Sel SEL-421 User manual

20111215
SEL-421 Relay
Protection and
Automation System
Instruction Manual
Reference Manual
*PM421-03-NB*

SEL-421 Relay Reference Manual Date Code 20111215
© 2001–2011 by Schweitzer Engineering Laboratories, Inc. All rights reserved.
All brand or product names appearing in this document are the trademark or registered trademark of their respective holders. No SEL
trademarks may be used without written permission. SEL products appearing in this document may be covered by US and Foreign patents.
Schweitzer Engineering Laboratories, Inc. reserves all rights and benefits afforded under federal and international copyright and patent laws in
its products, including without limitation software, firmware, and documentation.
The information in this manual is provided for informational use only and is subject to change without notice. Schweitzer Engineering
Laboratories, Inc. has approved only the English language manual.
This product is covered by the standard SEL 10-year warranty. For warranty details, visit www.selinc.com or contact your customer service
representative. PM421-03

Date Code 20111215 SEL-421 Relay
Table of Contents
Table of Contents................................................................................................................................................. i
List of Tables ...................................................................................................................................................... vii
List of Figures................................................................................................................................................... xxi
Preface .............................................................................................................................................................. xxxi
User’s Guide
Section 1: Introduction and Specifications
Features........................................................................................................................................................ U.1.2
Models and Options..................................................................................................................................... U.1.5
SEL-421 Versions and Supported Features ................................................................................................. U.1.7
Applications................................................................................................................................................. U.1.8
Specifications ............................................................................................................................................ U.1.13
Section 2: Installation
Shared Configuration Attributes.................................................................................................................. U.2.1
Plug-In Boards........................................................................................................................................... U.2.12
Jumpers...................................................................................................................................................... U.2.18
Relay Placement ........................................................................................................................................ U.2.30
Connection................................................................................................................................................. U.2.31
AC/DC Connection Diagrams ................................................................................................................... U.2.50
Section 3: PC Software
Installing the Computer Software................................................................................................................ U.3.2
Communications Setup................................................................................................................................ U.3.4
Settings Database Management and Drivers............................................................................................... U.3.6
Create and Manage Relay Settings.............................................................................................................. U.3.9
Expression Builder .................................................................................................................................... U.3.14
Analyze Events.......................................................................................................................................... U.3.16
HMI Meter and Control............................................................................................................................. U.3.21
Section 4: Basic Relay Operations
Inspecting a New Relay............................................................................................................................... U.4.1
Connecting and Applying Power................................................................................................................. U.4.3
Establishing Communication....................................................................................................................... U.4.4
Changing the Default Passwords................................................................................................................. U.4.6
Checking Relay Status............................................................................................................................... U.4.10
Making Simple Settings Changes.............................................................................................................. U.4.13
Examining Metering Quantities ................................................................................................................ U.4.33
Reading Oscillograms, Event Reports, and SER....................................................................................... U.4.42
Operating the Relay Inputs and Outputs ................................................................................................... U.4.56
Configuring High-Accuracy Timekeeping ................................................................................................ U.4.71
Readying the Relay for Field Application................................................................................................. U.4.79
Section 5: Front-Panel Operations
Front-Panel Layout...................................................................................................................................... U.5.2
Front-Panel Menus and Screens ................................................................................................................ U.5.13
Front-Panel Automatic Messages.............................................................................................................. U.5.34
Operation and Target LEDs....................................................................................................................... U.5.36
Front-Panel Operator Control Pushbuttons ............................................................................................... U.5.40

