ABB REG650 Technical Manual page 383

1MRK 502 034-UEN -
Technical Manual
IEC05000652 V2 EN
Figure 193: Calibration curves
The first current and voltage phase in the group signals will be used as reference
and the amplitude 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, U, 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 (1 k ) X
Old
EQUATION1407 V1 EN
where:
X is a new measured value (that is P, Q, S, U, I or PF) to be given out from the function
X is the measured value given from the measurement function in previous execution cycle
Old
X is the new calculated value in the present execution cycle
Calculated
k is settable parameter by the end user which influence the filter properties
Calculated
Section 13
Monitoring
(Equation 106)
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