Lenze E82EV113K4C - Page 352

Process controller
Setting of control characteristics
10
Function library
10.10
10.10.1
L
10.10-2
EDS82EV903-1.0-11/2002
Pressure control and flow rate control
l The differential component K
D
(C0072) is usually not required for pressure
and flow rate control.
l Set the influence (C0074) to 100 %.
l Deactivate the frequency precontrol (C0238 = 0).
Code Setting for
C
o
d
e
Gases Liquids
C0070 (K
P
) 0.1 0.02 ... 0.1
C0071 (T
r
) 5000 (T
r
=5s) 200 ... 1000 (T
r
= 0.2 s ... 1 s)
C0072 (K
D
) 0 0
Speed control
Code Setting
C0070 (K
P
) 5
C0071 (T
r
) 100 (T
r
=0.1s)
C0072 (K
D
) 0
l Activate frequency precontrol (C0238 = 1). Now the process controller has
only a limited influence:
– The control factor determines the influence of the process controller
(C0074).
– Control factor = C0050 (output frequency) - C0051 (actual process
controller value)
l C0074 refers to the maximum output frequency C0011.
l C0074 influences the control circuit stability:
– Set C0074 as low as possible.
– If C0074 is set too high, the control loop can get instable.
Calculate C 0074 Example
C
0
0
5
0
C
0
0
5
1
C0011 = 50 Hz, C0050 = 53 Hz, C0051 = 50 Hz:
C0074 [%] =
C0050 − C0051
C0011
⋅ 100 %
C0074 [%] =
53 Hz − 50 Hz
50 Hz
⋅ 100 % = 6%
Set the influence so that the process controller output covers the calculated value
in every operating point.
SetC0074 = 10 % asguide valuefor theexample (C0074 = 6 %). Theguidevalue
includes tolerances which must always be considered.
Pressure control and flow rate
control
Speed control
Setting of process controller
influence
Calculating the process
controller influence
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