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SEL-421 Relay Date Code 20111215
Table of Contents
Section 6: Testing and Troubleshooting
Testing Philosophy ...................................................................................................................................... U.6.1
Testing Features and Tools .......................................................................................................................... U.6.4
Relay Test Connections ............................................................................................................................... U.6.8
Test Methods ............................................................................................................................................. U.6.13
Checking Relay Operation ........................................................................................................................ U.6.24
Relay Self-Tests......................................................................................................................................... U.6.38
Relay Troubleshooting .............................................................................................................................. U.6.42
Factory Assistance..................................................................................................................................... U.6.45
Appendix A: Firmware and Manual Versions
Firmware..................................................................................................................................................... U.A.1
Instruction Manual.................................................................................................................................... U.A.11
Applications Handbook
Section 1: Protection Application Examples
Overview ..................................................................................................................................................... A.1.1
230 kV Overhead Transmission Line Example........................................................................................... A.1.2
500 kV Parallel Transmission Lines With Mutual Coupling Example ..................................................... A.1.18
345 kV Tapped Overhead Transmission Line Example ............................................................................ A.1.51
EHV Parallel 230 kV Underground Cables Example ............................................................................... A.1.84
Out-of-Step Logic Application Examples ............................................................................................... A.1.115
Auto-Reclose Example............................................................................................................................ A.1.133
Auto-Reclose and Synchronism Check Example.................................................................................... A.1.137
Circuit Breaker Failure Application Examples ....................................................................................... A.1.147
Section 2: Monitoring and Metering
Circuit Breaker Monitor .............................................................................................................................. A.2.1
Station DC Battery System Monitor.......................................................................................................... A.2.21
Metering .................................................................................................................................................... A.2.26
Section 3: Analyzing Data
Data Processing ........................................................................................................................................... A.3.2
Triggering Data Captures and Event Reports.............................................................................................. A.3.4
Duration of Data Captures and Event Reports ............................................................................................ A.3.5
Oscillography .............................................................................................................................................. A.3.7
Event Reports, Event Summaries, and Event Histories............................................................................. A.3.11
SER (Sequential Events Recorder)............................................................................................................ A.3.34
Section 4: Time-Synchronized Measurements
Relay Configuration for High-Accuracy Timekeeping ............................................................................... A.4.1
Fault Analysis.............................................................................................................................................. A.4.6
Power Flow Analysis................................................................................................................................... A.4.7
State Estimation Verification....................................................................................................................... A.4.9
Section 5: Substation Automatic Restoration
230 kV Tapped Transmission Line Application Example........................................................................... A.5.2
Section 6: SEL Communications Processor Applications
SEL Communications Processors................................................................................................................ A.6.1
SEL Communications Processor and Relay Architecture ........................................................................... A.6.3
SEL Communications Processor Example.................................................................................................. A.6.5

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Table of Contents
Section 7: Direct Network Communication
Direct Network Communication ................................................................................................................. A.7.1
Serial Networking........................................................................................................................................ A.7.2
Ethernet Card............................................................................................................................................... A.7.4
Direct Networking Example........................................................................................................................ A.7.7
Reference Manual
Section 1: Protection Functions
Current and Voltage Source Selection..........................................................................................................R.1.2
Frequency Estimation.................................................................................................................................R.1.15
Time-Error Calculation...............................................................................................................................R.1.16
Fault Location.............................................................................................................................................R.1.18
Open Phase Detection Logic ......................................................................................................................R.1.20
Pole Open Logic.........................................................................................................................................R.1.20
Loss-of-Potential Logic..............................................................................................................................R.1.23
Fault Type Identification Selection Logic ..................................................................................................R.1.27
Ground Directional Element.......................................................................................................................R.1.27
Phase and Negative-Sequence Directional Elements .................................................................................R.1.38
Directionality..............................................................................................................................................R.1.39
CVT Transient Detection............................................................................................................................R.1.40
Series-Compensation Line Logic ...............................................................................................................R.1.41
Load-Encroachment Logic .........................................................................................................................R.1.42
Out-of-Step Logic.......................................................................................................................................R.1.43
Mho Ground Distance Elements ................................................................................................................R.1.49
Quadrilateral Ground Distance Elements...................................................................................................R.1.54
Mho Phase Distance Elements ...................................................................................................................R.1.58
Zone Time Delay ........................................................................................................................................R.1.61
Instantaneous Line Overcurrent Elements..................................................................................................R.1.64
Inverse-Time Overcurrent Elements...........................................................................................................R.1.70
Switch-Onto-Fault Logic............................................................................................................................R.1.84
Communications-Assisted Tripping Logic.................................................................................................R.1.87
Directional Comparison Blocking Scheme ................................................................................................R.1.88
Permissive Overreaching Transfer Tripping Scheme .................................................................................R.1.91
Directional Comparison Unblocking Scheme Logic................................................................................R.1.100
Trip Logic .................................................................................................................................................R.1.105
Circuit Breaker Failure Protection............................................................................................................R.1.115
Section 2: Auto-Reclosing and Synchronism Check
Auto-Reclosing.............................................................................................................................................R.2.2
One-Circuit-Breaker Auto-Reclosing...........................................................................................................R.2.4
Two-Circuit-Breaker Auto-Reclosing ........................................................................................................R.2.10
Auto-Reclose Logic Diagrams ...................................................................................................................R.2.27
Manual Closing ..........................................................................................................................................R.2.41
Voltage Checks for Auto-Reclosing and Manual Closing..........................................................................R.2.44
Settings and Relay Word Bits for Auto-Reclosing and Manual Closing ...................................................R.2.46
Synchronism Check....................................................................................................................................R.2.50
Section 3: SELOGIC Control Equation Programming
SELOGIC Control Equation History .............................................................................................................R.3.1
Separation of Protection and Automation Areas ..........................................................................................R.3.2
SELOGIC Control Equation Programming ...................................................................................................R.3.4
SELOGIC Control Equation Setting Structure ..............................................................................................R.3.6
Multiple Setting Groups ...............................................................................................................................R.3.8
SELOGIC Control Equation Capacity .........................................................................................................R.3.11
SELOGIC Control Equation Elements.........................................................................................................R.3.12

