Moeller DF5 series - Structure and Parameters of the PID Controller

09/01 AWB8230-1412GB
PID controller
87
Structure and parameters of the PID controller
PID controller active/inactive
DF5 frequency inverters can operate in one of the following two
control modes:
• Frequency control active (i.e. PID closed loop control inactive)
• PID closed loop control active
You can switch between both modes with PNU A71 (PID control
active/inactive).
Frequency control is the standard method of control used by many
frequency inverters. A setpoint value is defined by a control unit
(keypad) as an analog voltage or current signal, or via a 4 bit wide
digital command applied to the control signal terminals.
With PID closed loop control, the inverter’s output frequency is
controlled by a control algorithm to ensure that the deviation
between the setpoint and actual value is kept at zero.
Parameter
The following figure illustrates which parameters are effective in
different areas of the PID block diagram. The stated parameters
(e.g. PNU A72) correspond to those on the integrated frequency
inverter keypad:
PNU Name Adjustable in
RUN mode
Value Function WE
A71 PID control active/inac-
tive
– 00 PID closed loop control is not used (inactive) 00
01 PID closed loop control is used (active)
Figure 88: PID closed loop control parameters
w: Setpoint value
x: Actual value
f
o
: output frequency
a Frequency definition with keypad, fixed frequency
b Analog definition with potentiometer, analog inputs, current or
voltage
a
b
P: PNU A72
I: PNU A73
D: PNU A74
PNU A75 PNU d04
f
O
PNU A75
PNU A01
PNU A75
-1
(PNU A76)
w
PNU F01
++
x
–
+
+
0
PNU A13
PNU A11
PNU A12
PNU A14