Getting Started with Maxwell 3D (ANSOFT)

[Fuxue Jin]

yes, you need to use transient solution in order to get losses.

Excitation 100*sin(W*t) is OK (I guess that should be 100*sin(2*pi*60*time), if frequency is 60Hz, for example)

But I don't know if you can overlap a dc voltage on top of the current excitation. I have not done that so far.

Fuxue;

i want to know that. i must be done transient analyses,arent i?

so can i apply ac current ? also i applied in windings and current value is a parametre(current1= 100*sin(w*t) ) is it true or false. Also i applied 500 Volt dc voltage in Winding part and 5 ohm resistance value. Is it ok?

 

[Fuxue Jin]

Also, when using voltage excitation, and your winding is specified as stranded, then Maxwell doesn't solve the resistance of the winding coil. The resistance you entered is the winding resistance of the coil, so it will be the same as you calculate the current V/R, and copper loss I^2R by hand. There will be no need to use Maxwell.

 

[emredemir]

so you say that don't use maxwell but i can see lots of map in power loss . For example stranded loss copper loss core loss they are avaible i think . in addition What do think about calculate power loss on coil is equal to stranded loss or copper lose.

 

[Fuxue Jin]

Sorry, but I don't understand your question very well.

In general,

If your copper winding is specified as stranded, and you use Voltage excitation, then there is no need to use Maxwell to calculate the copper loss, which is simply V/R = I, and loss is I^2R. Here V and R are specified by you as input, and you already know ahead.

If your copper winding is specified as stranded, and you use current excitation, then you will get strandedloss from Maxwell for your copper winding. However, if you can calculate the resistance of your winding using the length and cross section of your copper, then you will get the copper loss by I^2R since your current is known factor. This I^2R loss will be the same as you will get in Maxwell (the strandedloss).

If your copper winding is specified as solid, then you will get solidloss in Maxwell. In this case, the Maxwell will simulate the conduction path resistance and give out copper loss. When you specify your copper winding as solid, then you have to draw the real winding. Meaning if you have 10 turns, then you have to drawing real 10 turns. If you have 100 turns, you have to draw 100 turns. But it is not possible for Maxwell to simulate a 100 turns winding unless you have a very powerful machine with lots of memory.

So you have to decide how you want to specify your winding (solid or stranded) in order to know if using Maxwell makes sense to you or not.

so you say that don't use maxwell but i can see lots of map in power loss . For example stranded loss copper loss core loss they are avaible i think . in addition What do think about calculate power loss on coil is equal to stranded loss or copper lose.

 

[pourmoosa]

Dear all
I'm a new user and I need help about maxwell 2D transient.
i want to simulate a linear induction motor using maxwell 14.
when i define a band for transient state and then run maxwell,an error occures.
error is:"there might be an isolated hole in the band"

how i can remove this error?
sorry for my English;
thank you;

 

[emredemir]

Fuxue I'm now understand that everything you told me. i use copper windings stranded and voltage excitations on coil. So that is very senseless to calculate power . Because i would give the value of the voltage and resistance but i want to explain that i gave this excitations and i could saw the losses do you understand. for example i would give v=100 V and R= 5 ohm so İ = 20 A but if i gave V= 100*sin(W*t) i could see the losses because of the AC variables. Do you understand?

if i have wrong things you can say me... but what do you suggest me to solve?
Because this is my thesis so important for me and I'm grateful to you very very thank you Fuxue

 

[Fuxue Jin]

I have not done anything like this and may not be that helpful. But based on my understanding, a band object needs to be a sheet in 2D or a region in 3D without any interruption. The band object should not interfere with anything else. It is between the moving objects and the stationary ones.

The error sounds like the band object is discontinuous due to some interruption.

Dear all
I'm a new user and I need help about maxwell 2D transient.
i want to simulate a linear induction motor using maxwell 14.
when i define a band for transient state and then run maxwell,an error occures.
error is:"there might be an isolated hole in the band"

how i can remove this error?
sorry for my English;
thank you;

 

[Fuxue Jin]

Let's see the copper ohmic loss;

For DC, V=100V, R =5 ohm, we have I=20A, and power loss is 2000Watts.

