Sel SEL-421 - Page 25

xxviiList of Figures
Date Code 20020501 SEL-421/SEL-421-1 Relay
Applications Handbook
Section 1: Protection Application Examples
Figure 1.1 230 kV Overhead Transmission Line................................................................................. A.1.3
Figure 1.2 Circuit Breaker Arrangement at Station S.......................................................................... A.1.5
Figure 1.3 500 kV Parallel Overhead Transmission Lines................................................................ A.1.20
Figure 1.4 Circuit Breaker-and-a-Half Arrangement: Station S, Line 1. .......................................... A.1.23
Figure 1.5 Quadrilateral Ground Distance Element Reactive Reach Setting.................................... A.1.28
Figure 1.6 Definition of Homogeneous Network. ............................................................................. A.1.30
Figure 1.7 Tilt in Apparent Fault Impedance Resulting From Nonhomogeneity. ............................. A.1.31
Figure 1.8 Nonhomogeneous Angle Setting...................................................................................... A.1.32
Figure 1.9 Current Distribution During Cross-Country Fault. .......................................................... A.1.44
Figure 1.10 Simplified POTT Scheme KEY1/KEY3 Logic. .............................................................. A.1.45
Figure 1.11 345 kV Tapped Overhead Transmission Line.................................................................. A.1.53
Figure 1.12 Circuit Breaker Arrangement at Station S........................................................................ A.1.56
Figure 1.13 Reverse Zone 3 Coordination........................................................................................... A.1.62
Figure 1.14 Impedance Diagram. ........................................................................................................ A.1.63
Figure 1.15 Load-Encroachment Function.......................................................................................... A.1.67
Figure 1.16 345 kV Tapped Line Negative-Sequence Network.......................................................... A.1.72
Figure 1.17 345 kV Tapped Line Zero-Sequence Network................................................................. A.1.74
Figure 1.18 DC Schematic for DCB Trip Scheme. ............................................................................. A.1.79
Figure 1.19 230 kV Parallel Underground Cables............................................................................... A.1.86
Figure 1.20 Circuit Breaker Arrangement at Station S, Cable 1. ........................................................ A.1.89
Figure 1.21 Quadrilateral Ground Distance Element Reactive Reach Setting.................................... A.1.93
Figure 1.22 Circuit to Determine Network Homogeneity. .................................................................. A.1.95
Figure 1.23 Apparent Fault Impedance Resulting From Nonhomogeneity......................................... A.1.96
Figure 1.24 Nonhomogeneous Angle Setting...................................................................................... A.1.97
Figure 1.25 External Ground Fault.................................................................................................... A.1.100
Figure 1.26 Negative-Sequence Fault Current Distribution—External Ground Fault...................... A.1.103
Figure 1.27 Reverse Unbalanced Fault on Cable Circuit (Shunt Admittance).................................. A.1.107
Figure 1.28 500 kV Power System.................................................................................................... A.1.118
Figure 1.29 OOS Characteristic Settings Parameters. ....................................................................... A.1.120
Figure 1.30 Calculating Setting R1R7............................................................................................... A.1.122
Figure 1.31 Swing Trajectory to Determine the OSBD Setting. ....................................................... A.1.123
Figure 1.32 Inner Blinders................................................................................................................. A.1.126
Figure 1.33 OST Characteristics........................................................................................................ A.1.129
Figure 1.34 230 kV Example Power System..................................................................................... A.1.136
Figure 1.35 Circuit Breaker Arrangement at Station S...................................................................... A.1.136
Figure 1.36 Potential Sources. ........................................................................................................... A.1.138
Figure 1.37 500 kV Power System.................................................................................................... A.1.140
Figure 1.38 Partial Circuit Breaker-and-a-Half Arrangement at Station S, Line 1. .......................... A.1.142
Figure 1.39 Potential Sources. ........................................................................................................... A.1.145
Figure 1.40 Scheme 1 All Faults and Scheme 2 Multiphase Fault Timing Diagram. ....................... A.1.154
Figure 1.41 Scheme 2 Single-Phase Fault Timing Diagram. ............................................................ A.1.154
Figure 1.42 230 kV Power System for Circuit Breaker Failure Scheme 1........................................ A.1.155
Figure 1.43 Timing Diagram for Setting BFPU1—Scheme 1........................................................... A.1.156
Figure 1.44 Circuit Breaker Failure Trip and Circuit Breaker Trip DC Connections. ...................... A.1.159
Figure 1.45 500 kV Power System for Circuit Breaker Failure Scheme 2........................................ A.1.161
Figure 1.46 Fault Current Distribution Through Faulted Line at Station S....................................... A.1.162
Figure 1.47 Timing Diagram for Setting BFPU1—Scheme 2........................................................... A.1.163
Figure 1.48 Timing Sequences for Circuit Breaker Failure Protection Scheme 2. ........................... A.1.164
Figure 1.49 Circuit Breaker BK1 DC Connections (Two Trip Coils). .............................................. A.1.167
Section 2: Monitoring and Metering
Figure 2.1 SEL-421 Relay Intelligent Circuit Breaker Monitor. ......................................................... A.2.2
Figure 2.2 Circuit Breaker Maintenance Curve (Manufacturer’s Data).............................................. A.2.5
Figure 2.3 Circuit Breaker Contact Wear Curve With SEL-421 Relay Settings................................. A.2.5
Figure 2.4 Trip Bus Sensing With Relay Input IN106. ....................................................................... A.2.8