Valid Range
Limits for the smallest and largest input value. For lists, a list of all
elements.
Unit
Physical unit of the value.
Comments
Comments or explanations.
7.2.1 Current and voltage transformers
The current and voltage converters, which are connected to the AD-LU 60 FE , are
taken into account in the calculation of the currents, voltages, power and counter and
must be known.
Name
Default
Range
Unit
Primary current
5
1 ... 10000
A
Secondary current
5
1 ... 20
A
Primary voltage
230
50 ... 500000
V
Secondary voltage
230
50 ... 500
V
7.2.2 Filter
All measured values are filtered. The larger the filter number, the higher the effect of
the attenuation. Each measured value is filtered according to the following relationship.
M
t
=
M
t
−
1
+
M
t
−
M
t
−
1
F
where
•
M
t
Measured value at time t.
•
M
t
−
1
Measured value at time t-1, ie the last measured value.
•
F
Value of the filter number.
A filter number of 1 returns the current measured value unfiltered. A filter number of
2 gives the arithmetic mean value between the current and the last measured value.
The measured values are cyclically filtered. The attenuation depends on the cycle time
and the filter number. The timing is explained in chapter
??
.
The relationship between settling time, cycle time and filter number is
t
90
=
F
∗
2
,
26
∗
t
z
where
•
t
90
Settling time of the filtered measured value to 90 % with a signal change in
the input from 0 to 100 %.
•
t
z
Cycle time in seconds.
The desired settling time
t
90
can be entered directly in seconds as a parameter for
filtering the signals. The AD-LU 60 FE calculates the filter number from the settling
time and the sampling rate itself.
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