For AC = 100* Sin(W*t), in this case, 100 is peak current, you need take the rms value for power loss, so Vrms = 70.7. For R = 5ohm, the power loss is , 999.70Watts.

In order to have the same equivalent DC current 100A, the AC peak current need to be 141.4A.

For AC current, if the wire is multi-stranded, then the current density is uniform and it will have the same power loss if the AC rms value is equal to the DC current value. It doesn't matter it is AC or DC because the current density is uniform.

Now, for AC input, if you want to consider skin effect/eddy current at high frequency (say a few MHz), and want to show the different power loss between DC and AC, you need to specify the copper as solid, not stranded, in Maxwell. As I said, in order to specify the copper as solid, you have to draw your winding turns. If it is 10 turns or so, then it will be OK. Otherwise, it is not practical to draw a few hundred turns in Maxwell.

Fuxue I'm now understand that everything you told me. i use copper windings stranded and voltage excitations on coil. So that is very senseless to calculate power . Because i would give the value of the voltage and resistance but i want to explain that i gave this excitations and i could saw the losses do you understand. for example i would give v=100 V and R= 5 ohm so İ = 20 A but if i gave V= 100*sin(W*t) i could see the losses because of the AC variables. Do you understand?

if i have wrong things you can say me... but what do you suggest me to solve?
Because this is my thesis so important for me and I'm grateful to you very very thank you Fuxue

 

[gerbi]

Gerbi, question to you. When plot loss vs time, what value should be taken, RMS or AVG? I noticed AVG value of strandedloss is more close to I^2R value calculated by hand.

According to definitions, real power is calculated as average per cycle not rms.
From my expierence, as you've said, maxwell avg power and hand calcs are pretty close in value.

 

[emredemir]

Dear Fuxue;

now I'm understand and i want to see eddy current/skin effect. So power loss may be
different from the when we use stranded AC current values. So you suggest me to give Copper windings are solid current value,arent it? so i must draw real turns.

but i want to send you subject of my thesis :http://www.maglev.ir/eng/documents/papers/conferences/maglev2006/topic5/IMT_CP_M2006_T5_11.pdf

and i use a document from ansoft ,name was; Ansoft Maxwell 11 3D UserGuide you can see how did i draw coil.(page 149 150 151).

 

[gerbi]

Dear Fuxue;

now I'm understand and i want to see eddy current/skin effect. So power loss may be
different from the when we use stranded AC current values. So you suggest me to give Copper windings are solid current value,arent it? so i must draw real turns.

but i want to send you subject of my thesis :http://www.maglev.ir/eng/documents/papers/conferences/maglev2006/topic5/IMT_CP_M2006_T5_11.pdf

and i use a document from ansoft ,name was; Ansoft Maxwell 11 3D UserGuide you can see how did i draw coil.(page 149 150 151).

The way to draw a coil taken from Maxwell User Guide is good for stranded currents.
Yes, you need to create every turn to observe eddy effect. How many turns do you have ?

 

[emredemir]

Gerbi;


i have lots of turns but firstly i don't know how to draw this turns. draw by a helix or spiral? i really don't know but i made turns by helix a month ago. Gerbi my problem
is power loss and frequency. I am working in nearly 20 KHz. So What do suggest me to see power loss on coil. Fuxue said that If i wanted to see Eddy current and differ
between AC to DC power losses ,i must be draw turns. He said that me you can see.

İndeed ,The first problem for me power loss. so What do think, i have to draw solid turns or i m continue to Stranded Current windings

 

[gerbi]

Gerbi;


i have lots of turns but firstly i don't know how to draw this turns. draw by a helix or spiral? i really don't know but i made turns by helix a month ago. Gerbi my problem
is power loss and frequency. I am working in nearly 20 KHz. So What do suggest me to see power loss on coil. Fuxue said that If i wanted to see Eddy current and differ
between AC to DC power losses ,i must be draw turns. He said that me you can see.

İndeed ,The first problem for me power loss. so What do think, i have to draw solid turns or i m continue to Stranded Current windings

To observe eddy current losses in AC do as Fuxue Jin said. Draw solid turns of copper.

Lots of turns you say. I see no way to analyze this device in full geometry.
You need to reduce number of turns to pretty low number (it depends on computer CPU and RAM memory) or you won't be able to create proper mesh to calculate this accurately.

