Re: torque calculation

["David Meeker" <dmeeker@xxxxxxxx>]

The geometry that Juan defined was not unreasonable. No external air
region is necessary in his problem, because he has defined
antiperiodic boundary conditions that link various boundaries. If I'm
understanding Juan's machine correctly, his machine is an axial-flux
motor that he has essentially "unrolled" for the purposes of analysis,
allowing a 2D analysis to be done. He'd then calculate the force per
pole, multiply by the number of poles and by the moment area to get
the total torque.

Anyhow, there shouldn't be any methodological difference in
calculating force when you have currents in the windings as opposed to
just calculating cogging force. You can use the "weighted stress
tensor" integral, either selecting all regions on the rotor or all
regions on the stator--this way you don't have to worry about manually
drawing an integration contour.

Dave.

--- In femm@xxxxxxxxxxxxxxx, dazolee <daizolee@xxxx> wrote:
> Dear Juan,
> 
> I don't know how to calculating torgue, 
> But your FEMM analysis need little correction.
> I attached a modyfied your torque.fem file.
> Hopely it's help for your analysis.
> 
> Thanks,
> Daizo
> 9/1/2003
> 
> 
> --- Juan Tapia <jtapia@xxxx> wrote:
> > 
> > 
> > 
> > I'm having troubles calculating torque (excitation
> > and cogging torque).
> > The model represents an axial flux machine. Central
> > section is the
> > stator and lateral pieces are rotors with PM. In
> > order to, reduce the
> > problem I only work with a one-pole section. I used
> > lua scrip to
> > evaluate the cogging torque for different position
> > (in one slot pitch).
> > However I'm not sure how to calculate resultant
> > torque when current is
> > circulating by the winding. How do I have to define
> > the line in order to
> > obtain stress tensor torque?
> > 
> > Any help is welcome
> > 
> > Juan A.
> >