Tuning Pid Speed Control; Process Pid Control - GE AF-650 GP Design And Installation Manual

Application Set-Up Examples

6.5.1.1 Tuning PID Speed Control

The following tuning guidelines are relevant when using
one of the Flux motor control principles in applications
where the load is mainly inertial (with a low amount of
friction).
The value of parameter PI-02 Speed PID Proportional Gain
depends the combined inertia of the motor and load, and
the selected bandwidth can be calculated using the
following formula:
2
Total inertia kgm x par . P − 06
Par . PI − 02 =
Par . P − 07 x 9550
NOTICE
Parameter P-07 Motor Power [kW] is the motor power in
[kW] (that is, enter '4' kW instead of '4000' W in the
formula).

6.5.2 Process PID Control

The Process PID Control can be used to control application parameters that can be measured by a sensor (that is, pressure,
temperature, flow) and can be affected by the connected motor through a pump, fan or otherwise.
Table 6.18 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.
Parameter H-40 Configuration
Mode
[3] Process
Table 6.18 Control Figurations - Process Control
NOTICE
The Process Control PID works under the default parameter setting, but tuning the parameters is highly recommended
to optimize the application control performance. The two Flux motor control principles are specially dependent on
proper Speed Control PID tuning (before tuning the Process Control PID) to yield their full potential.
Illustration 6.18 Process PID Control Diagram
MG35M402
AF-650 GP™ Design and Installation Guide
x Bandwidth rad/s
Parameter H-41 Motor Control Principle
U/f Advanced Vector Control
N.A. Process
DET-767c All rights reserved.
Generally the practical maximum limit of
parameter PI-02 Speed PID Proportional Gain is determined
by the encoder resolution and the feedback filter time but
other factors in the application might limit the
parameter PI-02 Speed PID Proportional Gain to a lower
value.
To minimize the overshoot, parameter PI-03 Speed PID
Integral Time could be set to approx. 2.5 s (varies with the
application).
Parameter PI-04 Speed PID Differentiation Time should be set
to 0 until everything else is tuned. If necessary, finish the
tuning by experimenting with small increments of this
setting.
Flux Sensorless
Process & Speed
6
Flux w/ enc. feedb
Process & Speed
65
6