Power System Protection

1. Principle of Protection Practice1.1. Protection Equipment1.2. Zones of Protection1.3. Reliability, Selectivity, Stability1.4. Sensitivity1.5. Relay Output Devices1.6. Tripping Circuits

2. Fault Calculations2.1. Three-phase Fault Calculations2.2. Symmetrical Component Analysis of A Three-Phase Network2.3. Equations and Network Connections for Various Types of Faults2.4. Current and Voltage Distribution in a System due to a Fault2.5. Effect of System Earthing on Zero Sequence Quantities

3. Equivalent Circuits and Parameters of Power System Plant

3.1. Synchronous Machines3.2. Armature Reaction3.3. Steady State Theory3.4. Machine Reactances3.5. Effect of Saturation on Machine Reactances3.6. Transformers3.7. Transformer Equivalent Circuits3.8. Auto-Transformers3.9. Transformer Impedances3.10.Overhead Lines and Cables3.11.Overhead Line Circuits With or Without Earth Wires3.12.OHL Equivalent Circuits3.13.Cable Circuits

4. Current and Voltage Transformers

4.1. Electromagnetic Voltage Transfomers4.2. Capacitor Voltage Transfomers4.3. Current Transfomers4.4. Non-Conventional Instrument Transformers

5. Relay Technology

5.1. Electromechanical Relays5.2. Static Relays5.3. Digital Relays5.4. Numerical Relays5.5. Additional Features of Numerical Relays5.6. Numerical Relay Considerations

6. Protection: Signaling and Intertripping

6.1. Unit Protection Schemes6.2. Tele-protection Commands6.3. Performance Requirements6.4. Transmission Media, Interference and Noise6.5. Signaling Methods

7. Overcurrent Protection for Phase and Earth Faults

7.1. Co-ordination Procedure7.2. Principles of Time/Current Grading7.3. Standard IDMT Overcurrent Relays7.4. Combined IDMT and High Set Instantaneous7.5. Overcurrent Relays7.6. Very Inverse (VI) Overcurrent Relays7.7. Extremely Inverse (EI) Overcurrent Relays7.8. Other Relay Characteristics7.9. Independent (definite) Time Overcurrent Relays7.10.Relay Current Setting7.11.Relay Time Grading Margin7.12.Recommended Grading Margins7.13.Calculation of Phase Fault Overcurrent Relay Settings7.14.Directional Phase Fault Overcurrent Relays7.15.Ring Mains7.16.Earth Fault Protection7.17.Directional Earth Fault Overcurrent Protection7.18.Earth Fault Protection on Insulated Networks7.19.Earth Fault Protection on Petersen Coil Earthed Networks7.20.Examples of Time and Current Grading

8. Unit Protection of Feeders

8.1. Convention of Direction8.2. Conditions for Direction Comparison8.3. Circulating Current System8.4. Balanced Voltage System8.5. Summation Arrangements8.6. Examples of Electromechanical and Static Unit Protection Systems8.7. Digital/Numerical Current Differential Protection Systems8.8. Carrier Unit Protection Schemes8.9. Current Differential Scheme – Analogue Techniques8.10.Phase Comparison Protection Scheme Considerations

9. Distance Protection

9.1. Principles of Distance Relays9.2. Relay Performance9.3. Relationship Between Relay Voltage and Zs/Zl Ratio9.4. Voltage Limit for Accurate Reach Point Measurement9.5. Zones of Protection9.6. Distance Relay Characteristics

9.7. Distance Relay Implementation9.8. Effect of Source Impedance and Earthing Methods9.9. Distance Relay Application Problems9.10. Other Distance Relay Features9.11. Distance Relay Application Example

10. Protection of Complex Transmission Circuits

10.1. Parallel Feeders10.2. Multi-Ended Feeders – Unit Protection Schemes10.3. Multi-Ended Feeders - Distance Relays10.4. Multi-Ended Feeders – Application of Distance Protection Schemes10.5. Protection of Series Compensated Lines

11. Auto-Reclosing

11.1. Application of Auto-Reclosing11.2. Auto-Reclosing on HV Distribution Networks11.3. Factors Influencing HV Auto-Reclose Schemes11.4. Auto-Reclosing on EHV Transmission Lines11.5. High Speed Auto-Reclosing on EHV Systems

12. Busbar Protection

12.1. Busbar Faults12.2. Protection Requirements12.3. Types of Protection System12.4. System Protection Schemes12.5. Frame-Earth Protection (Howard Protection)12.6. Differential Protection Principles12.7. Numerical Busbar Protection Schemes12.8. Interlocked Overcurrent Busbar Schemes

13. Transformer and Transformer-Feeder Protection

13.1. Winding Faults13.2. Magnetising Inrush13.3. Transformer Overheating13.4. Transformer Protection – Overview13.5. Transformer Overcurrent Protection13.6. Restricted Earth Fault Protection13.7. Differential Protection13.8. Differential Protection Stabilisation During Magnetising Inrush Conditions13.9. Combined Differential and Restricted Earth Fault Schemes13.10. Earthing Transformer Protection13.11. Autotransformer Protection13.12. Overfluxing Protection13.13. Transformer-Feeder Protection13.14. Condition Monitoring of Transformers13.15. Transformer Asset Management

14. Generator and Generator-Transformer Protection

14.1. Generator Earthing14.2. Stator Winding Faults14.3. Stator Winding Protection14.4. Differential Protection of Direct Connected Generators14.5. Differential Protection of Generator- Transformers14.6. Overcurrent Protection14.7. Stator Earth Fault Protection14.8. Overvoltage Protection14.9. Undervoltage Protection14.10. Unbalanced Loading14.11. Under/Overfrequency/ Overfluxing Protection14.12. Rotor Faults14.13. Loss of Excitation Protection14.14. Pole Slipping Protection14.15. Stator Overheating14.16. Mechanical Faults14.17. Complete Generator Protection Schemes14.18. Embedded Generation

15. Industrial and Commercial Power System Protection

15.1. Busbar Arrangement15.2. Discrimination15.3. HRC Fuses15.4. Industrial Circuit Breakers15.5. Protection Relays15.6. Co-ordination Problems15.7. Fault Current Contribution from Induction Motors15.8. Automatic Changeover Systems15.9. Power Factor Correction and Protection of Capacitors

16. A.C. Motor Protection16.1. Modern Relay Design16.2. Thermal (Overload) Protection16.3. Start/Stall Protection16.4. Short-Circuit Protection16.5. Earth Fault Protection16.6. Negative Phase Sequence Protection16.7. Faults in Rotor Windings16.8. RTD Temperature Detection16.9. Bearing Failures16.10. Under voltage Protection16.11. Loss-of-load Protection

17. System Integrity Protection Schemes17.1. Summary of System Integrity Protection Schemes17.2. Time-Synchronized System Integrity Protection Schemes17.3. Non-Synchronized System Integrity Protection Schemes

18. Relay Testing and Commissioning21.1 Introduction21.2 Electrical Type Tests21.3 Electromagnetic Compatibility Tests21.4 Product Safety Type Tests21.5 Environmental Type Tests21.6 Software Type Tests21.7 Dynamic Validation Type Testing21.8 Production Testing21.9 Commissioning Tests21.10 Secondary Injection Test Equipment21.11 Secondary Injection Testing21.12 Primary Injection Tests21.13 Testing of Protection Scheme Logic21.14 Tripping and Alarm Annunciation Tests21.15 Periodic Maintenance Tests21.16 Protection Scheme Design for Maintenance

19. Substation Control and Automation