Finding the transfer function of a DC-DC Converter and then calculating PI values for controller

I am trying to understand transfer functions better. I have stumbled upon an example circuit from MATLAB on the Dual Active Bridge converter. From my understanding it has multiple inputs since it needs the input of the PI controller, the input dc voltage and the PWM signals. I have tried to use the information from Linearize Simulink Model at Model Operating Point - MATLAB & Simulink - MathWorks United Kingdom but it didnt quite help out. I would appreciate help on this.

I also want to understand how the PI values for the controller were selected to be 0.15 and 15. My guess is that it is was trial and error as these numbers appear too pretty lol. I have attached the example file and the matlab code needed for the variables.

Answer 1

[Shivam Lahoti]

Hi Chukwudalu,

To understand the Dual Active Bridge converter, you shall refer to the following demo on “Modeling and Control of a Dual Active Bridge (DAB) for Electric Vehicle and Battery Charging Applications”:

https://in.mathworks.com/videos/modeling-and-control-of-a-dual-active-bridge-dab-for-electric-vehicle-and-battery-charging-applications-1680202288419.html

All the files that you are referring to can be found here:

https://in.mathworks.com/matlabcentral/fileexchange/128704-dual-active-bridge-modulation-demo

I hope referring to the above demo and documentation could help you understand the transfer function better for this use case.

Regards,

Shivam.

[Chukwudalu]

Thank you but sadly, no it doesnt really answer the question.