Hello all!
I am trying to figure out how to tune PIDE for an unstable heater.
This is a startup tuning. My project was to remove old temp controllers and use something robust and cheaper to substitute temp controller.
So i am using 1734-IT2i thermocouple input module. I am also using PIDE function with SRTP to drive SSR.
I have 8 heaters in the machine, and i have managed to tune other 7, but this one is like impossible to tune. So this heater has design issues: it has small mass, and there is a thermocouple sensor in the same heater element. Also there is a vacuum turns on and blowing and heater while machine is running.
I tried to use Autotune on cold startup and while running the machine, and that number kind of worked, with +/- 3 degrees oscillation while running, but when i just turn the heater on, without vacuum and machine is not running, the oscillation is +/- 20 degrees. (P= 3.576, i=0.601, d=0 <- forgot what d was)
I also tried manually tune and seemed like i got +/- 3 degrees in oscillation on startup while machine is not running, and when i start the machine the oscillation is +/- 20 degrees.(P=60, i=30, d=0)
Do you think it is possible to stabilize it? If yes, what values or what do I need to change?
The previous temp controller was able to control heater with +/- 5 degrees oscillation. Is it a good thought to try to plug previous temp controller PID values? But temp controller methods are different...
Maybe I can disable it when it is trying to overheat?
Burnt 2 heaters already...
I would really appreciate your help. Really struggling here.
Thanks!
I am trying to figure out how to tune PIDE for an unstable heater.
This is a startup tuning. My project was to remove old temp controllers and use something robust and cheaper to substitute temp controller.
So i am using 1734-IT2i thermocouple input module. I am also using PIDE function with SRTP to drive SSR.
I have 8 heaters in the machine, and i have managed to tune other 7, but this one is like impossible to tune. So this heater has design issues: it has small mass, and there is a thermocouple sensor in the same heater element. Also there is a vacuum turns on and blowing and heater while machine is running.
I tried to use Autotune on cold startup and while running the machine, and that number kind of worked, with +/- 3 degrees oscillation while running, but when i just turn the heater on, without vacuum and machine is not running, the oscillation is +/- 20 degrees. (P= 3.576, i=0.601, d=0 <- forgot what d was)
I also tried manually tune and seemed like i got +/- 3 degrees in oscillation on startup while machine is not running, and when i start the machine the oscillation is +/- 20 degrees.(P=60, i=30, d=0)
Do you think it is possible to stabilize it? If yes, what values or what do I need to change?
The previous temp controller was able to control heater with +/- 5 degrees oscillation. Is it a good thought to try to plug previous temp controller PID values? But temp controller methods are different...
Maybe I can disable it when it is trying to overheat?
Burnt 2 heaters already...
I would really appreciate your help. Really struggling here.
Thanks!