modelling DC brush motor

Yuval

I want to model a basic DC brush motor in order to get the magnetic force versus the current, the flux, etc. The motor is in the form of this one:

 

I tried it in two different types of analyzes which did not work.

First, I made a transient magnetic 2D analysis. I made a circuit and a model but when there were many errors when I did the solving (for example:

PBEPAV_3 => Error 49, no treated error type
PBCEVL_4 => failed
PBCEVL_3 => Failed
PBERES_3 => failed
FL5RE4   => Command not executed correctly
FL5ERS   => failed
FL5ERS_1 => failed)

 

Afterwards, I made a model of 2D section of a DC brush motor in a magneto static 2D analysis.

In this analysis, I defined the rotor on a different coordinate system so it will be rotated. I wanted to make a magnetic force - angle graph of the rotor (which is the coil in this case), but I get an error because the relative permeability of the coil is close to 1. I defined a mass density to the coil so it won't have the properties of air but it still didn't work.

 

How is the best way to model this DC brush motor, 2D magneto static or transient magnetic 2D analysis? Is there a tutorial for this case? beacuse I did not find..

What caused the errors I have got and how to fix them?

 

Thank you!

asoualmi

Hi,

In Flux supervisor example, there is a tutorial about the DC motor. You can use it to create your own Dc motor.

Flux supervisor >> Open example >> Application note: DC motor

Best regards.  

Yuval

For my motor I need two slots but in the example it is possible to have minimum of 4 slots. There is no explanation of how the motor in the example was built and defined so i do not know how to do this myself from scratch.

If there is a video tutorial for this I would like to see it.

 

Thank you.

asoualmi

Hi,

Can you send  me your Flux project (zip format).

 

Thanks in advance.

Yuval

Hey,

 

The project file is attached.

After some more tries I did a magneto static 2D analysis and I've got the flux and the magnetic flux density, but it still need the force on the coil and the torque on the shaft as a function of the rotor's angle and there are still errors.

 

Thank you for your time.

Unable to find an attachment - read this blog

asoualmi

Hi,

Thanks for sharing the project. Analyzing the project I found that you use several mechanical sets. In your case you need to use two mechanical sets, mobile and fixed. You will find that I delete al the mechanical sets, I keep just two that I use in the face regions.

About the geometry, I modified it slightly because it is not symmetrical as indicated in the picture you sent. Also I create a new face region (mobile_air) to surround the moving part.

To compute the force on the coil, you need to create a sensor. To do it :

• Data tree

• Parameter/ quantity

• Sensor >> right click, select new

  • Put the name of sensor.

  • Type of sensors: integral (of spatial…)

    • Integral on all the domain

  • Spatial formula: dFlapV (to select the formula, click on the f(), select dFLaplace/dv)

  • Type of integration: integration on the domain..

For the torque, once the project is solved, in curve select new curve. A window opens, select Mechanical set: electromagnetic torque.

Best regards.

Unable to find an attachment - read this blog

Yuval

Hey,

 

Thank you for the detailed answer.

I can't open the project, is there a chance that this is because I have only a student edition?

 

asoualmi

Hi,

You are welcome. I used Flux 2018.1.3 , maybe this is due to the fact that you are using a student version.

I create a python script to modify the initial project. To run it you need:

• Open the initial project (flux_static.FLU)

• Run the python script:

  • Project >> commande file : run a python file

Best regards.

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