
⎯
72
⎯
6 F 2 S 0 8 4 6
2.4.7 Switch-Onto-Fault
Protection
In order to quickly remove a fault which may occur when a faulted line or busbar is energized, the
switch-onto-fault (SOTF) protection functions for a certain period after the circuit breaker is
closed.
The SOTF protection is performed by a non-directional overcurrent element and distance
measuring elements. The overcurrent protection is effective in detecting close-up three-phase
faults on the line in particular when the voltage transformer is installed on the line side. This is
because the voltage input to the distance measuring elements is absent continuously before and
after the fault, and thus it is difficult for the distance measuring elements to detect the fault.
The distance measuring elements can operate for faults other than close-up three-phase faults. One
of the zone 1 to zone ND elements can be used for the SOTF protection.
Scheme logic
The scheme logic for the SOTF protection is shown in Figure 2.4.7.1. The SOTF protection issues
a three-phase tripping signal M-TRIP for the operation of an overcurrent element OCH or distance
measuring elements Z1 to ZND for 500 ms after the circuit breaker is closed (CB-OR = 1) and/or
for 500ms after the undervoltage dead line detector resets. The method of controlling the SOTF
protection by CB closing and/or by undervoltage dead line detection is selected by scheme switch
[SOTF-DL]. Elements UVFS and UVLG provide undervoltage dead line detection.
Tripping by each element can be disabled by the scheme switches [SOTF-OC] to [SOTF-ZND].
When a VT failure is detected (NON VTF = 0), tripping by the distance measuring elements is
blocked.
≥
1
&
&
≥
1
1
0.5s
0 t
SOTF-TRIP
[SOTF-Z1]
[SOTF-OC]
NON VTF
CB-OR
OCH
Z1
"ON"
"ON"
Z2
"ON"
Z3
"ON"
0 - 300s
t 0
TSOTF
UVLS
≥
1
0 - 300s
t 0
TSOTF
"UV",
"Both"
"CB",
"Both"
[SOTF-DL]
[SOTF-Z2]
[SOTF-Z3]
[SOTF-F]
ZF
"ON"
ZR1
"ON"
ZR2
"ON"
ZND
"ON"
[SOTF-R1]
[SOTF-R2]
[SOTF-ND]
&
55: OCH-A
56: OCH-B
57: OCH-C
UVLG
78:UVLG-A
79:UVLG-B
80:UVLG-C
72:UVLS-AB
73:UVLS-BC
74:UVLS-CA
&
SOTF_BLOCK
1623
1
183
Figure 2.4.7.1 SOTF Scheme Logic
Setting
The setting elements necessary for the SOTF protection and their setting ranges are as follows:
Element Range
Step Default Remarks
OCH
2.0 - 15.0 A
0.1 A
6.0 A
Overcurrent setting
( 0.4 - 3.0 A
0.1 A
1.2 A) (*)
TSOTF
0 – 300 s
1 s
5 s
SOTF check timer
Содержание GRZ100 B Series
Страница 264: ... 263 6 F 2 S 0 8 4 6 Appendix A Block Diagram ...
Страница 271: ... 270 6 F 2 S 0 8 4 6 ...
Страница 272: ... 271 6 F 2 S 0 8 4 6 Appendix B Signal List ...
Страница 307: ... 306 6 F 2 S 0 8 4 6 ...
Страница 308: ... 307 6 F 2 S 0 8 4 6 Appendix C Variable Timer List ...
Страница 310: ... 309 6 F 2 S 0 8 4 6 Appendix D Binary Input Output Default Setting List ...
Страница 321: ... 320 6 F 2 S 0 8 4 6 ...
Страница 322: ... 321 6 F 2 S 0 8 4 6 Appendix E Details of Relay Menu and LCD Button Operation ...
Страница 331: ... 330 6 F 2 S 0 8 4 6 ...
Страница 340: ... 339 6 F 2 S 0 8 4 6 Appendix G Typical External Connections ...
Страница 377: ... 376 6 F 2 S 0 8 4 6 ...
Страница 384: ... 383 6 F 2 S 0 8 4 6 Appendix J Return Repair Form ...
Страница 388: ... 387 6 F 2 S 0 8 4 6 Customer Name Company Name Address Telephone No Facsimile No Signature ...
Страница 389: ... 388 6 F 2 S 0 8 4 6 ...
Страница 390: ... 389 6 F 2 S 0 8 4 6 Appendix K Technical Data ...
Страница 401: ... 400 6 F 2 S 0 8 4 6 ...
Страница 402: ... 401 6 F 2 S 0 8 4 6 Appendix L Symbols Used in Scheme Logic ...
Страница 405: ... 404 6 F 2 S 0 8 4 6 ...
Страница 406: ... 405 6 F 2 S 0 8 4 6 Appendix M Example of Setting Calculation ...
Страница 417: ... 416 6 F 2 S 0 8 4 6 ...
Страница 418: ... 417 6 F 2 S 0 8 4 6 Appendix N IEC60870 5 103 Interoperability and Troubleshooting ...
Страница 430: ... 429 6 F 2 S 0 8 4 6 Appendix O Programmable Reset Characteristics and Implementation of Thermal Model to IEC60255 8 ...
Страница 434: ... 433 6 F 2 S 0 8 4 6 Appendix P Inverse Time Characteristics ...
Страница 437: ... 436 6 F 2 S 0 8 4 6 ...
Страница 438: ... 437 6 F 2 S 0 8 4 6 Appendix Q Failed Module Tracing and Replacement ...
Страница 444: ... 443 6 F 2 S 0 8 4 6 Appendix R Ordering ...
Страница 447: ......