Schweitzer Engineering Laboratories SEL-421-4 - Page 20

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SEL-421 Relay Instruction Manual Date Code 20171021
List of Figures
Figure 6.17 345 kV Tapped Line Zero-Sequence Network..........................................................................6.75
Figure 6.18 DC Schematic for DCB Trip Scheme........................................................................................6.80
Figure 6.19 230 kV Parallel Underground Cables........................................................................................6.87
Figure 6.20 Circuit Breaker Arrangement at Station S, Cable 1...................................................................6.90
Figure 6.21 Quadrilateral Ground-Distance Element Reactive Reach Setting.............................................6.95
Figure 6.22 Circuit to Determine Network Homogeneity ............................................................................6.97
Figure 6.23 Apparent Fault Impedance Resulting From Nonhomogeneity..................................................6.98
Figure 6.24 Nonhomogeneous Angle Setting ...............................................................................................6.99
Figure 6.25 External Ground Fault .............................................................................................................6.102
Figure 6.26 Negative-Sequence Fault Current Distribution-External Ground Fault...........................................6.105
Figure 6.27 Reverse Unbalanced Fault on Cable Circuit (Shunt Admittance)...........................................6.109
Figure 6.28 500 kV Power System .............................................................................................................6.119
Figure 6.29 OOS Characteristic Settings Parameters .................................................................................6.121
Figure 6.30 Calculating Setting R1R7 ........................................................................................................6.123
Figure 6.31 Swing Trajectory to Determine the OSBD Setting .................................................................6.125
Figure 6.32 Inner Blinders ..........................................................................................................................6.127
Figure 6.33 OST Characteristics.................................................................................................................6.131
Figure 6.34 230 kV Example Power System ..............................................................................................6.137
Figure 6.35 Circuit Breaker Arrangement at Station S...............................................................................6.138
Figure 6.36 Potential Sources .....................................................................................................................6.140
Figure 6.37 500 kV Power System .............................................................................................................6.141
Figure 6.38 Partial Circuit Breaker-and-a-Half Arrangement at Station S, Line 1.....................................6.143
Figure 6.39 Potential Sources .....................................................................................................................6.147
Figure 6.40 Scheme 1 All Faults and Scheme 2 Multiphase Fault Timing Diagram .................................6.154
Figure 6.41 Scheme 2 Single-Phase Fault Timing Diagram.......................................................................6.155
Figure 6.42 230 kV Power System for Circuit Breaker Failure Scheme 1.................................................6.155
Figure 6.43 Timing Diagram for Setting BFPU1—Scheme 1....................................................................6.157
Figure 6.44 Circuit Breaker Failure Trip and Circuit Breaker Trip DC Connections ................................6.160
Figure 6.45 500 kV Power System for Circuit Breaker Failure Scheme 2.................................................6.162
Figure 6.46 Fault Current Distribution Through Faulted Line at Station S ................................................6.163
Figure 6.47 Timing Diagram for Setting BFPU1—Scheme 2....................................................................6.164
Figure 6.48 Timing Sequences for Circuit Breaker Failure Protection Scheme 2......................................6.165
Figure 6.49 Circuit Breaker BK1 DC Connections (Two Trip Coils) ........................................................6.168
Figure 6.50 230 kV Tapped Overhead Transmission Line.........................................................................6.170
Figure 6.51 Automatic Restoration Timing Diagram .................................................................................6.171
Figure 6.52 SEL-421 Inputs........................................................................................................................6.173
Figure 6.53 Protection Free-Form SEL
OGIC Control Equations.................................................................6.177
Figure 6.54 Protection Freeform SEL
OGIC Control Equations...................................................................6.181
Figure 6.55 Ladder Logic Representation, Protection Freeform SEL
OGIC Control Equations ..................6.183
Figure 7.1 Complex Power (P/Q) Plane........................................................................................................7.4
Figure 7.2 Fixed Analog Section of the Event Report..................................................................................7.9
Figure 7.3 Digital Section of the Event Report...........................................................................................7.11
Figure 7.4 Sample Digital Portion of the Event Report..............................................................................7.12
Figure 7.5 Summary Section of the Event Report ......................................................................................7.13
Figure 7.6 Sample Event Summary Report ................................................................................................7.13
Figure 7.7 Sample Event History................................................................................................................7.15
Figure 10.1 MAP 1:METER Command Example........................................................................................10.8