PAUL M. ANDERSON, PhD, (deceased) served as a professor of engineering at Iowa State University, Arizona State University, and as a visiting professor at Washington State University. He also founded consulting firm Power Math Associates, and was elected to the National Academy of Engineering in 2009. Dr. Anderson passed away in 2011.

CHARLES F. HENVILLE is the President and Principal Engineer of Henville Consulting, Inc. He is a Fellow of the IEEE Power and Energy Systems Society, and past Chairman of the Power Systems Relaying Committee of the IEEE Power and Energy Systems Society.

RASHEEK RIFAAT is a Technical Director, Electrical with more than 40 years of Canadian and overseas experience with various projects, ranging from installation of control panels and 600 V MCCs for material handling systems to large 800 MW thermal generating stations.

BRIAN JOHNSON, PhD, is a University Distinguished Professor of Electrical Engineering and Schweitzer Engineering Laboratories Endowed Chair in Power Engineering. He is a Senior Member of the IEEE, and an Individual Member of CIGRE.

SAKIS MELIOPOULOS, PhD, is a Distinguished Professor at Georgia Tech. He is the co-inventor of the Smart Ground Multimeter and the Macrodyne PMU-based Harmonic Measurement System for transmission networks.

Author Biographies xxv

Preface to the Second Edition xxvii

List of Symbols xxix

Part I Protective Devices and Controls 1

1 Introduction 3

1.1 Power System Protection 3

1.2 Prevention and Control of System Failure 3

1.3 Protective System Design Considerations 8

1.4 Definitions Used in System Protection 9

1.5 System Disturbances 11

1.6 Book Contents 12

Problems 14

References 15

2 Protection Measurements and Controls 17

2.1 Graphic Symbols and Device Identification 17

2.2 Typical Relay Connections 19

2.3 Circuit Breaker Control Circuits 22

2.4 Instrument Transformers 23

2.5 Relay Control Configurations 37

2.6 Optical Communications 38

Problems 42

References 44

3 Protective Device Characteristics 47

3.1 Introduction 47

3.2 Fuse Characteristics 48

3.3 Relay Characteristics 61

3.4 Power Circuit Breakers 87

3.5 Automatic Circuit Reclosers 93

3.6 Automatic Line Sectionalizers 98

3.7 Circuit Switchers 100

3.8 Digital Fault Recorders 101

Problems 103

References 103

4 Relay Logic 109

4.1 Introduction 109

4.2 Electromechanical Relay Logic 110

4.3 Electronic Logic Circuits 111

4.4 Analog Relay Logic 125

4.5 Digital Relay Logic 128

4.6 Hybrid Relay Logic 139

4.7 Relays as Comparators 140

Problems 153

References 157

5 System Characteristics 163

5.1 Power System Faults 163

5.2 Station Arrangements 176

5.3 Overhead Line Impedances 182

5.4 Computation of Available Fault Current 184

5.5 System Equivalent for Protection Studies 188

5.6 The Compensation Theorem 202

5.7 Compensation Applications in Fault Studies 205

Problems 210

References 214

Part II Protection Concepts 215

6 Fault Protection of Radial Lines 217

6.1 Radial Distribution Systems 217

6.2 Radial Distribution Coordination 219

6.3 Radial Line Fault Current Calculations 222

6.4 Radial System Protective Strategy 233

6.5 Coordination of Protective Devices 236

6.6 Relay Coordination on Radial Lines 241

6.7 Coordinating Protective Devices Measuring Different Parameters 258

Problems 269

References 276

7 Introduction to Transmission Protection 277

7.1 Introduction 277

7.2 Protection with Overcurrent Relays 278

7.3 Distance Protection of Lines 285

7.4 Unit Protection 299

7.5 Ground Fault Protection 301

7.6 Summary 310

Problems 311

References 315

8 Complex Loci in the Z and Y Planes 317

8.1 The Inverse Z Transformation 317

8.2 Line and Circle Mapping 320

8.3 The Complex Equation of a Line 327

8.4 The Complex Equation of a Circle 328

8.5 Inversion of an Arbitrary Admittance 330

8.6 Inversion of a Straight Line Through (1, 0) 333

8.7 Inversion of an Arbitrary Straight Line 335

8.8 Inversion of a Circle with Center at (1, 0) 336

8.9 Inversion of an Arbitrary Circle 338

8.10 Summary of Line and Circle Inversions 340

8.11 Angle Preservation in Conformal Mapping 341

8.12 Orthogonal Trajectories 342

8.13 Impedance at the Relay 346

Problems 348

References 350

9 Impedance at the Relay 351

9.1 The Relay Apparent Impedance, ZR 351

9.2 Protection Equivalent M Parameters 353

9.3 The Circle Loci Z = P/(1±YK) 356

9.4 ZR Loci Construction 357

9.5 Relay Apparent Impedance 363

9.6 Relay Impedance for a Special Case 371

9.7 Construction of M Circles 375

9.8 Phase Comparison Apparent Impedance 378

Problems 384

References 388

10 Admittance at the Relay 391

10.1 Admittance Diagrams 391

10.2 Input Admittance Loci 392

