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modeling a rotating electrical machine
Posted 10 feb 2011, 16:36 GMT-5 Low-Frequency Electromagnetics Version 4.3b 12 Replies
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Dear Comsol Users,
I am trying to model a simple rotating machine in Comsol 4.0a. I am attaching the model file.
Unfortunately, I couldn’t find any documentation or examples how to start up a model using the “Rotating Machinery, Magnetic (rmm)” physics interface, where a time dependent solution is done. Do you have any similar models available as an example for me?
It is hard to formulate my questions, as I basically cannot get the model to work properly. For example, the field lines I get in the airgap don’t seem to be continuous.
I tried opening the 2D generator example for v3.5 in v4.0 and tried to trace the steps back but it didn’t help as in v4 it didn’t make use of the physics interface I wanted.
I would be very happy if you could take a look in my (very simple) model and tell me
- how to define that rotating permanent magnet properly,
- how to model the rotation, moving mesh, airgap (continuity) boundary conditions
- how to post process in order to see the field lines for different time steps
I am sorry for formulating this in such a poor way, but I tried many different things and got confused over the settings, and I thought instead of going through what I did step by step, I should just ask for the better way of doing it on this really simple model. I hope someone could help me.
Best regards,
Arda
I am trying to model a simple rotating machine in Comsol 4.0a. I am attaching the model file.
Unfortunately, I couldn’t find any documentation or examples how to start up a model using the “Rotating Machinery, Magnetic (rmm)” physics interface, where a time dependent solution is done. Do you have any similar models available as an example for me?
It is hard to formulate my questions, as I basically cannot get the model to work properly. For example, the field lines I get in the airgap don’t seem to be continuous.
I tried opening the 2D generator example for v3.5 in v4.0 and tried to trace the steps back but it didn’t help as in v4 it didn’t make use of the physics interface I wanted.
I would be very happy if you could take a look in my (very simple) model and tell me
- how to define that rotating permanent magnet properly,
- how to model the rotation, moving mesh, airgap (continuity) boundary conditions
- how to post process in order to see the field lines for different time steps
I am sorry for formulating this in such a poor way, but I tried many different things and got confused over the settings, and I thought instead of going through what I did step by step, I should just ask for the better way of doing it on this really simple model. I hope someone could help me.
Best regards,
Arda
Attachments:
12 Replies Last Post 16 gen 2014, 05:02 GMT-5
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Posted:
1 decade ago
Hi
not all the features used for rotary machines were ironed out in 4.0, you should upgrade to the latest version, it would run far smoother and better !
--
Good luck
Ivar
not all the features used for rotary machines were ironed out in 4.0, you should upgrade to the latest version, it would run far smoother and better !
--
Good luck
Ivar
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Posted:
1 decade ago
Hi,
Thanks for the answer. I took the advise and tried it in v4.1.
I opened the model example of rotating generator (2D) for v3.5 in v4.1 and changed the physics a bit.
If you open the attached file, in the post processing window it is clear that there is something wrong, as the non-moving part is not updated as I try to look at the solutions of different time steps. I tried with the different x,y,z, or X,Y,Z frames but couldn't find the right-looking combination. Furthermore, the axial torque and the z-torque are not the same, which I wasn't expecting. Therefore I am not sure if I am having a post processing problem or if the model itself is wrong.
I would be very happy if you could take a look into the model. Thanks in advance!
Arda
Thanks for the answer. I took the advise and tried it in v4.1.
I opened the model example of rotating generator (2D) for v3.5 in v4.1 and changed the physics a bit.
If you open the attached file, in the post processing window it is clear that there is something wrong, as the non-moving part is not updated as I try to look at the solutions of different time steps. I tried with the different x,y,z, or X,Y,Z frames but couldn't find the right-looking combination. Furthermore, the axial torque and the z-torque are not the same, which I wasn't expecting. Therefore I am not sure if I am having a post processing problem or if the model itself is wrong.
I would be very happy if you could take a look into the model. Thanks in advance!
Arda
Attachments:
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Posted:
1 decade ago
Hi
there is also a rotary generator in v4.1, check the "Options - model library update" to get the latest models downloaded
--
Good luck
Ivar
there is also a rotary generator in v4.1, check the "Options - model library update" to get the latest models downloaded
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
Thanks for the quick reply. I just checked but could not see the rotary transformer model for v4.1. Are you sure it's not the static 3D generator example you mentioned?
Best,
Arda
Thanks for the quick reply. I just checked but could not see the rotary transformer model for v4.1. Are you sure it's not the static 3D generator example you mentioned?
Best,
Arda
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Posted:
1 decade ago
Hi
you are right that the model library example is a 3D withou any rotation part.
