Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Ansoft Maxwell, cannot apply Current Excitation to non planar entity error

Tags:
  1. Mar 29, 2012 #1
    Hello
    I am new with Maxwell. I made a motor drawing in solidworks and imported it in maxwell.
    I found some tutorials, and searched on the internet but could not find answer to my problem.
    So when i try to assign Excitation Current to an coil i get the message
    Excitation 'Current1' : Cannot apply Current Excitation to non planar entity.

    I dont understand what that means, i need to have a 2d surface to assigne current?
    Here is a picture of my coil
    Capture.jpg
     
  2. jcsd
  3. Mar 30, 2012 #2

    gerbi

    User Avatar
    Gold Member

    Yes, You need 2D surface to assign a current. Create a section of an object:
    select geometry->modeler->section. You need a coordinate system which will define a surface across element to create cross section. If there will be two cross sections created - separete the bodies (boolean operation).
     
  4. Mar 30, 2012 #3
    Thanks that worked.
     
  5. Apr 4, 2012 #4
    Unfortunitly i have now another problem. Seems like my computer has not a good procesor *** i need for the simulation of my project. So i need service like using a high cpu power server from my home which would solve the analyze and send me the results. For my 2core 2ghz amd procesor it would take days maybe weeks who knows. Do you know anyone who offers service that i need?
     
  6. Apr 9, 2012 #5
    Why not just give it a try? You may increase your error percentage to start with and see how long it takes. If it takes too long, you can always abort the process.

    Another way to reduce the timing is to use symmetry. Cut your model in half and it will save your time.
     
  7. Apr 18, 2012 #6
    ok it took a while but worked. Unfortunetly i have an matrix error
    It is ignoring the matrix i have made, i dont understand why. In the help guide is writen that i can use matrix on a core (what i did).
    here is my project http://www.4shared.com/rar/spcbB2Ms/Project2.html
     
  8. Apr 18, 2012 #7
    Did you get any error like below?

    Terminal surface mesh does not fit with conduction path in the following bodies {vodiczarotor}. Please verify them to ensure no bad effect on solutions!

    The rotor and stator material is metal and conductive, so rotor and vodiczarotor (the center coil) are touching which causes the problem. You need specify the surface as insulator. Click show conduction path, and you will see them.

     
  9. Apr 18, 2012 #8
    yes, i get that message to. So what i need is t o set all the coil surfaces to isolated, i will try it tomorow, and post here the results.
     
  10. Apr 19, 2012 #9
    I added boundery setting to isolation, on the cores but, now i am not getting that message you mentioned.
    Here is what messages i get:

    Maxwell3DDesign1 (Magnetostatic)
    [warning] Maxwell3DDesign1: Solutions have been invalidated. Undo to recover. (1:48:16 apr 19, 2012)
    [info] Verify conduction path: Conduction path validate success. (1:50:04 apr 19, 2012)
    [warning] Matrix cannot have geometry selection. Geometry selection is ignored. (1:50:07 apr 19, 2012)
    [error] Failed to load 'Matrix1' solution. (2:10:51 apr 19, 2012)
    [error] Simulation completed with execution error on server: Local Machine. (2:10:53 apr 19, 2012)

    So I have the problem with this matrix. I am new to maxwell and still learning, so please excause me if i aske dumb questions.
    Maybe i dont quite understand what matrix is been used for. I thing it can memorize the magnetic induction in the steel (the steel part around witch the coil is set).
    After i will use parametric analyse to rotate the rotor from zero to 90 degrees with 5 degree steps, so i wan to have all that mesurments in the matrix saved, so i can modifie the informations in matlab.
    Here is the project again http://www.4shared.com/rar/tDd1hAIn/Project2_2.html
     
  11. Apr 19, 2012 #10
    In your case, Matrix here is inductance of the center coil. You can do what you described.

    Your project2-2, run as it, I don't have any errors, and Matrix is 437nH. This number is for one turn winding inductance. You can specify the total winding turns and look at the postprocessed inductance.

