Danfoss FC 300 Design Manual page 36

3 Introduction to AutomationDrive FC 300
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 1-2*
Perform a full Automation Motor Adaptation
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.
3
Press "Hand On" LCP key. Check shaft direction by ap-
plying a manual reference.
If motor turns opposite of required direction:
1. Change motor direction in par. 4-10
Direction
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 . 6-xx
Set reference/feedback units
Set min. reference (10° C)
Set max. reference (80° C)
If set value is determined from a preset value (array
parameter), 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 LCP
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
Process PID Proportional Gain
(par. 7-33
be done by following the guidelines given below.
1. Start the motor
2. Set par. 7-33 Process PID Proportional Gain
value until the feedback signal has stabilised. Now lower the proportional gain by 40-60%.
Process PID Integral Time
3. Set par. 7-34
the integration time until the feedback signal stabilises, followed by an increase of 15-50%.
4. Only use par. 7-35
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.
36
Par. no. Setting
14-22
1-29
4-10
Motor Speed
1-00
1-05
3-01
3-02
3-03
3-10
3-41
3-42
6-10
6-11
6-24
6-25
7-20
7-30
7-31
7-32
0-50
Process PID Integral Time
, par. 7-34
to 0.3 and increase it until the feedback signal again begins to vary continuously. Then reduce the
to 20 sec. and reduce the value until the feedback signal again begins to vary continuously. Increase
Process PID Differentiation Time
for very fast-acting systems only (differentiation time). The typical value is four times the
MG.33.BC.02 - VLT
[2] Initialization - make a power cycling - press reset
As stated on motor name plate
[1] Enable complete AMA
Select correct motor shaft direction
[3] Process
[0] Speed Open Loop
[60] ° C Unit shown on display
-5° C
35° C
[0] 35%
Par . 3 − 10 ( 0 )
Ref × (( Par . 3 − 03 ) − (
=
100
Preset Relative Reference
par. 3-14 to par. 3-18
source [0] = No Function
20 sec.
20 sec.
300 RPM
1500 RPM
60 Hz
0 V
10 V
-5° C
35° C
[2] Analog input 54
[0] Normal
[1] On
300 rpm
[1] All to LCP
Process PID Differentiation Time
, par. 7-35
® is a registered Danfoss trademark
FC 300 Design Guide
par . 3 − 02 )) = 24, 5° C
Relative Scaling Reference Re-
). In most processes, this can