ABB RELION REB500 Technical Manual page 75

1MRK 505 406-UEN B
coupler inputs), the power swing blocking [PS_BLOCK] and the VT supervision [VT_BLOCK]
functions received by the SUPBL segment block all the distance protection functions [DISTBL]
with the exception of the backup overcurrent function.
EXTBLK_DIST
PSBBLOCK
VTFAIL
IEC19000421 V1 EN-US
Figure 20: SUPBL segment
Table 52:
Signal
EXTBLK_DIST
PSBBLOCK
VTFAIL
DISTBL
Switch-onto-fault logic (SOTF)
When a circuit-breaker is closed onto and existing three-phase fault anywhere in the power
system, instantaneous three-phase tripping takes place.
The fault detectors in this case are the non-directional starters (overcurrent or
underimpedance units) or optionally the over-reaching zone, but this is only used in the
following special cases:
• Power transformer with high inrush currents at the remote end of the line. In such cases,
fault detection involving the distance measuring units is safer.
• Close faults with complete voltage collapse may possibly not otherwise be detected, in
which case the parameter
The switch-onto-fault logic can be activated and the switch-onto-fault signal [SOTF] set to
1 in one of three ways:
logical
1. by an auxiliary contact on the CB control switch when closing the CB (optocoupler input
Manual close [MANCL_DIST])
2. by an auxiliary contact on the CB when opening the CB (optocoupler input Dead line
[DEADLINE])
3. by prolonged undervoltage (U weak) on all three phases and no current enable which
corresponds to a dead line [UWEAK_L1, L2, L3]
Alternative 2) is used, if the VTs are connected to the busbars and alternative 1) is not possible.
The criteria of alternatives 2) and 3) are only effective after either 200 ms or 10 s [SOTF_10S]
(setting), depending on whether the switch-onto-fault logic is required to operate after
Bay protection functions REB500
Technical manual
100
Signals VT SUPBL
In
X
X
X
See Figure 18.
MemDirMode has to be set to Trip .
© Copyright 2019 ABB. All rights reserved
DISTBL
OR
18000019-IEC19000421-1-en.vsdx
Out Source
Binary input: Ext Blk Dist
Binary output: Ext Blk PSB
Binary output: VT Sup Delay
X Binary output: Dist Block
Section 5
Bay protection functions
Drain
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