Need help with the boost converter simulink model (average model).

Hello ! I am trying to implement an MPPT and for that I need a boost converter. Since the average model works better I am using the average model boost converter with a P&O code, however when I use the P&O code, it decrements the duty cycle untill it is 0. However the same code works fine with the conventional self made converter (but response is slow).

Please provide feedback.

Answer 1

[Sebastian Castro]

It could potentially be that switching from PWM to Average mode is messing with the sample rate of your P&O MATLAB Function block, as it could be inheriting sample times (the default setting).

Go to "Display > Sample Time > All" and see whether the sample rate of that block changes depending on which converter to use.

The best option is to explicitly set your P&O algorithm sample time by going to the block properties and choosing a Discrete sample time of your choice: https://www.mathworks.com/help/simulink/ug/matlab-function-block-editor.html#bqoe0f9

- Sebastian

[Haider Agha]

Thank you for your reply Sebastian ! I checked the sample times for both the function blocks and they both seem to be working at the same sample times which the hold block is providing them (in my case 0.01). Could have to do something with my design of the system ? I don't understand the reason, because when I provide a 0.5 constant block input to the duty cycle to the Average model block, it doubles the ref voltage perfectly. The issues seems to be only when I insert the function block.

[Nisar Ahmed]

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