Toshiba GR200 Series - 2.3 Zero-sequence current differential protection (DIFGL); 2.3.1 Differential protection characteristics (DIFGL); (i) Ir-Id plane for DIFGL function

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 41 -
◆ Connection point in PLC logic
DIFL (Function ID: 41001)
Element ID
Name
Description
830001EBB0
ADD.DIFLFS
Add File-safe condition
810002EBB1
DIFL-CTF_BLOCK
DIF-L ctf detect block
820000EBB2
DIFL-RDIF_BLOCK
Remote differential detect block
830003EBB3
DIFL-SV_BLOCK
Differential current monitoring block
800000EBB0
DIFL-TP_BLOCK
DIF-L trip block
810000EBB6
DIFL_3PTP
Trip signal by DIF-L protection operation (3-phase)
820000EBB7
DIFL_ARCBLOCK
Autoreclose block signal by DIF-L protection operation
8F0000EBB4
DIFL_BLOCK
Block all the above four
800000EBB5
DIFL_INST_OP
DIF-L protection instant operation command
840002EBB0
EXTERNAL_DIFL-CTF
External CTF condition
800000EBB8
R1.DIFL-A_OP
Receiving signal from Remote Terminal 1 (phase-A)
810000EBB9
R1.DIFL-B_OP
Receiving signal from Remote Terminal 1 (phase-B)
820000EBBA
R1.DIFL-C_OP
Receiving signal from Remote Terminal 1 (phase-C)
800000EBBB
R2.DIFL-A_OP
Receiving signal from Remote Terminal 2 (phase-A)
810000EBBC
R2.DIFL-B_OP
Receiving signal from Remote Terminal 2 (phase-B)
820000EBBD
R2.DIFL-C_OP
Receiving signal from Remote Terminal 2 (phase-C)
800000EBBE
R3.DIFL-A_OP
Receiving signal from Remote Terminal 3 (phase-A)
810000EBBF
R3.DIFL-B_OP
Receiving signal from Remote Terminal 3 (phase-B)
820000EBC0
R3.DIFL-C_OP
Receiving signal from Remote Terminal 3 (phase-C)
800000EBC1
R4.DIFL-A_OP
Receiving signal from Remote Terminal 4 (phase-A)
810000EBC2
R4.DIFL-B_OP
Receiving signal from Remote Terminal 4 (phase-B)
820000EBC3
R4.DIFL-C_OP
Receiving signal from Remote Terminal 4 (phase-C)
Zero-sequence current differential protection (DIFGL)
Zero-sequence current differential protection (DIFGL) function is provided to enhance
sensitivity upon occurrence of an earth fault having high impedance. To perform sensitive
protection in the DIFGL function, residual current (Ie) is applied. Note that the residual
current is introduced by the CT for the residual circuit.
2.3.1 Differential protection characteristics (DIFGL)
(i) Ir-Id plane for DIFGL function
Figure 2.3-1 shows the percentage restraining characteristic in the DIFGL element.
Differential current (I
d0
) denotes a vector summation of the residual currents in all terminals;
restraining current (I
r0
) denotes a scalar summation of the residual currents in all terminals.
The I
d0
and I
r0
currents are also derived using Equations (2.3-1) and (2.3-2):






 

 


(2.3-1)