Learning Forum

[Lukas Hildebrand]

Dear Ansys community,

I have a problem with my project and I dont know the answere. It seems like Ansys regards closed conduction paths differently depending on wether there is a winding/ coil terminal defined within or not. I want to see the result of a short circuit in a transformer and read the Inductances of the two main coils. If the short circuits have no excitation, the results are satisfying and compare to expected ones. In order to ckeck the current flowing though the SC I added a winding with 0V excitation but the result differs heavily from the one without the terminal in the SC. Can someone explain to me how Ansys handles excitations in Eddy Current simulation?

An image for a better visualization is following:

Thanks in advance for your response!

Lukas

[NKC]

Hi Lukas,

How are you setting up short circuit without terminals? We should have terminals in order to set up short circuit.

Please share more details on how you setup both cases with screenshots.

Regards,

Navya

[Lukas Hildebrand]

 

Dear Navya,

thank you for your reply. I try to clarify and add additional Screenshots:

You can see one conductor which (I assume) works like a shortcirquit without the terminal because its a closed conductive object. There is no terminal necessary for the SC to work. However if I itroduce the terminal (visible on the other screenshots) the results differ and are not correct anymore. I wanted to start like this and compare the results before adding more windings and a stranded form but already the simplest terminal with 0V excitation changes the solution.

Hope this clarification helped. If not please feel free to ask further questions.

Greetings,

Lukas

 

[HDLI]

Hello Lukas,

       There are different geometries between this and original description. Do we discuss the same coil?

       Could you show result difference? Thanks.

       Could you check if eddy effect of conductors is selected for both model? 

Howard

[Lukas Hildebrand]

Dear Howard, thanks for your reply. The geometries are identical, only in my latest answer the shortcuts are isolated for a better visibility. Please refer to the screenshot below of the geometry from a different angle for further clarification.

Eddy currents are in effect for the conductors, as well as the main coils in both models.

Below you see the different solutions, first without terminal and winding in short circuit:

And here with the above described terminal:

You can clearly see, that the self inductances are different for both primary coils which for me makes no sense since the winding in the SC has 1 solid conductor with 0V excitation. In my understanding this should not have an effect on the solution and it should be the same as above.

 

I hope this clarifies the question enought and eagerly await your response!

Kind regards

Lukas

 

[Lukas Hildebrand]

Hello Howard,

thanks for your response to my topic. The geometries are the same, in my response the shortcut is just isolated for better visibility. Please refer to the screenshots below for further visualization.

The Eddy Effects are selected for both conductors, as well as the main coils for both cases.

Following I share the solution of the resistance and inductance of the main coils for both cases, fist without the terminal and winding in the SC:

 

And here with the above mentioned terminal and winding:

You can clearly see the different solutions. The self inductance values are also not the same with the above mentioned winding. Since the SC excitation is 0V and has just 1 solid conductor I expect no change in the solution, still the difference is clearly there.

 

I hope this clarifies the question enough and eagerly await your answere!

Kind regards

Lukas

[HDLI]

Hello Lukas,

      Do you check eddy effect setting in both models? Are they same? Thanks.

Howard

 

[Lukas Hildebrand]

Yes, as I wrote before, the eddy effects are set exactly the same in both models.

Lukas

 

[HDLI]

Hello Lukas,

       Is it solid for top and bottom connection of the coils? It is so thin like sheets.

Howard