ABB Relion 650 Series Technical Manual page 434

Section 13
Monitoring
IMagComp5
IMagComp30
IMagComp100
Degrees
IAngComp30
IAngComp5
IAngComp100
ANSI05000652 V3 EN-US
Figure 233: 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 measured quantity.
Filtering is performed in accordance with the following recursive formula:
= ×
X k X
EQUATION1407 V1 EN-US
where:
X
X
Old
X
Calculated
k
428
Magnitude
% of In
compensation
+10
5
-10
Angle
compensation
+10
5
-10
+ - ×
(1 k ) X
Old Calculated
is a new measured value (that is P, Q, S, V, I or PF) to be given out from the function
is the measured value given from the measurement function in previous execution cycle
is the new calculated value in the present execution cycle
is settable parameter by the end user which influence the filter properties
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30
0-5%: Constant
5-30-100%: Linear
>100%: Constant
30
1MRK 506 326-UUS B
Measured
current
100
% of In
Measured
current
100
% of In
ANSI05000652_3_en.vsd
SEMOD54417-233 v3
(Equation 82)
Line distance protection REL650
Technical manual