Parameters: Controllers - Danfoss FC 300 Design Manual

FC 300 Design Guide

Parameters: Controllers

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7-** Controllers
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Parameter group for configuring application controls.
7-0* Speed PID Ctrl.
"
Parameters for configuring the speed PID control.
7-00 Speed PID Feedback Source
Option:
*
Motor feedb. P1-02 (FC 302 only)
24V encoder
MCB 102
MCO 305
Function:
Select the encoder for closed loop feedback.
The feedback may come from a different encoder
(typically mounted on the application itself)
than the motor mounted encoder feedback
selected in par. 1-02.
This parameter cannot be adjusted while
the motor is running.
NOTE
If separate encoders are used (FC 302
only) to ramp settings parameters in
the following groups: 3-4*, 3-5*, 3-6*,
3-7* and 3-8* must be adjusted according to the
gear ratio between the two encoders.
7-02 Speed PID ProportionalGain
Range:
0.000 - 1.000
Function:
Enter the speed controller proportional gain.
The proportional gain amplifies the error (i.e.,
the deviation between the feedback signal and
the set-point). This parameter is used with par.
1-00 Speed open-loop [0] and Speed closed-loop
[1] control. Quick control is obtained at high
amplification. However if the amplification is too
great, the process may become unstable.
7-03 Speed PID Integral Time
Range:
2.0 - 20000.0 ms
default setting ( ) display text
*
208
How to Program
Enter the speed controller integral time, which
determines the time the internal PID control takes
to correct errors. The greater the error, the more
quickly the gain increases. The integral time causes
a delay of the signal and therefore a damping effect,
and can be used to eliminate steady state speed
error. Obtain quick control through a short integral
time, though if the integral time is too short, the
process becomes unstable. An excessively long
[0]
integral time disables the integral action, leading
[1]
to major deviations from the required reference,
[2]
since the process regulator takes too long to
[3]
regulate errors. This parameter is used with Speed
open-loop [0] and Speed closed-loop [1] control,
set in par. 1-00 Configuration Mode.
Enter the speed controller differentiation time. The
differentiator does not react to constant error. It
provides gain proportional to the rate of change of
the speed feedback. The quicker the error changes,
the stronger the gain from the differentiator. The
gain is proportional with the speed at which errors
change. Setting this parameter to zero disables
the differentiator. This parameter is used with
par. 1-00 Speed closed-loop [1] control.
*
0.015
Set a limit for the gain provided by the differentiator.
Since the differential gain increases at higher
frequencies, limiting the gain may be useful.
For example, set up a pure D-link at low
frequencies and a constant D-link at higher
frequencies. This parameter is used with par.
1-00 Speed closed loop [1] control.
*
8.0 ms
[ ] value for use in communication via serial communication port
MG.33.B6.22 - VLT is a registered Danfoss trademark
Function:
7-04 Speed PID Differentiation Time
Range:
0.0 - 200.0 ms
Function:
7-05 Speed PID Diff Gain Limit
Range:
1.000 - 20.000
Function:
7-06 Speed PID Lowpass Filter Time
Range:
1.0 - 100.0 ms
*
30.0 ms
*
5.000
*
10.0ms