Method Of Operation; Permissive Underreach Transfer Trip With Pick-Up (Putt) - Siemens siprotec 7SA6 User Manual

Functions
6.4.1

Method of Operation

Switching
On and Off
6.4.1.1

Permissive Underreach Transfer Trip with Pick-up (PUTT)

Principle
6-76
For the other schemes at least one communication channel in each direction is
required. For example, fibre optic connections or voice frequency modulated high
frequency channels via pilot cables, power line carrier or microwave radio links can be
used for this purpose.
The 7SA6 also makes provision for the transmission of phase segregated signals. For
this purpose, three transmission channels are required in each direction. The
additional expense for the signal transmission is weighed up by the advantage that
dependable single-pole automatic reclosure can be carried out even when two single-
phase faults occur on different lines in the system.
The signal transmission schemes are also suited to three terminal lines (teed feeders).
In this case, signal transmission channels are required from each of the three ends to
the each of the others in both directions. Phase segregated signal transmission is
however not provided for three terminal line applications.
During disturbances in the receiver or on the transmission path, the teleprotection
supplement may be blocked via a binary input, without affecting the normal time
graded distance protection. The measuring reach control (enable zone Z1B) can be
obtained via the binary input "!(QDEOH $5]RQHV" (see also Figure 6-38 above) from
an external reclosure device or from the internal automatic reclose function.
The teleprotection function can be switched on and off by means of the parameter
 )&7 7HOHS (), or via the system interface (if available) and via binary input
(if this is allocated). The switched state is saved internally (refer to Figure 6-41) and
secured against loss of auxiliary supply. It is only possible to switch on from the source
where previously it had been switched off from. To be active, it is necessary that the
function is switched on from all three switching sources.
!  A8UÃUryrƒÃ9v†
ON
„1"
OFF
>Dis.Telep.OFF
>Dis.Telep. ON
System port: Dis.Telep.OFF
System port: Dis.Telep.ON
Figure 6-41 Switching on and off of the teleprotection
Figure 6-42 shows the operation scheme of the permissive underreach transfer trip
scheme. In the case of a fault inside zone Z1, the transfer trip signal is sent to the
opposite line end. The signal received at that end causes the tripping if the
≥1
S
Dis Telep. off
R
S
R
7SA6 Manual
C53000-G1176-C133-1