Maxwell v15		6.3
	Eddy Current – Application Note

PART 2 - The 3D Eddy Project

Now the identical model will be simulated in Maxwell 3D.

Setup the Design

1.Click on the menu item Project > Insert Maxwell 3D Design

2.Click on the menu item Maxwell 3D > Solution Type ...

•Select the radio button Magnetic: Eddy Current

3.Draw the Solution Region

oClick on Draw > Box (Enter the following points using the tab key).

X: 0, Y: -150, Z: -150

dX: 10, dY: 300, dZ: 300

oChange its properties:

Name: Region

Display Wireframe: Checked

o Select View > Fitall > Active View to resize the drawing window.

Create the Model

Now the model can be created. This model also consists of a left and right busbar that have a 4mm square cross-section and a length of 10mm.

Create the Left Busbar

Click on Draw > Box

X: 0 Y: -12, Z: -2

dX: 10, dY: 4, dZ: 4

Change its properties:

Name: left

Material: Copper

Color: Red

Create the Right Busbar

Click on Draw > Box

X: 0 Y: 8, Z: -2

dX: 10, dY: 4, dZ: 4

Change its properties:

Name: Right

Material: Copper

Color: Red

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Maxwell v15		6.3
	Eddy Current – Application Note

Assign the Boundaries and Sources

The current is assumed to be 1A at 0 degrees in the left busbar and -1A at 60 degrees in the right busbar. The default boundary in Maxwell 3D in no-fringing. So a boundary does not need to be explicitly assigned.

1.To assign the source current, the four (4) end faces of the conductors must be selected. Choose Edit > Select > Faces to change the selection mode from object to face.

2.Zoom in to the busbars using:View > Zoom In

3.Click on the front face of the left busbar.

•Click on Maxwell > Excitations > Assign > Current o Name: Current1

o Value: 1A o Phase: 0

o Type: Solid

3.Select the other face of the left busbar. Select it and then:

•Click on Maxwell > Excitations > Assign > Current

o Name: Current2

o Value: 1A

o Phase: 0

o Type: Solid

oClick on Swap Direction to be sure that the red directional arrow is pointing out of the conductor

5.Click on the front face of the right busbar.

•Click on Maxwell > Excitations > Assign > Current

oName: Current3

oValue: 1A

oPhase: 60

oType: Solid

6.Select the other face of the left busbar. Select it and then:

•Click on Maxwell > Excitations > Assign > Current

oName: Current4

o Value: 1A

o Phase: 60

o Type: Solid

oClick on Swap Direction to be sure that the red directional arrow is pointing out of the conductor

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Maxwell v15		6.3
	Eddy Current – Application Note

Turn on the Eddy Effects in the winding

In order to consider the skin effects in the busbars, the eddy effect must be turned on.

1.Choose Maxwell 3D > Excitations > Set Eddy Effects ...

2.Verify that the eddy effect for left and right is checked.

3.Un-check the displacement current calculation.

Assign the Parameters

In order to automatically calculate force on an object, it must be selected in the Parameters panel. In Maxwell 3D, you can calculate both virtual and Lorentz force. Note however that Lorentz force is only valid on objects with a permeability = 1.

1.Select the left busbar by clicking on it in the history tree or on the screen.

2.Click on Maxwell > Parameters > Assign > Force

3.Name: Force_Virtual

4.Type: Virtual

5.Click OK to enable the virtual force calculation.

6.Click on Maxwell > Parameters > Assign > Force

7.Name: Force_Lorentz

8.Type: Lorentz

9.Click OK to enable the lorentz force calculation.

Add an Analysis Setup

1.Click Right on the Analysis folder in the Model Tree and select Add Solution Setup…

2.On the General tab, re-set the Number of passes to 15.

3.Percent Error to 0.01

4.On the Solver tab, re-set the Adaptive Frequency to 100kHz.

5.Click OK to save the setup.

Solve the Problem

1.Save the project by clicking on menu item File > Save

2.Select the menu item Maxwell 3D > Validation Check to verify problem setup

3.Click on Maxwell 3D > Analyze All.

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Maxwell v15		6.3
	Eddy Current – Application Note

View the Results

3.Select Maxwell 3D > Results > Solution Data… and click on the Force tab. Notice that the 3D results are reported for a 10mm depth while the 2D results were for 1meter depth. The DC forces are shown below.

4.Now select Type:AC<Mag,Phase> This shows the magnitude of the force F(y)Mag is

approximately 5e-8 (N) and the phase F(y)Phase is -2.0 radians or -120 degrees. F(y) in 3D is same direction as F(x) in 2D and has a magnitude 1/100th of 2D since the modeled length is 10mm compared to 1m in 2D.

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