ABB RELION 650 SERIES, Technical Manual

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If the fault inception function has detected a system fault, a block signal CS will be
issued and sent to remote end in order to block the overreaching zones. Different
criteria has to be fulfilled for sending the CS signal:
1. The breaker has to be in closed condition, that is, the input signal CBOPEN is
deactivated.
2. A fault inception should have been detected while the carrier send signal is not
blocked, that is, the input signal BLKCS is not activated.
If it is later detected that it was an internal fault that made the function issue the CS
signal, the function will issue a CHSTOP signal to unblock the remote end.
The received signal, which is connected to the CR input, is not used to accelerate
the release of the overreaching zone to clear the fault instantaneously. The
overreaching zone to be accelerated is connected to the input CACC, see
Figure
218 .
In case of external faults, the blocking signal (CR) must be received before the
settable timer
tCoord elapses, to prevent a false trip, see Figure 218 .
The function can be totally blocked by activating the input BLOCK, block of trip
by activating the input BLKTR, block of carrier send by activating the input
BLKCS.
CACC
CR
tCoord
TRIP
AND
t
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IEC05000512 V1 EN-US
Figure 218: Basic logic for trip signal in delta blocking scheme
Channels for communication in each direction must be available.
12.1.6.3 Permissive underreaching scheme
M13893-13 v6
In a permissive underreaching scheme, a forward directed underreaching
measuring element (normally zone1) sends a permissive signal CS to the remote
end if a fault is detected.in forward direction. The received signal CR is used to
allow an overreaching zone to trip after the
tCoord timer has elapsed. The tCoord
in permissive underreaching schemes is normally set to zero.
The logic for trip signal in permissive scheme is shown in figure 219 .
CACC
CR
tCoord
TRIP
AND
t
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IEC05000513 V1 EN-US
Figure 219: Logic for trip signal in permissive scheme
1MRK 506 382-UEN A
Section 12
Scheme communication
Line distance protection REL650 2.2 IEC 437
Technical manual