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Strange magnetic flux density and source phase dependence
Posted Apr 28, 2011, 10:38 a.m. EDT Low-Frequency Electromagnetics Version 4.1 1 Reply
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Hi,
I have to model 3 phase device (transformer). I need time dependent solution with voltage source from external circuit. Because of improper results of some expressions applied to COMSOL I decided to simplify my problem.
I've modeled simple coil. Then I faced with strange results just changing 'source phase' in electrical circuit. For different source phase I get different values of magnetic flux density in the core.
It doesn't look properly even if we assume transient phenomena. For longer simulation time (after 10[s]) result is similar.
I would like to ask also if my approach of modeling two parts of one winding in 2D and connect it with two 'External I Vs. U' blocks like in my attached model is suitable way.
Another thing is that 'source phase' has 'rad' unit but for proper phase shift we have to put values in degrees.
I attach my test model with average B fields in core versus time (for different phases).
For watch graphs: Results -> B in different phases - Table Plot 1 (and click Plot)
Best Regards,
Przemek
I have to model 3 phase device (transformer). I need time dependent solution with voltage source from external circuit. Because of improper results of some expressions applied to COMSOL I decided to simplify my problem.
I've modeled simple coil. Then I faced with strange results just changing 'source phase' in electrical circuit. For different source phase I get different values of magnetic flux density in the core.
It doesn't look properly even if we assume transient phenomena. For longer simulation time (after 10[s]) result is similar.
I would like to ask also if my approach of modeling two parts of one winding in 2D and connect it with two 'External I Vs. U' blocks like in my attached model is suitable way.
Another thing is that 'source phase' has 'rad' unit but for proper phase shift we have to put values in degrees.
I attach my test model with average B fields in core versus time (for different phases).
For watch graphs: Results -> B in different phases - Table Plot 1 (and click Plot)
Best Regards,
Przemek
Attachments:
1 Reply Last Post Apr 28, 2011, 4:14 p.m. EDT
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Posted:
1 decade ago
Hi
for the deg/rad issue it looks like a typo, I have too in V4.1.0.185, I agree it should be "deg" and not RAD
But for the rest I'm not sure what to say. And I'm not sure you really need the CIR physics to link the coils, you have the specific variables you might use to add an equation to "link" your two "rails" into a half loop coil,
I have seen an example in a model recently, but I cannot remember where, was certainly on the Forum, or the model exchange ?
--
Good luck
Ivar
for the deg/rad issue it looks like a typo, I have too in V4.1.0.185, I agree it should be "deg" and not RAD
But for the rest I'm not sure what to say. And I'm not sure you really need the CIR physics to link the coils, you have the specific variables you might use to add an equation to "link" your two "rails" into a half loop coil,
I have seen an example in a model recently, but I cannot remember where, was certainly on the Forum, or the model exchange ?
--
Good luck
Ivar