Single-loop PID control problem
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The Allen-Bradley M4.6.1 system features a single-loop flow control in \"automatic\" mode with feedback; the valve opening is adjusted by 5% at a time (from 100% to 95%, and from 95% to 100%). If process engineers want to make fine adjustments, the configuration is the same as that for other single loops. Is this a matter related to the \"P\", \"I\", and \"D\" parameter settings? Have you ever encountered this situation?
Adjusting the gain and integration time appropriately should work
I don’t quite understand the question. If the valve opening remains around 5% in automatic mode, it is because the valve diameter (Cv value) has been chosen too large, or the output and input signals of the valve positioner are not matched (not properly adjusted).
If the opening is constantly being adjusted between 95 and 100, is the opening limit set too high?
I didn’t quite understand the question. The flow control loop can have its proportionality setting adjusted appropriately, with the proportional gain ranging from 1.0 to 1.5 (proportionality range: 100%–75%). The integration time can also be set as needed; no derivative action should be used.