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SELOGIC Control Equation Operators........................................................................................................R.3.25
Effective Programming...............................................................................................................................R.3.34
SEL-311 and SEL-351 Series Users...........................................................................................................R.3.36
Section 4: Communications Interfaces
Communications Interfaces ..........................................................................................................................R.4.1
Serial Communication..................................................................................................................................R.4.2
Communications Card..................................................................................................................................R.4.4
Section 5: SEL Communications Protocols
Serial Port Hardware Protocol......................................................................................................................R.5.1
Software Protocol Selections........................................................................................................................R.5.2
Protocol Active When Setting PROTO := SEL............................................................................................R.5.3
Virtual File Interface...................................................................................................................................R.5.11
SEL MIRRORED BITS Communications......................................................................................................R.5.15
SEL Distributed Port Switch Protocol (LMD) ...........................................................................................R.5.21
SEL-2600A RTD Module Operation..........................................................................................................R.5.23
Section 6: DNP3 Communications
Introduction to DNP3 ...................................................................................................................................R.6.1
DNP3 in the SEL-421...................................................................................................................................R.6.5
DNP3 Documentation ................................................................................................................................R.6.12
Application Example ..................................................................................................................................R.6.27
DNP LAN/WAN.........................................................................................................................................R.6.32
DNP LAN/WAN in the SEL-421 ...............................................................................................................R.6.32
DNP LAN/WAN Documentation ...............................................................................................................R.6.41
DNP LAN/WAN Application Example......................................................................................................R.6.49
Section 7: Synchrophasors
Introduction ..................................................................................................................................................R.7.1
Synchrophasor Measurement .......................................................................................................................R.7.6
Settings for Synchrophasors.........................................................................................................................R.7.9
Synchrophasor Relay Word Bits.................................................................................................................R.7.19
Synchrophasor Analog Quantities..............................................................................................................R.7.20
View Synchrophasors by Using the MET PM Command..........................................................................R.7.24
C37.118 Synchrophasor Protocol...............................................................................................................R.7.25
SEL Fast Message Synchrophasor Protocol...............................................................................................R.7.31
Synchrophasor Protocols and SEL Fast Operate Commands.....................................................................R.7.37
Section 8: IEC 61850 Communications
Features.........................................................................................................................................................R.8.1
Introduction to IEC 61850............................................................................................................................R.8.2
IEC 61850 Operation....................................................................................................................................R.8.3
IEC 61850 Configuration ...........................................................................................................................R.8.12
Logical Nodes.............................................................................................................................................R.8.16
Protocol Implementation Conformance Statement: SEL-400 Series Devices ...........................................R.8.31
ACSI Conformance Statements..................................................................................................................R.8.37
Section 9: ASCII Command Reference
Description of Commands............................................................................................................................R.9.2
Section 10: Settings
Alias Settings..............................................................................................................................................R.10.3
Global Settings ...........................................................................................................................................R.10.4
Breaker Monitor Settings .........................................................................................................................R.10.11
Group Settings ..........................................................................................................................................R.10.14
Protection Free-Form SELOGIC Control Equations .................................................................................R.10.34
Automation Free-Form SELOGIC Control Equations...............................................................................R.10.35
Output Settings .........................................................................................................................................R.10.35

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Date Code 20111215 SEL-421 Relay
Table of Contents
Front-Panel Settings .................................................................................................................................R.10.37
Report Settings .........................................................................................................................................R.10.44
Port Settings..............................................................................................................................................R.10.46
DNP3 Settings—Serial Port .....................................................................................................................R.10.50
Appendix A: Relay Word Bits
Alphabetic....................................................................................................................................................R.A.1
Row List ....................................................................................................................................................R.A.22
Appendix B: Analog Quantities
Quantities Listed Alphabetically .................................................................................................................R.B.1
Quantities Listed by Function .....................................................................................................................R.B.8
Glossary
Index
SEL-421 Relay Command Summary

