Discrepancy between 3D and simple 2D simulation in inductance calculation

Please login with a confirmed email address before reporting spam

Hi everyone,

I am using the COMSOL AC/DC module with a magnetic field (mf) physics in the frequency domain (1 kHz). I have simulated a rectangular coil in both 3D and 2D space (note the model is simple 2D, not 2D axi-symmetric) and computed its inductance values. My coil dimension is 100mm x 100 mm x 2 mm (i.e. length = 100mm, breadth = 100mm and diameter = 2mm). However, the inductance value from 2D FEA is much higher than the equivalent 3d FEA.

In 3D, I created the same rectangular loop and gave the appropriate excitation, meshing, and region and then, obtained the inductance value. The 3D FEA result matches my hardware results. Please see the attached link: https://drive.google.com/open?id=1L-9eyQ3RzHZ67-O4HqAMA9CeexfBUxfn&usp=drive_fs

In 2D, I have properly defined the out-of-plane thickness (as 100mm) and given excitation of +1v and -1v to the cross-section of each coil. The entire domain is meshed with extremely fine elements. Further, I also selected the region properly to get a constant inductance value. (For 2D, see the attached file) The results for 3D FEM is 334uH and 2D FEM is 388uH. For multiple turn coils, I am getting the same error in inductance results.

Note: For the circular coil, I have used 2D axi-symmetric and obtained the correct results. What could be the problem with simple 2D? Please help me solve this problem. I have been stuck here for a long time.



Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

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.