Danfoss vlt FC 102 Programming Guide

21-14 Ext. 1 Feedback Source
Option: Function:
[104] Sensorless
Flow
[105] Sensorless
Pressure
[110] Air Pres. to
Flow
21-15 Ext. 1 Setpoint
Range: Function:
0
ExtPID1Uni
t*
[ par. 21-11 -
par. 21-12
ExtPID1Unit]
The setpoint reference is used in
extended 1 closed loop. Ext.1
setpoint is added to the value from
the Ext.1 reference source selected
in parameter 21-13 Ext. 1 Reference
Source.
21-17 Ext. 1 Reference [Unit]
Range: Function:
0
ExtPID1Uni
t*
[-999999.999
- 999999.999
ExtPID1Unit]
Readout of the reference value for
the closed-loop 1 controller.
21-18 Ext. 1 Feedback [Unit]
Range: Function:
0
ExtPID1Uni
t*
[-999999.999
- 999999.999
ExtPID1Unit]
Readout of the feedback value for
the closed-loop 1 controller.
21-19 Ext. 1 Output [%]
Range: Function:
0 %* [0 - 100 %] Readout of the output value for the
closed-loop 1 controller.
3.19.3 21-2* Closed Loop 1 PID
21-20 Ext. 1 Normal/Inverse Control
Option: Function:
[0] * Normal Reduces the output when feedback
is higher than the reference.
[1] Inverse Increase the output when feedback
is higher than the reference.
21-21 Ext. 1 Proportional Gain
Range: Function:
0.01* [0 - 10 ]
NOTICE
Always set
parameter 20-14 Maximum
Reference/Feedb. before setting
the values for the PID
controller in parameter group
20-9* PID Controller.
21-21 Ext. 1 Proportional Gain
Range: Function:
The proportional gain indicates the
number of times the error between
the setpoint and the feedback
signal is to be applied.
If (error x gain) jumps with a value equal to what is set in
parameter 20-14 Maximum Reference/Feedb., the PID
controller tries to change the output speed equal to what
is set in parameter 4-13 Motor Speed High Limit [RPM]/
parameter 4-14 Motor Speed High Limit [Hz]. However, the
output speed is limited by this setting.
The proportional band (error causing output to change
from 0–100%) can be calculated with the formula
1
ProportionalGain
× MaxReference
21-22 Ext. 1 Integral Time
Range: Function:
10000 s* [0.01 - 10000
s]
Over time, the integrator
accumulates a contribution to the
output from the PID controller as
long as there is a deviation
between the reference/setpoint and
feedback signals. The contribution
is proportional to the size of the
deviation. This ensures that the
deviation (error) approaches 0.
Quick response on any deviation is
obtained when the integral time is
set to a low value. Setting it too
low, however, may cause the
control to become unstable.
The value set is the time needed
for the integrator to add the same
contribution as the proportional for
a certain deviation.
If the value is set to 10000, the
controller acts as a pure propor-
tional controller with a P-band
based on the value set in
parameter 20-93 PID Proportional
Gain. When no deviation is present,
the output from the proportional
controller is 0.
21-23 Ext. 1 Dierentation Time
Range: Function:
0 s* [0 - 10 s] The dierentiator does not react to
a constant error. It only provides a
gain when the feedback changes.
The quicker the feedback changes,
the stronger the gain from the
dierentiator.
Parameter Descriptions
VLT
®
HVAC Drive FC 102
192 Danfoss A/S © 10/2019 All rights reserved. M0010001
33

Danfoss vlt FC 102 Specifications

General

Brand	Danfoss
Model	vlt FC 102
Category	DC Drives
Language	English