Closed loop discrete PI controller

how to find integral and proportional constants.how can i interface it with a PWM and switch input to get desired op.

[Joel Van Sickel]

What type of system are you trying to control?

[Pranav Pillai]

A closed loop system.Im designing a boost converter.PI controller is for the voltage correction.

[Sam Chak]

Could you provide the transfer function of the boost converter? It helps to determine the suitable values for the PI gains.

Answer 1

[Joel Van Sickel]

Hello,

please use the references on this page to dive deeper into designing closed loop control for boost converters.

https://www.mathworks.com/solutions/power-electronics-control/boost-converter-simulation.html

Regards,

Joel

Answer 2

[Pranav Pillai]

I have figured out the PI gains using ziegler-nicholas method.

How can i find my boost converters transfer function?

[Joel Van Sickel]

Hello Pranav, if you use average mode converter models, you can do it fairly simply using the controls toolboxed and the model linearizer app.

https://www.mathworks.com/help/slcontrol/ug/linearize-simulink-model.html

If you want to keep switching involved, you'll need to do a frequency reponse

Here is the basics for frequency response estimation.

https://www.mathworks.com/company/newsletters/articles/estimating-the-frequency-response-of-a-power-electronics-model.html

One other alternative is since it's a boost converter, you can derive the 2nd order transfer function of the system, and close the loop with your PI controller using matlab commands or do it analytically. Wikipedia has the equivalent closed loop system for controller and plant defined as transfer functions available publicly, but getting the 2nd order transfer function for a boost converter is mostly in conference and journal papers.