Lenze E82MV152_4B

Function library
Process controller, current limitation controller
7−51
L
EDB82MV752 EN 5.2
Pressure control and flow control
 The differential component K
D
(C0072) is generally not required for pressure and flow control.
 Set the influence (C0074) to 100 %.
 Deactivate the frequency feedforward control (C0238 = 0).
Code
Setting for
Gases Fluids
C0070 (K
P
) 0.1 0.02 ... 0.1
C0071 (T
N
) 5000 (T
N
= 5s) 200 ... 1000 (T
N
= 0.2s ... 1s)
C0072 (K
D
) 0 0
Speed control
Code Setting
C0070 (K
P
) 5
C0071 (T
N
) 100 (T
N
= 0.1s)
C0072 (K
D
) 0
Setting of process controller influence
 Activate frequency feedforward control (C0238=1). Now the process controller has only
limited influence:
– The control factor determines the influence of the process controller (C0074).
– Control factor = C0050 (output frequency) − C0051 (actual process controller value)
 C0074 refers to the maximum output frequency C0011.
 C0074 influences the stability of the control loop:
– Set C0074 as low as possible.
– If C0074 is set too high, the control loop can become unstable.
Calculation of process controller influence
Calculate C0074 Example
C0074[%] 
C0050  C0051
C0011
 100%
C0011=50Hz, C0050=53Hz, C0051=50Hz:
C0074[%] 
53Hz  50Hz
50Hz
 100%  6%
Set the influence so that the process controller output covers the calculated value in every working
point.
Set C0074=10% as guide value for the example (C0074=6%). The guide value contains
tolerances which must always be observed.
Example of additive influence
The effective direction of the process controller output to the main setpoint is additive.
Settings
 C0051=positive actual value
 C0181=select positive setpoint
 C0238=1 (with frequency feedforward control)
 Potentiometer terminals of the dancer
– End (E)=+10V
– Start (A)=GND