Toshiba GRZ100 B Series, Instruction Manual

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When autoreclose is out of service, the zone 1 extension protection is blocked.
C B
Zone 3
Zone 2
Zone 1
Zone 1X
T3
T2
T 1
A
T 4 Zone R
Time
Figure 2.4.2.1 Time/Distance Characteristics of Zone 1 Extension Protection
and Time-Stepped Distance Protection
Scheme Logic
The scheme logic of the zone 1 extension protection is shown in Figure 2.4.2.2. Zone 1X outputs
single-phase tripping signal S-TRIP or three-phase tripping signal M-TRIP through phase
selection logic on condition that the reclosing mode selection switch [ARC-M] of autoreclose be
set to "TPAR" or "SPAR & TPAR" and condition REC-READY1 = 1 be established. The phase
selection logic is the same as that for the zone 1 protection shown in Figure 2.4.1.7, except that
Z1XG and Z1XS are employed instead of Z1G and Z1S. When a power swing is detected (PSB =
1) and when a VT failure is detected (VTF = 1), tripping is blocked. Power swing blocking can be
disabled by the scheme switch [PSB-Z1X].
The zone 1 extension protection is disabled by the binary input signal (PLC signal)
Z1XG_BLOCK and Z1XS_BLOCK.
S-TRIP
M-TRIP
Phase
Selection
"SPAR","TPAR",
"SPAR + TPAR"
[ARC-M]
+
PSB
[PSB-Z1X]
"ON"
VTF
REC-READY1
Z1X
&
&
≥
1
Z1X_INIT
1540
Z1XG_BLOCK
1617
Z1XS_BLOCK
1633
22:Z1XG-A 23:Z1XG-B 24:Z1XG-C
37:Z1XS-AB 38:Z1XS-BC 39:Z1XS-CA
1
&
≥
1
"Z1-EXT"
Protection scheme
+
Z1X_F.ENABLE
1659
Figure 2.4.2.2 Zone 1 Extension Scheme Logic
REC-READY1 is a signal in the autoreclose function, and as shown in Figure 2.4.2.3,
REC-READY1 = 1 is established when the reclaim time has elapsed, that is, when autoreclose is
ready, and reset when a reclosing command is output.
Zone 1 extension can provide protection in the case of evolving faults provided that they occur
before the reclosing command is output. Otherwise, in the case of a permanent fault, it will not