## Electronics

#### How to determine the depth of a 2D model

• Amir_agha
Subscriber

Dear All,

I have a transient 3D model of a single-phase transformer. To decrease the amount of calculation, I decided to use 2D analysis instead. However, I do not know how to determine the depth of this 2D model. The diameter of the core of the 3D model is 830 mm. I really appreciate it if you can help me to find the answer. Do I have to use 830 mm or 415 mm is enough?

Thank you in advance.

• Navya C
Ansys Employee
Hi @Amir_agha Assuming that you are using planar symmetry and taking the model section across the XY plane, you should use the total length of the core along the Z direction as the depth of the model (or symmetry multiplier).
Make sure you use correct units (M, cm, mm)

Regards Navya
• Amir_agha
Subscriber
Hi Nchode Thank you for your response. So for this case , I have to use 830 mm as the depth of the 2D simulation?
• Navya C
Ansys Employee

Yes, If you have considered symmetry correctly and the model is symmetrical along the Z-axis.

Regards Navya
• Amir_agha
Subscriber
Hi @nchode Thank you for your response.
My 3D model is a symmetric one.
I just realized that I must use 2*830mm (1660 mm) if I want to have the same result for both 2D and 3D simulations.
It makes me confused since based on the same volume of the core (I mean if I want to determine the depth of the 2D model to have the same volume as the 3D model), the depth must be 623mm. However, 623 mm does not give me the correct result.
At this time, I am not sure which one must be selected.

• HDLI
Ansys Employee

What is the geometry in 3D? If the geometry is rational symmetry, we could use "Cylindrical about Z" in menu Maxwell 2D -> Solution type.
HDLI
• Amir_agha
Subscriber
Hi @HDLI.
It is my 3D design.
• HDLI
Ansys Employee

I suggest to use 3D Maxwell to simulate it, and the 2D model will not present it perfectly for inductance and flux density distribution.
HDLI