3d low frequency em tutorial #2 transformer · assembly_3d_tutorial_fem1.fem”. this will make the...

Simcenter 3D Low Frequency EM Tutorial #2

Power Transformer

Version: Simcenter 3D 2020.1

Table of Contents 1. Introduction .......................................................................................................................................... 1

2. CAD Model Pre‐processing ................................................................................................................... 2

2.1. Creating the enclosure air region .................................................................................................... 3

3. Finite Element model ............................................................................................................................ 7

3.1. Prepare Materials ............................................................................................................................ 8

3.2. Mesh Mating .................................................................................................................................. 13

3.3. Generate Mesh .............................................................................................................................. 15

4. Simulation Set‐Up ............................................................................................................................... 21

4.1. Create Coils .................................................................................................................................... 21

4.2. Create excitation ............................................................................................................................ 25

4.3. Setup Boundary Conditions ........................................................................................................... 28

4.4. Setup solving options ..................................................................................................................... 30

4.5. Solve ............................................................................................................................................... 31

4.6. Clone solution and solve ................................................................................................................ 31

5. Results ................................................................................................................................................. 33

5.1. Results for Solution 1 ..................................................................................................................... 33

5.2. Results for Solution 2 ..................................................................................................................... 35

Table of Figures Figure 1: Transformer tutorial model in Simcenter 3D 2020.1 ..................................................................... 1 Figure 2: Transformer 3D assembly .............................................................................................................. 2 Figure 3: Create new FEM and Simulation .................................................................................................... 3 Figure 4: Setup for new FEM and Simulation ............................................................................................... 3 Figure 5: Create Air Region ........................................................................................................................... 4 Figure 6: Edit Object Display ......................................................................................................................... 4 Figure 7: Edit Object Display ......................................................................................................................... 4 Figure 8: Split Body Command ...................................................................................................................... 4 Figure 9: Split air region ................................................................................................................................ 5 Figure 10: Hide partial air region .................................................................................................................. 5 Figure 11: Promote bodies ............................................................................................................................ 5 Figure 12: Split all bodies .............................................................................................................................. 6 Figure 13: Front view .................................................................................................................................... 6 Figure 14: Final quarter model with air region ............................................................................................. 6 Figure 15: Make fem being work part .......................................................................................................... 7 Figure 16: Edit FEM ....................................................................................................................................... 7 Figure 17: Physical Properties ....................................................................................................................... 8 Figure 18: Create physical property table ..................................................................................................... 8 Figure 19: Physical Property table ................................................................................................................ 9 Figure 20: Create new material .................................................................................................................... 9 Figure 21: Property view ............................................................................................................................. 10 Figure 22: Simcenter MAGNET Electromagnetic Property View ................................................................ 10 Figure 23: Set Electrical Properties ............................................................................................................. 11 Figure 24: Set Magnetic Properties ............................................................................................................ 11 Figure 25: Import BH curve data ................................................................................................................. 12 Figure 26: Create BH curve ......................................................................................................................... 12 Figure 27: BH curve plot .............................................................................................................................. 12 Figure 28: Final Physical Property table ...................................................................................................... 13 Figure 29: Mesh Mating command ............................................................................................................. 13 Figure 30: Settings for Mesh Mating Condition .......................................................................................... 13 Figure 31: Mesh Mating Condition information ......................................................................................... 14 Figure 32: Find Exterior Faces command .................................................................................................... 14 Figure 33: 3D Tetrahedral command .......................................................................................................... 15 Figure 34: 3D Tetrahedral Mesh Settings ................................................................................................... 15 Figure 35: 3D mesh settings for shunts ...................................................................................................... 16 Figure 36: Mesh Collector Settings for shunts ............................................................................................ 16 Figure 37: 3D Mesh Settings for frame ....................................................................................................... 16 Figure 38: Mesh Collector Settings for frame ............................................................................................. 17 Figure 39: 3D Mesh Settings for tank.......................................................................................................... 17 Figure 40: Mesh Collector Settings for tank ............................................................................................... 17 Figure 41: Make all bodies visible ............................................................................................................... 18 Figure 42: 3D Mesh Settings for coils ......................................................................................................... 18 Figure 43: Mesh Collector Settings for coils ............................................................................................... 18 Figure 44: 3D Mesh Settings for core.......................................................................................................... 19 Figure 45: Mesh Collector Settings for core ............................................................................................... 19 Figure 46: 3D Mesh Settings for inner air ................................................................................................... 19 Figure 47: Mesh Collector Settings for inner air ......................................................................................... 20 Figure 48: 3D Mesh Settings for outer air ................................................................................................... 20

