I am working on a CIP project. There is a tank which is about 1500L. We need to keep the water volumn inside the tank to be SP:200L. The control valve is at the outlet of the tank. There is a constant water flow in the tank at rate about 200 kg/min. So in order to keep the 200L water inside tank, Outlet control valve should be opened at certain value all the time. I will use PIDE and autotune. My questions are as below:
(1) Shall I use SP-PV or PV-SP for control action?
(2) Shall I use Output Bias%, because if error equal to 0, the calculated output from PID will be 0, but we need to keep outlet valve at certain openess.
(3) What is the procedure to get right Kp and Ki ( we use indpendent Paramenter)?
Thanks very much for your help
(1) Shall I use SP-PV or PV-SP for control action?
(2) Shall I use Output Bias%, because if error equal to 0, the calculated output from PID will be 0, but we need to keep outlet valve at certain openess.
(3) What is the procedure to get right Kp and Ki ( we use indpendent Paramenter)?
Thanks very much for your help