Hi:
I have a process where I need to control flow with a bomb with Powerflex700. I have a periodic PIDE instruction, Flowmeter is the PV and CV is PowerFlex Speed. A very simple an standard configuration.
The problem is that the flow is very unstable, even with the pump at fixed speed (working with PIDE in Manual mode).
With fixed speed I have fluctuations of up to 30 m3/hr in a span of 0-500 m3/hr of the flowmeter.
For example the meter is reading 341, 310, 340, 360, 355, 350, 330, 320, 325, 315, etc, etc every one second update rate.
I have tried to tune the PIDE with a lot of methods (Logix AutoTune, RSTune, test and error, Ziegler-Nichols, using just P, just PI, etc) without good results.
Something that I am missing or definitely PIDE isntruction never will work here?
thanks
I have a process where I need to control flow with a bomb with Powerflex700. I have a periodic PIDE instruction, Flowmeter is the PV and CV is PowerFlex Speed. A very simple an standard configuration.
The problem is that the flow is very unstable, even with the pump at fixed speed (working with PIDE in Manual mode).
With fixed speed I have fluctuations of up to 30 m3/hr in a span of 0-500 m3/hr of the flowmeter.
For example the meter is reading 341, 310, 340, 360, 355, 350, 330, 320, 325, 315, etc, etc every one second update rate.
I have tried to tune the PIDE with a lot of methods (Logix AutoTune, RSTune, test and error, Ziegler-Nichols, using just P, just PI, etc) without good results.
Something that I am missing or definitely PIDE isntruction never will work here?
thanks