Re: [femm] help

[David Meeker <dmeeker@xxxxxxxxxxxxxxxxx>]

mercedes sampere wrote:

> Hello
> I'm trying to simulate the model I send you. It's a part of an induction
> motor (only two slots, one from the stator and the other from the rotor).
> The problem is that self inductance for any slot is bigger than mutual
> inductance between them, and this couldn't (or shouldn't) be.
> I've tried with other materials but I can't find the problem.

Like Keith was saying, it is generally perfectly reasonable for the self inductances to be larger than
the mutual inductance because of slot leakage, which bumps up the self inductance, but doesn't increase
the mutual.

Anyhow, there are a couple of other things you should also think about with your geometry. Each of the
coil regions has all wires being members of either the "estator superior" or "estator inferior"
circuits. Defining things this way makes things behave like a single big multi-stranded conductor (i.e.
driven in parallel), rather than a bunch of turns that are driven in series. Is this what you intended?
Also, I'm guessing that this is part of a motor that you're modeling. However, the domain that you are
modeling and the currents that you've defined don't make much sense to me. Could you take sort of a
step back and say something about the machine that you are trying to model and what result you are
trying to obtain? Then, it would be easier for me to say something useful.

Dave.


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