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Input series inductor waveform for a full-bridge isolated converter

0 votes

I encountered the strange inductor current waveform (Lin in the picture attached) when calculating the input capacitor to ensure a certain input voltage ripple and would like to know what caused the waveform to be like this. I think it is probably related to the input capacitance value but I am sure I used the correct method of calculating it. If implemented correcly this should be a smooth sine waveform without different values of peaks.

Thank you.
asked Dec 4, 2021 by Haochen Tao (14 points)
Hi Haochen, It would be helpful if you could post your model in addition to the screenshots so we can see more about the modulation scheme and circuit values.  Regards,Bryan
Thank you for your reply!

I am currently an undergraduate student and actually I am designing this converter when the problem occured, so I guess for the model, all I can provide is the document below summarizing all my parameters. If you need more information please let me know.

Haochen Tao

1 Answer

0 votes


I went through the exercise of creating a phase-shifted full bridge converter with the parameters outlined in the document.  I observed a clean sinusoidal waveform on the input current.  Please see the attached model.  Note the component parameters are defined in the Initialization tab of the Simulation + Simulation Parameters... drop-down menu.

In the future if you could post the PLECS model file (*.plecs) you are working with it would be helpful.  There likely is a small error in a circuit parameter or in the implementation that would be very difficult to detect without the exact simulation model.



answered Dec 8, 2021 by Bryan Lieblick (908 points)
Thank you for your advice! It is indeed a good way to define and show the parameters. I will go and check what went wrong compared with your model.


Haochen Tao