Omron SYSDRIVE 3G3FV User Manual page 221

Advanced Operation
PID Control Applications
The following table shows examples of PID control applications using the Inverter.
Application
Speed control
Pressure control
Flow control
Temperature control
PID Control Operations
In order to distinguish the separate PID control operations (i.e., proportional, integral, and derivative),
the following diagram shows the changes in the control input (i.e., the output frequency) when the devi-
ation between the target value and the feedback is held constant.
P Control
A control input proportional to the deviation is output. The deviation cannot be zeroed by P control
alone.
I Control
A control input which is an integral of the deviation is output. This is effective for matching the feedback
to the target value. Sudden changes, however, cannot be followed.
D Control
A control input which is an integral of the deviation is output. Quick response to sudden changes is
possible.
PID Control
Optimum control is achieved by combining the best features of P, I, and D control.
Types of PID Control
Two types of PID control are possible with the 3G3FV: measured-value derivative PID control and basic
PID control. The type that is normally used is measured-value derivative PID control.
Control contents
Speeds are matched to target values as speed
information in a mechanical system.
Speed information for another mechanical system is
input as target values, and synchronized control is
executed by feeding back actual speeds.
Pressure information is returned as feedback for
stable pressure control.
Flow information is returned as feedback for accurate
flow control.
Temperature information is returned as feedback to
control temperature by turning a fan.
Deviation
Control input
D control
Chapter 6
Sensors used
(example)
Tacho-generator
Pressure sensor
Flow sensor
Thermocouple
Thermistor
Time
PID control
I control
P control
Time
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