Process Pid Control - Danfoss VLT AutomationDrive FC 300 Design Manual

3. Introduction to FC 300
Par
. 7 − 02
A good start value for par. 7-06
higher filter value). Typically a Max Torque Ripple of 3 % is acceptable. For incremental encoders
the Encoder Resolution is found in either par. 5-70 (24V HTL on standard drive) or par. 17-11 (5V
TTL on MCB102 Option).
3
Generally the practical maximum limit of par. 7-02 is determined by the encoder resolution and
the feedback filter time but other factors in the application might limit the par. 7-02
Gain
To minimize the overshoot, par. 7-03
application).
Par. 7-04
tuning by experimenting with small increments of this setting.

3.3.3. Process PID Control

The Process PID Control can be used to control application parameters that can be measured by
a sensor (i.e. pressure, temperature, flow) and be affected by the connected motor through a
pump, fan or otherwise.
The table shows the control configurations where the Process Control is possible. When a Flux
Vector motor control principle is used, take care also to tune the Speed Control PID parameters.
Refer to the section about the Control Structure to see where the Speed Control is active.
Par. 1-00 Configu-
ration Mode
[3] Process
Note: The Process Control PID will work under the default parameter setting, but tuning the pa-
rameters is highly recommended to optimise the application control performance. The two Flux
motor control principles are specially dependant on proper Speed Control PID tuning (prior to
tuning the Process Control PID) to yield their full potential.
Illustration 3.1:
The following parameters are relevant for the Process Control
34
0.01
=
MAXIMUM
Speed Filter Time
to a lower value.
Differential Time
should be set to 0 until everything else is tuned. If necessary finish the
Par. 1-01 Motor Control Principle
U/f
N.A.
Process PID Control diagram
MG.33.B9.02 - VLT
x x Encoder Resolution x par
4
x
2 π
is 5 ms (lower encoder resolution calls for a
Integral Time
could be set to approx. 2.5 s (varies with the
VVC plus Flux Sensorless
Process Process & Speed
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FC 300 Design Guide
. 7 − 06
x M ax torque ripple
Proportional
Flux w/ enc. feedb
Process & Speed
%