ABB 650 series, Technical Manual

Page: 540 / 778

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
245 .
100 30 5
IMagComp5
IMagComp30
IMagComp100
-10
+10
Magnitude
compensation
% of In
Measured
current
% of In
0-5%: Constant
5-30-100%: Linear
>100%:
Constant
100 30 5
IAngComp5
IAngComp30
IAngComp100
-10
+10
Angle
compensation
Degrees
Measured
current
% of In
ANSI05000652_3_en.vsd
ANSI05000652 V3 EN
Figure 245: 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 the
Section 14
1MRK 502 048-UUS A
Monitoring
534
Technical manual