Feedback Conversion; Process Pid Feed Forward Factor; On Reference Bandwidth - Danfoss VLT CDS 303 Operating Instructions Manual

Parameter Descriptions

7-38 Process PID Feed Forward Factor

Range:
0 % [0 -
*
200 %]
6 6

7-39 On Reference Bandwidth

Range:
5 % [0 -
*
200 %]

6.8.2 7-6* Feedback Conversion

Select how the signals from the feedback sources must be
converted.
7-60 Feedback 1 Conversion
Option:
[0] Linear
*
[1] Square root
[2] Pressure to
temperature
7-61 Feedback 1 Source Unit
Option:
78
Function:
Enter the PID feed forward (FF) factor. The FF
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 will
thus affect the motor speed. When the FF 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:
Enter the On Reference bandwidth. When the
PID Control Error (the difference between the
reference and the feedback) is less than the set
value of this parameter the On Reference
status bit is high, i.e. =1.
Function:
Selects the conversion to apply to the
feedback signal measured on the analog
input selected as feedback 1 source in 7-20
Process CL Feedback 1 Resource.
No conversion is applied. The feedback
signal is assumed to be in the unit selected
in 3-01 Reference/Feedback Unit and enters
the process controller unchanged.
The square root of the feedback signal is
calculated before passing it to the process
controller.
The feedback signal is a pressure with units
as specified in 7-61 Feedback 1 Source Unit.
It is converted to a temperature before
passing it to the process controller. The
pressure to temperature conversion is based
on the refrigerant selected in 7-70
Refrigerant.
Function:
Select the pressure unit applicable to feedback
source 1 defined in 7-20 Process CL Feedback 1
Resource.
Danfoss A/S © Rev. 2013-07-03 All rights reserved.
®
VLT Compressor Drives CDS 302/CDS 303
7-61 Feedback 1 Source Unit
Option:
[70] mbar
[71] bar
[72] Pa
[73] kPa
[74] m WG
[170] psi
[171] lb/in2
[172] in WG
[173] ft WG
7-62 Feedback 2 Conversion
Option:
[0] Linear
*
[1] Square root
[2] Pressure to
temperature
7-63 Feedback 2 Source Unit
Option:
[70] mbar
[71] bar
[72] Pa
[73] kPa
[74] m WG
[170] psi
[171] lb/in2
[172] in WG
[173] ft WG
Function:
Function:
Selects the conversion to apply to the
feedback signal measured on the analog
input selected as feedback 2 source in 7-22
Process CL Feedback 2 Resource.
No conversion is applied. The feedback
signal is assumed to be in the unit selected
in 3-01 Reference/Feedback Unit and enters
the process controller unchanged.
The square root of the feedback signal is
calculated before passing it to the process
controller.
The feedback signal is a pressure with units
as specified in 7-62 Feedback 2 Source Unit.
It is converted to a temperature before
passing it to the process controller. The
pressure to temperature conversion is based
on the refrigerant selected in 7-70
Refrigerant.
Function:
Select the pressure unit applicable to feedback
source 1 defined in 7-22 Process CL Feedback 2
Resource.
MG34M422