# Demagnetization

## Recommended Posts

I am simulating a machine considering three ways of defining the materials for PMs to see the impact of demagnetization on the machine performance.

In the first simulation, I considered the linear characteristics for the magnet, the second one I used nonlinear magnet described by Hc and Br modules, and last one nonlinear magnet described by a spline.

The obtained torque in these models are different. Why? How does the working points of the magnet is defined in the nonlinear condition?

How can I calculate the "Transversal relative permeability "???

##### Share on other sites

Hi,

The difference of the torque is due to the type of the materials that you use in the magnet. When you change the type of the material, you change the level on the induction in the motor. As yo know the torque depend on the magnetic induction, for this reason the value of the torque change as function of the type of the material used in the magnet.

About the transversal relative permeability, usually we use “1” it is like air.

Best regards.

##### Share on other sites
On 2/6/2020 at 2:41 PM, Abdessamed said:

Hi,

The difference of the torque is due to the type of the materials that you use in the magnet. When you change the type of the material, you change the level on the induction in the motor. As yo know the torque depend on the magnetic induction, for this reason the value of the torque change as function of the type of the material used in the magnet.

About the transversal relative permeability, usually we use “1” it is like air.

Best regards.

Hi

Thank you so much for your quick response.

Maybe I did not explain the problem properly. I just use one type of material for PM and used different way to model it and see the impact of demagnetization on the machine performance.

I had expected to get the similar results in all models in case there is no demagnetization (I used one type of magnet with the same properties, just I considered different way to model the PM materials, a very simple way to consider Br and Ur (linear) and complete demagnetization curve (nonlinear)) . However, the obtained torque for for the nonlinear condition was more than 2 times of the linear material. I know about the working point in the PMs but the thing I would like to know is that flux considers this in nonlinear condition. and how we can study demagnetization in a correct way.

Best regards,

Mostafa

##### Share on other sites

Hi,

If you want to study the magnet demagnetization, there is a function in Flux allows to do it. You need to use nonlinear magnet. Once the project is solved:

• Select computation in the toolbar

• Select evaluation of the demagnetization

Best regards.

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.