Learning Forum

[Purity]

Hi,

I designed a PM motor using 2D maxwell without using user defined primitive. Please I need help on

1) How to determine my initial position in motion setup.

2) How to get a positive average torque instead of a negative average torque.

3) How I can produce a plot of steady state torque against the angle.

Thank you.

[Ivonne Marti]

Hi Purity,

Thank for your great questions. Please find below my answers.

1)        How to determine my initial position in motion setup.

The initial position can be specified inside the Motion Setup/ Data tab

2)        How to get a positive average torque instead of a negative average torque.

You can simply use a negative speed or plot “-Torque”

3)        How I can produce a plot of steady state torque against the angle.

If you are doing a simulation with the Magnetostatic solver and you want to simulate the rotation of the motor, then you need to create the “angle” variable. To do this select the objects you want to move and then go to Edità Arrangeà Rotate, then create a parameter named “angle”. Afterwards, you can run a parametric sweep calculation for several “angle” value. Once the calculation is done, you will be able to plot Torque vs Angle.

If you want detailed information and you have access to Ansys Learning Hub, you can investigate the Maxwell Advance Motor Training/ Cogging Torque / WS02.1

The direct link is https://learninghub.ansys.com/learn/courses/314/ansys-maxwell-advanced-motor-training/lessons/2181/workshop-12

I hope this information helps you. Ivonne

[Purity]

Hi Ivonne,

Thank you for your detailed explanation.

Please, when I completed a cycle of the transient analysis, I got 0.9747 as the average moving torque meaning that the machine has no torque. Please what can lead to this?

Thank you.

 

[Ivonne Marti]

Hi Purity,

It is hard to say without checking the model. But maybe there is a mistake in the simulation setup. To be sure your setup is correct, you can open the installation example “Interior Permanent Magnet” and check that you have a similar setup.

You can open the example going to: Open Examples/Maxwell/Electrical Machines -> Interior Permanent Magnet

Please note that if you are computing the cogging torque using the Magnetostatic solver,  you need to specify the torque calculation in the Parameters/Torque and include all moving parts (rotor, magnets, shaft).

I hope this helps you

Ivonne

[Purity]

Hi Ivonne,

Thank you for replying. 

Please, this is the first time I am designing electrical machines without using a user-defined primitive or template. I am designing a Surface-mounted permanent magnet using 2D Maxwell and have watched many videos on rotating machine design but have not seen where a detailed calculation and the determination of the initial position in motion setup are fully discussed during design.

I am still at the level of getting a positive valve of an average moving torque with time.

Below is my moving torque graph after simulation.

Thank you.

[Ivonne Marti]

Hi Purity,

I would encourage you to look at the workshop I have mentioned before “Maxwell Advance Motor Training/ Cogging Torque / WS02.1”. Here you will find step by step explanation about how to compute the cogging torque and how to get the initial angle value. For this calculation I would advise to use the Magnetostatic solver.

The direct link is https://learninghub.ansys.com/learn/courses/314/ansys-maxwell-advanced-motor-training/lessons/2181/workshop-12

If you are interested in calculating an electrical machine, I suggest looking into the lecture and workshops from the “Maxwell Advance Motor Training”

The direct link is https://learninghub.ansys.com/learn/courses/314/ansys-maxwell-advanced-motor-training

I hope it helps. Ivonne

[Purity]

Hi Ivonne,

I will try it out.

Thank you very much.