Danfoss VLT AutomationDrive FC 301 Programming Manual page 130

Parameter Descriptions
3.8.6 7-3* Process PID Ctrl.
7-30 Process PID Normal/ Inverse Control
Option:
3 3
[0] Normal Set process control to increase the output
*
[1] Inverse Set process control to decrease the output
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
Range:
0 RPM [0 -
*
6000
RPM]
7-33 Process PID Proportional Gain
Range:
0.01 N/A [0.00 - 10.00
*
N/A]
7-34 Process PID Integral Time
Range:
10000.00 s
*
10000.00 s]
7-35 Process PID Differentiation Time
Range:
0.00 s [0.00 -
*
10.00 s]
128
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:
Enter the PID proportional gain. The
proportional gain multiplies the
error between the setpoint and the
feedback signal.
Function:
[0.01 - 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:
Enter the PID differentiation time. The
differentiator does not react to a constant
error, but provides a gain only when the
error changes. The shorter the PID differen-
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®
VLT AutomationDrive FC 301/302
7-35 Process PID Differentiation Time
Range:
7-36 Process PID Diff. Gain Limit
Range:
5.0
N/A
*
7-38 Process PID Feed Forward Factor
Range:
0 %
*
500 %]
7-39 On Reference Bandwidth
Range:
5 %
*
200 %]
3.8.7 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
Function:
tiation time, the stronger the gain from the
differentiator.
Function:
[1.0 - Enter a limit for the differentiator gain. If
50.0 N/A] there is no limit, the differentiator gain
increases when there are fast changes. To
obtain a pure differentiator gain at slow
changes and a constant differentiator gain
where fast changes occur, limit the differ-
entiator 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 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.
MG33MO02