    However, a few things I don't know for sure.

    I would assume this is 50Hz or 60Hz application, so skindepth is not relevant here. Also, you have so many mesh operation defined, I don't see the point of necessary.

    Another thing, you have two movement operation for all objects. This is OK but I would think (1) you can use one move instead of two 92) defining a offset coordinate system is a better way.


     
  12. Apr 19, 2012 #11
    When rotate rotor, it intersects with stator, so you need check out the dimension
     
  13. Apr 20, 2012 #12
    Ok i made some changes and now i have no errors here is the project
    http://www.4shared.com/rar/cvi5mkWo/ispravka.html
    Now i need to analyse the data are there any guides how to analyse, how to see now the maximal magnetic induction in the stator
    About the meshes, do i need to make more densty mesh, so i get more precise solution?
     
  14. Apr 20, 2012 #13
    I don't really know much about motor and not sure what is your objective.

    I haven't looked your latest file yet. But if everything goes well, then you will have the solution of Matrix which is the inductance, and force.

    Now, if you want to rotate the rotor, you can name a parameter, for example, [rotation] as angle degree, then set that to the rotor around z-axis. Now you can run the analysis using this parameter, later, you can plot the inductance vs rotation angle and something similar.

    I am not really sure what you are looking for.

    To me, most motor only have coils on stator, no coil on the rotor. So when you rotate rotor, you need rotate your coil as well the terminal all together.

    Mesh density is relative and tradeoff. Beyond certain level, more mesh only increase simulation time, not necessarily more accurate.

     
  15. Apr 20, 2012 #14
    Ok, i will try to explain what i need to do.
    I wannted to do:
    Rotate the rotor around the Z-os and messure the voltage inducated in the coils of stator, unfortunetlly that seemed to complicated. So i decided just to mesure the magnetic flux through one of the coils and then usin dfi/dt to find the induced voltage.
    What i decided to to:
    I found out that its not easy to make the rotor just rotate and mesure all that, so i decided to use parametric analyse. Make static analyse by rotatin the rotor from position 0 to 90 degree (5 degree steps) messure the magnetic induction, find the magnetic flux and after that the induced voltage.
    I hope i could explain what i am trying to do. I am Electrical power engineering student, and this is my project. :)
     
  16. Apr 20, 2012 #15
    This is not that difficult.

    First, it is easier to and you should use transient solver. The workflow is this,

    You need make terminals in all coils on stator, just like you did on the coil on the rotor.

    You need add windings. You can have one primary winding for the coil on the rotor, and one secondary winding for the group of coils on the stator.

    You need add terminals to the windings. The terminal on the rotor coil goes to the primary winding, and all the terminals of the coils on the stator go to the secondary winding.

    (note: if you want to see individual induced voltage on each coil on the stator, you need create that many secondary windings for that many coils)

    You need assign AC current excitation on the primary winding.

    Then you specify setup for how many AC period to sweep the time.

    You then can plot induced voltage of secondary winding (or windings) vs time. From here, you can get peak or rms value of induced voltage.

    Then you can rotate rotor for other angle.

    You don't have to change the project from magnetostatic to transient. It's much better to copy the project, and past into it, then change the second one. Transient solver doesn't do adaptive mesh, only use initial mesh, it may be good enough. If you want more accuracy for transient, you can link to the mesh in magnetostatic, that's why it's better to keep it there.



     
  17. Apr 20, 2012 #16
    You can do parametric analysis in transient solver as well
     
  18. Apr 21, 2012 #17
    Ok
    I understand whu i need to ad terminals on the coils of stator, so that voltage can be inducated.
    I dont really understand this windings, isnt one winding equal to one of the coils i have around the stator?
    So i accually dont know what windings means in maxwell, i see i can adn RLC branches in it, and set it like more paralel conected
    branches.
    Then again add terminals to windings, why do that if i allready have terminals on the coil?

