Each analog output has a corresponding supervision level output (X_RANGE). The
output signal is an integer in the interval 0-4, see section "Measurement supervision".
Calibration of analog inputs
Measured currents and voltages used in the CVMMXN function can be calibrated to
get class 0.5 measuring accuracy. This is achieved by magnitude and angle
compensation at 5, 30 and 100% of rated current and voltage. The compensation below
5% and above 100% is constant and linear in between, see example in figure
107.
100305
IMagComp5
IMagComp30
IMagComp100
-10
+10
Magnitude
compensation
% of In
Measured
current
% of In
0-5%: Constant
5-30-100%: Linear
>100%: Constant
100305
IAngComp5
IAngComp30
IAngComp100
-10
+10
Angle
compensation
Degrees
Measured
current
% of In
ANSI05000652_3_en.vsd
ANSI05000652 V3 EN
Figure 107: Calibration curves
The first current and voltage phase in the group signals will be used as reference and
the magnitude and angle compensation will be used for related input signals.
Low pass filtering
In order to minimize the influence of the noise signal on the measurement it is possible
to introduce the recursive, low pass filtering of the measured values for P, Q, S, V, I
and power factor. This will make slower measurement response to the step changes in
Section 12 1MRK 505 277-UUS C
Monitoring
244
Technical Manual
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