 

[emredemir]

To observe eddy current losses in AC do as Fuxue Jin said. Draw solid turns of copper.

Lots of turns you say. I see no way to analyze this device in full geometry.
You need to reduce number of turns to pretty low number (it depends on computer CPU and RAM memory) or you won't be able to create proper mesh to calculate this accurately.

but i want to know that how can i draw this turns . draw helix is usefull or not.
i think 1 turn even enough for me but HOW? in addition gerbi can i send you my maxwell project by mail or other ways. may be it is very easy to see what i do

 

[gerbi]

but i want to know that how can i draw this turns . draw helix is usefull or not.
i think 1 turn even enough for me but HOW? in addition gerbi can i send you my maxwell project by mail or other ways. may be it is very easy to see what i do

Tricky job. Coil will be made of rectangular or round conductor ? It's wounded on rectangular core, right ?

If this is rectangular wire then just draw rectangles as part of conductor, merge all and fillet the edges.

If this is round wire: draw a cylinder of required length and diameter of straight part of wire. Then duplicate it around axis (90 deg). You'll have two cylinders perpedicular with one common corner (there is a hole but it can be filled with spherical element). Merge all and you have one element ready.

I don't know how good are you in drawing in maxwell. There are pretty many options there (merging, substracting, splitting.. - planes can be changed) so take your time.

I'm sorry but currently I'm pretty busy with some other projects.

 

[emredemir]

Ok Gerbi;


i really understand you are bussy but when you have free time Can you turn me for this topic.
also i can say my coil made by rectangular so i have to use rectangular for turns ,arent i? So i draw lots os rectangular and merge them . but i think draw one rectangular also useful for me,isnt it? because i will be take same results from programme.

For example one turn with current is 500 A. Other type is 5 turn with 100 A. they are the same things F= N*I . so Fuxue said and show me that i have to give in windings part Current= 100*sin(2*pi*20000*time) and solid . so it will solve eddy current and skin effect i think so...

 

[Fuxue Jin]

Give me some time and I will prepare some pictures to show how. I just finished a similar project.

Ok Gerbi;


i really understand you are bussy but when you have free time Can you turn me for this topic.
also i can say my coil made by rectangular so i have to use rectangular for turns ,arent i? So i draw lots os rectangular and merge them . but i think draw one rectangular also useful for me,isnt it? because i will be take same results from programme.

For example one turn with current is 500 A. Other type is 5 turn with 100 A. they are the same things F= N*I . so Fuxue said and show me that i have to give in windings part Current= 100*sin(2*pi*20000*time) and solid . so it will solve eddy current and skin effect i think so...

 

[Fuxue Jin]

Let's start with what's in the real world and then take a look at what can be done in Maxwell that is close to the real world.

The follow picture is a ferrite RM6 core with 24 turns winding. This is a real inductor model, made by SolidWorks. I don't think Maxwell can create this model.

For this 3D model, after imported into Maxwell, it takes about 20GB memory to generate mesh, and may take a few days for a single CPU machine to finish the solution (given the core material is BH curve, not linear). So for you, it is not practical.

The following is a simplified model.

It still has 24 turns. But each turn is represented by a single ring. In Maxwell, all these single ring will be added into one winding. So electrically, it is equivalent to the previous real model. And this is much easier for Maxwell to generate mesh and finish the solution. On top of that, the 3D model can be split into 1/8 of it and reduce the simulation time by 1/8.

(to be continued)

 

[Fuxue Jin]

Before we talk about your project, and I assume you understand what is skin effect, here let's review it again.

In the following pictures, the circle represents the cross section of a solid round wire, with 2mm diameter. An AC current at 1KHZ, 100KHZ, and 1MHZ are applied to the wire. The color represents the current density distribution.

1KHZ

100KHZ

1MHZ

So, due to skin effect, the whole cross section area of the wire is not fully used at high frequency, resulted in high resistance and hence higher power loss comparing DC current.

(to be continued)

 

[Fuxue Jin]

Now let's talk about your project.

First, since your main interest is the power loss in the copper, so you may just ignore the core loss, and then you don't have to have core in your project. A simple air coil will be good enough.