Figure 49: Mesh Collector Settings for outer air ......................................................................................... 20 Figure 50: 3D Mesh of the model ............................................................................................................... 21 Figure 51: Make sim the work part ............................................................................................................. 21 Figure 52: create a new solution ................................................................................................................ 21 Figure 53: Create Time Harmonic solution ................................................................................................. 22 Figure 54: Make Top view ........................................................................................................................... 22 Figure 55: Launch Create Coil tool .............................................................................................................. 22 Figure 56: Select coil method and set coil name ........................................................................................ 22 Figure 57: Select coil object ........................................................................................................................ 23 Figure 58: Set Coil type and properties ...................................................................................................... 23 Figure 59: Set LV Coil pattern definition ..................................................................................................... 23 Figure 60: Set HV Coil pattern definition .................................................................................................... 24 Figure 61: Coil‐Pattern folder ..................................................................................................................... 24 Figure 62: Edit Coil ...................................................................................................................................... 25 Figure 63: Set Excitation type ..................................................................................................................... 25 Figure 64: Create an excitation ................................................................................................................... 25 Figure 65: Excitation settings ...................................................................................................................... 26 Figure 66: Excitation Modeling Object ........................................................................................................ 26 Figure 67: Create an excitation from Modeling Objects ............................................................................. 26 Figure 68: Modeling Objects Manager ....................................................................................................... 27 Figure 69: Create a voltage excitation modeling object ............................................................................. 27 Figure 70: Assign voltage excitation to coil ................................................................................................. 27 Figure 71: Make Bottom View .................................................................................................................... 28 Figure 72: Select Field Normal Boundary condition ................................................................................... 28 Figure 73: Smart Selection .......................................................................................................................... 28 Figure 74: Set Tangent Faces method ......................................................................................................... 29 Figure 75: Apply Field Normal Boundary condition .................................................................................... 29 Figure 76: Constraint Container .................................................................................................................. 29 Figure 77: Select Surface Impedance boundary condition ......................................................................... 29 Figure 78: Set Surface Impedance boundary condition for frame and tank .............................................. 30 Figure 79: Edit Solution 1 ............................................................................................................................ 30 Figure 80: Edit solution name and source frequency ................................................................................. 30 Figure 81: Launch active solution solve ...................................................................................................... 31 Figure 82: Solver monitor ........................................................................................................................... 31 Figure 83: Clone a solution ......................................................................................................................... 31 Figure 84: Edit solution 2 ............................................................................................................................ 32 Figure 85: Edit mesh collector Shunt .......................................................................................................... 32 Figure 86: Edit mesh collector attributes override ..................................................................................... 32 Figure 87: Attribute overridden mesh collector ......................................................................................... 32 Figure 88: Launch Results Viewer from Low Frequency EM ribbon ........................................................... 33 Figure 89: Low Frequency EM Results viewer ............................................................................................ 33 Figure 90: Add filters for RMS |B| field of solution 1 ................................................................................. 33 Figure 91: Edit Object filter properties ....................................................................................................... 34 Figure 92: RMS |B| field plot ...................................................................................................................... 34 Figure 93: Low Frequency EM Results viewer of Solution 2 ....................................................................... 35 Figure 94: Add filters for RMS |B| field plot of solution 2 .......................................................................... 35 Figure 95: Edit Object filter properties ....................................................................................................... 36 Figure 96: RMS |B| field plot comparison between solutions 1 and 2 ...................................................... 36

Simcenter 3D Low Frequency EM Tutorial #2 2020.1

Restricted © Siemens AG 2020 Page 1 Power Transformer Siemens PLM Software

1. Introduction With growing transformer ratings, the stray loss problem due to leakage flux becomes increasingly important. In such cases, the stray losses in structural components can constitute anywhere from 10% to 40% of the total load losses. This can result in a substantial increase in tank hot spots.

