ABB Relion 670 Series Technical Reference Manual page 910

Section 15
Monitoring
904
Each analog output has a corresponding supervision level output (X_RANGE). The
output signal is an integer in the interval 0-4, see section
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 456.
Magnitude
% of In
compensation
+10
IMagComp5
IMagComp30
IMagComp100
5
-10
Angle
Degrees
compensation
+10
IAngComp30
IAngComp5
IAngComp100
5
-10
ANSI05000652 V3 EN
Figure 456: 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
30
0-5%: Constant
5-30-100%: Linear
>100%: Constant
30
1MRK505222-UUS C
"Measurement supervision".
Measured
current
100
% of In
Measured
current
100
% of In
ANSI05000652_3_en.vsd
Technical reference manual