Siemens 6MD85, Manual

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Figure 7-150 Logic Diagram of the Definite-Time Undervoltage Protection with 3-Phase Voltage
Method of Measurement
With the
Method of measurement
parameter, you select the relevant method of measurement, depending
on the application.
•
Measurement fundamental component:
This method of measurement processes the sampled voltage values and filters out the fundamental
component numerically.
•
Measurement RMS value:
This method of measurement determines the voltage amplitude from the sampled values according to
the defining equation of the RMS value. Harmonics are included in the analysis.
Measured Value
With the
Measured value
parameter, you define whether the stage analyzes the phase-to-phase voltages
V
AB
, V
BC
, and V
CA
, or the phase-to-ground voltages V
A
, V
B
, and V
C
.
If the measured value is set to phase-to-phase, the function reports those measuring elements that have
picked up.
Protection and Automation Functions
7.16 Undervoltage Protection with 3-Phase Voltage
SIPROTEC 5, High-Voltage Bay Controller, Manual 807
C53000-G5040-C015-9, Edition 11.2017