Technological advances and structural changes within the electric utility industry mandate that protection engineers develop a solid understanding of the related new technologies as well as of power system operations and economics in order to function proficiently. Continuing in the bestselling tradition of the previous editions by the late J. Lewis Blackburn, Protective Relaying: Principles and Applications, Third Edition retains the fundamentals of protection relays and power system protection while incorporating new developments in the field. Thoroughly updated and revised, this third edition focuses on technological changes in the design of protective systems, the practical concerns of power system protection encountered by users, and the techniques for protecting typical facilities used in modern power systems. New to the Third Edition Expanded coverage of the requirements for generator intertie protection, generator protection, and generator excitation systems The latest technologies in microprocessor applications, including digital-based devices and designs Protection issues, such as capacitor bank protection, underfrequency and undervoltage load shedding, special protection schemes, DC tripping scheme designs, fault location, and event reports Building on the excellence of the preceding editions, this book will continue to serve as a basic reference for newcomers to the area as well as for experienced engineers. By sharing his first-hand experience with protection practices, the author offers valuable realistic insight into this field.

Table of Contents:
PREFACES INTRODUCTION AND GENERAL PHILOSOPHIES Introduction and Definitions Typical Protective Relays and Relay Systems Typical Power Circuit Breakers Nomenclature and Device Numbers Typical Relay and Circuit Breaker Connections Basic Objectives of System Protection Factors Affecting the Protection System Classification of Relays Protective Relay Performance Principles of Relay Application Information for Application Structural Changes within the Electric Power Industry Reliability and Protection Standards Bibliography FUNDAMENTAL UNITS: PER UNIT AND PERCENT VALUES Introduction Per Unit and Percent Definitions Advantages of Per Unit and Percent General Relations between Circuit Quantities Base Quantities Per Unit and Percent Impedance Relations Per Unit and Percent Impedances of Transformer Units Per Unit and Percent Impedances of Generators Per Unit and Percent Impedances of Overhead Lines Changing Per Unit (Percent) Quantities to Different Bases Bibliography PHASORS AND POLARITY Introduction Phasors Circuit and Phasor Diagrams for a Balanced Three-Phase Power System Phasor and Phase Rotation Polarity Application of Polarity for Phase-Fault Directional Sensing Directional Sensing for Ground Faults: Voltage Polarization Directional Sensing for Ground Faults: Current Polarization Other Directional-Sensing Connections Application Aspects of Directional Relaying Summary SYMMETRICAL COMPONENTS: A REVIEW Introduction and Background Positive-Sequence Set Nomenclature Convenience Negative-Sequence Set Zero-Sequence Set General Equations Sequence Independence Positive-Sequence Sources Sequence Networks Shunt Unbalance Sequence Network Interconnections Example: Fault Calculations on a Typical System Shown in Figure 4.16 Example: Fault Calculation for Autotransformers Example: Open-Phase Conductor Example: Open Phase Falling to Ground on One Side Series and Simultaneous Unbalances Overview Summary Bibliography Appendix 1: Short-Circuit MVA and Equivalent Impedance Appendix 2: Impedance and Sequence Connections for Transformer Banks Appendix 3: Sequence Phase Shifts through Wye-Delta Transformer Banks RELAY INPUT SOURCES Introduction Equivalent Circuits of Current and Voltage Transformers Current Transformers for Protection Applications Current Transformer Performance on a Symmetrical AC Component Secondary Burdens during Faults CT Selection and Performance Evaluation for Phase Faults Performance Evaluation for Ground Relays Effect of Unenergized CTs on Performance Flux Summation Current Transformer Current Transformer Performance on the DC Component Summary: Current Transformer Performance Evaluation Current Transformer Residual Flux and Subsidence Transients Auxiliary Current Transformers in CT Secondary Circuits Voltage Transformers for Protective Applications Optical Sensors Bibliography PROTECTION FUNDAMENTALS AND BASIC DESIGN PRINCIPLES Introduction Differential Principle Overcurrent-Distance Protection and the Basic Protection Problem Backup Protection: Remote vs. Local Basic Design Principles Ground Distance Relays Solid-State Microprocessor Relays Summary Bibliography SYSTEM-GROUNDING PRINCIPLES Introduction Ungrounded Systems Transient Overvoltages Grounded-Detection Methods for Ungrounded Systems High-Impedance Grounding Systems System Grounding for Mine or Other Hazardous-Type Applications Low-Impedance Grounding Solid (Effective) Grounding Ferroresonance in Three-Phase Power Systems Safety Grounding Grounding Summary and Recommendations References GENERATOR PROTECTION/INTERTIE PROTECTION FOR DISTRIBUTED GENERATION Introduction Generator Connections and Overview of Typical Protection Stator Phase-Fault Protection for All Size Generators Unit Transformer Phase-Fault Differential Protection (87TG) Phase-Fault Backup Protection (51V) or (21) Negative-Sequence Current Backup Protection Stator Ground-Fault Protection Multiple Generator Units Connected Directly to a Transformer: Grounding and Protection Field Ground Protection (64) Generator Off-Line Protection Reduced or Lost Excitation Protection (40) Generator Protection for System Disturbances and Operational Hazards Loss of Voltage Transformer Signal Generator Breaker Failure Excitation System Protection and Limiters Synchronous Condenser Protection Generator-Tripping Systems Station Auxiliary Service System Distributed Generator Intertie Protection Protection Summary Bibliography TRANSFORMER, REACTOR, AND SHUNT CAPACITOR PROTECTION Transformers Factors Affecting Differential