Re: [femm] Three phase induction motor

[dcm3c@xxxxxxx]

In a message dated 9/24/01 10:54:54 AM Eastern Daylight Time, albertoperarnau@xxxxxxxx writes:

> I'm simulating three phase induction motor, I have one
> problem with frecuency because frequency of stator is
> different of rotor by the sliding. How can I introduce
> frequency of problem if I want to consider the
> sliding [slip]?


Well, sort of a shortcoming of femm is that it doesn't do motion-induced eddy currents right now.  When I have analyzed induction motors before, I generally end up finding what I'm interested in by solving a harmonic problem and choosing the frequency to be the slip frequency.  You have to be careful about doing this, though--you get the "right" results for the fundamental, but the winding harmonics don't affect forces and losses in the machine in the same way that they do when the machine is actually spinning.

A different approach is to use femm to get good estimates of the motor's flux linkages (perhaps as a function of position) and then use this in a circuit model of the machine.

Dave.
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