Nick Jenkins, Cardiff University, UK
Nick is a Professor at the Cardiff School of Engineering. He is also the Director of the Centre for Integrated Renewable Energy Generation and Supply (CIREGS) at Cardiff University and is a special advisor to a House of Commons Select Committee (Innovation, Universities and Skills) in regard to their enquiries into Renewable Energy-Generation Technologies. He has set the Engineering Council examination on Power Systems for ten years.

Goran Strbac, Imperial College, London, UK
Goran is Professor of Electrical Energy Systems at Imperial College, London. He is also the Director of the DTI Centre for Distributed Generation and Sustainable Electrical Energy, the Convener of CIGRE International Working Group on Economics of Integration of Distributed Generation and a member of the Executive Team of the IEE Professional Network on Power Trading and Control. He is a co-author of 3 books and has published more than 100 scientific papers.

Preface to First Edition ix

Preface to Fourth Edition xi

Preface to Fifth Edition xiii

Symbols xv

1 Introduction 1

1.1 History 1

1.2 Characteristics Influencing Generation and Transmission 2

1.3 Operation of Generators 4

1.4 Energy Conversion 5

1.5 Renewable Energy Sources 12

1.6 Energy Storage 17

1.7 Environmental Aspects of Electrical Energy 23

1.8 Transmission and Distribution Systems 27

1.9 Utilization 40

Problems 43

2 Basic Concepts 45

2.1 Three-Phase Systems 45

2.2 Three-Phase Transformers 55

2.3 Active and Reactive Power 57

2.4 The Per-Unit System 61

2.5 Power Transfer and Reactive Power 68

2.6 Harmonics in Three-Phase Systems 74

2.7 Useful Network Theory 75

Problems 78

3 Components of a Power System 83

3.1 Introduction 83

3.2 Synchronous Machines 83

3.3 Equivalent Circuit Under Balanced Short-Circuit Conditions 90

3.4 Synchronous Generators in Parallel 94

3.5 The Operation of a Generator on an Infinite Busbar 95

3.6 Automatic Voltage Regulators (AVRs) 100

3.7 Lines, Cables and Transformers 103

3.8 Transformers 124

3.9 Voltage Characteristics of Loads 131

Problems 134

4 Control of Power and Frequency 139

4.1 Introduction 139

4.2 The Turbine Governor 142

4.3 Control Loops 146

4.4 Division of Load between Generators 147

4.5 The Power-Frequency Characteristic of an Interconnected System 151

4.6 System Connected by Lines of Relatively Small Capacity 152

Problems 159

5 Control of Voltage and Reactive Power 161

5.1 Introduction 161

5.2 The Generation and Absorption of Reactive Power 163

5.3 Relation between Voltage, Power, and Reactive Power at a Node 165

5.4 Methods of Voltage Control: (a) Injection of Reactive Power 170

5.5 Methods of Voltage Control: (b) Tap-Changing Transformers 176

5.6 Combined Use of Tap-Changing Transformers and Reactive-Power Injection 183

5.7 Phase-Shift Transformer 188

5.8 Voltage Collapse 191

5.9 Voltage Control in Distribution Networks 195

5.10 Long Lines 197

5.11 General System Considerations 198

Problems 200

6 Load Flows 205

6.1 Introduction 205

6.2 Circuit Analysis Versus Load Flow Analysis 206

6.3 Gauss-Seidel Method 212

6.4 Load Flows in Radial and Simple Loop Networks 216

6.5 Load Flows in Large Systems 219

6.6 Computer Simulations 231

Problems 234

7 Fault Analysis 239

7.1 Introduction 239

7.2 Calculation of Three-Phase Balanced Fault Currents 241

7.3 Method of Symmetrical Components 247

7.4 Representation of Plant in the Phase-Sequence Networks 251

7.5 Types of Fault 252

7.6 Fault Levels in a Typical System 259

7.7 Power in Symmetrical Components 265

7.8 Systematic Methods for Fault Analysis in Large Networks 265

7.9 Neutral Grounding 270

7.10 Interference with Communication Circuits-Electromagnetic Compatibility (EMC) 274

Problems 275

8 System Stability 281

8.1 Introduction 281

8.2 Equation of Motion of a Rotating Machine 283

8.3 Steady-State Stability 284

8.4 Transient Stability 287

8.5 Transient Stability-Consideration of Time 293

8.6 Transient Stability Calculations by Computer 298

8.7 Dynamic or Small-Signal Stability 301

8.8 Stability of Loads Leading to Voltage Collapse 305

8.9 Further Aspects 309

8.10 Multi-Machine Systems 311

8.11 Transient Energy Functions (TEF) 312

8.12 Improvement of System Stability 314

Problems 315

9 Direct-Current Transmission 319

9.1 Introduction 319

9.2 Current Source and Voltage Source Converters 320

9.3 Semiconductor Valves for High-Voltage Direct-Current

Converters 322

9.4 Current Source Converter h.v.d.c. 325

9.5 Voltage Source Converter h.v.d.c. 346

Problems 352

10 Overvoltages and Insulation Requirements 355

10.1 Introduction 355

10.2 Generation of Overvoltages 356

10.3 Protection Against Overvoltages 365

10.4 Insulation Coordination 369

10.5 Propagation of Surges 373

10.6 Determination of System Voltages Produced by Travelling Surges 382

10.7 Electromagnetic Transient Program (EMTP) 391

Problems 399

11 Substations and Protection 403

11.1 Introduction 403

11.2 Switchgear 404

11.3 Qualities Required of Protection 415

11.4 Components of Protective Schemes 416

11.5 Protection Systems 424

11.6 Distance Protection 427

11.7 Unit Protection Schemes 429

11.8 Generator Protection 430

11.9 Transformer Protection 432

11.10 Feeder Protection 435

Problems 439

12 Fundamentals of the Economics of Operation and Planning of Electricity Systems 443

12.1 Economic Operation of Generation Systems 444

12.2 Fundamental Principles of Generation System Planning 451

12.3 Economic Operation of Transmission Systems 457

12.4 Fundamental Principles of Transmission System Planning 460

12.5 Distribution and Transmission Network Security Considerations 463

12.6 Drivers for Change 466

Problems 467

Appendix A Synchronous Machine Reactances 473

Appendix B Typical Transformer Impedances 477

Appendix C Typical Overhead Line Parameters 481

Further Reading 487

Index 491