10.3 The Relay Admittance Characteristic 395

10.4 Parallel Transmission Lines 400

10.5 Typical Admittance Plane Characteristics 404

10.6 Summary of Admittance Characteristics 407

Problems 408

Reference 411

Part III Transmission Protection 413

11 Analysis of Distance Protection 415

11.1 Introduction 415

11.2 Analysis of Transmission Line Faults 415

11.3 Impedance at the Relay 429

11.4 Distance Relay Settings 439

11.5 Ground Distance Protection 447

11.6 Distance Relay Coordination 449

Problems 452

References 454

12 Transmission Line Mutual Induction 457

12.1 Introduction 457

12.2 Line Impedances 458

12.3 Effect of Mutual Coupling 469

12.4 Short Transmission Line Equivalents 476

12.5 Long Transmission Lines 484

12.6 Long Transmission Line Equivalents 493

12.7 Solution of the Long-line Case 501

Problems 504

References 507

13 Pilot Protection Systems 509

13.1 Introduction 510

13.2 Physical Systems for Pilot Protection 512

13.3 Non-unit Pilot Protection Schemes 523

13.4 Unit Protection Pilot Schemes 536

13.5 An Example of EHV Line Protection 548

13.6 Pilot Protection Settings 554

13.7 Traveling Wave Relays 561

13.8 Monitoring of Pilot Performance 567

Problems 567

References 569

14 Complex Transmission Protection 573

14.1 Introduction 573

14.2 Single-phase Switching of Extra-high-voltage Lines 573

14.3 Protection of Multiterminal Lines 581

14.4 Protection of Mutually Coupled Lines 590

Problems 613

References 617

15 Series Compensated Line Protection 619

15.1 Introduction 619

15.2 Faults with Unbypassed Series Capacitors 621

15.3 Series Capacitor Bank Protection 634

15.4 Relay Problems Due to Compensation 653

15.5 Protection of Series Compensated Lines 674

15.6 Line Protection Experience 678

Problems 680

References 683

Part IV Apparatus Protection 685

16 Bus Protection 687

16.1 Introduction 687

16.2 Bus Configurations and Faults 688

16.3 Bus Protection Requirements 689

16.4 Bus Protection by Backup Line Relays 691

16.5 Bus Differential Protection 692

16.6 Other Types of Bus Protection 708

16.7 Auxiliary Tripping Relays 716

16.8 Summary 717

Problems 717

References 719

17 Transformer and Reactor Protection 721

17.1 Introduction 721

17.2 Transformer Faults 722

17.3 Magnetizing Inrush 729

17.4 Protection Against Incipient Faults 732

17.5 Protection Against Active Faults 735

17.6 Combined Line and Transformer Schemes 748

17.7 Regulating Transformer Protection 750

17.8 Shunt Reactor Protection 752

17.9 Static Var Compensator Protection 755

Problems 759

References 761

18 Generator Protection 763

18.1 Introduction 763

18.2 Generator System Configurations and Types of Protection 764

18.3 Stator Protection 766

18.4 Rotor Protection 781

18.5 Loss of Excitation Protection 785

18.6 Other Generator Protection Systems 789

18.7 Summary of Generator Protection 794

Problems 800

References 803

19 Motor Protection 805

19.1 Introduction 805

19.2 Induction Motor Analysis 806

19.3 Induction Motor Heating 824

19.4 Motor Problems 837

19.5 Classifications of Motors 843

19.6 Stator Protection 845

19.7 Rotor Protection 851

19.8 Other Motor Protections 852

19.9 Summary of Large Motor Protections 853

Problems 854

References 858

Part V System Aspects of Protection 861

20 Protection Against Abnormal System Frequency 863

20.1 Abnormal Frequency Operation 863

20.2 Effects of Frequency on the Generator 864

20.3 Frequency Effects on the Turbine 866

20.4 A System Frequency Response Model 869

20.5 Off Normal Frequency Protection 886

20.6 Steam Turbine Frequency Protection 887

20.7 Underfrequency Protection 889

Problems 903

References 905

21 Protective Schemes for Stability Enhancement 909

21.1 Introduction 909

21.2 Review of Stability Fundamentals 909

21.3 System Transient Behavior 918

21.4 Automatic Reclosing 929

21.5 Loss of Synchronism Protection 949

21.6 Voltage Stability and Voltage Collapse 957

21.7 System Integrity Protection Schemes (SIPS) 960

21.8 Summary 968

Problems 968

References 970

22 Line Commutated Converter HVDC Protection 973

22.1 Introduction 973

22.2 LCC Dc Conversion Fundamentals 974

22.3 Converter Station Design 992

22.4 Ac Side Protection 999

22.5 Dc Side Protection Overview 1002

22.6 Special HVDC Protections 1012

22.7 HVDC Protection Settings 1015

22.8 Summary 1016

Problems 1016

References 1018

23 Voltage Source Converter HVDC Protection 1021

23.1 Introduction 1021

23.2 VSC HVDC Fundamentals 1022

23.3 Converter Control Systems 1028

23.4 HVDC Response to Ac System Faults 1030

23.5 Ac System Protection 1031

23.6 Dc Faults 1035

23.7 Multiterminal Systems 1037

23.8 Hybrid LCC-VSC Systems 1037