Danfoss VLT AutomationDrive FC 301 Programming Manual page 177

Parameter Descriptions
VLT 1
Set-point
Calculation
VLT 2
Set-point
External Set-point
Calculation
VLT 3
Set-point
Calculation
Illustration 3.48 Speed Trim
Illustration 3.48 shows a single source set-up where the
master sends the torque signal to all followers. The
number of available analog outputs on the master limits
this set-up. To overcome the limitation of the number of
analog outputs, use a cascade principle. The cascade
principle makes the control slower and less accurate
compared with the set-up using analog outputs.
7-01 Speed PID Droop
The droop function allows the frequency converter to decrease
the motor speed proportional to the load. The droop value is
directly proportional to the load value. Use the droop function
when several motors are mechanically connected and the load
on motors can differ.
Ensure that parameter 1-62 Slip Compensation has a default
setting.
Range: Function:
0 RPM [0 - 200 Enter the droop value at 100% load.
*
RPM]
7-02 Speed PID Proportional Gain
Range: Function:
0.015 [0 - 1 ] Enter the speed controller propor-
*
tional gain. The proportional gain
amplifies the error (that is the
M0013101
Programming Guide
Speed
Ramp
Speed
Ramp
-
Droop
Speed
Ramp -
Droop
7-02 Speed PID Proportional Gain
Range:
7-03 Speed PID Integral Time
Range:
Size
related
*
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Torque
PID PID
Torque
PID PID
Torque
PID
PID
Function:
deviation between the feedback
signal and the setpoint). This
parameter is used with
parameter 1-00 Configuration Mode
[0] Speed open loop and [1] Speed
closed loop control. Quick control is
obtained at high amplification.
Increasing amplification makes the
process less stable.
For values with 4 decimals, use
parameter 30-83 Speed PID Propor-
tional Gain.
Function:
[1.0 - 20000 Enter the speed controller integral
ms] 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
dampening effect and can be used
M1
3 3
M2
M3
175