A Image Method for B-Field Calculation on Iron Plate

[glj6]

Hello,

I am wondering if it is possible to calculate the B-field of a conductor above an iron plate just using the complex image method. To keep it simple let’s consider a 2D calculation, the metal plate is infinitely deep and wide and the conductor is infinitely long and thin. If the metal plate has perfect conductivity, then it is sufficient to reflect the current only at the surface of the metal plate. If µr = 1 and the conductivity is not perfect, then the image current must be shifted by twice the distance of the complex skin depth. The approach gives very good results in comparison with Comsol results.

Now I ask myself how can a µr > 1 still be introduced there? A ferrite, on the other hand, can be calculated without problems using the image method, but the mixed form, e.g. iron, is problematic.
I hope someone can help me, at least with a source where someone has done something like this. Or someone can explain to me why such a calculation is not possible.

Thanks in advance!

 

[marcusl]

The problem with any magnetic calculation involving iron is it’s hysteresis loop. For very weak currents/fields, the response is approximately linear, but in general the material properties are non-linear and involve memory effects so computer codes are the way to go.

 

[glj6]

The problem with any magnetic calculation involving iron is it’s hysteresis loop. For very weak currents/fields, the response is approximately linear, but in general the material properties are non-linear and involve memory effects so computer codes are the way to go.

Thank you very much for your answer. The hysteresis loop is only a problem near saturation, I would consider a linear behavior in my calculation. The same is true for my Comsol model.