The Relay Testing Handbook: Principles and Practice

1 Professional EngineerJourneyman Power System ElectricianElectrical Engineering TechnologistThe Relay Testing HandbookPrinciples and PracticeixTable of ContentsAuthor s Note vAcknowledgments viiChapter 1: Electrical Fundamentals 11. The three -Phase Electrical System 12. transformers 273. Instrument transformers 344. Fault Types 405. Grounding 476. Sequence Components 527. Fault Types and Sequence Components 58 Chapter 2: Introduction to Protective Relays 651. What are Protective Relays? 652. Time Coordination Cur ves (TCC) and Coordination 73 Chapter 3: A Brief Histor y of Protective Relays 831.

2 Electromechanical Relays 832. Solid-State Relays 873. Microprocessor Based Relays 87 Chapter 4: Relay Testing Fundamentals 951. Reasons for Relay Testing 952. Relay Testing Equipment 983. Relay Testing Methods 1014. Relay Test Procedures 109 Chapter 5: Test Sheets and Documentation 1351. Your Company Name and Logo 1362. Project Details 1363. Nameplate Data 1374. CT and PT Ratios 1385. Comments and Notes 1386. Metering Test Data 1387. Input / Output Tests 139 Principles and Practicex8. Element Test Results 1409. Element Characteristics 14210. Final Output Checks 14411.

3 Test Sheet Template 14512. Final Report 149 Chapter 6: Testing Over voltage (59) Protection 1511. Application 1512. Settings 1523. Pickup Testing 1544. Timing Tests 1585. Tips and Tricks to Overcome Common Obstacles 164 Chapter 7: Under voltage (27) Protection Testing 1651. Application 1652. Settings 1663. Pickup Testing 1694. Timing Tests 1755. Tips and Tricks to Overcome Common Obstacles 181 Chapter 8: Over/Under Frequency (81) Protection Testing 1831. Application 1832. Settings 1853. Pickup Testing 1874. Timing Tests 1925. Tips and Tricks to Overcome Common Obstacles 193 Chapter 9: Instantaneous Overcurrent (50) Element Testing 1951.

4 Application 1952. Settings 1983. Pickup Testing 1994. Timing Tests 2065. Residual Neutral Instantaneous Overcurrent Protection 2096. Tips and Tricks to Overcome Common Obstacles 209 Chapter 10: Time Overcurrent (51) Element Testing 2111. Application 2112. Settings 2133. Pickup Testing 2144. Timing Tests 2205. Reset Tests 2286. Residual Neutral Time Overcurrent Protection 2287. Tips and Tricks to Overcome Common Obstacles 228 Principles and PracticexiChapter 11: Directional Overcurrent (67) Element Testing 2311. Application 2312. Operation 2353. Settings 2364.

5 Pickup Testing 2385. Timing Test Procedures 2466. Tips and Tricks to Overcome Common Obstacles 246 Chapter 12: Simple Percent Differential (87) Element Testing 2471. Application 2472. Settings 2573. Restrained-Differential Pickup Testing 2594. Restrained-Differential Timing Test Procedure 2645. Restrained-Differential Slope Testing 2666. Tips and Tricks to Overcome Common Obstacles 283 Chapter 13: Percent Differential (87) Element Testing 2851. Application 2862. Settings 3123. Current Transformer Connections 3164. 3-Phase Restrained-Differential Pickup Testing 3215.

6 Restrained-Differential Timing Test Procedure 3306. 3-Phase Restrained-Differential Slope Testing 3327. 1-Phase Restrained-Differential Slope Testing 3588. Harmonic Restraint Testing 3649. Tips and Tricks to Overcome Common Obstacles 370 Chapter 14: Unrestrained-Differential Testing 3711. Settings 3722. Test-Set Connections 3733. Simple Pickup Test Procedure 3764. Alternate Pickup Test Procedure 3795. Timing Test Procedure 3826. Tips and Tricks to Overcome Common Obstacles 383 Chapter 15: Line Distance (21) Element Testing 3851. Impedance Relays 3902.

