
#127
Jan213, 07:36 AM

P: 5

Hi
Greetings to you all!!! I got the three phase currents as a unique pattern with phase difference. but i got the peak to peak current value is 9A only. my configuration of the machine is rated voltage 415V rated power 27.75kW Frequency 50Hz, Rated Speed  1470 rpm i need to get peak to peak current value around 60A.... what should i need to do in the maxwell design? thanks for your help in advance!! and one more thing also.. how to calculate the power of an induction machine when the total number of strands are reduced to 3 from 4 strands? The rated output power of an existing machine is 37kW which has 4 strands and 11 turns. now it is reduced to 3 strands and 11 turns. now what will be the output power for the same machine? rated voltage is 410V, 50 Hz freq. machine has 60 slots. (basically i am from mechanical engineering, but i am working in electromechanical interactions in induction machine) Thanks Siva 



#128
Jan2613, 12:21 PM

P: 1

Dear friends
I am student and I have exam about ansoft maxwell 3D. I should simulate 3 phase asynchronous motor in ansoft maxwell 3D and to make several magnetostatic analysis. Can someone help me? I am beginner, so the best help for me is one finished project. Please someone send me .rar file... 



#129
Feb713, 07:13 PM

P: 9

I am designing a 2D model of a threephase coretype transformer in ANSOFT MAXWELL 14.0. While doing so I have encountered a strange problem.
Start of the problem: While designing the transformer, I wanted to incorporate core losses. So, I did the following steps: Excitations > Set Eddy Effects > checked the various core sections in my model (because eddy current effects occur in the transformer core) and also Excitations > Set Core Loss  > checked the various core sections in my model (because core loss effects occur in the transformer core) Symptoms : Model simulated (using transient solution type) and then gives the following wrong results: 1) Line currents on the primary side (starconnected) are very high (about 10 times) 2) Secondary side (delta connected) phase currents lose their phase dependence, i.e. the phase currents are no more 120 degrees apart, they all are in phase now. However, the secondary line currents are Ok though. Additional Information : If I do not consider eddy current and core loss effects, then the model simulates to give correct results. Please provide me suggestions/hints/solutions to my problem  how to incorporate core losses correctly in my model. 



#130
Feb813, 12:03 AM

P: 147

Hi
Turn off eddy effect in core (turn it off in the windings as well), use only core loss calculations (based on core material loss curve P[W/kg] vs B [T] at single frequency). Set core conductivity to 0 (leave core material density, stacking factor, stacking direction unchanged  as for real core material). Using eddy effect can give unrealistic results when done unwisely. Use eddy effect calculations only when you are considering induced losses in solid elements (tank, tank cover etc).. Applying it to windings or core (full scale model) would need very detailed design. 



#131
Feb813, 12:28 PM

P: 9

Thanks Gerbi for your response. Ok, I will shut down the settings for eddycurrents and concentrate only on the core loss settings.
So, I purchased this transformer from the manufacturer and at present I do not have the specified P (W/kg) vrs B (T). What I do have is a curve for Magnetizing inductance (Lm) VRS. Magnetizing current (Im). Can that be helpful ? 



#132
Feb1013, 12:45 PM

P: 136

What is the purposes of your simulation? How accurate loss calculations do you need?
Hysteresis curve don't do you any good in accurate calculation of core losses. But hysteresis losses (part of core losses) are proportional to the area under the hysteresis curve. P(T) curves at 50/60 Hz you can find at many electrical steel manufacturers. E.g sura.se Also, since you got the transformer, you can do some measurements and find the core losses. 



#133
Feb1013, 02:13 PM

P: 2

Hi all
Please can you tell me how can I create equivalent circuit in MAXWELL 3D in version 15? Specially,where is "export matrix to lookup table using Equivalent Circuit Extractor" menu? Thank you for our reply 



#134
Feb1113, 02:07 PM

P: 9

Thanks for your suggestion. Yes, I followed your steps. Actually, I created a new material. Firstly, I got a BH curve for hotrolled lowcarbon steel from the Sawhney machine design book and incorporated that into the material (since my transformer's material is hotrolled lowcarbon steel). Next up, I got the P (W/kg) versus B (T) for that material from the same book and incorporated it as well. I set the material density, bulk conductivity etc to optimum values. The transformer model now simulates and gives correct results. Thanks, Shantanav 



