PID motor control surging/overshooting
Posted: Tue May 04, 2021 10:34 pm
I can't get the PID motor control to settle down, when starting the motors.
It surges past the desired vacuum level and then back below it.
This is so extreme, that I need to switch it immediately back to manual in order to not overshoot the 40" DM limit.
When I got the bench together, I could and still can use the automatic PID control when the cfm is high.
The problem is, that starting the measurement @0.100" the flow is very low and the PID control doesn't settle down,
but keeps hunting the set value.
The bench is the 8 motor 3-phase version in Europe.
It now has the soft start enabled and that might be causing the behavior.
I just can't remember, how to disable the soft/delayed motor spooling ?
All the parts are from the PTS store: SSRs, DM, PID motor control.
I've tried to start the motors slowly and gradually, but that did not do the trick.
I also tried to set the pressure manually an then flipping the switch to auto, but that failed also.
It surges past the desired vacuum level and then back below it.
This is so extreme, that I need to switch it immediately back to manual in order to not overshoot the 40" DM limit.
When I got the bench together, I could and still can use the automatic PID control when the cfm is high.
The problem is, that starting the measurement @0.100" the flow is very low and the PID control doesn't settle down,
but keeps hunting the set value.
The bench is the 8 motor 3-phase version in Europe.
It now has the soft start enabled and that might be causing the behavior.
I just can't remember, how to disable the soft/delayed motor spooling ?
All the parts are from the PTS store: SSRs, DM, PID motor control.
I've tried to start the motors slowly and gradually, but that did not do the trick.
I also tried to set the pressure manually an then flipping the switch to auto, but that failed also.