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 The information provided may be out of date.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.

Magnetodynamics - Step Response

Please login with a confirmed email address before reporting spam

Hi, I have successfully modeled a solenoid using magnetostatics, and have achieved results (force on the armature) that are accurate when compared to actual test data. I would now like to take that one step further, and determine the transient response to a current step - the end result that I would like would be a force/time plot and a current/time plot.

However, I am stuck in changing the successful statics model into a dynamics model. I have added a new study with step 1 being "coil current calculation" and step 2 being "time dependent". I have added a step response function named "current_step" to the global definitions, which is a step from 0A current to the final 0.1A current.

I set the coil excitation for my Multi-Turn Coil physics to "current_step(t)[A}" but I get the warning "unexpected unit of input".

Also, the current is not simply a step input as I have defined in my "current_step" function - it is affected by the magnetization of the iron. How do I link these two together? Is it done automatically, or is there some link that I must define? If I provide a step input in voltage to the Multi-Turn Coil physics rather than a step input in current, will that cause the current to then be linked to the iron magnetization automatically?

1 Reply Last Post 15 août 2014, 02:29 UTC−4

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 15 août 2014, 02:29 UTC−4
take a look at this example:

www.comsol.de/model/transient-modeling-of-a-capacitor-in-a-circuit-12695

From this model you can adapt the principle.

At the moment I've no access to comsol, I can send later a simple transient coil model.

take a look at this example: http://www.comsol.de/model/transient-modeling-of-a-capacitor-in-a-circuit-12695 From this model you can adapt the principle. At the moment I've no access to comsol, I can send later a simple transient coil model.

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.