Before carrying out the PID auto tuning, set the following
parameters according to the load inertia:
•
•
.
or
•
•
If PID auto tuning is carried out with slow ramp times, the
auto-tuned parameters typically result in very slow control.
Before activating PID auto tuning, remove excessive
feedback sensor noise using the input filter (parameter
groups AN-##, E-6# and AO-##, terminal 53/54 filter time
constant/pulse filter time constant 29/33) before activating
PID auto tuning. To obtain the most accurate controller
parameters, carry out PID auto tuning when the
application runs in typical operation, that is with a typical
load.
CL-70 Closed Loop Type
Option:
Function:
Select the application response speed if it
is known. The default setting is sufficient
for most applications. A more precise
value decreases the time needed for
carrying out PID adaptation. The setting
has no impact on values of parameters
and only affects the auto tuning speed.
[0]
*
Auto
Takes 30–60 s to complete.
[1]
Fast Pressure
Takes 10–20 s to complete.
[2]
Slow Pressure
Takes 30–60 s to complete.
[3]
Fast
Temperature
Takes 10–20 minutes to complete.
[4]
Slow
Temperature
Takes 30–60 minutes to complete.
CL-71 PID Performance
Option:
Function:
[0]
*
Normal Normal setting of this parameter is suitable for
pressure control in fan systems.
[1]
Fast
Fast setting is used in pumping systems, where a
faster control response is wanted.
CL-72 PID Output Change
Range:
Function:
0.10
*
[0.01
- 0.50]
This parameter sets the magnitude of step
change during auto tuning. The value is a
percentage of full speed. That is, if maximum
parameter F-15 Motor Speed High
is set to 50 Hz, 0.10 is 10% of 50 Hz,
which is 5 Hz. Set this parameter to a value
resulting in feedback changes of 10–20% for best
tuning accuracy.
CL-73 Minimum Feedback Level
Range:
Function:
-999999
ProcessCtrlUnit
*
[-999999.999 -
par. CL-74
ProcessCtrlUnit]
Enter the minimum allowable
feedback level in user units as
defined in
parameter CL-12 Reference/
Feedback Unit
. If the level
, auto tuning is
aborted and an error message
appears in the keypad.
CL-74 Maximum Feedback Level
Range:
Function:
999999
ProcessCtrlUnit
*
[par. CL-73 -
999999.999
ProcessCtrlUnit]
Enter the maximum allowable
feedback level in user units as
defined in
parameter CL-12 Reference/
Feedback Unit
. If the level
rises above
, auto tuning is
aborted and an error message
appears in the keypad.
CL-79 PID Autotuning
Option:
Function:
This parameter starts the PID auto tuning
sequence. Once the auto tuning has successfully
completed and the settings have been accepted
or rejected by pressing [OK] or [Cancel] at the
end of tuning, this parameter is reset to
[0]
Disabled
.
[0]
*
Disabled
[1]
Enabled
3.22.5 CL-8# PID Basic Settings
This parameter group is used to configure the basic
operation of the PID controller, including how it responds
to feedback that is above or below the setpoint, the speed
at which it first starts functioning, and when it indicates
that the system has reached the setpoint.
CL-81 PID Normal/ Inverse Control
Option:
Function:
[0]
*
Normal The frequency converter’s output frequency
decreases when the feedback is greater than the
setpoint reference. This behaviour is common for
pressure-controlled supply fan and pump
applications.
[1]
Inverse The frequency converter’s output frequency
increases when the feedback is greater than the
Parameter Description
162
03/2016 All rights reserved.
DET-620D
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