Power System Data 1
27
7UM62 Manual
C53000-G1176-C149-3
2.3
Power System Data 1
2.3.1
Functional Description
General
The device requires certain basic data regarding the protected equipment, so that the
device will be compatible with its desired application. These may be, for instance,
rated power system and transformer data, measured quantity polarities and their
physical connections, breaker properties etc. There are also certain parameters that
are common to all functions, i.e. not associated with a specific protection, control or
monitoring functions. The following section discusses these Power System Data 1.
2.3.2
Setting Hints
The Power System Data 1 can be changed from the operator or service interface with
a personal computer using DIGSI
®
4.
In DIGSI
®
4, double-click
Settings
to display the data available.
Connection of the
Current
Transformer Sets
At address
you specify the polarity of the CTs of plant side
1, i.e. the location of the CT starpoint with reference to the protected object. At address
the polarity of the CTs of side 2 is specified. This setting
determines the measuring direction of the 7UM62 (
=
Yes
=
Forwards = line direction). Figure 2-6 shows the definition even in cases where there
are no starpoint CTs.
Figure 2-6
Location of Starpoints for CTs of S1 and S2
- Addresses
and
0210 -
If the device is to be used for transverse differential protection of generators or motors,
a particularity must be observed in the connection of the current transformers. In this
case, all currents flow in healthy operation into the protected object, as opposed to all
other applications. Therefore, a “wrong” polarity must be set for one set of CTs. The
“sides” here are equivalent to the machine winding sections.
b)
STRPNT
→
OBJ S1 =
NO
a)
STRPNT
→
OBJ S1 =
YES
G
Side 2
Side 1
Side 2
Side 1
G
STRPNT
→
OBJ S2 =
YES
STRPNT
→
OBJ S2 =
NO
