Application And Setting Notes For Measuring Point Voltage 3-Phase (V-3Ph) - Siemens 6MD85 Manual

Application and Setting Notes for Measuring Point Voltage 3-Phase (V-3ph)

5.1.4
Settings for the supervision functions are also located in the voltage measuring point. You can find the
description of these settings in chapter Supervision Functions.
Parameter: Rated primary voltage
•
Default setting (_:8911:101) Rated primary voltage = 400.000 kV
The Rated primary voltage parameter is used to set the primary rated voltage of the voltage trans-
former.
Parameter: Rated secondary voltage
•
Default setting (_:8911:102) Rated secondary voltage = 100 V
The Rated secondary voltage parameter is used to set the secondary rated voltage of the voltage trans-
former.
Parameter: Matching ratio Vph / VN
•
Default setting (_:8911:103) Matching ratio Vph / VN = 1.73
With the parameter Matching ratio Vph / VN, you set the deviation between the calculated zero-
sequence voltage and the residual voltage measured directly via a measuring input. The different transmission
ratio of the voltage transformers is the cause for the deviation (see
The Matching ratio Vph / VN is equal to the ratio 3V
with
V Calculated zero-sequence voltage
0 sec
V Measured residual voltage
N sec
The zero voltage is calculated as phase-to-ground voltages. The residual voltage is measured on the broken-
delta winding of the voltage transformer. For 1-phase voltage transformers, the residual voltage is measured
in the generator or the transformer neutral point.
NOTE
i
i
The measurement residual voltage V
SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
/V
0 sec N sec
is converted to a zero-sequence voltage in the device as follows:
N sec
Function-Group Types
5.1 Power-System Data
Figure 5-2).
183