Toshiba GR200 Series - 2.1 Current differential protection for the line

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 24 -
Current differential protection for the line
Current differential protection function (DIF) at local-terminal and remote-terminal can
operate by comparing the currents flow in and out in the line. The value of the current-
difference is close to zero when a fault does not occur (i.e., No fault). The DIF function consists
of a current segregated current differential protection (DIFL) and a zero-sequence current
differential protection (DIFG); they can detect phase-to-phase fault, phase-to-ground fault, and
a phase-to-ground fault. The DIFL and DIFGL functions can operate for on the three-terminal
line; remote differential trip (RDIF) function can substitute the operation of the DIFL and
DIFGL functions when an error occurs on the communication channel.
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Note: The implementation of such features is dependent upon the selection of hardware and
the configuration of functions. Several IED models do not support certain features. To
determine whether a particular feature has been implemented within an IED, identify the IED
ordering number; and check the order number at the ‘G&T position’ referring to the comparison
table below. For more information, see Appendix: Ordering .
Table 2.1-1 Comparative table in respective ordering numbers
Section
feature
Relay function/ features
Ordering No. at ‘G&T’
33
37
2.2.1
DIFL
Current differential
✓
✓
2.2.2
Check relay OC (OCs)
✓
✓
2.2.2
Check relay UV (UVs)
✓
✓
2.2.2
CT failure detection using Id (DIFL-CTF)
✓
✓
2.2.3
CT circuit failure detection (DIFL-CTF)
✓
✓
2.2.4
Charging current compensation (DIFL-Ic)
✓
✓
2.2.5
Id current monitoring (DIFL-IdSV)
✓
✓
2.3.1
DIFGL
Zero sequence current differential
✓
✓
2.3.2
Check relay EF (EFD)
✓
✓
2.3.3
CT circuit failure detection (DIFGL-CTF)
✓
✓
2.3.4
Charging current compensation (DIFGL-Ic)
✓
✓
2.4
CTsat
CT saturation countermeasure
✓
✓
2.5
CT matching
CT ratio/rating and fault currents
✓
✓
2.6
Usage in 1.5CB
TFC and Stub features
✓
✓
2.7
RDIF
Remote differential trip
✓
✓
2.8
Misc.
Blind zone protection
✓
✓
✓: Applicable NA: Not applicable