There are several difficulties in performing simulations of stray losses in structural components. Firstly, there is a small penetration depth of the electromagnetic field into the structural steel. Secondly, the structural components are meters long. So these two problems would require an enormous number of elements, making the computation very expensive. However, we can solve this issue by using the Surface Impedance boundary condition, which is available in Simcenter 3D’s Low Frequency EM environment.

This tutorial introduces the 3D workflow of a Power transformer stray losses analysis in the Simcenter 3D Low‐Frequency EM environment. It will cover the model’s pre‐processing and the post‐processing of the typical results (i.e. flux density distribution and losses).

It is important to note that in low‐frequency electromagnetic analysis, the device under analysis needs to be enclosed with a fluid material (in most case, air) that defines the computation domain. Applying the proper boundary conditions to the device results in a unique solution of the problem.

Figure 1: Transformer tutorial model in Simcenter 3D 2020.1

Estimated duration: 1.5 hours



2. CAD Model Pre‐processing In this section, the CAD model is prepared for finite element discretization and EM simulation setup. This involves adding the enclosing air region.

In the Start model folder, you will find all the part files and one assembly part file “Transformer 100MVA

assembly_3D_Tutorial.prt”. We will start from this model.

Launch Simcenter 3D by double‐clicking the desktop icon

Click File|Open , in Open window, navigate to Start model folder, select Part File(*.prt) as Files of type and select “Transformer 100MVA assembly_3D_Tutorial.prt” , then click OK

The “Transformer 100MVA assembly_3D_Tutorial.prt” is a half model of the assembly of the transformer as shown below:

Figure 2: Transformer 3D assembly



2.1. Creating the enclosure air region The air region enclosing the model is created automatically.

Right‐click Transformer 100MVA assembly_3D_Tutorial.prt in the Simulation Navigator and select New FEM and Simulation

Figure 3: Create new FEM and Simulation

In the New FEM and Simulation setup window:

o Check the option Create Idealized Part

o Set “Polygon Body Resolution” to High

o Set Solver to Simcenter MAGNET

o Set Analysis Type to Electromagnetic 3D

Figure 4: Setup for new FEM and Simulation

After clicking OK, the solution setup window will pop up. We will return to the solution setup

later so, for now, click Cancel

Double click “Transformer 100MVA assembly_3D_Tutorial_fem1_i.prt” in the Simulation Navigator to make it the work part

Click “Create Air Region” from the Low Frequency EM ribbon.



In the Air Enclosure window, select 3D and Box and set the scale factors: X=1.75, Y=3.25, Z=1.75

Figure 5: Create Air Region

Click OK; the enclosing air region is done. For a better view, click Edit Object Display from View tab

Figure 6: Edit Object Display

In the Class Selection window, select the created air region from the view window as Select Object, and click OK. Then set Translucency to 90 and click OK in Edit Object Display window.

Figure 7: Edit Object Display

Since it is a half model, the air region needs to be split. Click Split Body from Home|Geometry

Preparation commands group.

Figure 8: Split Body Command



In the Split Body window, select the air region body from view window as the Select body. Set New

Plane as Tool option and select XC‐ZC plane as Specify Plane with Distance=0. Then click OK.

Figure 9: Split air region

Change the selection filter to Solid Body, right‐click the split small air region and select Hide icon. The final model with air region is shown as right image below.

Figure 10: Hide partial air region

Taking advantage of the symmetry of upper and lower parts, the model can be further split into a quarter model. Before modifying the geometry, click Promote command from Home|Start. In Promote Body window, use Ctrl+A to select all the bodies and click OK.

