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Problem current modelling for ring core inductor (axialsymmetrical)
Posted 18 sept. 2014, 10:44 UTC−4 Low-Frequency Electromagnetics Version 4.4 4 Replies
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I am trying to model a ring core inductor.
For the winding I do not assume discrete turns but a kind of toroid with the ring core within the toroid. In this way I can model the inductor in 2d with axialsymmetrical (at least I think so)
However, I don't get reasonable result.
The winding is modelled by a circle with a surface current density, which is divided by the factor 2*pi*r to provide current conversation. By plotting the surface current density I can verify that my modelling of the current is correct.
However the solver does not converge for the stationary case. Since I want to calculate the eddy current losses in the core I also simulate in frequency domain. Depending on the frequencies the solver converges with a solution (i.e. for 900kHz with a skin constant of 0.1m where my ring core has got ID 20mm OD 34mm and height 13mm) but not always.
I also tried gauge fixing without any success.
I calculate with an in-plane vector potential.
I have attached my model. Simulation in 3d gives me more or less the same problem. If I model the winding with discrete turns (for example 10) the model doesn't converge either.
Since I have tried many different ways I think a make serious mistake in my model building and seem to violate some basic principle.
Grateful for help
Stefan Herzog
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the air box around the ring core and ring current was not included in the mf physics and no domain was assigned in the Gauge fixing node.
No convergence issue as soon as I fixed that.
Cheers
Edgar
--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
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thanks you very much!
That has solved the problem.
What a stupid mistake.
Best regards,
Stefan
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now I have another problem.
Since I want to include a relative permittivity of 75000 into the model I have switched to "Magnetic and electric field formulation (mef).
I have applied all the options which I have used in mf-formulation.
Now again I have this convergence problem.
What can I do?
I have attached the model.
Grateful for help
Stefan
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