Frequency dependent resister during AC sweep

Chad Whiteley
Chad Whiteley Altair Community Member
edited June 21 in Community Q&A

Hello,

Is it possible (using a C-block or other means) to implement a frequency dependent resistor in my PSIM model? 

I am using the AC sweep function to model the output impedance of a switching converter. In my application, there is a large capacitor at the output with ESR that is dependent on frequency. If the frequency of each AC sweep simulation is an accessible global variable (or available to the C-block in some other way) I thought it may be possible to adjust the ESR resistor value (via C code function) for each iteration of the AC sweep.

Or maybe there is another way to achieve this...

Thanks!
Chad W.

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Answers

  • Albert_Dunford
    Albert_Dunford
    Altair Employee
    edited June 21

    So, you can go to level 2 on the cap model to include a few other parameters to help give the impedance more of a dependency on frequency.

    image

     

    Additionally, we have recently made it possible to include s-parameters into the simulation, but this forces you to use the spice engine of PSIM which might not be ideal depending on what you are doing. Recently one of my colleagues has been investigating the use of curve fitting functions to introduce RL ladder circuits to simplify the s-parameter response.

    What you describe is possible with regards to having a linked value of the resistor for the frequency of interest, but this would require that superposition would hold and with each frequency response being independent which in a power converter application is tricky. But yes a c block could be used to modify a variable or you could use scripting with OML, python, or PSIM scripts

    you might find this article interesting about s-parameter simulation: https://community.altair.com/community/en/busbar-s-parameter-modeling-to-simulate-mosfet-current-sharing?id=kb_article_view&sysparm_article=KB0124643

    Also, this article about hyperstudy: https://youtu.be/vNfawWZMHS4?si=nGz8lKWSWd8_mOxY hyperstudy will allow you to easily link parameters and is a no code interface.

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