Transfer Tripping; Remote Tripping; Figure 4.8 Coupling Of Pilot Wire Monitoring - Siemens SIPROTEC 7SD600 System Manual

4
Method of operation
Numerical line differential protection SIPROTEC 7SD600 V3.0
Station 1
MT
I
1
I
b
Legend:
MT - Summation transformer
T - Transmitter (current source)
R - Receiver
C - Coupling capacitor
K

Figure 4.8 Coupling of pilot wire monitoring

4.4.2

Transfer tripping

In the event of single-ended infeed, the line is only
tripped at the infeed end following a short-circuit on
the line, as the local line current may be used as an
additional criterion for tripping (see section 4.3.6).
If it is desired to also trip the non-infeeding end, the
transfer trip function can be enabled (parameter "10
TTF.FE"). This operates with a pulsed tone frequency
via the pilot wires and is therefore only available in
devices with tone frequency generator (also used for
pilot wire monitoring).
The transfer trip signal can be prolonged by setting
"10 T.PROL". The alarm "TTF.sen" (Fno. 3028) is
generated.
4 - 12
1
I R
a
C
K
T
2
System manual Order no. E50417-G1176-C069-A1
2
T
C
C
R
1
4.4.3

Remote tripping

The 7SD600 line differential protection version with
pilot wire monitoring also has an integrated remote
tripping function. This can be implemented for remote
tripping of the other line end via a signal generated
outside the 7SD600, e.g. by a circuit-breaker failure
protection.
The command is then fed to the device via a binary
input (marshalling">R-Tr." (Fno. 3306)). This can be
prolonged when it is transmitted to the other line end
via the pilot wires, so that even a very short control
pulse is reliably received at the other line end (para
meter "12 C.PROL).
By marshalling the binary input with the ">RT blk"
(Fno. 3303) function, the remote tripping function can
be blocked.
The remote tripping function generates the following
alarms:
D "RT blk" (Fno. 3312) - function blocked
D "RT send" (Fno. 3316) - signal is transmitted
Similarly, the incoming signal can be delayed and/or
prolonged at the receiving line end so that, even in
the case of a very short signal, the circuit-breaker can
be reliably switched.
Station 2
MT
I I
a 2
Siemens AG January 1999