NOTE
From V7.30 on, the value VN measured is no longer provided. If you have selected this value in earlier
versions, you can use either the following methods instead after upgrading the configuration to V7.30 or a
later version:
•
Select the value V0 calculated for the Measured value parameter in the function Overvoltage
protection with any voltage.
•
Use the function Overvoltage protection with zero-sequence voltage/residual voltage.
If the function Overvoltage protection with any voltage is used in a 1-phase function group, the param-
eter Measured value is not visible.
Parameter: Threshold
•
Default setting (_:391:3) Threshold = 110 V
Specify the Threshold (pickup threshold) for the specific application.
Depending on the measured value, the Threshold is set either as Measured voltage or as Phase-to-
phase quantity.
NOTE
If the function is used in a Voltage-current 1-phase function group connected to the 1-phase voltage
measuring point with the voltage type VN broken-delta, you set the threshold value based on the
equivalent zero-sequence voltage.
Calculate the equivalent zero-sequence voltage V
0 equiv. sec
from the measured voltage V
N sec
with the
following formula:
You can find more information about the Matching ratio Vph / VN parameter in chapter 5.1.4 Appli-
cation and Setting Notes for Measuring Point Voltage 3-Phase (V-3ph).
Parameter: Operate delay
•
Default setting (_:391:6) Operate delay = 3 s
The Operate delay must be set for the specific application.
Parameter: Dropout ratio
•
Recommended setting value (_:391:4) Dropout ratio = 0.95
The recommended set value of 0.95 is appropriate for most applications. To achieve high measurement preci-
sion, the Dropout ratio can be reduced, to 0.98, for example.
Operation as Supervision Function
If you want the tripping stage to have a reporting effect only, generation of the operate indication and fault
logging can be disabled via the Operate & flt.rec. blocked parameter.
Protection and Automation Functions
7.15 Overvoltage Protection with Any Voltage
802 SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
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