7 Settings 4013. Preventing Interference in Digital Relays 4054. 3-Phase Line Distance Protection Testing 4075. Phase-to-Phase Line Distance Protection Testing 4256. Phase-to-Ground Line Distance Protection Testing 451 Principles and PracticexiiChapter 16: Understanding Digital Logic 4731. Understanding Logic 4732. Relay Labels 4793. Internal Relay Control Schemes 4814. Individual Element Schemes 4925. Binar y Relays 4946. Arithmetic (Math) Scheme 4997. General Electric FlexLogic 524 Chapter 17: Review the Application 5431. Introduction 5432. Collecting Information 545 Chapter 18: Preparing to Test 5751.

8 Prepare to Test 5752. Establish Communication 5753. Apply Settings 5794. Connect Your Relay Test-Set 5795. Creating the Test Plan 590 Chapter 19: Testing the Relay 6091. Perform Relay Self-checks 6092. Verify Digital Inputs and Outputs 6093. Verify Current and Voltage Inputs 6104. Element Testing 6125. Final Output Tests 6156. Prepare Relay for Ser vice 6217. Final Report 622 Bibliography 623 Index 627xiiiTable of FiguresFigure 1-1: Simple Single-Phase Generator2 Figure 1-2: Simple three -Phase Generator3 Figure 1-3: Phase Sequence Examples4 Figure 1-4: Phasor Diagram Example5 Figure 1-5: Electrical Diagram Comparison6 Figure 1-6: Electrical Diagram Comparison with Van Reference7 Figure 1-7: Phasor Diagram 17 Figure 1-8: Phasor Diagram 28 Figure 1-9: Phasor Diagram 39 Figure 1-10: A-B-C / A-C-B Phasor Diagrams9 Figure 1-11: Current and Voltage Phasors10 Figure 1-12.

9 Vector Diagrams on Different Axis11 Figure 1-13: Wye Connection14 Figure 1-14: Phase to Line Conversion15 Figure 1-15: delta /Wye Connected Vector Diagram16 Figure 1-16: delta Connection17 Figure 1-17: delta connection Vector Diagram for Balanced System with 30 Lag17 Figure 1-18: Watts - Current and Voltage Are In-Phase18 Figure 1-19: Inductive VARs - Current Lags the Voltage by 30 19 Figure 1-20: Capacitive VARs - Current Leads the Voltage20 Figure 1-21: three -Phase Power Formulas21 Figure 1-22: three -Phase Power Formulas Assuming Balanced Conditions21 Figure 1-23: three -Phase Power Triangle - Watts Only22 Figure 1-24: Power Triangle - Only Inductive VARs22 Figure 1-25: Power Triangle - Only Capacitive VARs23 Figure 1-26: Power Triangle24 Figure 1-27: Example three -Phase Power/VARS/VA Formula Calculations24 Figure 1-28: Simple Transformer Construction28 Figure 1-29: Transformer Voltage Ratio Calculation29 Figure 1-30: Transformer Current Ratio Calculation29 Figure 1-31: Wye- delta Transformer Connections31 Figure 1-32.

10 Wye- delta Transformer Calculations31 Figure 1-33: delta -Wye Transformer Connections32 Figure 1-34: delta -Wye Transformer Calculations32 Principles and PracticexivFigure 1-35: Wye-Wye Transformer Connections 33 Figure 1-36: Auto-Transformer Connections 33 Figure 1-37: delta - delta Transformer Connections 34 Figure 1-38: Wye-Wye and delta - delta Transformer Calculations 34 Figure 1-39: CT Ratio Calculations 35 Figure 1-40: CT Polarity Connections 36 Figure 1-41: CT Accuracy Class 37 Figure 1-42: PT Voltage Ratio Calculation 37 Figure 1-43: 3-Wire delta PT Configurations 38 Figure 1-44: 4-Wire Wye PT Configurations 38 Figure 1-45: Nominal PT Voltages 39 Figure 1-46: three -Phase Fault 3-Line Drawing 40 Figure 1-47: three -Phase Fault Phasor Diagram 41 Figure 1-48: Phase-Phase Fault 3-Line Drawing 42 Figure 1-49: Fault Current vs.