Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Half-symmetry air coil frequency domain simulation

Please login with a confirmed email address before reporting spam

I created a simple coil model for frequency domain simulation. It uses half-symmetry for the domains and homogenized multi-turn circular for the coil.

The stationary simulation completed without any problem. However, error saying "Matrix has zero on diagonal" occured for frequency domain simulation.

Please let me know where is the problem. Thank you!



3 Replies Last Post 2020年11月5日 GMT-5 23:12
Robert Koslover Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 2020年11月4日 GMT-5 21:52

Hmm. It executed without generating any error message, on my computer. Perhaps a Comsol Multiphysics employee can help you. Or maybe, just restart Comsol Multiphsics, open the file you uploaded to the forum, and try again. Maybe it will work this time. :)

-------------------
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
Hmm. It executed *without* generating any error message, on my computer. Perhaps a Comsol Multiphysics employee can help you. Or maybe, just restart Comsol Multiphsics, open the file you uploaded to the forum, and try again. Maybe it will work this time. :)

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 2020年11月4日 GMT-5 22:35
Updated: 4 years ago 2020年11月5日 GMT-5 06:22

Thank you Robert. I followed your suggestion to run the uploaded file. It worked without such error.

However, the operator linper() is not used in the model. The simulation result (field) is zero.

I added the operator to the coil current as linper(1[A]). Simulation did not converge. I then remebered the model may need "Gauge Fixing for A-field". I did that and had it converged to a solution looking sensible.

Based on the knowledge gained with this model, I created a 1/4-3D motor (coil, magnet and soft iron). The geometry is basically a revolved version of the loudspeaker transducer application example. Spring foundation is used in solid to contraint the coil. It will not fly away in the presence of Lorentz force.

The stationary study again completed without problem. I have tried many different options but still can't get the frequency domain simulation going without errors. The errors seem to happen at the third step (freq domain perturbation) of the study. Any idea?

Thank you Robert. I followed your suggestion to run the uploaded file. It worked without such error. However, the operator linper() is not used in the model. The simulation result (field) is zero. I added the operator to the coil current as linper(1[A]). Simulation did not converge. I then remebered the model may need "Gauge Fixing for A-field". I did that and had it converged to a solution looking sensible. Based on the knowledge gained with this model, I created a 1/4-3D motor (coil, magnet and soft iron). The geometry is basically a revolved version of the loudspeaker transducer application example. Spring foundation is used in solid to contraint the coil. It will not fly away in the presence of Lorentz force. The stationary study again completed without problem. I have tried many different options but still can't get the frequency domain simulation going without errors. The errors seem to happen at the third step (freq domain perturbation) of the study. Any idea?


Please login with a confirmed email address before reporting spam

Posted: 4 years ago 2020年11月5日 GMT-5 23:12
Updated: 4 years ago 2020年11月6日 GMT-5 05:23

Just discovered the problem was related to using soft iron with losses and freq. set too low at 10 Hz.

Just discovered the problem was related to using soft iron with losses and freq. set too low at 10 Hz.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.