Functions
6-937SA522 Manual
C53000-G1176-C119-2
The following teleprotection schemes are available:
− 3877 = permissive underreach transfer trip, as referred to in Sub-
section 6.4.1.1,
− 3277 = permissive overreach transfer trip, as referred to in Sub-
section 6.4.1.3,
− 8QEORFNLQJ = Unblocking with Z1B, as referred to in Sub-section
6.4.1.4,
− %ORFNLQJ = Blocking scheme, as referred to in Sub-section 6.4.1.5.
In address )&77HOHS'LV the application of a teleprotection scheme can
be switched 21 or 2)).
If the teleprotection is applied to a line with three ends, the address must be set
to /LQH&RQILJ = 7KUHHWHUPLQDOV, otherwise it remains at the setting 7ZR
7HUPLQDOV.
Distance Protection
Prerequisites
For all applications of teleprotection schemes (except PUTT), it must be ensured that
the fault detection of the distance protection in the reverse direction has a greater
reach than the overreaching zone of the opposite line end (refer to the shaded areas
in Figure 6-56 on the right hand side)! For this purpose, at least one of the distance
stages must be set to 5HYHUVH or 1RQ'LUHFWLRQDO. During a fault in the shaded
area at the left of Figure 6-56, this fault would be in zone Z1B of the protection at B as
zone Z1B is set incorrectly. The distance protection at A would not pick up and there-
fore interpret this as a fault with single end infeed from B (echo from A or no block sig-
nal at A). This would result in a false trip!
Figure 6-56 Distance protection setting with permissive overreach schemes
Time Settings The send signal prolongation 6HQG3URORQJ (address ) must ensure that the
send signal reliably reaches the opposite line end, even if there is very fast tripping at
the sending line end and/or the signal transmission time is relatively long. In the case
of the permissive overreaching schemes 3277 and 8QEORFNLQJ this signal prolon-
gation time is only effective if the device has already issued a trip command. This en-
sures the release of the other line ends even if the short-circuit has been cleared very
rapidly by the instantaneous zone Z1. In the case of the blocking scheme %ORFNLQJ
the send signal is always prolonged by this time. In this case it corresponds to a tran-
sient blocking following a reverse fault. This setting can only be modified with DIGSI
®
4 under “Additional Settings”.
With the release delay 79 (address ) the release of the zone Z1B can be de-
layed. This is only necessary for the blocking scheme %ORFNLQJ, to allow sufficient
transmission time for the blocking signal during external faults. This delay
only
has an
A
B
Z1B(A)
Z1B(B)
PICKUP(A)
PICKUP(B)
correct
incorrect!
PICKUP(B)
PICKUP(A)
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