Siemens siprotec 7SA522 User Manual

Functions
6-184 7SA522 Manual
C53000-G1176-C119-2
− Does the angle difference |ϕ
line
– ϕ
bus
| lie within the permissible tolerance 0D[
$QJOH'LII?
A check that the synchronous system conditions are maintained for the minimum du-
ration 76<1&67$% is carried out. When the conditions are satisfied for this duration
within the synchronous supervision time 76<1'85$7,21, the closing command
is released.
Closing at asyn-
chronous system
conditions
For release of a closing command with asynchronous system conditions, the following
conditions are checked:
− Does the bus-bar voltage U
bus
lie above the set value /LYH9ROW7KU, but be-
low the maximum operating voltage 8PD[?
− Does the feeder voltage U
line
lie above the set value /LYH9ROW7KU, but below
the maximum operating voltage 8PD[?
− Does the voltage magnitude difference |U
line
| – |U
bus
| lie within the permissible
tolerance 0D[9ROW'LII?
− Do both the frequencies f
bus
and f
line
lie within the permissible operating range
f
N
±3Hz?
− Does the frequency difference |f
line
– f
bus
| lie within the permissible tolerance 0D[
)UHT'LII?
When the conditions are satisfied, the device calculates the time upto the next instant
of voltage phase synchronism, from the rate-of-change of angle and the frequency dif-
ference. The closing command is then released at the instant when the remaining time
upto the the next instant of synchronism equals the closing time of the breaker.
6.12.2 Applying the Function Parameter Settings
Preconditions When setting the general power system data (Power system data 1, refer to Section
6.1.1) a number of parameters regarding the measured quantities and the operating
mode of the synchronism check function must be applied. This concerns the following
parameters:
 8QRP35,0$5< rated primary voltage of the feeder voltage transformers
(phase-to-phase) in kV;
 8QRP6(&21'$5< rated secondary voltage of the feeder voltage transform-
ers (phase-to-phase) in V;
 8WUDQVIRUPHU connection of the additional voltage transformer input U
4
of the device; must be 8EXV²WUQVI and connected to
any voltage of the bus-bar;
 Usync connect. type of voltage which is connected to the device from the
bus-bar voltage transformer;
214A j Usync-Uline phase angle displacement between the voltage of the
bus-bar and that of the feeder in case a power transform-
er is installed inbetween;
 8OLQH8V\QF the ratio of the secondary feeder voltage to the secondary
bus-bar voltage under nominal voltage conditions;

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English