Maxwell 3D (ANSOFT)

eddyrooney87

Hi everyone,

Need you guys help with Ansoft Maxwell 13. I am currently working on electromagnetic linear actuator as a vehicle suspension system. My design should look like below:
_____
| s |
| h |_____ ____ ______
| a | N | | C | | S |
| f |_____| |___| |_____|
| t |

It will be in cylindrical shape. Hope you understand.
N = north pole (magnet material, Neodymium)
S = south pole
C = coil winding

I already design the geometry in Ansoft. But I do have some question related to Maxwell:

1. How to assign magnetic pole (N/S) to my design.
2. How to assign coil polarity during current excitation.
3. Can we create external force to excite the shaft downward or upward?
4. What type of solver should be used for this kind of design?

Sorry for my english. Appreciate your help.
Eddy

gerbi

Ad. 1: Assign material (permeant magnet) to object. In it's properties You can select how magnetic coercivity vector is oriented
Ad. 2: by altering current direction. Coil polarity depends on direction of current
Ad. 3: Yes, there is such a posibility (assigning a band with mechanical transient)
Ad. 4: Transient (Magnetic)

One more thing, I suggest reading some tutorials and searching Maxwell On-Line Help for vital information about preparing simulation. If You do not have tutorials write me a PM with your e-mail adress and I will send them.

annalisemalta

gerbi,

is it possible to send me some tutorials on annalisexuereb@gmail.com

Thanks
Annalise

Fuxue Jin

You don't necessarily input extra inductance. The simulation will use the modeled inductance of the coil. Induced current will have 90 degree phase shift from the input voltage.

eddyrooney87

Hi gerbi,

Ad. 1: Assign material (permeant magnet) to object. In it's properties You can select how magnetic coercivity vector is oriented

It is we change the magnitude value to negative(-)/positive(+). Not really understand what you are suggesting.

Ad. 3: Yes, there is such a posibility (assigning a band with mechanical transient)

I did try to assign the shaft as a band but error come out. "Invalid object selected for band. No objects within the band". How could I assign the shaft in mechanical transient?

Appreciate if you could share with me some tutorials for Maxwell 3D for my reference. Please send to dey_ad@yahoo.com.

gerbi

You can change Magnitude but X-Y-Z components aswell. Field with orientation (1x,0y,0z) will be perfect opposite to (-1x,0y,0z).

About band.. You need to close moving object inside other object to which You'll asign a band.

Please, read the tutorials (especialy about Toyta Prius motor) - all basics are explained there.

annalisemalta

"You don't necessarily input extra inductance. The simulation will use the modeled inductance of the coil. Induced current will have 90 degree phase shift from the input voltage."


I know that... my problem is that the shift is a dc shift between the currents of the phases not between the voltage and the current, as in the attached screenshot

annalisemalta

Hi,

regarding the transient plots in Maxwell... What is the Moving1.Toqrue? and when exciting winding by current what is the voltage that is available for plotting? the induced voltage or the terminal voltage?

Thanks

cimopata

Hy Everyone!

I would like to ask for your help. There is a transformer transient tests on which I am doing.
I want to calculate or measure the amount of heat loss in [W] occurs in the core.

How do I do this?
Thanks
Bálint

gerbi

Don't know. There is no info on it in help. Try plotting it and see how it behaves.
it's voltage induced by the current, across the considered element

In transient solver there is a possibility to define core loss model. Go to material properties, from menu choose "core loss type" -> "electrical steel". Some more coefficients are now avaible in your window. At the bottom from the menu choose "calculate properties for" -> "core loss at one frequency". In new window enter data You have (frequency, thickness etc.), You should have it from core material manufarcturer and transformer design data. If You don't know sheet material conductivity, which is not so easy to obtain, go with ~2 MS/m.

Ok, with material properties setup ready go to Maxwell2D/3D -> Excitations -> Set Core Loss. Pick core element (if material props are fine, there should be check in right column).
Make mesh refinement in core (accuracy of losses calculation depends on calculated flux distribution) and solve model.
For results plot core loss vs time in results -> create transient report-> rectangular plot.

cimopata

Thanks for your help!

Yes, I found this options and I adjusted the core losses in 25°C(by the "power ferrit" core loss type).
Actually I'm using N87 ferrit core. I already can measure the core loss. The results is very nice :)
The next step what I would like to do is the "Thermal modifier".
By the core loss type I have Power ferrite. There is 3 value (Cm, X, Y). Every value have "Edit thermal modifier" option. In this window how can I adjust the loss for example 100°C?

Thanks!
Best Regards!
Bálint

cimopata

Other quoestion:

The simulation is very slow. 50us transient (0.5us step) takes about 20 hour. I would like to speed up. My toroids dimension is about 50mmx16mm. What is the recomended mesh size (faster simulation/precise caltulation).

My compure:
Intel core i7
6GB 1333mHz RAM

Thanks!

gerbi

I'm sorry, but I have no expierence in this field. It appears that You'll need to read some articles about material properties of power ferrite. Maxwell help contain no detailed information on this one.

It depends. For some crude calculations (to get familiar with model, results etc) mesh shouldn't be very fine.
For this first few simulations and 3D model about few thousand elements ? Thats my guess. For more detailed calculations few times more, but do not create monstrous mesh because it won't help accuracy much.

Some more hints on mesh:
1) Observe calculated energy error in solution data. If it is below 0,5% You can assume it is quite accurate (very accurate below 0,1%).
2) Do some simulations in static solvers (like Eddycurrent). Mesh is done adaptively then. You can observe which areas have increased meshing and do similary in transient solver manually.
3) Observe results (mostly flux distribution). Field details like increased density (if present) should be visible and look natural.
3) Meshing is one of most important things in FEM, it's better to learn how good mesh looks like.

eddyrooney87

hi gerbi,

i have difficulties on assigning current to my coil as it is wounded on cylinder core. When I want to assign current, this error occur "Excitation 'Current 1':Cannot apply Current Excitation to non planar entity". Any tips and help from you.

Thanks

cimopata

Thanks gerbi!

I am going to try it!

Maybe have you any experience the distributed mode computing between computers?
I tried, but there is something error message:
"Error: Unable to contact AnsoftRSMService, Reason: ANS_CANNOT_CONNECTTO_ANSOFTRSMSERVICE
Testing Completed.
Error: Some tests have failed.

siva0707

hello frnds..
hoep you all doing good.
i am a mechanical engineer but works in electrical engineering. my work is electromechanical interactions in induction motors. so i started working in ansoft. so kindly anyone help me in the modeling of induction machine in ansoft. i am working with 3 phase 4 pole induction machine and it will me helpful for my work.

thanks
with regards
siva

nautylus

Hi,
i'm new user and i've studied ansoft maxwell for three months..
i need some help : i wanna do calculate second harmonics in a magnetic material (for examp. between 2 magnetic rings center)
how can i calculate that by field calculator ??
thanks with regards