Siemens siprotec 7SA522, User Manual

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Functions
6-75
7SA522 Manual
C53000-G1176-C119-2
Power Swing
Tripping If tripping in the event of an instable power swing (out-of-step condition) is desired, the
parameter
3RZHU6ZLQJWULS
=
<HV
is set. If the criteria for power swing detection
are satisfied, the distance protection is initially blocked according to the configured
program for power swing blocking, to avoid tripping by the distance protection.
When the impedance vectors identified by the power swing detection exit the power
swing characteristic PPOL, the R components are used to check if the vectors have
the same sign as was the case when they entered the power swing characteristic. If
this is the case, the power swing process is inclined to stabilize. Otherwise, the vector
passed through the power swing characteristic (loss of synchronism, case (4) in Fig-
ure 6-41). The device issues a three-pole trip command, thereby isolating the two sys-
tem segments from each other. Power swing tripping is alarmed.
As the operating range of the power swing supplement depends on the distance pro-
tection settings, the power swing tripping can also only be active, when the distance
protection has been activated.
6.3.2 Applying the Function Parameter Settings
The power swing supplement is only active if it has been set to
3RZHU6ZLQJ
=
(Q
DEOHG
(address ) during the configuration.
The four possible programs may be set in address
362SPRGH
, as described
in Sub-section 6.3.1:
$OO]RQHVEORFN
or
==%EORFN
or
=WR=EORFN
or
==%=EORFN
.
Additionally the tripping function for unstable oscillations (out-of-step condition, loss of
system synchronism) can be set with parameter
3RZHU6ZLQJWULS
(address ),
which should be set to
<HV
if required (presetting is
1R
). In the event of power swing
tripping it is sensible to set
362SPRGH
=
$OO]RQHVEORFN
for the power swing
blocking, to avoid premature tripping by the distance protection.
6.3.3 Settings
6.3.4 Information Overview
Addr. Setting Title Setting Options Default Setting Comments
2002 P/S Op. mode all zones blocked
Z1/Z1B blocked
Z2 to Z5 blocked
Z1,Z1B,Z2 blocked all zones blocked Power Swing Operating mode
2006 PowerSwing trip NO
YES NO Power swing trip
F.No. Alarm Comments
4164 Power Swing Power Swing detected
4166 Pow. Swing TRIP Power Swing TRIP command