Thank you for the great videos. It's very helpful for new COMSOL users like me:) I also want to see the result animation when the frequency 'f' is smaller than 10hz. But after changing 'f' from initial value 1e^5 [hz] to 5 [hz] , an error window "Failed to find a solution. The relative error (2.1e+02) is greater than the relative tolerance. There was a warning message from the linear solver. Iterative refinement triggered. Returned solution is not converged. Not all parameter steps returned. " shows up.. Could I know what problem is?
Can you try changing the electrical conductivity of air from 0 to a small number (like 0.1 or 1)? A value of zero can cause numerical instability sometimes.
do you think a simple test in comsol can be done using a cylindrical conductor with a sum of sine waves going through it, and then loop antenna/coil mounted on the outside of the conductor to see if they can read the signal on the line?
hi, i am trying to simulates the iron core lamination but the anistropic model (neuberts papers) propose but I don't have good results with it (skin effect is causing density flux over the window), have you some advice to how yo proper implement laminated core on comsol?
So your core is made of laminations that are separated by an insulator? I can think of two options: (1) I would suggest splitting the core into sections (using planes) to represent the laminations. Then insert 'surface current density' on the insulation planes and specify the current to be zero in the direction perpendicular to the laminations. (2) Define a custom material where the electrical conductivity of the core in the direction perpendicular to the laminations is close to zero. This simplification resembles the effect of the laminations wherein the eddy current cannot flow between laminations. Option 2 might be easier. Give it a try!
@@JafScience HI, thanks for your suggestion, actually the ansitropic material is the electrical conductivity matrix with zero on the direction perpendicular to the lamination. But, so far, I have tried several ways for do it (that's why I mentioned neubert paper) but the results are kinda bad, it's like the core is just a solid block . The other one maybe would work but It seems heavily in computational time and I don't think my pc would handle it. However, I would give it a try with few lamination to see what happen. Thanks for your suggestions!
You're right, you may significantly increase the number of mesh elements if you divide the geometry. Try using swept elements. When you say the results are bad do you mean electricity can still flow perpendicular to the laminations? Can you try putting a high electrical conductivity along that direction to see if the results look worse or the same?
@@JafScience when I say bad I mean like the skin effect on the window get worse, see when I simule a high eddy current scenario (open circuit) the flux gets spikes only on the window of the core and the rest of it its low flux. Thats the same effect that a solid core has when high conductivity is applied to them. However I will see what happen if I try the opposite and try to understand the phenomena
@@angelmachuca4696 Without seeing the set-up and results it's difficult for me to assess but the main purpose of the laminations is to reduce the flow of eddy current across the core. Not sure how that'll affect the skin effect. My knowledge in electrical machines in limited so I could be missing something.
Great video. However I followed this exactly but I get an error "attempt to evaluate negative power of zero". Have no clue what might be causing it and google is no help :(
Fixed it! The whole "study" had gotten stuck on old settings/variables somehow. Added anew study and it worked. This is a very fast way of simulating inductors :)
Thank you for the video. What about the way around? I'm trying to simulate a magnetic core around which a winding coil and Apply an external AC current (from a powerline for example, generating an AC magnetic field of course) and see the resulting induced current/voltage from the winding coil. Can you please give me some steps on how to do it? Could you please afford your email, I've few other questions, I would be grateful. Thank you
@@JafScience @Jaf-Science Thank you for your answer. It's quite the opposite way compared to the video because the coil will induce current instead of supplying a current to it. I will send you a detailed description of the problem via e-mail. I already designed the geometry of the problem yet it's a bit complicated when it comes to physics. I hope you can help. Thanks a lot !!
@@JafScience when modelling a multi-turn loop antenna, I will have to use the magnetic field (mf) interface since I would have to adjust the amount of turns.
Hi! When I made this simulation according to the video, there was no magnetic flux in the iron oxygen body in the final result. Which step will cause this problem?
@@Nami_Jhon Air volume is just a box around the components and we define air properties for it. This would allows the magnetic field to spread in space.
@@JafScience Thank you very much!!!! I have completed the simulation and found the issue. The version of COMSOL I am using has some differences in settings compared to the version you used. Once I made the necessary adjustments, it worked.🥳🥳thank you for your help
Hey Jaf! Thanks for your video! Could you also post some links which should be watched prior to this one? I am very new to COMSOL and this video seems to have skipped select "study" or what :-)
Welcome to Comsol modelling! The video shows how to add the study at 05:40. If you are asking how to select the study for values of dependent variables at 06:25, then you can select from the drop down list of available studies. In this video, the study "coil geometry analysis" was chosen automatically. I hope this helps.
@@JafScience Hey Jaf! Really thanks for your video now I can manage to follow these steps now:) I am also wondering if you can make a video showing how to work with the SPICE circuit in COMSOL?
You're welcome! Yes, Comsol has a circuits interface that can model electrical circuits. It doesn't require any geometry. I plan to produce a tutorial soon.
@@JafScience Yeah it's a great idea! I don't know if my follow-up comment would be a bit irrelevant here, but actually, I am curious about how to model a magnetic component (like the magnetic core in a converter circuit). Because to perform this kind of modeling in COMSOL, it may require importing the external circuit (maybe from LTspice ) into COMSOL (this is how I see it now). However, I hardly figure these steps out how to combine the circuit in SPICE and COMSOL together. I read some application notes from COMSOL, which says I may need to work with "electrical circuit interface" and "SPICE netlist". But as a lack of an intuitive demonstration, it sounds still vague to me. I would appreciate it if you also have any comments on this question! With regards.
Yes you can import a SPICE circuit into Comsol but an easier alternative is to build the circuit in comsol and then couple with another physics interface. You can add voltage/current sources, resistors, capacitors, inductors, transformers, etc. It's actually easy to implement. I plan to make a tutorial of a circuit with resistors/capacitors to demonstrate how a circuit can be built.
