Learning Forum

[thece]

Hello

Is it possible to create a real hysteresis (or BH) curve in Maxwell for a specific material?

For example, fair-rite provides the following BH for 95 material

from which it's possible to create a XY dataset of points. The problem is that I am not sure if Maxwell can understand the difference between the coercive +Hc and the remanent Br vs. the -Hc and -Br.

Thank you!

P.s.: I am aware a can import the points which represent the initial magnetization curve. I am just curious if it is possible to simulate something more realistic.

[NA]

Hello,
You can calculate core loss properties using a hysteresis loop while using the transient solver by following the steps below:

1. Click Tools>Edit Configured Libraries>Materials. to open the Edit Libraries dialog box.

• Alternatively, in the project tree, you can right-click Materials, under Definitions, and select Edit All Libraries.

2. Click Add Material to open the View/ Edit Material dialog box.
3. In the Core Loss Model row, select Hysteresis Model from the Value pull-down list.

If you select either View/Edit Material for: This Product or All Products radio button, additional parameters appear in the table below Core Loss Model (Intrinsic Coercivity Hci, Remanency Br, Kc, and Equiv. Cut Depth). You can input these values directly. You can also supply the Hci and Br values in the Properties for Hysteresis Loop dialog box as described below.

The Hysteresis Loop selection in the Calculate Properties for pull-down list at the bottom of the dialog box is also enabled. This allows the coefficients Hci, and Br to be derived from a manufacturer-provided core loss curve.

4. Select Hysteresis Loop from the Calculate Properties for pull-down list at the bottom of the dialog box to open the Properties for Hysteresis Loop dialog box The current BH curve coordinates are loaded by default. Hci and Br values from the Intrinsic Coercivity Hci, Remanency Br fields in the View / Edit Material dialog box are also displayed.
5. Do one of the following to specify the hysteresis loop curve:
   Enter the B and H values in each row of the Coordinates table manually. The graph updates as you enter values. Buttons allow you Add, Append, and Delete table rows as needed
   
   • You can also import the hysteresis loop coordinates from a saved file.
   1. Click Import Dataset to open the Import Dataset dialog box.
   2. Find and select either the BH Data .bh file, or the tab-delimited .tab file containing the curve data points. Click Open to import the data.
   3. Optionally, click Swap X-Y Data to switch the B and H values if they are in the wrong columns

  6.Optionally, enter the Hci and Br values and choose appropriate units for them. Input Br must be enabled to enable the Br entry box; otherwise, the default zero value indicates that Br will be determined automatically by the software. (These fields may already have values in them if previously supplied in the View / Edit Material dialog box.) Disabling Input Br resets the Br value to zero.

  7.Optionally, select either Normal (the default) or Intrinsic for BH curve input and plot display. When changing from Normal to Intrinsic (or vice-versa) the following dialog displays, allowing you to choose whether or not to convert B values.

   8. Optionally, you can export data for the descending and ascending curve of the hysteresis loop. You can also export the BH curve as well as the smoothed BH curve.

   9. Click OK to close the Properties for Hysteresis Loop dialog.

10. Click OK to close the View / Edit Material dialog box.
11. Click OK to close the Edit Libraries dialog box.

You can find more information on this on Maxwell Help under Assigning Materials > Permanent Magnets > Calculating Properties Using a Hysteresis Loop in Maxwell

or under the direct link:

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/Electronics/v231/en/home.htm%23../Subsystems/Maxwell/Content/CalculatingPropertiesUsingaHysteresisLoopinMaxwell.htm?Highlight=Hysteresis%20loop

 

 

[thece]

Ok, the procedure was slightly different but the end result is fine. The easiest way is to modify an already existing material.

I think that this will do!

One more question: if the initial curve has changing curvature as the one that is presented in Maxwell manual, does Maxwell calculates the BH relationship from the initial curve or the ascending/decending curve?

Thank you

 

 

[NA]

The initial magnetization curve is used in the first pass of the simulation. Afterwards the loop is used.

[thece]

Thank you for your time :)