Learning Forum

[Brad_H]

Hello, I am trying to simulate inductance of a nonlinear transformer in magnetostatic mode of Ansys Maxwell. I created a custom BH curve for the transformer, shown below. However, when simulating the transformer, the value of B in the core is much lower than what the BH curve would dictate.

When looking at the left leg of the transformer, the H field is about 6.67 - 13.33 A/m. The nonlinear BH curve would say that this corresponds to a B field of about 1 T, but I am seeing a B field about 2 orders of magnitude lower. Are there any simulation settings that could mess up my BH curve? How could I go about trying to debug this problem? Thank you.

[AndyJP]

please show the screenshot of the setup. Rather checks yourself how you enter numbers. A common mistake is forgetting to click "intrinsic"(i.e. Magnetization from H), or mistaking units.
Intrinsic is when your guess hte magnetization yourself. External is for feeding the measured data. The difference is just the field H added to M (Bex=mo(M+H) , Bin=moM - a virtual quantity in measurements, or just 4piM in Gaussian, which has a natural meaning of normalized magnetization). So feed it in Gaussian for avoiding conversion mistakes.
(ok. I myself often make mistakes when converting back and forth, correct me if I did it here)

[Brad_H]

Thanks for your help.
I figured out the problem. I specified a stacking factor of 0.78 in the y direction, which messed up the solution of the B and H field. If I set the stacking factor to 1, the results are a lot closer.
One potential problem was that I used a coarse meshing resolution. Perhaps Ansys Maxwell does not work well if you combine a a coarse meshing resolution, a stacking factor (0.78), and a nonlinear core.
Stacking factor of 0.78 is on the left, stacking factor of 1 is on the right. You can see that with the stacking factor of 0.78, the B field only went vertically up and down, in the direction of laminations.

[Brad_H]

Ignore my previous comment.
As a follow up, I figured out the problem. I put the stacking factor in the direction that the flux is supposed to go in. This created a higher reluctance path for the flux, since the flux had to go directly through insulating layers to go from one core arm to the other core arm.