Schweitzer Engineering Laboratories SEL-321 - Section 5: Applications

Date Code 20011026 Applications i
SEL-321/321-1 Instruction Manual
TABLE OF CONTENTS
SECTION 5: APPLICATIONS.................................................................5-1
A 230 kV Application Example for POTT Scheme with Time-Stepped Backup ........................5-1
Purpose..................................................................................................................................5-1
System Data ..........................................................................................................................5-2
Relay Settings .......................................................................................................................5-2
Relay Terminal Settings................................................................................................ 5-2
Identifier................................................................................................................5-2
Positive- and Zero-Sequence Line Impedances ....................................................5-3
Fault Locator Enable and Line Length..................................................................5-3
Current and Potential Transformer Ratios ............................................................5-3
Enable Desired Distance Zones and Directional Sense ................................................5-3
Phase and Ground Distance Element Setting Criteria ..................................................5-4
Zone 1 Setting .......................................................................................................5-4
Zone 2 Setting .......................................................................................................5-4
Zone 3 Setting .......................................................................................................5-5
Phase Distance Overcurrent Supervision Setting Criteria ............................................5-6
Zone 1 Setting .......................................................................................................5-6
Zone 2 Setting .......................................................................................................5-6
Zone 3 Setting .......................................................................................................5-6
Ground Distance Overcurrent Supervision Setting Criteria .........................................5-7
Zone 1 Setting .......................................................................................................5-7
Zone 2 Setting .......................................................................................................5-7
Zone 3 Setting .......................................................................................................5-7
Distance Element Setting Calculations ......................................................................... 5-8
Zero-Sequence Compensation Factor and Non-homogeneous Angle Settings.............5-9
Zero-Sequence Compensation Factor Setting ....................................................... 5-9
Non-homogeneous Angle Setting..........................................................................5-9
Out-of-Step Setting ..................................................................................................... 5-10
Load-Encroachment Logic Setting..............................................................................5-10
Negative-Sequence Directional Element Settings ......................................................5-11
Phase Time-Overcurrent Element Setting...................................................................5-13
Residual Overcurrent Settings ....................................................................................5-13
Residual Time-Overcurrent Settings...................................................................5-13
Instantaneous/Definite-Time Residual Overcurrent Settings..............................5-13
Negative-Sequence Overcurrent Settings ...................................................................5-14
Negative-Sequence Time-Overcurrent Settings..................................................5-14
Instantaneous/Definite-Time Negative-Sequence Setting...................................5-14
Voltage Elements ........................................................................................................5-15
Time-Step Backup Time Delay Settings.....................................................................5-15
Permissive Overreaching Scheme Logic.....................................................................5-16
Directional Comparison Unblocking Scheme Logic .................................................. 5-18
Zone 1 Extension Logic Setting..................................................................................5-18
Remote-End-Just-Opened (REJO) Enable Setting (EREJO)......................................5-18
Switch-Onto-Fault Logic Setting ................................................................................5-18
Loss-of-Potential (LOP) Enable Setting (ELOP)........................................................5-19