Protection False Differential Current Transformer Differential Relay Characteristics Application and Connection of Transformer Differential Relays Example: Differential Protection Connections for a Two-Winding Wye-Delta Transformer Bank Load Tap-Changing Transformers Example: Differential Protection Connections for Multiwinding Transformer Bank Application of Auxiliaries for Current Balancing Paralleling CTs in Differential Circuits Special Connections for Transformer Differential Relays Differential Protection for Three-Phase Banks of Single-Phase Transformer Units Ground (Zero-Sequence) Differential Protection for Transformers Equipment for Transfer Trip Systems Mechanical Fault Detection for Transformers Grounding Transformer Protection Ground Differential Protection with Directional Relays Protection of Regulating Transformers Transformer Overcurrent Protection Transformer Overload-Through-Fault-Withstand Standards Examples: Transformer Overcurrent Protection Transformer Thermal Protection Overvoltage on Transformers Summary: Typical Protection for Transformers Reactors Capacitors Power System Reactive Requirements Shunt Capacitor Applications Capacitor Bank Designs Distribution Capacitor Bank Protection Designs and Limitation of Large Capacitor Banks Protection of Large Capacitor Banks Series Capacitor Bank Protection Capacitor Bank Protection Application Issues Bibliography BUS PROTECTION Introduction: Typical Bus Arrangements Single Breaker-Single Bus Single Buses Connected with Bus Tie Main and Transfer Buses with Single Breaker Single Breaker-Double Bus Double Breaker-Double Bus Ring Bus Breaker-and-Half Bus Transformer-Bus Combination General Summary of Buses Differential Protection for Buses Other Bus Differential Systems Ground-Fault Bus Protection Summary Bus Protection-Practical Considerations Bibliography MOTOR PROTECTION Introduction Potential Motor Hazards Motor Characteristics Involved in Protection Induction Motor Equivalent Circuit General Motor Protection Phase-Fault Protection Differential Protection Ground-Fault Protection Thermal and Locked-Rotor Protection Locked-Rotor Protection for Large Motors (21) System Unbalance and Motors Unbalance and Phase Rotation Protection Undervoltage Protection Bus Transfer and Reclosing Repetitive Starts and Jogging Protection Multifunction Microprocessor Motor Protection Units Synchronous Motor Protection Summary: Typical Protection for Motors Practical Considerations of Motor Protection Bibliography LINE PROTECTION Classification of Lines and Feeders Line Classifications for Protection Techniques and Equipment for Line Protection Coordination Fundamentals and General Setting Criteria Distribution Feeder, Radial Line Protection, and Coordination Example: Coordination for a Typical Distribution Feeder Distributed Generators and Other Sources Connected to Distribution Lines Example: Coordination for a Loop System Instantaneous Trip Application for a Loop System Short-Line Applications Network and Spot Network Systems Distance Protection for Phase Faults Distance Relay Applications for Tapped and Multiterminal Lines Voltage Source for Distance Relays Distance Relay Applications in Systems Protected by Inverse-Time-Overcurrent Relays Ground-Fault Protection for Lines Distance Protection for Ground Faults and Direction Overcurrent Comparison Fault Resistance and Relaying Directional Sensing for Ground-Overcurrent Relays Polarizing Problems with Autotransformers Voltage Polarization Limitations Dual Polarization for Ground Relaying Ground Directional Sensing with Negative Sequence Mutual Coupling and Ground Relaying Ground Distance Relaying with Mutual Induction Long EHV Series-Compensated Line Protection Backup: Remote, Local, and Breaker Failure Summary: Typical Protection for Lines Practical Considerations of Line Protection Bibliography PILOT PROTECTION Introduction Pilot System Classifications Protection Channel Classifications Directional Comparison Blocking Pilot Systems Directional Comparison Unblocking Pilot System Directional Comparison Overreaching Transfer Trip Pilot Systems Directional Comparison Underreaching Transfer Trip Pilot Systems Phase Comparison: Pilot Wire Relaying-Wire-Line Channels Phase Comparison: Audio Tone or Fiber-Optic Channels Segregated Phase Comparison Pilot Systems Single-Pole-Selective-Pole Pilot Systems Directional Wave Comparison Systems Digital Current Differential Pilot Scheme Enhancements Transfer Trip Systems Communication Channels for Protection Summary and General Evaluation of Pilot Systems Pilot Relaying-Operating Experiences Bibliography Appendix: Protection of Wire-Line Pilot Circuits STABILITY, RECLOSING, LOAD SHEDDING, AND TRIP CIRCUIT DESIGN Introduction Electric Power and Power Transmission Steady-State Operation and Stability Transient Operation and Stability System Swings and Protection Out-of-Step Detection by Distance Relays Automatic Line Reclosing Distribution Feeder Reclosing Subtransmission and Transmission-Line Reclosing Reclosing on Lines with Transformers or Reactors Automatic Synchronizing Frequency Relaying for Load Shedding-Load Saving Underfrequency Load Shedding Design Performance of Underfrequency Load Shedding Schemes Frequency Relaying for Industrial Systems Voltage Collapse Voltage Collapse Mitigating Techniques Protection and Control Trip Circuits Substation DC Systems Trip Circuit Devices Trip Circuit Design Trip Circuit Monitoring and Alarms Special Protection Schemes Practical Considerations-Special Protection Schemes Bibliography MICROPROCESSOR APPLICATIONS AND SUBSTATION AUTOMATION Introduction Microprocessor-Based Relay Designs Programable Logic Controllers Application of Microprocessor Relays Programming of Microprocessor Relaying Attributes of Microprocessor-Based Relays Protection Enhancements Multifunctional Capability Wiring Simplification Event Reports Commissioning and Periodic Testing Setting Specifications and Documentation Fault Location Power System Automation Practical Observations-Microprocessor Relay Application Bibliography PROBLEMS INDEX