Parameters: 7-** Controllers - Danfoss VLT AutomationDrive FC 302 Programming Manual

Parameter Descriptions

3.9 Parameters: 7-** Controllers

3.9.1 7-0* Speed PID Ctrl.
7-00 Speed PID Feedback Source
Option: Function:
NOTICE
This parameter cannot be
adjusted while the motor is
running.
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 parameter 1-02 Flux Motor
Feedback Source.
[0] Motor feedb. P1-02
[1] 24V encoder
[2] MCB 102
[3] MCB 103
[4] MCO Encoder 1 X56
[5] MCO Encoder 2 X55
[6] Analog Input 53
[7] Analog Input 54
[8] Frequency input 29
[9] Frequency input 33
[11] MCB 15X
NOTICE
If separate encoders are used (FC 302 only), the ramp
settings parameters in parameter groups 3-4*, 3-5*, 3-6*,
3-7* and 3-8* must be adjusted according to the gear
ratio between the 2 encoders.
7-01 Speed PID Droop
The droop function allows the frequency converter to decrease
the motor speed by the droop value. The droop value is directly
proportional to the load value. This parameter defines the droop
value at 100% load. Use the droop function when several motors
are mechanically connected and the load on motors can differ.
To use this parameter, set parameter 1-62 Slip Compensation to
[0], otherwise parameter 7-01 Speed PID Droop is ignored.
Range:
0 RPM [0 - 200 RPM]
*
7-02 Speed PID Proportional Gain
Range: Function:
Size [0 - Enter the speed controller proportional gain.
related 1] The proportional gain amplifies the error (i.e.
*
the deviation between the feedback signal and
MG33MJ02
Programming Guide
7-02 Speed PID Proportional Gain
Range:
7-03 Speed PID Integral Time
Range:
Size
related
7-04 Speed PID Differentiation Time
Range:
Size
related
Function:
Enter the droop value at
100% load. 7-05 Speed PID Diff. Gain Limit
Range:
5
Danfoss A/S © Rev. 10/2014 All rights reserved.
Function:
the set-point). 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.
However, if the amplification is too great, the
process may become unstable.
Use this parameter for values with 3 decimals.
For a selection with 4 decimals, use
parameter 3-83 Quick Stop S-ramp Ratio at Decel.
Start.
Function:
[1.0 - Enter the speed controller integral time,
20000 which determines the time the internal PID
*
ms] 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 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
integral time disables the integral action,
leading to major deviations from the
required reference, since the process
regulator takes too long to regulate errors.
This parameter is used with [0] Speed open
loop and [1] Speed closed loop control, set in
parameter 1-00 Configuration Mode.
Function:
[0 - Enter the speed controller differentiation
200 time. The differentiator does not react to
*
ms] 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 differen-
tiator. The gain is proportional with the
speed at which errors change. Setting this
parameter to zero disables the differen-
tiator. This parameter is used with
parameter 1-00 Configuration Mode [1] Speed
closed loop control.
Function:
[1 - Set a limit for the gain provided by the differen-
*
20] tiator. 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
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