But for me your model seems OK (apart that there is no current in the coils=air so OK you are probably in generator mode, but more important: you are in geoemtry "union" mode so the rotating part is "fixed"
you must group (composed geometry but that is already done) all but the central ring and then use "assembly" mode + add a continuity/identity pair for boundaries
{32, 33, 63, 64} with {121, 122, 138, 139]
+ add the "continuity pair" in the physics
you should also use L=0.4[m forthe physics length (Z direction) I believe or you have foreseen to calculate per 1[m] and normalise with L ?
and your internal variables should use "rmm.Ez" and not the 3.5a name emqa.Ez
finally use a finer time step to better resolve the oscillations with 1 turn/sec and 8 poles you have 4 sinus per turn
With that I see a 4V amplitude sinus out
--
Good luck
Ivar
you are right that the model library example is a 3D withou any rotation part.
But for me your model seems OK (apart that there is no current in the coils=air so OK you are probably in generator mode, but more important: you are in geoemtry "union" mode so the rotating part is "fixed"
you must group (composed geometry but that is already done) all but the central ring and then use "assembly" mode + add a continuity/identity pair for boundaries
{32, 33, 63, 64} with {121, 122, 138, 139]
+ add the "continuity pair" in the physics
you should also use L=0.4[m forthe physics length (Z direction) I believe or you have foreseen to calculate per 1[m] and normalise with L ?
and your internal variables should use "rmm.Ez" and not the 3.5a name emqa.Ez
finally use a finer time step to better resolve the oscillations with 1 turn/sec and 8 poles you have 4 sinus per turn
With that I see a 4V amplitude sinus out
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
I am also working with Comsol to develop a cooling system for a given electric machine. This moment is the starting time with Comsol. Can you let me ask you that is there any geometry database for electric machine provided in Comsol capabilities? Do you have any ideas about this?
Thank you
I am also working with Comsol to develop a cooling system for a given electric machine. This moment is the starting time with Comsol. Can you let me ask you that is there any geometry database for electric machine provided in Comsol capabilities? Do you have any ideas about this?
Thank you
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Posted:
1 decade ago
Hi
the DB is only for materials, but there are a few examples of rotary machines in the Model builder and other on the CD's and the main web site as articles
--
Good luck
Ivar
the DB is only for materials, but there are a few examples of rotary machines in the Model builder and other on the CD's and the main web site as articles
--
Good luck
Ivar
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Posted:
1 decade ago
Thank you for your reply. But I can't find out any examples of rotating electric model in the Model builder as you said. It would be nice if you could advice me more clearly.
Regarding a cooling system in electric machine that I have done, I feel so confused with many things to start modelling an electric machine with such requirements. As I understand, firstly I should model an electric machine, then add heating physic in Heat transfer module. Being an expert in using Comsol, can you outline generally what should be done in this work?
By the way, those who have ever experienced this problem, please share with me your modelling or experiences.
Thank you.
Regarding a cooling system in electric machine that I have done, I feel so confused with many things to start modelling an electric machine with such requirements. As I understand, firstly I should model an electric machine, then add heating physic in Heat transfer module. Being an expert in using Comsol, can you outline generally what should be done in this work?
By the way, those who have ever experienced this problem, please share with me your modelling or experiences.
Thank you.
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Posted:
1 decade ago
I try to aswer your question,
1. Add study (Heat transfer)
2. If necessary add cooling fin, it depens and it can be more complex.
3. If not, add boundary condition, convektive cooling and define heat-transfer coefficient etc.
4 Define heat source
and so on..
-akmal
1. Add study (Heat transfer)
2. If necessary add cooling fin, it depens and it can be more complex.
3. If not, add boundary condition, convektive cooling and define heat-transfer coefficient etc.
4 Define heat source
and so on..
-akmal
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Posted:
1 decade ago
Thank you so much.
Have a nice day!
Have a nice day!
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Posted:
1 decade ago
Hello Ivar
Im trying to simulate a smiple rotating machine but I have problems with the restulted magnetic fields they are not moving in the right way please see the attchment
You can download my modell through the following link
www.dropbox.com/s/d8pns2qtnrjnaxk/drehstrom_2.mph
Thanks in Advance
Im trying to simulate a smiple rotating machine but I have problems with the restulted magnetic fields they are not moving in the right way please see the attchment
You can download my modell through the following link
www.dropbox.com/s/d8pns2qtnrjnaxk/drehstrom_2.mph
Thanks in Advance
Attachments:
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Posted:
1 decade ago
Hello Aeda
I have the same problems you have or had
Did you solve it ?
I would be thankfull if you could reply
Thanks in advance
I have the same problems you have or had
Did you solve it ?
I would be thankfull if you could reply
Thanks in advance