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Date Code 20111215 SEL-421 Relay
List of Tables
User’s Guide
Table 1.1 Application Highlights ..................................................................................................... U.1.11
Table 2.1 Recommended Control Input Pickup Settings ................................................................... U.2.5
Table 2.2 Required Settings for Use with AC Control Signals.......................................................... U.2.7
Table 2.3 I/O Interface Boards Control Inputs................................................................................. U.2.14
Table 2.4 I/O Interface Boards Control Outputs .............................................................................. U.2.15
Table 2.5 Main Board Jumpers ........................................................................................................ U.2.20
Table 2.6 Main Board Jumpers—JMP1, JMP2, and JMP3.............................................................. U.2.21
Table 2.7 I/O Board Jumpers ........................................................................................................... U.2.28
Table 2.8 Jumper Positions for Breaker OPEN/CLOSE Indication................................................. U.2.29
Table 2.9 Jumper Positions for Arc Suppression ............................................................................. U.2.29
Table 2.10 Front-Panel LED Option .................................................................................................. U.2.29
Table 2.11 Fuse Requirements for the SEL-421 Power Supply......................................................... U.2.39
Table 3.1 System Requirements for ACSELERATOR QuickSet.......................................................... U.3.2
Table 3.2 ACSELERATOR QuickSet HMI Tree View Functions....................................................... U.3.22
Table 4.1 Power Supply Voltage Inputs ............................................................................................. U.4.3
Table 4.2 General Serial Port Settings ............................................................................................... U.4.6
Table 4.3 SEL-421 Access Levels...................................................................................................... U.4.7
Table 4.4 Access Level Commands and Passwords........................................................................... U.4.7
Table 4.5 Settings Classes and Instances ....................................................................................... U.4.15
Table 4.6 Actions at Settings Prompts ............................................................................................. U.4.16
Table 4.7 Actions at Text-Edit Mode Prompts................................................................................. U.4.19
Table 4.8 Control Inputs in the SEL-421 ......................................................................................... U.4.65
Table 4.9 SEL-421 Timekeeping Modes.......................................................................................... U.4.71
Table 4.10 Date/Time Last Update Sources....................................................................................... U.4.76
Table 4.11 Communications Port Commands That Clear Relay Buffers .......................................... U.4.80
Table 5.1 Front-Panel Inactivity Time-Out Setting............................................................................ U.5.4
Table 5.2 Metering Screens Enable Settings...................................................................................... U.5.5
Table 5.3 SER Point Settings ............................................................................................................. U.5.8
Table 5.4 Display Point Settings—Boolean..................................................................................... U.5.11
Table 5.5 Display Point Settings—Analog ...................................................................................... U.5.11
Table 5.6 Display Point Settings—Boolean and Analog Examples ................................................ U.5.11
Table 5.7 Front-Panel Pushbutton Functions While Viewing SER Events...................................... U.5.20
Table 5.8 Local Bit Control Settings................................................................................................ U.5.26
Table 5.9 Local Bit SELOGIC ........................................................................................................... U.5.26
Table 5.10 Settings Available From the Front Panel.......................................................................... U.5.28
Table 5.11 Front-Panel Target LEDs.................................................................................................. U.5.37
Table 5.12 TIME Target LED Trigger Elements—Factory Defaults................................................. U.5.38
Table 5.13 Operator Control Pushbuttons and LEDs—Factory Defaults .......................................... U.5.41
Table 6.1 Acceptance Testing ............................................................................................................ U.6.2
Table 6.2 Commissioning Testing...................................................................................................... U.6.2
Table 6.3 Maintenance Testing .......................................................................................................... U.6.3
Table 6.4 UUT Database Entries for SEL-5401 Relay Test System Software—5 A Relay .............. U.6.7
Table 6.5 UUT Database Entries for SEL-5401 Relay Test System Software—1 A Relay .............. U.6.8
Table 6.6 Phase Instantaneous Overcurrent Pickup ......................................................................... U.6.14
Table 6.7 Selectable Operating Quantity Time-Overcurrent Element (51S1) Default Settings ...... U.6.21
Table 6.8 Negative-Sequence Directional Element Settings AUTO Calculations ........................... U.6.32
Table 6.9 Troubleshooting Procedures............................................................................................. U.6.42
Table A.1 Firmware Revision History ............................................................................................... U.A.1
Table A.2 Ethernet Card Firmware Revision History........................................................................ U.A.9

