Protective Relays

1. Purpose of Protective Relays and Relaying. Causes of Faults. Definitions. Functions of Protective Relays. Application to a Power System.- 2. Relay Design and Construction. Characteristics. Choice of Measuring Units. Construction of Measuring Units. Construction of Timing Units. Details of Design. Cases. Panel Mounting. Operation Indicators. Finishes.- 3. The Main Characteristics of Protective Relays. Phase and Amplitude Comparators. Relay Characteristics. General Equation for Characteristics. Inversion Chart. Resonance. Appendix.- 4. Overcurrent Protection. Time-Current Characteristics. Application. Limits of Error. Ratings. Directional Overcurrent Protection. A.C. Tripping. Schemes for Radial Feeders. Construction. Application. Problem.- 5. Distance Relays. General Principles. Special Characteristics. Limitations. Application to Lines. Settings. Multi-terminal Lines. Construction. A.C. Potential Supply. Simultaneous Ground Faults. Auto-reclosing Zero Sequence Compensation.- 6. Switched and Polyphase Distance Relays. Reduction of Measuring Units. Automatic Switching Schemes. Polyphase Distance Relays. Phase and Amplitude Comparators. Analysis of Polyphase Comparators.- 7. Directional Pilot Relaying. Basic Principles. Pilot Wire Schemes. Carrier Channel Schemes. Carrier Signal Checking. Future Trends.- 8. A.C. Pilot Relaying. Pilot Wire Schemes. Phase and Amplitude Comparators. Effect of Load Current. Multi-terminal Lines. Pilot Wire Limitations. Pilot Supervision. Phase Comparison Carrier.- 9. Protection of A.C. Machines. Generator Protection. Stator Faults. Rotor Faults. Miscellaneous Faults. Motor Protection. Faults. Unbalanced Conditions. Power Station Auxiliaries. Current Differential Relaying.- 10. Power Transformer Protection. Types of Faults. Gas Relays. Differential Relays. Magnetising Inrush. Minimising of Effects. Relay Solutions. Grounding Transformers. Generator Transformer Units. Transformer Feeders.- 11. Bus-Zone Protection. General Principles. Current Differential Protection. Voltage Differential. Frame Leakage Protection. Directional Comparison. Back-up. Supervision.- 12. Back-Up Protection. Basic Principles. Precautions for Reliability Remote Back-up. Local Back-up. Relay Back-up. Breaker Back-up. A.C. Supplies. D.C. Supply.- 13. Maintenance and Testing of Relays. Commissioning. Periodic Maintenance. Transfer to Test Circuit. Tools. Safety Measures. Mechanical Tests. Electrical Tests. Manufacture Tests.- 14. Miscellaneous. Static Relays. Future of Electromagnetic Relays. D.C. Protection Relays. Protection Engineering as a Career.- References.