Second, if you don't need to have a real model representing a real transformer or inductor, you may simply using a circle to represent a round wire, and you can use Maxwell 2D instead of 3D for your project. A circle with symmetry around Z axis in 2D represent a ring in 3D. You can start with only one ring for the winding (one turn winding), and add more rings later (into one winding) to the extend that your machine can handle.

The resistance of a single ring can be calculated by the length and cross section area, so you can compare your simulated results easily.

Hope this helps.

 

[emredemir]

So Fuxue you explain me lots of think but why you don't say me to draw this coil on solid i have lots of machine engineer friends and they could draw me easily. anyway i want to send you my project if you accept by mail or other.

Firstly my first point is calculate power loss on a coil. The secon one is observe that increased the frquency and its effects on power loss.


So Which type of solutiion do you prefer to me? ...

 

[Fuxue Jin]

My suggestion is to draw a ring in Maxwell, assign copper to the material property, and go from there, to calculate the copper loss, stranded and solid, so you can get used to Maxwell.

After that, you can work on your real model, whether created in Maxwell or imported from SolidWorks.

So Fuxue you explain me lots of think but why you don't say me to draw this coil on solid i have lots of machine engineer friends and they could draw me easily. anyway i want to send you my project if you accept by mail or other.

Firstly my first point is calculate power loss on a coil. The secon one is observe that increased the frquency and its effects on power loss.


So Which type of solutiion do you prefer to me? ...

 

[emredemir]

Fuxue you said me that i have to draw a ring but how? for example draw ring by torus is usefull for 3D?Fuxue i want to send you my project and you can easily find what is my problem ,İf you have enough time. Furthermore, it doesn't take your time really. Because my problem very simple and you understood what i want. May it is very easy to describe me something.You don't think that i don't want from you to do my work . Only analyze my work and tell me about What i did wrong or i didnt use


Thanks Fuxue again...

 

[Fuxue Jin]

I don't have access to Maxwell until next week so cannot look at your project.

You can draw a ring in a few ways. You can also import a ring from SolidWork if you have someone else help you in SolidWork.

In Maxwell, you can draw a torus. You can also draw a circle and sweep around an axis to make a ring.

Fuxue you said me that i have to draw a ring but how? for example draw ring by torus is usefull for 3D?Fuxue i want to send you my project and you can easily find what is my problem ,İf you have enough time. Furthermore, it doesn't take your time really. Because my problem very simple and you understood what i want. May it is very easy to describe me something.You don't think that i don't want from you to do my work . Only analyze my work and tell me about What i did wrong or i didnt useThanks Fuxue again...

 

[emredemir]

Fuxue :


i want to insert a variable like that but i don't know Is it true or false?

Current1= 400*sin(2*pi*2000*time)


i inserted this variable in Winding part but when i make analyses i didnt see any sinusoidal figure on the Loss map. So is it a true or false situation for me? I saw just the same things when i inserted the dc current. There was nothing unchanged.

I wonder Current1 variable is true or not inserted.

 

[Fuxue Jin]

The current is correct.

You can plot input current vs time to verify it is sine wave. Loss is not sine wave, you need take average value on the loss vs time curve. Make sure you plot solidloss if your copper is solid.

Fuxue :


i want to insert a variable like that but i don't know Is it true or false?

Current1= 400*sin(2*pi*2000*time)


i inserted this variable in Winding part but when i make analyses i didnt see any sinusoidal figure on the Loss map. So is it a true or false situation for me? I saw just the same things when i inserted the dc current. There was nothing unchanged.

I wonder Current1 variable is true or not inserted.

 

[emredemir]

Fuxue i create coil by polyline is it solid or not? i inserted the solid winding current so that it is true? furthermore i see losses from ''Create Transient REport'' part on Results,arent i? So i want to send some you some picture of my project . may be you can understand easily i hope. but i don't have i send photos you from this forum


İn Addition Do you know What is the ohmic loss and What Do we doo in Field overlays?

 

[Fuxue Jin]

Polyline is a line, not sure how you create a coil with that. Anyway, a coil needs to be a 3D object with volume.

Yes, you will be able to plot a rectangular plot for loss vs time in "Create Transient Report".

Ohmic loss only appears in calculator, I think. That is the I^2R loss in a conductive object.

Field overlay allows you to create B or J filed on certain plane.