Figure 11: Promote bodies



Click Split Body from Home|Geometry Preparation commands group. In the Split Body window, use Ctrl+A select all bodies as Select body. Set New Plane as Tool option and select XC‐YC plane

as Specify Plane with Distance=0. Then click OK.

Figure 12: Split all bodies

Right‐click the blank region in the view window, and select Front from Orient View.

Figure 13: Front view

Change the selection filter to Solid Body, drag a box to select the lower parts and select Hide icon. The final model with the air region is shown in the image below (far right).

Figure 14: Final quarter model with air region



3. Finite Element model In Simcenter 3D, all the operations related to mesh and materials are done in the fem file. This section will create meshes for each parts of the motor and assign the materials to the corresponding mesh collectors.

Right‐click “Transformer 100MVA assembly_3D_Tutorial_fem1_i.prt” in the Simulation Navigator, select Display FEM and then “Transformer 100MVA assembly_3D_Tutorial_fem1.fem”. This will make the fem the work part.

Figure 15: Make fem being work part

Right‐click “Transformer 100MVA assembly_3D_Tutorial_fem1.fem” in the Simulation Navigator, select Edit. In the Edit FEM window, check option Edit Bodies to Use and set All Visible.

Click OK.

Figure 16: Edit FEM



3.1. Prepare Materials The materials in the model are listed below:

Air region: Air

Coil material: Copper 5.77e7

Core material: MU3: Relative permeability 1000

Shunt material: M6: Unisil/alphasil 35 M6

Structure material: Carbon Steel

Since different mesh collectors might have the same material, the Physical Properties table will be used to better organize the material selection.

In Home|Properties commands group, click Physical Properties.

Figure 17: Physical Properties

In the Physical Property Table Manager window, set the Type to Solid and Name to Air and click Create.

In Solid window, click Choose material button beside Material cell. In the Material List window, select AIR and click OK

Figure 18: Create physical property table

In Solid window, Click OK.



The Air physical property is listed under Selection in Physical Property Table Manager window. Follow the same steps to create the other physical properties that are required:

o Coil material: (Copper 5.77e7) o Core material: (MU3: Relative permeability 1000) o Shunt material: (M6: Unisil/alphasil 35 M6) o Structure material: (Carbon Steel)

Figure 19: Physical Property table

Since the structural steel Carbon Steel is not available in the predefined library, users need to create it manually.

Set the name as StrucSteel, click Create button. In Solid window, click Choose material button beside Material cell

In the Material List window, select Isotropic as Type and then click Create material button in New

Material section

Figure 20: Create new material



In the Isotropic Material window, the Property View lets the users filter material properties in the

dialog. So, instead of showing all properties, users can select one property view. For Simcenter

Low Frequency EM environment, there are four view options:

Simcenter MAGNET Electromagnetic

‐‐ shows electromagnetic material properties

Simcenter MAGNET Electric

‐‐ shows electrical material properties

Simcenter MAGNET Electromagnetic Thermal

‐‐ shows electromagnetic and thermal material properties

Simcenter MAGNET Electric Thermal

‐‐ shows electrical and thermal material properties

Figure 21: Property view

Select the Simcenter MAGNET Eelctromagnetic property view. Here, only Electromagnetic properties

are shown.

Figure 22: Simcenter MAGNET Electromagnetic Property View



Specify the following settings as shown in the image below:

Name: Carbon steel

Mass Density=7830 kg/m3

Resistivity=1.05e‐7 Ωm

Linear Permittivity=1

Figure 23: Set Electrical Properties

Check Soft Magnet and Nonlinear Permeability. A table for BH Curve is displayed. Set Temperature

to 20. Click = button in BH Curve (1) cell and select New Field and then Table.

Figure 24: Set Magnetic Properties



Click Next to accept all defaults until the Definition table appears. In the Table Field/Definition window, click Import from Text File.

