Applying The Function Parameter Settings - Siemens SIPROTEC 7SA6 Manual

Functions
Closing at
Asynchronous
System Conditions

6.15.2 Applying the Function Parameter Settings

Preconditions
6-220
− Does the angle difference | ϕ
Angle Diff ?
A check that the synchronous system conditions are maintained for the minimum du-
ration T SYNC-STAB is carried out. When the conditions are satisfied for this duration
within the synchronous supervision time T-SYN. DURATION , 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 Umax ?
− Does the feeder voltage U
the maximum operating voltage Umax ?
− Does the voltage magnitude difference  |U
tolerance Max. Volt. Diff ?
− Do both the frequencies f
f ± 3 Hz?
N
− Does the frequency difference |f
Freq. Diff ?
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 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:
203 Unom PRIMARY
204 Unom SECONDARY
210 U4 transformer
212 Usync connect.
214A ϕ Usync-Uline
215 U-line / Usync
– ϕ
| lie within the permissible tolerance Max.
line bus
lie above the set value Live Volt. Thr. , but be-
bus
lie above the set value Live Volt. Thr. , but below
line
| – |U
line
and f lie within the permissible operating range
bus line
| lie within the permissible tolerance Max.
– 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 Ubus–trnsf 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
7SA6 Manual
C53000-G1176-C156-2
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