Siemens siprotec 7SA6 User Manual

Functions
6-122 7SA6 Manual
C53000-G1176-C133-1
6.6.1 Method of Operation
Switching On and
Off
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 inputs
(if these are allocated). The switched state is saved internally (refer to Figure 6-70)
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.
X
Figure 6-70 Switching on and off of the signal transmission logic
6.6.1.1 Directional Comparison Scheme
Principle The directional comparison scheme is a permissive scheme. In Figure 6-71 the
oper-
ation scheme
is shown.
When the earth fault protection recognizes a fault in the forward direction, it initially
sends a permissive signal to the opposite line end. If a permissive signal is also
received from the remote end, the trip signal is passed on to the tripping relay.
Accordingly it is a prerequisite for fast tripping that the fault is recognized in the forward
direction at both line ends.
The send signal can be prolonged by T
S
(parameter setting). The prolongation of the
send signal only comes into effect if the protection has already issued a trip command.
This ensures that the permissive signal releases the opposite line end even if the earth
fault is very rapidly cleared by a different independent protection.
Figure 6-71 Operation scheme of the directional comparison method
≥1
EF TeleprotOFF
EF Telep. OFF
ON
OFF
)&77HOHS()
EF Teleprot.ON
S
R
System port: EF Telep. OFF
S
R
„1“

System port: EF Telep. ON
rec.
transm.
AB
E/F.
frwd.
T
S
&
trip
rec.
&
≥1
E/F.
frwd.
T
S
&
trip
transm
&
≥1

Siemens siprotec 7SA6 Specifications

General

Brand	Siemens
Model	siprotec 7SA6
Category	Relays
Language	English