Siemens siprotec 7SA6, Manual

Page: 410 / 876

Functions
6-220
7SA6 Manual
C53000-G1176-C156-2
−
Does the angle difference |
ϕ
line
–
ϕ
bus
| lie within the permissible tolerance
Max.
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.
Closing at
Asynchronous
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
Live Volt. Thr.
, but be-
low the maximum operating voltage
Umax
?
−
Does the feeder voltage U
line
lie above the set value
Live Volt. Thr.
, but below
the maximum operating voltage
Umax
?
−
Does the voltage magnitude difference

|U
line
| – |U
bus
|

lie within the permissible
tolerance
Max. Volt. Diff
?
−
Do both the frequencies f
bus
and f
line
lie within the permissible operating range
f
N
± 3 Hz?
−
Does the frequency difference |f
line
– f
bus
| lie within the permissible tolerance
Max.
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.
6.15.2 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:
203 Unom PRIMARY
rated primary voltage of the feeder voltage transformers
(phase-to-phase) in kV;
204 Unom SECONDARY
rated secondary voltage of the feeder voltage transform-
ers (phase-to-phase) in V;
210 U4 transformer
connection of the additional voltage transformer input U
4
of the device; must be
Ubus–trnsf
and connected to
any voltage of the bus-bar;
212 Usync connect.
type of voltage which is connected to the device from the
bus-bar voltage transformer;
214A
ϕ 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;
215 U-line / Usync
the ratio of the secondary feeder voltage to the secondary
bus-bar voltage under nominal voltage conditions;