Control Techniques COMMANDER SE, Руководство для продвинутых пользователей

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Commander SE Advanced User Guide
Issue Number: 4
12.20 PID loop
The Commander SE drive software has a dedicated PID control loop. This can be configured to control the speed of a motor
with reference to a feedback signal. In PID control, the error resulting from differences between the PID feedback and the PID
reference source is passed through a limiter, a scaling stage and finally the error is added or taken away from the main
reference source.
Common applications where a PID loop is used are pressure control, level control and temperature control.
Pressure control
The system will regulate a constant pressure to a process set point, where an analog signal proportional to pressure is fed
back to the PID loop. The speed demand for the drive should vary inversely proportional to the system process error i.e. as
the pressure increases the drive’s speed decreases and vice versa.
Level control
The system will regulate a constant level to a process set point, where an analog signal proportional to level is fed back to the
PID loop. The speed demand for the drive should vary proportional to the system process error i.e. as the level increases, the
drive’s speed increases and vice versa.
Temperature control
The system will regulate a constant water temperature to a process set point by varying a cooling fan speed. An analog signal
proportional to water temperature is fed back to the PID loop. The speed demand for the drive should vary proportional to the
system process error i.e. as the water temperature increases the drive speed increases and vice versa.
Example of pressure control
System set-up
T
Pressure
Transducer
Air Flow
Fan