Danfoss VLT AutomationDrive FC 361 Programming Manual page 94

Parameter Descriptions
7-45 Process PID Feed Fwd Resource
Option:
[0] No function
*
4 4
[1] Analog Input
53
[2] Analog Input
54
[7] Frequency
input 29
[8] Frequency
input 33
[11] Local bus
reference
[32] Bus PCD
7-46 Process PID Feed Fwd Normal/ Inv. Ctrl.
Option:
[0] Normal
*
[1] Inverse
7-48 PCD Feed Forward
Range:
0
*
7-49 Process PID Output Normal/ Inv. Ctrl.
Option:
[0] Normal
*
[1] Inverse
92
Function:
Select which frequency converter
input should be used as the feed-
forward factor. The factor is added
to the output of the PID controller.
This increases dynamic
performance.
Selects a fieldbus reference
configured by
parameter 8-02 Control Word Source.
Change parameter 8-42 PCD Write
Configuration for the bus used to
make the feed forward available in
parameter 7-48 PCD Feed Forward.
Use index 1 for feed forward [748]
(and index 2 for reference [1682]).
Function:
Select [0] Normal to set the feed-
forward factor to treat the FF
resource as a positive value.
Select [1] Inverse to treat the feed-
forward resource as a negative
value.
Function:
[0 - 65535] This parameter contains the value
of parameter 7-45 Process PID Feed
Fwd Resource [32] Bus PCD.
Function:
Select [0] Normal to use the
resulting output from the process
PID controller as is.
Select [1] Inverse to invert the
resulting output from the process
PID controller. This operation is
performed after the feed-forward
factor is applied.
Danfoss A/S © 03/2019 All rights reserved.
VLT® AutomationDrive FC 361
4.8.5 7-5* Ext. Process PID Ctrl.
This parameter group is only used if parameter 1-00 Config-
uration Mode is set to [7] Extended PID speed CL.
7-50 Process PID Extended PID
Option:
[0]
[1]
*
7-51 Process PID Feed Fwd Gain
Range:
1
*
7-52 Process PID Feed Fwd Ramp up
Range:
0.01 s
*
7-53 Process PID Feed Fwd Ramp down
Range:
0.01 s
*
7-56 Process PID Ref. Filter Time
Range:
0.001 s
*
Function:
Disabled Disable the extended parts of the
process PID controller.
Enabled Enable the extended parts of the
PID controller.
Function:
[0 - 100] The feed forward is used to obtain
the required level based on a well-
known signal available. The PID
controller then only takes care of
the smaller part of the control,
necessary because of unknown
characters. The standard feed-
forward factor in
parameter 7-38 Process PID Feed
Forward Factor is always related to
the reference, whereas
parameter 7-51 Process PID Feed Fwd
Gain has more options. In winder
applications, the feed-forward factor
is typically the line speed of the
system.
Function:
[0.01 - 10 s] Controls the dynamics of the feed-
forward signal when ramping up.
Function:
[0.01 - 10 s] Controls the dynamics of the feed-
forward signal when ramping down.
Function:
[0.001 - 1 s] Set a time constant for the
reference first-order low-pass filter.
The low-pass filter improves steady-
state performance and dampens
oscillations on the reference/
feedback signals. However, severe
filtering can be detrimental to
dynamic performance.
MG06J202