Electric Power Systems

Nick Jenkins, Cardiff University, UKNick 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, UKGoran 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 ixPreface to Fourth Edition xiPreface to Fifth Edition xiiiSymbols xv1 Introduction 11.1 History 11.2 Characteristics Influencing Generation and Transmission 21.3 Operation of Generators 41.4 Energy Conversion 51.5 Renewable Energy Sources 121.6 Energy Storage 171.7 Environmental Aspects of Electrical Energy 231.8 Transmission and Distribution Systems 271.9 Utilization 40Problems 432 Basic Concepts 452.1 Three-Phase Systems 452.2 Three-Phase Transformers 552.3 Active and Reactive Power 572.4 The Per-Unit System 612.5 Power Transfer and Reactive Power 682.6 Harmonics in Three-Phase Systems 742.7 Useful Network Theory 75Problems 783 Components of a Power System 833.1 Introduction 833.2 Synchronous Machines 833.3 Equivalent Circuit Under Balanced Short-Circuit Conditions 903.4 Synchronous Generators in Parallel 943.5 The Operation of a Generator on an Infinite Busbar 953.6 Automatic Voltage Regulators (AVRs) 1003.7 Lines, Cables and Transformers 1033.8 Transformers 1243.9 Voltage Characteristics of Loads 131Problems 1344 Control of Power and Frequency 1394.1 Introduction 1394.2 The Turbine Governor 1424.3 Control Loops 1464.4 Division of Load between Generators 1474.5 The Power-Frequency Characteristic of an Interconnected System 1514.6 System Connected by Lines of Relatively Small Capacity 152Problems 1595 Control of Voltage and Reactive Power 1615.1 Introduction 1615.2 The Generation and Absorption of Reactive Power 1635.3 Relation between Voltage, Power, and Reactive Power at a Node 1655.4 Methods of Voltage Control: (a) Injection of Reactive Power 1705.5 Methods of Voltage Control: (b) Tap-Changing Transformers 1765.6 Combined Use of Tap-Changing Transformers and Reactive-Power Injection 1835.7 Phase-Shift Transformer 1885.8 Voltage Collapse 1915.9 Voltage Control in Distribution Networks 1955.10 Long Lines 1975.11 General System Considerations 198Problems 2006 Load Flows 2056.1 Introduction 2056.2 Circuit Analysis Versus Load Flow Analysis 2066.3 Gauss-Seidel Method 2126.4 Load Flows in Radial and Simple Loop Networks 2166.5 Load Flows in Large Systems 2196.6 Computer Simulations 231Problems 2347 Fault Analysis 2397.1 Introduction 2397.2 Calculation of Three-Phase Balanced Fault Currents 2417.3 Method of Symmetrical Components 2477.4 Representation of Plant in the Phase-Sequence Networks 2517.5 Types of Fault 2527.6 Fault Levels in a Typical System 2597.7 Power in Symmetrical Components 2657.8 Systematic Methods for Fault Analysis in Large Networks 2657.9 Neutral Grounding 2707.10 Interference with Communication Circuits–Electromagnetic Compatibility (EMC) 274Problems 2758 System Stability 2818.1 Introduction 2818.2 Equation of Motion of a Rotating Machine 2838.3 Steady-State Stability 2848.4 Transient Stability 2878.5 Transient Stability–Consideration of Time 2938.6 Transient Stability Calculations by Computer 2988.7 Dynamic or Small-Signal Stability 3018.8 Stability of Loads Leading to Voltage Collapse 3058.9 Further Aspects 3098.10 Multi-Machine Systems 3118.11 Transient Energy Functions (TEF) 3128.12 Improvement of System Stability 314Problems 3159 Direct-Current Transmission 3199.1 Introduction 3199.2 Current Source and Voltage Source Converters 3209.3 Semiconductor Valves for High-Voltage Direct-CurrentConverters 3229.4 Current Source Converter h.v.d.c. 3259.5 Voltage Source Converter h.v.d.c. 346Problems 35210 Overvoltages and Insulation Requirements 35510.1 Introduction 35510.2 Generation of Overvoltages 35610.3 Protection Against Overvoltages 36510.4 Insulation Coordination 36910.5 Propagation of Surges 37310.6 Determination of System Voltages Produced by Travelling Surges 38210.7 Electromagnetic Transient Program (EMTP) 391Problems 39911 Substations and Protection 40311.1 Introduction 40311.2 Switchgear 40411.3 Qualities Required of Protection 41511.4 Components of Protective Schemes 41611.5 Protection Systems 42411.6 Distance Protection 42711.7 Unit Protection Schemes 42911.8 Generator Protection 43011.9 Transformer Protection 43211.10 Feeder Protection 435Problems 43912 Fundamentals of the Economics of Operation and Planning of Electricity Systems 44312.1 Economic Operation of Generation Systems 44412.2 Fundamental Principles of Generation System Planning 45112.3 Economic Operation of Transmission Systems 45712.4 Fundamental Principles of Transmission System Planning 46012.5 Distribution and Transmission Network Security Considerations 46312.6 Drivers for Change 466Problems 467Appendix A Synchronous Machine Reactances 473Appendix B Typical Transformer Impedances 477Appendix C Typical Overhead Line Parameters 481Further Reading 487Index 491