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SEL-421 Relay Date Code 20111215
List of Tables
Table A.3 Compatible SEL-421 and Ethernet Card Firmware Versions ......................................... U.A.10
Table A.4 ACSELERATOR Architect CID File Compatibility .......................................................... U.A.10
Table A.5 Instruction Manual Revision History .............................................................................. U.A.11
Applications Handbook
Table 1.1 System Data—230 kV Overhead Transmission Line ........................................................ A.1.2
Table 1.2 Secondary Impedances....................................................................................................... A.1.3
Table 1.3 LOP Enable Options........................................................................................................... A.1.6
Table 1.4 Options for Enabling Pole-Open Logic............................................................................ A.1.12
Table 1.5 Setting TULO Unlatch Trip Options................................................................................ A.1.13
Table 1.6 Settings for 230 kV Overhead TX Example .................................................................... A.1.14
Table 1.7 System Data—500 kV Parallel Overhead Transmission Lines........................................ A.1.19
Table 1.8 Secondary Impedances..................................................................................................... A.1.19
Table 1.9 LOP Enable Options......................................................................................................... A.1.24
Table 1.10 Tilt Resulting From Nonhomogeneity ............................................................................. A.1.29
Table 1.11 Options for Enabling Pole-Open Logic............................................................................ A.1.35
Table 1.12 Trip Unlatch Options........................................................................................................ A.1.39
Table 1.13 Settings for 500 kV Parallel TX Example........................................................................ A.1.45
Table 1.14 System Data—345 kV Tapped Overhead Transmission Line.......................................... A.1.52
Table 1.15 Secondary Impedances..................................................................................................... A.1.53
Table 1.16 LOP Enable Options......................................................................................................... A.1.58
Table 1.17 Local Zone 2 Fault Impedance Measurements ................................................................ A.1.59
Table 1.18 Apparent Impedance Measurement for Remote Faults.................................................... A.1.60
Table 1.19 Options for Enabling Pole-Open Logic............................................................................ A.1.74
Table 1.20 Setting TULO Unlatch Trip Options................................................................................ A.1.78
Table 1.21 Settings for 345 kV Tapped TX Example ........................................................................ A.1.79
Table 1.22 System Data—230 kV Parallel Underground Cables ...................................................... A.1.85
Table 1.23 Secondary Impedances..................................................................................................... A.1.85
Table 1.24 LOP Enable Options......................................................................................................... A.1.90
Table 1.25 Tilt Resulting From Nonhomogeneity ............................................................................. A.1.95
Table 1.26 XAG Measurement for Remote AG Fault
(k01 = 0.374 —39.2°, sheath and ground return path) ................................................ A.1.97
Table 1.27 XAG Measurement for Remote AG Fault
(k01 = 0.385 —46.7°, sheath return path) ................................................................... A.1.97
Table 1.28 XAG Measurement for Remote AG Fault
(k0 = 6.105 44.5°, ground return path) ........................................................................ A.1.98
Table 1.29 Options for Enabling Pole-Open Logic.......................................................................... A.1.106
Table 1.30 Setting TULO Unlatch Trip Options.............................................................................. A.1.109
Table 1.31 Settings for 230 kV Parallel Cables Example ................................................................ A.1.110
Table 1.32 Positive-Sequence Impedances (Secondary).................................................................. A.1.115
Table 1.33 Automatically Calculated/Hidden Settings .................................................................... A.1.125
Table 1.34 Relay Configuration (Group) ......................................................................................... A.1.125
Table 1.35 Out-of-Step Tripping/Blocking ...................................................................................... A.1.126
Table 1.36 Automatically Calculated/Hidden Settings .................................................................... A.1.132
Table 1.37 Relay Configuration (Group) ......................................................................................... A.1.132
Table 1.38 Out-of-Step Tripping/Blocking ...................................................................................... A.1.132
Table 1.39 Settings for Auto-Reclose Example ............................................................................... A.1.136
Table 1.40 Settings for Auto-Reclose and Synchronism Check Example ....................................... A.1.145
Table 1.41 Secondary Quantities...................................................................................................... A.1.152
Table 1.42 Settings for Circuit Breaker Failure Example 1 ............................................................. A.1.156
Table 1.43 Secondary Quantities...................................................................................................... A.1.158
Table 1.44 Settings for Circuit Breaker Failure Example 2 ............................................................. A.1.164
Table 2.1 Circuit Breaker Monitor Configuration.............................................................................. A.2.2
Table 2.2 Circuit Breaker Maintenance Information—Example ....................................................... A.2.4
Table 2.3 Contact Wear Monitor Settings—Circuit Breaker 1 .......................................................... A.2.5
Table 2.4 Circuit Breaker Monitor Initiate SELOGIC Control Equations........................................... A.2.7
Table 2.5 Circuit Breaker Monitor Close SELOGIC Control Equations............................................. A.2.9