Siemens SIPROTEC 7UM62 - Measurement (Secondary;Primary;Percentage Values); Functional Description

Functions
2.49 Auxiliary Functions
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
333
2.49.3 Measurement (Secondary/Primary/Percentage Values)
A series of measured values and the values derived from them are constantly available for call up on site, or
for data transfer (see table 2-19, as well as the following list).
Measured values can be retrieved by a central control system (SCADA).
2.49.3.1 Functional Description
Display of Measured Values
The operational measured values listed in Table 2-19 can be read out as secondary, primary or percentage
values. A precondition for correctly displaying the primary and percentage values is complete and correct entry
of the nominal values for the current transformers, and protected equipment as well as current and voltage
transformer ratios in the ground paths, in accordance with Subsections 2.5 and 2.7. Table 2-19 lists the formu-
lae for the conversion of secondary into primary or percentage values.
Depending on the version ordered, the type of device connection and the configured protection functions, only
a part of the operational measured values listed in the following table may be available. The displacement
voltage U
0
is calculated from the phase-earth voltages: U
0
=
1
/
3
· |U
L1
+ U
L2
+ U
L3
|. For this, the three voltage
inputs phase-to-earth must be connected.
Table 2-19 Conversion formulae between secondary values and primary/percentage operational measur-
ing values
Measured
Values
second-
ary
primary %
I
L1 S2
,
I
L2 S2
,
I
L3 S2
,
I
1 S2
,
I
2 S2
,
3I
0 S2
,
I
sec S2
I
L1 S1
,
I
L2 S1
,
I
L3S1
I
sec S1
Differential Protection for Generators and
Motors:
Differential Protection for Three Phase Trans-
former:
I
Ns1
I
EE1 sec
FACTOR IEE1 · I
EE1 sec.
I
Ns2
I
EE2 sec.
FACTOR IEE2 · I
EE1 sec.