Section 8. PID controller
8. PID controller
Frequency converter has a PID controller (Proportional - Integral - Differential). The controller can be used for
stabilization of any parameters at fixed level (fig. 8.1).
CONTROL
MFC710
PID
TRANSDUCER of monitor
of process
(parameter measuring of
process)
Value of
process
referencing
+
-
PROCESS
MOTOR
par. 2.60
par. 2.61
Fig. 8.1 - Use of the PID controller for adjusting process parameter
8.1. Turning on and a configuration of the PID controller
To enable PID controller as a source of referenced frequency it is necessary to set up par.
2.2 (for control A) or 2.3 (for control B) on value “137 OutPID” (fig. 8.2).
Table 8.1 - Control and information parameters of the PID controller
Parameter
Name
Description
2.60
PID Ref.Src
Source of ref.-unit for PID controller. It serves for setting process referenced value. Possible values:
Keyb.P
– referencing PID from control board
Ref.A0, Ref.A1, Ref.A2
– analog referencing-units from analog inputs
RS PID
– analog referencing-units from communication module RS232/485 (Modbus)
MP-PID
– motopotentiometer PID
2.61
PID Inp.Src
Signal source of feedback PID controller.
Ref.A0, Ref.A1, Ref.A2
– feedback is connected to one of the analog inputs.
2.62
Error inversion
Error inversion (difference between tasked value and feedback signal)
NO / YES
2.63
P amplification
(Kp)
Amplification of proportional component of PID controller. The bigger amplification, the faster reaction
to speed error
2.64
I Const (Ki)
So called time of PID controller doubling.
0.01 ... 320.00s (0.01 ... 320.00 s)
2.65
D Amp. (Kd)
Amplification of differential component of PID controller.
2.66
Max.Out.PID
Max value which output signal of PID controller can achieve (limitation of saturation)
0.0 .... 3000.0 %
2.67
Min.Out.PID
Min value which output signal of PID controller can achieve (limitation of saturation)
0.0 .... 3000.0 %
2.68
PID Out.res
Resetting PID output when device is stopped: 0,1,2
2.69
PID type
0 / 1
Choice of regulator's algorithm operation. Recommended setting is 0.
2.70
SLEEP time
Time after which SLEEP blockade will activate, when the regulator output maintain on minimal value
determined by par. 2.67
0 ... 32000 s,
0 = SLEEP function is not active
2.71
SLEEP
threshold
The program of shut down of SLEEP blockade 0.0...100.0 %
Blocking will be switched off, when: the output of the regulator will achieve value above than (par.
2.67 + par. 2.71) or error will be higher, than par. 2.71
0.30
RefPID
Value of current PID referencing-unit
. READ ONLY.
0.31
InPID
Current value of PID controller input.
READ ONLY
0.32
PID error
Value of current regulator error par 0.32 = par 0.30 – par 0.31
READ ONLY
0.33
OutPID
Current value of PID controller output.
READ ONLY
Frequency converter MFC710 type. TWERD Power Electronics
51
A
PI
LO
137 OutPID
2.2 Ref.unit A
2 Refer. & control
Fig. 8.2 – PID controller in
the capacity
of set-point device A
