Issues for Consideration Concerning the Integration of Wind-Energy Generation into an Electric Power System 207

8.2.1 Energy credit 208

8.2.2 Capacity credit 210

8.2.3 Control and reliability 211

8.3 The Effect of Integrated Wind Generation on Steady-State System Voltages 212

8.4 The Effect of Integrated Wind Generation on Dynamic and Transient System Voltages 216

8.4.1 Lightning strikes 216

8.4.2 Voltage flicker 217

8.4.3 Harmonics 218

8.4.4 Self-excitation of induction generators 223

References 224

9 Environmental Aspects of Wind Energy 227

9.1 Reduction of Emissions 227

9.1.1 World consumption of coal 227

9.1.2 Open coal fires 229

9.2 Effluents due to Coal Burning 230

9.2.1 Sulphur oxides 230

9.2.2 Nitrogen oxides 230

9.2.3 Particulates 231

9.2.4 Carbon dioxide 232

9.3 Wind Turbine Noise 235

9.3.1 Measurement of wind turbine aerodynamic noise 235

9.3.2 Mechanical noise 239

9.4 Electromagnetic Interference from Wind Turbines 241

9.4.1 Electromagnetic interference radiated from wind turbines 241

9.4.2 Electromagnetic interference effects due to the totaling blades 241

9.5 Effect of a Wind Turbine on Wildlife 243

9.6 Visual Impact of Wind Turbines 244

9.6.1 Individual response 244

9.6.2 Shadow flicker 245

9.7 Safety Aspects of Wind-Turbine Operation 245

References 246

10 Economic Aspects of Wind Power 249

10.1 Major Cost Items of Wind-Powered Electricity Generation 249

10.1.1 Costs of the turbines and generators 252

10.1.2 Costs of the turbine site, construction, and grid connection 253

10.1.3 Operation and maintenance (O and M) costs 253

10.1.4 Tuibine lifetime and depreciation rate 254

10.1.5 Cost associated with the financing of wind farm building and operation 255

10.1.6 Wind regime at the turbine site 258

10.2 Comparative Costs or Generating Electricity from Different Fuel Sources 261

References 263

Answers to the End of Chapter Problems 265