Modeling a planar 2-terminal inductor

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Dear reader,

 

I am modelling a planar inductor in Altair Flux 3D. The planar inductor is evaluated at a frequency of 10MHz and the geometry is variable to obtain a specific inductance with minimal AC-resistance and area. To simulate the inductor, the volume is configured as a solid conductor region and an electrical circuit is made with a current source of 1A and the two terminals of the solid conductor. The face where the current flows into the coil is and a face where the current leaves the coil are assigned:

 

Meshed Geometry 

 

It is not clear from the image, but the height of the trace is 36um, a meshed is the Z-axis with 10 imposed points in this 36um). Other dimensions are roughly: inner diameter 5mm, trace width 6mm, spacing between traces 0.6mm.

 

My first question is: why can the predefined inductance sensor only be used on a stranded coil conductor, not a solid coil conductor?

 

Now I have been calculating the inductance with an integral over the complete domain and multiplying B*H. This magnetic field integral could be used for determining the inductance but the result is way off when comparing to the modified wheeler equation (function used to estimate the inductance of a square planar inductor). How would you suggest to determine the inductance and AC-resistance from the simulation result?

 

Current density in coil

 

Hopefully you can give me some directions.

 

Best regards,

Bart

 

 

 

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Answers

  • Farid zidat_20516
    Farid zidat_20516
    Altair Employee
    edited June 2020

    Dear Flux user, 

     

    Please find bellow the answer to your questions:

     

    First question:

    1- The formulation used for solid conductor is different to the one used for coil region, Anyway, I will add this request for our R&D team. The inductance can be computed from the magnetic Energy. You can compute the magnetic Energy using a sensor on the domain, and then use compute the inductance, before that you have to recover the RMS value of the current.

     

    I can not see second question in your email, but feel free to comeback to us if needed.

     

    Regards 

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