You need to be a little patience to learn the basic. Maxwell is not a car you jump into drive, but it's an aircraft.

Fuxue i create coil by polyline is it solid or not? i inserted the solid winding current so that it is true? furthermore i see losses from ''Create Transient REport'' part on Results,arent i? So i want to send some you some picture of my project . may be you can understand easily i hope. but i don't have i send photos you from this forum


İn Addition Do you know What is the ohmic loss and What Do we doo in Field overlays?

 

[emredemir]

hello Fuxue:

i m annoyed to you again so thet i have some problems. firstly i want to calculate a power. this power is on a coil. but there is no excitation. two line is coupled with this coil and so excitations were given by this lines. for example one of these have 540 A AC and the other one is the same which inductively effects coil and make up current and a power on coil. So my teacher wants from me to calculate power and current on this coil. Is it impossible or not?

 

[Fuxue Jin]

In Maxwell, excitation is applied to an area which is a 2D object. Excitation cannot be on a line.

Calculate power is possible depending on how complicate your model will be.

Take a screen shot of your model and post it here. Let's take a look at your model.

hello Fuxue:

i m annoyed to you again so thet i have some problems. firstly i want to calculate a power. this power is on a coil. but there is no excitation. two line is coupled with this coil and so excitations were given by this lines. for example one of these have 540 A AC and the other one is the same which inductively effects coil and make up current and a power on coil. So my teacher wants from me to calculate power and current on this coil. Is it impossible or not?

 

[emredemir]

This is my model and you may not understand there is two line which have current excitations and they are colored grey (iron). also red one is ferrit model and brown one is coil ( copper). my work is give the lines current excitation and calculate the current and power on coil. This is possible?

http://https://www.physicsforums.com/attachment.php?attachmentid=47762&stc=1&d=1338311715

 

[Fuxue Jin]

I am not sure how much you understand about a transformer. Just by looking at the model, a few questions here;

You have an E core, but only half. Normal transformer need two E cores mating together to close the magnetic path without gap. Only half E core means a huge air gap.

You have orange color coil around center core leg, which is good. But that is what we have been talking about so much previously. This coil may represent a multi-winding turns which you cannot use for solid power loss simulation.

Two grey wires in the model are strange, totally wrong to me. You never have a transformer made that way.

There is another mistake. You don't have region defined, so that is the reason you have those error messages.

I am really sorry but I have to say, based on these, you don't have good understanding about transformer and Maxwell. Your assignment may be over your capability and you need much more time to get the basic.

This is my model and you may not understand there is two line which have current excitations and they are colored grey (iron). also red one is ferrit model and brown one is coil ( copper). my work is give the lines current excitation and calculate the current and power on coil. This is possible?

http://https://www.physicsforums.com/attachment.php?attachmentid=47762&stc=1&d=1338311715

 

[emredemir]

Fuxue i erased the region when i attached the photo. i now transformer model but i use different type of this. i want to show you real image of model. may be you can understand simply. but i want to ask you can i draw this iron tracks by cylinder? also how can i calculate power on coil? and how can i see the current and voltaj on this coil? the current which on these tracs coupling with coil and generate current on this coil. are you understand what i say? also you can easily say me what i done wrong . it is not important for me. :)

 

[Fuxue Jin]

In the picture, I don't see coils on the core center leg. Do you have windings on the center leg?

I assume those two black long bars are what you called "iron tracks". If so, yes, you can drawing them by cylinder and assign voltage or current to them. And then obtain power loss in Maxwell.

Fuxue i erased the region when i attached the photo. i now transformer model but i use different type of this. i want to show you real image of model. may be you can understand simply. but i want to ask you can i draw this iron tracks by cylinder? also how can i calculate power on coil? and how can i see the current and voltaj on this coil? the current which on these tracs coupling with coil and generate current on this coil. are you understand what i say? also you can easily say me what i done wrong . it is not important for me. :)

 

[emredemir]

fuxue i draw new things and i send you now. but which analyses type do you suggest me? transient or magnetostatic? in addition iin transient analyses: do i give these tracks coil terminal and define winding on this tracs ? also winding you say on coil is excitation one or mean turn which one i didnt understand. and finaly haw can we calculate power on this coil:)