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Magnetic Fields: 2D Axisymmetric Model of Toroid Inductor

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Hey guys,

I want to determine the inductance of a toroid core + winding as shown in .jpg

I specify an external current density, such that the current flows around the core (in r and z direction).

Under magnetic fields I set Components to In-plane vector.


But it won't converge, I get the message:

Failed to find a solution.
The relative residual (61) is greater than the relative tolerance.
Returned solution is not converged.

I already set some 1S/m conductivity for air and core material, doesn't help.

It would converge, if I set Components to Out-of-plane vector, but then the magnetic field is zero, because all currents are in plane...

I don't want to use a 3D model, since I want to run a sweep through hundreds of simulations... so I really need to get the 2D model running.

I hope somebody can help me out here.

Michael


2 Replies Last Post 13 juin 2013, 06:24 UTC−4

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Posted: 1 decade ago 13 juin 2013, 06:23 UTC−4
OK, problem solved.

I contacted support and they told me to:

"add Gauge fixing if you solve for in-plane components"

With Comsol 4.2a I did that by right clicking on Magnetic Fields -> Ampere's Law and select 'Gauge Fixing for A-Field'.

I think in Comsol 4.3 this is found directly by right clicking Magnetic Fields..

After that it worked immediately..

OK, problem solved. I contacted support and they told me to: "add Gauge fixing if you solve for in-plane components" With Comsol 4.2a I did that by right clicking on Magnetic Fields -> Ampere's Law and select 'Gauge Fixing for A-Field'. I think in Comsol 4.3 this is found directly by right clicking Magnetic Fields.. After that it worked immediately..

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Posted: 1 decade ago 13 juin 2013, 06:24 UTC−4
Hey,

two remarks:

1) Use copper instead od air for the windings domain

2) Use a frequency domain study, since you cannot determine the inductance with a stationary analysis.

And you might enlarge the air domain, its boundary is quite close to the coil domains...
Hey, two remarks: 1) Use copper instead od air for the windings domain 2) Use a frequency domain study, since you cannot determine the inductance with a stationary analysis. And you might enlarge the air domain, its boundary is quite close to the coil domains...

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