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Modelling magnetic field excited by AC current
Posted 08.11.2015, 15:34 GMT-5 Low-Frequency Electromagnetics, Studies & Solvers Version 5.1 1 Reply
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Hi all,
I am now simulating the magnetic field excited by AC current. I want to observe the skin effect (a plot of current density against depth) and the time variance magnetic field (a plot of magnetic flux at a fixed point against time). I made my own model in 2D but it seems incorrect.
Firstly, what is the best way to apply an AC current in this case? I defined a sinusoidal function for current density but I guess this will lead to confusion for multiphysics to determine skin effect? Similarly, I will finally move onto transient DC current. How should I apply this transient DC current to my wire?
Then, I would like to change time range in time-dependent solver but it seems to be fixed to 0.02s. Why would this happen and how should I fix it?
Finally, as can be found in my model, I placed two probes, one for current density and the other for magnetic flux. However, there is always one plot generated. Whenever I update solutions of one of the probes, the newly calculated results will cover the previous ones. How to make two separate plots for two probes respectively? Or alternatively is there any other way to observe data on a certain point?
Please find the attached file, have a look and propose any suggestions and solutions. Thank you for your patience.
Kind regards
Junjie Tu
I am now simulating the magnetic field excited by AC current. I want to observe the skin effect (a plot of current density against depth) and the time variance magnetic field (a plot of magnetic flux at a fixed point against time). I made my own model in 2D but it seems incorrect.
Firstly, what is the best way to apply an AC current in this case? I defined a sinusoidal function for current density but I guess this will lead to confusion for multiphysics to determine skin effect? Similarly, I will finally move onto transient DC current. How should I apply this transient DC current to my wire?
Then, I would like to change time range in time-dependent solver but it seems to be fixed to 0.02s. Why would this happen and how should I fix it?
Finally, as can be found in my model, I placed two probes, one for current density and the other for magnetic flux. However, there is always one plot generated. Whenever I update solutions of one of the probes, the newly calculated results will cover the previous ones. How to make two separate plots for two probes respectively? Or alternatively is there any other way to observe data on a certain point?
Please find the attached file, have a look and propose any suggestions and solutions. Thank you for your patience.
Kind regards
Junjie Tu
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1 Reply Last Post 09.11.2015, 11:03 GMT-5
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Posted:
9 years ago
Hi
I would suggest you select frequency domain for your study and analyse the response for a given fixed (or a series of frequencies). This is far quicker and more precise than getting the time dependent AC behaviour running, as you will get initial condition transients to cope with in the time domain.
To get the trick to displace a plot to have multiple plots, you need to study the postprocessing videos in the main COMSOL site, you can use the "displacement" sub node with a fixed value
--
Good luck
Ivar
I would suggest you select frequency domain for your study and analyse the response for a given fixed (or a series of frequencies). This is far quicker and more precise than getting the time dependent AC behaviour running, as you will get initial condition transients to cope with in the time domain.
To get the trick to displace a plot to have multiple plots, you need to study the postprocessing videos in the main COMSOL site, you can use the "displacement" sub node with a fixed value
--
Good luck
Ivar