    Wont assingning AC current to the primary winding (around the rotor) make A. magnetic field?
    I need the magnetic field around the rotor not to be alternating (from the point of rotor view)
    http://www.4shared.com/rar/8-X05-nA/ispravkatransient.html
     
  19. Apr 21, 2012 #18
    Before we go into the "winding", for what you want to see, you still can use magnetostatic solution.

    You need create terminal on the coils of stator, as you do on the rotor, and assign current to the terminals, you may just set current to zero, and then specify Matrix on these currents. Then run the simulation. Later you can look at mutual inductance between each currents. Matrix for Current(1,1), (2,2),,,,, is the self inductance, for Current(1,2) (1,3),,,,is the mutual inductance between these two currents (these two coils). This mutual inductance will vary if you rotate your rotor. High mutual inductance means more magnetic linkage. I think this is what you try to look for.


    Now back to the winding. In your case, you have enclosed coil. Hence only one terminal assigned. So this one coil with one terminal is one winding. In other cases, the conduction path may be open ended, meaning one conduction path with two terminals, start end and finish end. Current goes from one end, must exit from the other end. Current cannot accumulate in the region not going out. In this case, the winding is one conduction path with two terminals. In transient solution, you specify the terminal as solid or stranded with turns, and assign excitation (current or voltage) on the winding not terminals. And there are other cases, for example, one winding may have more coils connected in series or parallel. So a winding is a group of coils and terminals. In Maxwell, a winding is not related to any object in the project until you add terminals to the winding. Of course you can assign one winding to one conduction path, and post-process the result yourself in any conduction paths are in series or parallel



     
  20. Apr 22, 2012 #19
    Aha, so how i understand, i can make more windings, but does not have to.
    I could just let it like now (one winding) and afterwards calculate how would it be with more etc.
    Also i was thinking maybe i should only make the terminals on one stator coil?
    Because the others have the same inductance only 60 degree later.
    So i made the terminal one one stator coil, assignee current zero, and added matrix 1,2; 1,1 and 2,2 but receive those errors

    [error] Null body found for part vodiczastator_1_Section1. (3:39:24 apr 22, 2012)
    [error] Null body found for part vodiczastator_2_Section1. (3:39:24 apr 22, 2012)
    [error] Null body found for part vodiczastator_2_Section2. (3:39:24 apr 22, 2012)
    [error] Null body found for part vodiczastator_2_Section3. (3:39:24 apr 22, 2012)
    [error] Null body found for part vodiczastator_2_Section4. (3:39:24 apr 22, 2012)
    [error] Simulation completed with execution error on server: Local Machine. (3:39:24 apr 22, 2012)
    i dont understand what he means with null body :S, a did exactly the same like on the rotor coil
    http://www.4shared.com/rar/I38pu-Hq/ispravka_3.html
    edit: i just saw those sections, dont know why maxwell made them :s, however i deleted them and now the simulation started, cant wait to see what results i will become


    and here are the new errors :(

    [error] Body could not be created for part vodiczastator_2_Section1 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:04 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section2 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:04 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section3 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:04 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section4 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:04 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section1 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section2 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section3 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section1 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section2 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Body could not be created for part vodiczastator_2_Section1 because of invalid parameters of this part or some of its parent part/coordinate system. (3:52:10 apr 22, 2012)
    [error] Failed to load 'rotorStatorInduktance' solution. (4:05:39 apr 22, 2012)
    [error] Simulation completed with execution error on server: Local Machine. (4:05:39 apr 22, 2012)

    Maybe the problem is that the current is set to zero in the stator coil?
     
    Last edited: Apr 22, 2012
  21. Apr 22, 2012 #20
    You have objects (section of other coils on stator)) under "Unclassified" , you need delete them.

     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Ansoft Maxwell, cannot apply Current Excitation to non planar entity error
  1. MAxwell Ansoft (Replies: 4)

Loading...