⎯
407
⎯
6
F
2
S
0
8
4
6
Therefore, load current IL is:
IL = (Source voltage)/(A s/s back imp Line imp B s/s impedance)
=
(150kV/ 3 )/(0.94
×
75 + 16.8
×
(0.0197
2
+ 0.2747
2
) + 0.94
×
75)
=
594.7A
3.2
Minimum fault current
The minimum fault current Ifmin on a protected transmission line is the current of the phase to
earth fault on the nearest remote terminal.
To calculate Ifmin, zero sequence earth fault current (Io), positive sequence earth fault current
(I1) and negative earth fault current (I2) are calculated as follows:
I0 = I1 = I2 = (Source voltage)/{(Back impedance of A s/s)
+ (Transmission line zero sequence impedance)
+ (Transmission line positive sequence impedance)
×
2*}
=
(150kV/ 3 )/{(0.94
×
75) + 16.8
×
(0.4970
2
+ 1.4387
2
)
+
2
×
16.8
×
(0.0197
2
+ 0.2747
2
) }
=
822.28A
So,
Ifmin= I0 + I1+ I2 = 3
×
822.28 = 2.47kA
*Note:
Assuming that positive sequence impedance = negative sequence impedance.
B s/s
Line length: 16.8km
A s/s
M
Earth fault
GRZ100
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: ......