Convergence Problem

zainab

hi dears,

i make two designs of induction motors , with both design i have problem of convergence, i can not know where is the error, please can you check them and help me?

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asoualmi

Hi,

Can you modify the solver used in your project. To do it:

Solving >> solving process options : select edit >> select nonlinear system >> select method for computing the relaxation…  modify the method used (use for example optimal method ).  

 

Best regards.

Yann_Le_Floch

Hi,

The Fujirawa method works fine on exemple 1, but your mesh is not good enough

In the new version, you will have an automatic mesh

Yann

zainab

Hi,

i used optimal method and the problem of convergence is solved but my results have error, the torque is very small and nagative. Are there any advice to solve this problem? thanks.

zainab

Any help?

asoualmi

Hi,

Sorry for may late answer. The fact that you have a negative torque, the fact that you have a negative torque that means that you have reversed the phases. Can you check the assignment of the phases and the winding of the motor?

Thanks.

zainab

Hi Abdessamed,

can you check the attached file, i have error with the results in torque and current and can not know the reason, i attach the project and information about it, please help me.

thanks.

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asoualmi

 Hi,

Checking the file that you send me, here my remarks:

1. You need to add a boundary condition (infinite box)

2. Split the air in two regions: one for the stator and the second for the rotor

3. You need to use two mechanical sets (don’t need a compressible)

In your case, you sue three phase induction motor? If it is the case, you will find attached a pdf file about the induction motor in Flux. This example is available in Flux supervisor example.

I attached the new Flux project with modification (to do I use Flux 2020; may you will get an error message when you try to open it with the student version). I still get a small value of the torque (but in the new model, I get a positive torque).

Best regards.

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zainab

Hi
Thanks for advances, but my project is a single phase induction motor, are there reasons to make the value of torque error? The calculation of torque depends on any speed? The speed rpm or rad/s
T=Pout/N(rpm)
or
T=Pout/w(rad/s) ?
Thanks.

asoualmi

Hi,

For the torque the formula is T=Pout/N(rpm). you need to convert the speed into rpm.

In the Flux supervisor example, there is an example about single phase induction motor. You can use to create your own motor.

Best regards.

zainab

Hi

You mean if i have speed in rpm, i should convert it to rad/s by using this formula

(rad/s) =[2*pi*rpm]/60

or the used speed is in rpm

for example if i have speed = 245 rpm and power 75 w the torque equal to what?

T=75/245

or T= 75/(2*pi*245/60)?

yes i saw the example and make like it but i have the proplem in results, so i ask if there is reason to make torque have error value.

thanks.

asoualmi

Hi,

For the couple, in Flux you unit of the speed is rad/s. About the value of the torque, I check the iron length of the motor I found 15 mm. can you check this value? Because the torque depends also the iron length of the motor.

Best regards.  

zainab

Hi,

the iron length is 15 mm because this motor for fan, so it short, i need to know another reason to make the torque error

thanks

asoualmi

Hi,

Try to use a transient magnetic application.

Best regards;