Danfoss VLT AutomationDrive FC 301 Programming Manual page 128

Parameter Descriptions
3.9.5 7-3* Process PID Ctrl.
7-30 Process PID Normal/ Inverse Control
Option:
3 3
[0] Normal Sets process control to increase the output
*
[1] Inverse Sets process control to decrease the output
7-31 Process PID Anti Windup
Option: Function:
[0] Off Continues regulation of an error even when the
output frequency cannot be increased or decreased.
[1] On Ceases regulation of an error when the output
*
frequency can no longer be adjusted.
7-32 Process PID Start Speed
Range:
0 RPM [0 -
*
6000
RPM]
7-33 Process PID Proportional Gain
Range:
0.01 [0 - 10] Enter the PID proportional gain. The proportional
*
7-34 Process PID Integral Time
Range:
10000 s [0.01 -
*
10000 s]
7-35 Process PID Differentiation Time
Range:
0 s [0 - 10 s] Enter the PID differentiation time. The differen-
*
126
Function:
Normal and inverse controls are implemented by
introducing a difference between the reference
signal and the feedback signal.
frequency.
frequency.
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:
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.
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®
VLT AutomationDrive FC 301/302
7-36 Process PID Diff. Gain Limit
Range:
5 [1 - 50] Enter a limit for the differentiator gain. If there is
*
7-38 Process PID Feed Forward Factor
Range:
0 %
*
200 %]
7-39 On Reference Bandwidth
Range:
5 %
*
200 %]
3.9.6 7-4* Advanced Process PID Ctrl.
This parameter group is only used if parameter 1-00 Config-
uration Mode is set to [7] Extended PID speed CL or [8]
Extended PID Speed OL.
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 %
*
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.
Function:
[0 - Enter the PID feed forward factor. The 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 feed forward factor is
activated, it provides less overshoot and high
dynamics when changing the set-point.
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 - par. 7-42 %] Enter a negative limit for the
process PID controller output.
MG33ML02