Winding Loss Modelling in Planar Magnetics

[SenpaiAbdullah]

Hi, I've been trying to design a planar inductor and transformer for my project.

I have not found a good explanation or model for proximity effect losses in planar non-interleaved winding structures.

Also, I still do not understand that why, in basic transformer design, we can ignore the vertical proximity losses (by estimating one vertical layer as a porous foil winding to convert it into a 1D problem) as there will still be eddy effects between the individual turns in a single layer.

Is there any literature or rules of design that I can refer to, to accurately model the winding losses as seen by Ansys simulations?

Thanks

 

[24vtingle]

You just generally use a couple of strands, and pander to the skin effect like that, and the proximity effect then takes care of itself so to speak.
And just dont use too many layers for example....eg use the next-size-up bobbin so you dont have to.

Planar design is all done by application software. It (the software) costs a lot of money....it calcs out all the proximity effects etc for you, and also has a mech eng type of thing aswell. Unless you have the software you wont be able to do much in planar design other than just tell your planar designer your Np/Ns, Max leakage, irms pri, irms sec, fsw.....and see what they come back with.
With planars, as i remember, you dont tend to have very many turns on any coil. And multiple interleaving is very easy for them.

 

[FvM]

What is a "vertical layer" in planar design? I thought layers to be orientated horizontally. What are vertical losses? Losses caused by vertical current components respectively horizontal magnetic field? If so they disappear for small layer thickness.

 

[SenpaiAbdullah]

What is a "vertical layer" in planar design? I thought layers to be orientated horizontally. What are vertical losses? Losses caused by vertical current components respectively horizontal magnetic field? If so they disappear for small layer thickness.

Yes, the higher losses caused by current distribution in the cross section in the vertical direction (z direction if planar winding is in xy). I am currently building an inductor (two turn planar structure) and I want to understand how to think of the current distribution along the cross section to have an accurate loss model.

 

[SenpaiAbdullah]

Planar design is all done by application software

Yes, Im using Ansys for simulations, I want to characterize which one between Maxwell and HFSS is more accurate and hence need an analytical model for first order design and optimization