Simulate a shimming coil in HFSS

[Louis2133]

Hi there!

it seems this platform is more active than official ANSYS forums !!

Currently, i am teaching myself HFSS and Maxwell, and struggling to chose the right solution space for my circuit.Hope you guys can give me a hand !

i am creating the model as following, it is a shimming coil in MRI, but the coil only allows DC current flow in, so there are some LC part to tune the current to the desired frequency.

what i did in HFSS so far, I created a 2D Torus, excited it with lumped port 50 ohm, and placed several lumped port boundaries as the LC circuits in figure. but the problem for HFSS is it looks like i can not adjust the current value, and I even dont know if coil can be excited by the DC current in HFSS!?

I also try the Maxwell 3D, i can created a surface as current source within the 3D torus and adjust the current value, however, i can not create the lumped port boundary for the coil....

My objective is following...
1. Create the circuit model which is shown above.
2. Excite the coil with continuous DC current, and adjust its value.

Thank you for. your help...I would really appreciate!!

Best wishes

Louis

 

[PlanarMetamaterials]

Hi there!

it seems this platform is more active than official ANSYS forums !!

Welcome, Louis2133. I'm not surprised by that at all.

what i did in HFSS so far, I created a 2D Torus, excited it with lumped port 50 ohm, and placed several lumped port boundaries as the LC circuits in figure.

Don't use lumped ports as reactive elements. They will not give you the behavior you're looking for. You can insert reactive elements by applying a surface boundary condition; Menu->HFSS->Boundaries->Assign->Lumped RLC.

but the problem for HFSS is it looks like i can not adjust the current value, and I even dont know if coil can be excited by the DC current in HFSS!?

If you want to adjust current specifically, you need to apply a current source excitation. Ports by default excite power quantities.

I also try the Maxwell 3D, i can created a surface as current source within the 3D torus and adjust the current value, however, i can not create the lumped port boundary for the coil....

My objective is following...
1. Create the circuit model which is shown above.
2. Excite the coil with continuous DC current, and adjust its value.

I believe Maxwell would be a better choice for a DC simulation, though I haven't used it much myself. I believe it can still handle RLC boundaries and current sources.

 

[Louis2133]

@PlanarMetamaterials hi! haha! thank you so much for your reply.

If you want to adjust current specifically, you need to apply a current source excitation. Ports by default excite power quantities.

What do you mean by this? you means. set up the current by giving excitation>current. then go to the the set up HFSS>field>editing source adjust the magnitude?

I believe Maxwell would be a better choice for a DC simulation, though I haven't used it much myself. I believe it can still handle RLC boundaries and current sources.

I am trying! it does have current sources, but I havent seen the place that allows me to set up the RLC boundaries. Hopefully I can figure it out today.

 

[PlanarMetamaterials]

What do you mean by this? you means. set up the current by giving excitation>current. then go to the the set up HFSS>field>editing source adjust the magnitude?

Yes, exactly.

I am trying! it does have current sources, but I havent seen the place that allows me to set up the RLC boundaries. Hopefully I can figure it out today.

I took a look at it myself, and it unfortunately appears that Maxwell does not support this kind of boundary. I might suggest running an HFSS simulation at a low frequency like 1 Hz? The newest version (2021.R2) is supposed to have better low-frequency support.

 

[Louis2133]

Yes, exactly.


I took a look at it myself, and it unfortunately appears that Maxwell does not support this kind of boundary. I might suggest running an HFSS simulation at a low frequency like 1 Hz? The newest version (2021.R2) is supposed to have better low-frequency support.

haha!! I did as well!! thank you for looking at it!!d