martinrelayer
Electrical
hello,
I would like to ask if someone was involved in a level control of a *very* large tank or some advice.
We have a water treatment plant, very large, and they want to control a very large output tank level automatically with a water pump
The water demand may change and this causes problems to the level control.
As a constraint we have water turbidity, and "speeding up the pump" causes troubles, so the increments shall be moderate.
The designer made a PI control, that didn't work well, after that someone did like a step logic, working better.
But still the error in the level is too much (setpoint at 95%, you can see oscillating from 80 to 100%) and this is not a PI control, only adding or substracting steps in flow setpoint.
Also you can see turbidity going up when flow goes up.
I was thinking of adding like a correction factor, a PID correction to the controlled variable, like plus minus 10 litres/second to the steps with the same setpoint as the tank level, the same process value and the output or CV adding or substracting to the flow setpoint.
but before I would like to ask for you opinion!!
please see attached graph
kind regards,
martin.
I would like to ask if someone was involved in a level control of a *very* large tank or some advice.
We have a water treatment plant, very large, and they want to control a very large output tank level automatically with a water pump
The water demand may change and this causes problems to the level control.
As a constraint we have water turbidity, and "speeding up the pump" causes troubles, so the increments shall be moderate.
The designer made a PI control, that didn't work well, after that someone did like a step logic, working better.
But still the error in the level is too much (setpoint at 95%, you can see oscillating from 80 to 100%) and this is not a PI control, only adding or substracting steps in flow setpoint.
Also you can see turbidity going up when flow goes up.
I was thinking of adding like a correction factor, a PID correction to the controlled variable, like plus minus 10 litres/second to the steps with the same setpoint as the tank level, the same process value and the output or CV adding or substracting to the flow setpoint.
but before I would like to ask for you opinion!!
please see attached graph
kind regards,
martin.