Hi everyone,
I have encountered some problems when the PID controller(type23) was used for controling the outlet air temperature of cooling coil.
The fluid flow rate of cooling coil is conected with a outlet of flow diverter(type11), the fluid flow rate of cooling coil is determined by the control signal of the flow diverter. It is in order to model a cooling cooling with a bypass in fluid side.
Then, the PID control is used for keeping the outlet air temperature (Controlled variable) of cooling coil at a setpoint, the control signal is the fluid proportion of the flow diverter.
But no matter how to adjust the parameters of PID, the outlet air temperature oscillation cann't be eliminated.
so, I have two questions about this simulation.
1)How to determine the parameters of PID controller, sunch as Gain constant, Integral time and Derivative time, to avoid Controlled variable oscillation ?
2)is there some regular between the simulation time step and the parameters ?
If anyone has experience in this respect, could please tell me how to choose the simulation time step and the PID parameters ?