Danfoss VLT Midi Drive FC 280 Programming Manual page 70

Parameter Descriptions
7-31 Process PID Anti Windup
Option: Function:
[0] Off Continue regulation of an error even when the output
frequency cannot be increased or decreased.
[1] On Cease regulation of an error when the output
*
frequency can no longer be adjusted.
7-32 Process PID Start Speed
4 4
Range:
0 RPM [0 -
*
6000
RPM]
7-33 Process PID Proportional Gain
Range:
0.01 [0 - 10 ] Enter the PID proportional gain. The propor-
*
7-34 Process PID Integral Time
Range:
9999 s [0.10 -
*
9999 s]
7-35 Process PID Differentiation Time
Range:
0 s [0 - 20 s] Enter the PID differentiation time. The differen-
*
7-36 Process PID Diff. Gain Limit
Range:
5 [1 - 50] Enter a limit for the differentiator gain. If there is
*
68
Function:
Enter the motor speed to be attained as a
start signal for commencement of PID
control. When the power is switched on, the
frequency converter starts to ramp and then
operates under speed open-loop control.
When the process PID start speed is reached,
the frequency converter changes to process
PID control.
Function:
tional gain multiplies the error between the
setpoint and the feedback signal.
Function:
Enter the PID integral time. The integrator
provides an increasing gain at a constant
error between the setpoint and the
feedback signal. The integral time is the
time needed by the integrator to reach the
same gain as the proportional gain.
Function:
tiator does not react to a constant error, but
provides a gain only when the error changes.
The shorter the PID differentiation time, the
stronger the gain from the differentiator.
Function:
no limit, the differentiator gain increases when
there are fast changes. To obtain a pure differen-
tiator gain at slow changes and a constant
differentiator gain where fast changes occur, limit
the differentiator gain.
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®
VLT Midi Drive FC 280
7-38 Process PID Feed Forward Factor
Range:
0 %
*
200 %]
7-39 On Reference Bandwidth
Range:
5 %
*
200 %]
7-40 Process PID I-part Reset
Option:
[0] No
*
[1] Yes Select [1] Yes to reset the I-part of the process PID
7-41 Process PID Output Neg. Clamp
Range:
-100 %
*
7-42 Process PID Output Pos. Clamp
Range:
100 %
*
7-43 Process PID Gain Scale at Min. Ref.
Range:
100 %
*
Function:
[0 - Enter the PID feed forward (FF) factor. The FF
factor sends a constant fraction of the reference
signal to bypass the PID control, so the PID
control only affects the remaining fraction of the
control signal. Any change to this parameter
affects the motor speed. When the FF factor is
activated, it provides less overshoot, and high
dynamics when changing the setpoint.
Parameter 7-38 Process PID Feed Forward Factor is
active when parameter 1-00 Configuration Mode
is set to [3] Process.
Function:
[0 - Enter the on-reference bandwidth. When the
PID control error (the difference between the
reference and the feedback) is less than the
value of this parameter, the on-reference
status bit is 1.
Function:
controller. The selection automatically returns to [0]
No. Resetting the I-part makes it possible to start from
a well-defined point after changing something in the
process, for example changing a textile roll.
Function:
[ -100 - 100 %] Enter a negative limit for the process
PID controller output.
Function:
[ -100 - 100 %] Enter a positive limit for the process
PID controller output.
Function:
[0 - Enter a scaling percentage to apply to the
100 %] process PID output when operating at the
minimum reference. The scaling percentage is
adjusted linearly between the scale at
minimum reference (parameter 7-43 Process PID
Gain Scale at Min. Ref.) and the scale at
maximum reference (parameter 7-44 Process
PID Gain Scale at Max. Ref.).
MG07C302