GE AF-650 GP Design Manual page 34

Example of Process PID Control set-up
Function
Initialize the frequency converter
1) Set motor parameters:
Set the motor parameters according to name plate data P-02 to
Perform a full auto tune
2) Check that motor is running in the right direction.
When motor is connected to frequency converter with straight forward phase order as U - U; V- V; W - W motor shaft usually turns clockwise seen into shaft
end.
Press "Hand" Keypad key. Check shaft direction by apply-
ing a manual reference.
If motor turns opposite of required direction:
1. Change motor direction in par. H-08 Reverse Lock
2. Turn off mains - wait for DC link to discharge - switch
two of the motor phases
Set configuration mode
Set Local Mode Configuration
3) Set reference configuration, ie. the range for reference handling. Set scaling of analog input in par. AN-##
Set reference/feedback units
Set min. reference (10° C)
Set max. reference (80° C)
If set value is determined from a preset value (array pa-
rameter), set other reference sources to No Function
4) Adjust limits for the frequency converter:
Set ramp times to an appropriate value as 20 sec.
Set min. speed limits
Set motor speed max. limit
Set max. output frequency
Set S201 or S202 to wanted analog input function (Voltage (V) or milli-Amps (I))
NOTE! Switches are sensitive - Make a power cycling keeping default setting of V
5) Scale analog inputs used for reference and feedback
Set terminal 53 low voltage
Set terminal 53 high voltage
Set terminal 54 low feedback value
Set terminal 54 high feedback value
Set feedback source
6) Basic PID settings
Process PID Normal/Inverse
Process PID Anti Wind-up
Process PID start speed
Save parameters to Keypad
Optimisation of the process regulator
The basic settings have now been made; all that needs to be done is to optimise the proportional gain, the integration time and the differentiation time
(par. PI-33 Process PID Proportional Gain, par. PI-34 Process PID Integral Time, par. PI-35 Process PID Differentiation Time). In most processes, this can be done by
following the guidelines given below.
1. Start the motor
2. Set par. PI-33 Process PID Proportional Gain to 0.3 and increase it until the feedback signal again begins to vary continuously. Then reduce the value
until the feedback signal has stabilised. Now lower the proportional gain by 40-60%.
3. Set par. PI-34 Process PID Integral Time to 20 sec. and reduce the value until the feedback signal again begins to vary continuously. Increase the integration
time until the feedback signal stabilises, followed by an increase of 15-50%.
4. Only use par. PI-35 Process PID Differentiation Time for very fast-acting systems only (differentiation time). The typical value is four times the set integration
time. The differentiator should only be used when the setting of the proportional gain and the integration time has been fully optimised. Make sure that
oscillations on the feedback signal is sufficiently dampened by the lowpass filter on the feedback signal.
NB!
If necessary, start/stop can be activated a number of times in order to provoke a variation of the feedback signal.
Par. no. Setting
H-03 [2] Initialization - make a power cycling - press reset
As stated on motor name plate
P-07
F-04 &
F-05
P-04 [1] Enable complete auto tune
H-08 Select correct motor shaft direction
H-40 [3] Process
H-45 [0] Speed Open Loop
[60] ° C Unit shown on display
F-51
F-52
-5° C
F-53
35° C
C-05
[0] 35%
Par C
. − 05 ( 0 )
Ref
=
100
par. F-64 Preset Relative Reference to par. F-68 Relative Scaling Reference Resource
[0] = No Function
F-07 20 sec.
F-08 20 sec.
F-18 300 RPM
F-17 1500 RPM
F-03 60 Hz
AN-10 0 V
AN-11 10 V
AN-24 -5° C
AN-25
35° C
PI-20
[2] Analog input 54
PI-30 [0] Normal
PI-31 [1] On
PI-32 300 rpm
K-50 [1] All to Keypad
AF-650 GP Design Guide
× (( − 53 ) − ( − 52 )) = 24, 5°
Par F par F
. .
3
C
33