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Eddy current losses in variable reluctance machine
Posted 9 mag 2012, 14:00 GMT-4 Version 4.2a 1 Reply
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I am modeling a variable reluctance machine where a magnetic field is generated by the stator windings and the rotor rotates in order to minimize the relucatance of the magnetic circuits. I am using the magnetic fields interface in a static study.
If possible I would like to calculate eddy current losses in the motor core, how do I model these correctly? Or should I just use apply some B^2*f^2 to my resulting dataset and integrate wrt time? Is it sufficient to apply a Lorentz velocity term to the rotating regions? That won't take care of the eddy current losses in the stator?
How about hysteresis losses, as I've understood it Comsol does not support this feature? Again, would it be a useful to apply a function like C*B^2*f to your solution data set and then integrate? How do you do that?
Thank you for your help.
Best Regards,
Mike
If possible I would like to calculate eddy current losses in the motor core, how do I model these correctly? Or should I just use apply some B^2*f^2 to my resulting dataset and integrate wrt time? Is it sufficient to apply a Lorentz velocity term to the rotating regions? That won't take care of the eddy current losses in the stator?
How about hysteresis losses, as I've understood it Comsol does not support this feature? Again, would it be a useful to apply a function like C*B^2*f to your solution data set and then integrate? How do you do that?
Thank you for your help.
Best Regards,
Mike
1 Reply Last Post 9 mag 2012, 15:13 GMT-4
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Posted:
1 decade ago
Hi
Eddy currents implies MEF physics hence solving for both A and V, that is far heavier than MF physics (only solving for A), so I woud suggest start with MF (without Eddy currents, then move your working model to MEF with the Eddy currents.
For hysteresis it's trickier, as you would need to have time or previous value dependent material characteristics dependence. One way to approach this is to run a time series over a full period (for harmonic cases) with an appropriate time driving material characterisitics then estimate the rms values, and then use the rms heat generated or whatever for a time series solving model
for RF there are a few solvers set up for this combining frequency domain and transient or stationary, check the doc
--
Good luck
Ivar
Eddy currents implies MEF physics hence solving for both A and V, that is far heavier than MF physics (only solving for A), so I woud suggest start with MF (without Eddy currents, then move your working model to MEF with the Eddy currents.
For hysteresis it's trickier, as you would need to have time or previous value dependent material characteristics dependence. One way to approach this is to run a time series over a full period (for harmonic cases) with an appropriate time driving material characterisitics then estimate the rms values, and then use the rms heat generated or whatever for a time series solving model
for RF there are a few solvers set up for this combining frequency domain and transient or stationary, check the doc
--
Good luck
Ivar