Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Electromagnetic couplings of Transmission Lines

Posted Apr 17, 2014, 3:20 a.m. EDT Low-Frequency Electromagnetics Version 4.3b 7 Replies

Dejan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi everybody,

I want to study electromagnetic couplings of Transmission Lines on a tower in
quasi-static domain (50 Hz).
I use the 2D dimension and as physics I use Magnetic and Electric Fields (mef).
The solver is in the frequency domain.
My sources should be:

L1=I*sin(wt)
L2= I*sin(wt+240°)
L2= I*sin(wt+120°)

But my sources are currently
L1=I
L2= I
L3= I

My problem is I do not know if I can model something like this in frequency domain.
And I cannot find a boundary for the grounding.

I have a picture and my model attached and hope someone can help me.

Best regards
Dejan
7 Replies Last Post Apr 24, 2014, 9:48 a.m. EDT
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 17, 2014, 5:45 a.m. EDT
Dejan,

you can apply phase shift using complex notation. Ground or electric potential BC is available under the Magnetic Insulation node.

Cheers
Edgar

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Dejan, you can apply phase shift using complex notation. Ground or electric potential BC is available under the Magnetic Insulation node. Cheers Edgar -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com
Dejan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 17, 2014, 6:30 a.m. EDT
Hello Edgar

Thank you for your quick response.
Is it possible in Comsol (frequency domain) at least in the post process to produce a sinusoidal signal?
Maybe with the 1D plot (Global).

Best regards
Dejan
Hello Edgar Thank you for your quick response. Is it possible in Comsol (frequency domain) at least in the post process to produce a sinusoidal signal? Maybe with the 1D plot (Global). Best regards Dejan
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 17, 2014, 6:48 a.m. EDT

Yes, you can use the phase as x-axis parameter.

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Yes, you can use the phase as x-axis parameter. -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com
Dejan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 17, 2014, 7:07 a.m. EDT
Hi Edger,

thanks again for your help, but something I'm doing wrong.
Could you, if you have time, look at my model, I cannot produce sinusoidal curve?
And I do not know why?

Best regards
Hi Edger, thanks again for your help, but something I'm doing wrong. Could you, if you have time, look at my model, I cannot produce sinusoidal curve? And I do not know why? Best regards

Attachments:

Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 17, 2014, 7:36 a.m. EDT
The parameter J3 is a constant per your definition. You have to use a field parameter, e.g. a point plot of a magnetic flux density component or a current density component. Keep in mind that only vector components are phase dependent, the normalized quantities are not (in COMSOL). You can add points into your geometry or use probe plots.

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
The parameter J3 is a constant per your definition. You have to use a field parameter, e.g. a point plot of a magnetic flux density component or a current density component. Keep in mind that only vector components are phase dependent, the normalized quantities are not (in COMSOL). You can add points into your geometry or use probe plots. -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com
Dejan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 23, 2014, 2:53 a.m. EDT
Hello Edgar,

once again thank you for taking the time and helping me.
I have learned a lot.

Best regards
Dejan
Hello Edgar, once again thank you for taking the time and helping me. I have learned a lot. Best regards Dejan
Dejan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 24, 2014, 9:48 a.m. EDT
Hi everybody,

I have one another problem with the post-processing.
A line is supplied with the boundary “External Current Density at a current of 1000 A.

But if I measure the current with intop1 (mef.Jz), I get a current of only 1.6 A peak.

However, when I measure the current with intop1 (mef.Jez)
I get a current of 1000 A peak.

What is the difference between Jz and Jez.
The current is measured with intop1 (mef.Jz ) must be 1000 A peak, or ?.

Best regards
Dejan
Hi everybody, I have one another problem with the post-processing. A line is supplied with the boundary “External Current Density at a current of 1000 A. But if I measure the current with intop1 (mef.Jz), I get a current of only 1.6 A peak. However, when I measure the current with intop1 (mef.Jez) I get a current of 1000 A peak. What is the difference between Jz and Jez. The current is measured with intop1 (mef.Jz ) must be 1000 A peak, or ?. Best regards Dejan

Attachments:

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content