Siemens 7SJ82, Manual

Page: 1062 / 1638

Function Group Capacitor Bank
Only the parameters important for the application of the differential protection function are discussed here.
You can find setting notes for more parameters in chapter
5.4.3 Application and Setting Notes (Capacitor
bank function group).
Parameter:
Capacitor reference curr.
•
Default setting
(_:14641:101) Capacitor reference curr.
=
1000 A
With the parameter
Capacitor reference curr.
, you determine the reference current of the capacitor
bank to be protected. The capacitor reference current set here is the reference value for the percentage meas-
ured values and setting values in percent.
For differential protection these values are added to the correction amount (rated current of the protected
object).
Depending on user philosophy you use the rated current of the capacitor bank as a reference value including
the harmonic or the fundamental component current.
Function Group Capacitor Bank Side
Make the following settings in the Capacitor bank side function group:
Parameter:
Capacitor reference curr.
•
Default setting
(_:1781:15571:101) Capacitor reference curr.
=
1000 A
With the parameter
Capacitor reference curr.
, you determine the reference current of the capacitor
bank to be protected. The capacitor reference current set here is the reference value for the percentage meas-
ured values and setting values in percent.
For differential protection these values are added to the correction amount (rated current of the protected
object).
If the capacitor bank is in a delta connection, the value to be set can differ from the capacitor-bank reference
current set in the function group Capacitor bank (by a factor √3). Otherwise always use the same value
settings.
Depending on user philosophy you use the rated current of the capacitor bank as a reference value including
the harmonic or the fundamental component current.
Parameter:
Capacitor reference volt.
•
Default setting
(_:1781:15571:102) Capacitor reference volt.
=
400.00 kV
With the parameter
Capacitor reference volt.
, you set the reference voltage of the capacitor bank to
be protected. The reference voltage set here is the reference value for the percentage measured values and
setting values in percent.
Depending on user philosophy you can set the system reference value of the system voltage (busbar voltage)
or the capacitor rated voltage as a reference.
Parameter:
Neutral point
•
Default setting
(_:1781:15571:149) Neutral point
=
isolated
With the parameter
Neutral point
, you specify whether the the neutral point in the protection range of
the differential protection is
grounded
or
isolated
. As this is not the case for the example application
described, use the default setting
isolated
.
You can find further information in the device manual 7UT8, chapter 6.2.3 Function Description Neutral-Point
Current Treatment.
Capacitor Bank Protection
7.8 Differential Protection for Capacitor Banks
1062 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017