Applying The Function Parameter Settings - Siemens siprotec 7SA522 User Manual

Functions
Closing at asyn-
chronous system
conditions

6.12.2 Applying the Function Parameter Settings

Preconditions
6-184
− Does the angle difference |ϕ
$QJOH 'LII?
A check that the synchronous system conditions are maintained for the minimum du-
ration 7 6<1&67$% is carried out. When the conditions are satisfied for this duration
within the synchronous supervision time 76<1 '85$7,21, the closing command
is released.
For release of a closing command with asynchronous system conditions, the following
conditions are checked:
− Does the bus-bar voltage U
low the maximum operating voltage 8PD[?
− Does the feeder voltage U
the maximum operating voltage 8PD[?
− Does the voltage magnitude difference |U
tolerance 0D[ 9ROW 'LII?
− Do both the frequencies f
f ± 3 Hz?
N
− Does the frequency difference |f
)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.
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<
 8QRP 6(&21'$5<
 8 WUDQVIRUPHU
 Usync connect.
214A j Usync-Uline
 8OLQH  8V\QF
– ϕ
| lie within the permissible tolerance 0D[
line bus
lie above the set value /LYH 9ROW 7KU, but be-
bus
lie above the set value /LYH 9ROW 7KU, but below
line
| – |U
line
and f lie within the permissible operating range
bus line
| lie within the permissible tolerance 0D[
– f
line bus
rated primary voltage of the feeder voltage transformers
(phase-to-phase) in kV;
rated secondary voltage of the feeder voltage transform-
ers (phase-to-phase) in V;
connection of the additional voltage transformer input U
of the device; must be 8EXV²WUQVI and connected to
any voltage of the bus-bar;
type of voltage which is connected to the device from the
bus-bar voltage transformer;
phase angle displacement between the voltage of the
bus-bar and that of the feeder in case a power transform-
er is installed inbetween;
the ratio of the secondary feeder voltage to the secondary
bus-bar voltage under nominal voltage conditions;
| lie within the permissible
bus
7SA522 Manual
C53000-G1176-C119-2
4