PPI Controller (PIDAdvancedCC) Spiking at the end of deadtime
Hello,
I am working on a process that needs PID Control with a deadtime compensation. It's set up now, and works okay except for the fact that the output spikes every 2.5hrs. (Length of deadtime).
Can someone point me in the right direction here? I feel like it's some reset setting I have misconfigured.
I am working on a process that needs PID Control with a deadtime compensation. It's set up now, and works okay except for the fact that the output spikes every 2.5hrs. (Length of deadtime).
Can someone point me in the right direction here? I feel like it's some reset setting I have misconfigured.
Asked 6 months ago
Answers
0
So it spikes every 2.5 hours or it spikes once, 2.5 hours after you put it in Auto ?
Tuning settings for a PI + Deadtime should be pretty simple .... Only use P + I + Deadtime. The Deadtime compensator is continuous, so once the initial 2.5 hours has passed, each execution should be based on the preceding 2.5 hours - ie you should not be getting an event every 2.5 hours.
Are you sure this is ONLY a PI+Deadtime controller and that nobody has tried to add some "clever" logic to speed things up but instead just breaks things ? ( This is the most common reason for PID Controls not working )
With a large deadtime like this ....
- What is the execution rate ? - ie how big is the memory queue inside the controller. 1 second for 2.5 hours is 9000 values and I don't expect the queue can be this long.
- What Reset Time ( Integral ) are you using ?
- Do you have any Feed Forward compensator connected?
Post a screenshot of your settings.
Tuning settings for a PI + Deadtime should be pretty simple .... Only use P + I + Deadtime. The Deadtime compensator is continuous, so once the initial 2.5 hours has passed, each execution should be based on the preceding 2.5 hours - ie you should not be getting an event every 2.5 hours.
Are you sure this is ONLY a PI+Deadtime controller and that nobody has tried to add some "clever" logic to speed things up but instead just breaks things ? ( This is the most common reason for PID Controls not working )
With a large deadtime like this ....
- What is the execution rate ? - ie how big is the memory queue inside the controller. 1 second for 2.5 hours is 9000 values and I don't expect the queue can be this long.
- What Reset Time ( Integral ) are you using ?
- Do you have any Feed Forward compensator connected?
Post a screenshot of your settings.
Answered 6 months ago
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