Temperature control with inertia

I am trying to model a control system for a heater that heats a container full of a liquid. When the set point is reached the heater switches off, but, due to heat stored in the heating element , the temperature continues to rise for approximately 15 degs. Similarly when the temperature falls below the set point the heater switches on, but the temperature falls for another 15 degs. I intend to control the power of the heater using PWM but I cannot design the PID controller until I have a model of the heater/container.

Answer 1

[Siddharth Jawahar]

Hi Julian,

If you do not have a good understanding or a prespective of the system dynamics to model it in Simulink, you can use system identification techniques to estimate a plant and then tune the PID controller using that plant model. We have good resources which talks about your same exact question of tuning a PID controller when a plant model is not available. Please take a read of this article below or watch the video:

https://www.mathworks.com/company/newsletters/articles/tuning-a-pid-controller-when-a-plant-model-is-not-available.html

https://www.mathworks.com/videos/pid-controller-tuning-based-on-measured-input-output-data-89348.html?s_tid=srchtitle

HTH,

Sid