#135
Feb1113, 02:10 PM

P: 9

Purpose of my simulation  Trying to simulate the transformer under healthy condition and get current waveforms as close as possible to my actual labtransformer. So, I am trying to model the core as similar as possible to the actual specimen I have. Yes, I incorporated the P versus B curve for my core material and the model simulates now. Shantanav 



#136
Feb1813, 12:44 AM

P: 3

hello guys,
i want to model a switched reluctance motor in ansoft maxwell with double layered winding, but i am not being able to find the option for layers of winding. please help me with a solution for it if anyone is dealing with switched reluctance motor in ansoft maxwell. thanks Firdausa 



#137
Feb1813, 10:25 AM

P: 76

In Maxwell, most of time you don't draw the real winding (turns, layers and so on). You draw a 3D object and specify the cross section as stranded and define how many turns.




#138
Mar2813, 09:20 AM

P: 2

Hi everbody,
I have created project for my thesis and everything is already set up.The problem is that my Maxwell version sent me back message error about "setting up first generation" when i start genetic algorithm in optimetrics analysis. I hear that can be bug. So I want to ask for help, I sent you my project,you try to run it on your machine and sent me result back with all project. Please,Is here someone who would do it? Thank a lot. 



#139
Apr313, 03:52 AM

P: 1

Hello,
I have worked a good deal with Magnetostatic solutions in Maxwell; however, I now have to design an electromagnetic system that requires a transient setup. I have a single coil electromagnet with a ferrite core that I need to operate at a frequency of 50 kHz. I set up the meshes, including the skin depth, as well as an external circuit with a sinusoidal current source. My solution time step is therefore 1e6 and the stop time is 1e4. I specified that I want the field values saved at the same points by adding them to the list under 'Save Fields', but after I run the simulation, I do not see how to view these results. Does anyone know the best way to view the fields calculated at these time steps? Thanks, Arielle 



#140
Apr313, 04:39 AM

P: 147

Hi Arielle,
after the solution is complete (for a specific time moment) it can be viewed by double clicking on "Time" button in your main window (in left bottom corner, just under your model or Viev/Set Solution Context). There you can choose solution to view (and when you will select one you can update your Fields Overlays to this specific time moment). 



#141
Apr2613, 06:11 AM

P: 6

Hello,
I am working on modeling in Maxwell an inductive charger for electric vehicles. The whole concept is quite similar to a transformer, though instead of simple windings or coils, litz wire is used. Would it be possible to design litz wire like a normal coil? Would it be all right if I drew a circular or rectangular conductor with a specified diameter? And if so what would be the size of the cross section of the conductor? 



#142
Apr2613, 12:03 PM

P: 136

If I state that: A solid circular or rectangular conductor would be a good approximation to a litz wire, IF you specify that eddycurrents are NOT induced in the conductor. Would you agree? And can you give a reasoning behind the statement?
As for the cross section, it depends on the effects you want to model. In reality a coil, and especially a litz wire would give a "copper fill factor" of less than 1, due to insulation. If you are unsure if the radius and fill factor has a effect on the solution you can try using different radii and see if there is a difference in your "answer". 



#143
Apr2713, 07:32 AM

P: 6

SirAskalot thanks a lot for your answer.
I agree that if I specify that eddycurrents are not induced in the conductor, a better approximation of a litz wire can be achieved. Considering the radius, I will try using different radii and see how my answer is affected. Yet i am unsure of how to model the litz wire considering the number of turns: For my application I need a litz wire of two turns for the "primary" of my charger (for a transformer the litz wire would be a coil of two turns) carrying a current of 200A at 20kHz. I also need 16 turns of litz wire for the "secondary". Would it be OK to define the conductor as stranded and specify the number of conductors as 2 for the "primary" and 16 for the "secondary"? Or would it be a better idea to draw two connected conductors for the primary and 16 conductors for the secondary and define them as solid? 



#144
Apr2713, 09:56 AM

P: 136

It again depends on what effects you want to model, but most times its not necessary to draw each turn.(most times are when eddy currents like proximity effect, skin effect etc. are neglected in the coil/winding) So I would agree with you regarding defining the conductor as stranded, and use a multiplier like 2 and 16 (number of turns or similar in a dialog box).
The reason for neglecting these effect in coils are due to the complexity of drawing and meshing such small elements. Analytic formulas may be used instead for calculating the neglected phenomena, like resistive losses etc. 


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