Siemens siprotec 7SA522 User Manual

2 Functions
262
7SA522 Manual
C53000-G1176-C155-3
8V\QF8OLQH = Release for de-energized busbar (Ubus<) and de-en-
ergized line (Uline<).
29(55,'( = Release without any check.
Each of these conditions can be enabled or disabled individually; combinations are
also possible (e.g., release if 8V\QF!8OLQH or 8V\QF8OLQH! are fulfilled).
Combination of 29(55,'( with other parameters is, of course, not reasonable.
The release conditions can be configured individually either for automatic reclosing or
for manual closing or for closing via control commands. For example, manual closing
and control closing can be allowed in cases of synchronism or dead line, whilst, before
an automatic reclose attempt dead line conditions are only checked at one line end
and after the automatic reclose attempt only synchronism at the other end.
Dead Line or Dead
Bus Closing
For release of the closing command to energize a voltage overhead line from a live
busbar, the following conditions are checked:
• Does the feeder voltage U
line
lie below the set value 'HDG9ROW7KU?
• Does the busbar voltage U
bus
lie above the set value /LYH9ROW7KU, but below
the maximum operating voltage 8PD[?
• Is the frequency f
bus
within the permitted operating range f
N
± 3 Hz?
After successful check the closing command is released.
Corresponding conditions apply when switching a live line onto a dead busbar or a
dead line onto a dead busbar.
Closing at Synchro-
nous System Con-
ditions
Before releasing a closing command at synchronous conditions, the following condi-
tions are checked:
• Does the busbar voltage U
bus
lie above the set value /LYH9ROW7KU, but below
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[?
• Is the voltage difference |U
line
– U
bus
| within the permissible tolerance 0D[9ROW
'LII?
• Are the two frequencies f
1bus
and f
line
within the permitted operating range f
N
± 3Hz?
• Does the frequency difference |f
line
– f
bus
| lie within the permissible tolerance 0D[
)UHT'LII?
• Is the angle difference |ϕ
line
– ϕ
bus
| within the permissible tolerance 0D[$QJOH
'LII?
To check whether these conditions are observed for a certain minimum time, you can
set this minimum time as 76<1&67$%. Checking the synchronism conditions can
also be confined to a maximum monitoring time 76<1'85$7,21. This implies that
the conditions must be fulfilled within the time 76<1'85$7,21 for the duration of
76<1&67$%. If this is the case, the closing command is released.
Closing at Asyn-
chronous System
Conditions
Before releasing a closing command at asynchronous conditions, the following condi-
tions are checked:
• Does the busbar voltage U
bus
lie above the set value /LYH9ROW7KU, but below
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[?

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English