In Table Data Import window, navigate to Start model folder and select Carbon steel BH data.txt.

Click OK.

Figure 25: Import BH curve data

The imported data are shown in the Definition table.

Click OK; the BH Curve (1) is created.

Figure 26: Create BH curve

Users can plot the BH curve by selecting Plot(XY) from the editing button. In the Viewport

window, select Create New Window; the plot is shown in a Graph Window.

Figure 27: BH curve plot



Close the graph window and click OK in Isotropic Material window to finish the new material

creation. In Material List window, all the materials used in the model are listed as Local Materials.

In Solid window, click OK; the created Carbon steel is shown. Click OK again to finish the StrucSteel

physical property definition. Then close the Physial Property Table Manager window.

Figure 28: Final Physical Property table

Now that the materials are all prepared, we can continue to the next steps in the tutorial.

Click File|Save|Save all to save the files.

3.2. Mesh Mating For EM analysis, a conformed mesh is needed. For 3D cases, Mesh Mating should be always applied before starting mesh.

Click Home|Connection|Mesh Mating.

Figure 29: Mesh Mating command

Change the selection filter to Polygon Body, use Ctrl+A select all bodies as Selection in Mesh Mating

Condition window, making sure the mesh mating type is Glue‐Coincident. Keep all other settings and click OK.

Figure 30: Settings for Mesh Mating Condition



After finishing the process, 106 Glue Coincident MMCs are created.

Figure 31: Mesh Mating Condition information

To check if all the MMCs are applied properly , click Find Exterior Faces command from Low Frequency EM ribbon. This feature will group all the exterior faces under Groups in the Simulation

Navigator. Click Exterior Faces group; the view window will update to show all the exterior faces. If there are no interior faces, this means all MMCs have been applied properly.

Figure 32: Find Exterior Faces command




3.3. Generate Mesh Click 3D Tetrahedral from Home|Mesh tab

Figure 33: 3D Tetrahedral command

In the 3D Tetrahedral Mesh window, the following selections (highlighted below) are required settings for EM models:

For 3D case, the only available mesh type is Linear Tetrahedron

Internal Mesh Gradation should be always set to 1

Small Feature Tolerance should be always set to 0

Figure 34: 3D Tetrahedral Mesh Settings



Due to Simcenter 3D’s meshing paradigm, the order of the mesh assignments is important. Where faces/edges meet, it is recommended that you start the mesh from the one that has the smaller mesh element size.

Make the core, windings and air regions invisible. Select the 9 pieces shunt as Objects to Mesh.

Set Element Size=9 mm, keep all other settings. Create a mesh collector “Shunt” with ShuntSteel

as Solid Property.

Figure 35: 3D mesh settings for shunts

Click Apply to keep the the 3D Tetrahedral Mesh window open with the same settings. After finishing the mesh processing, the Shunt is listed under 3D Collectors in the Simulation Navigator.

Figure 36: Mesh Collector Settings for shunts

Select the frame as Objects to Mesh. Set Element Size=9 mm and keep all other settings. Create a

mesh collector “Frame” with StrucSteel as Solid Property.

Figure 37: 3D Mesh Settings for frame



Click Apply to keep the 3D Tetrahedral Mesh window open with the same settings. After finishing the mesh processing, the Frame is listed under 3D Collectors in the Simulation Navigator.

Figure 38: Mesh Collector Settings for frame

Select the tank pieces as Objects to Mesh. Set Element Size=22 mm, check Minimum Two Elements

Through Thickness option. Keep all other settings. Create a mesh collector “Tank” with StrucSteel

as Solid Property.

Figure 39: 3D Mesh Settings for tank

Click OK. After finishing the mesh processing, Tank is listed under 3D Collectors in the Simulation

Navigator. To obtain a better view of the mesh, click Home|Utilities|More and select Model Display

Preferences. In Model Display window, under Element page, select Mesh Collector for Color Basis and click Set Mesh Colors button.

Figure 40: Mesh Collector Settings for tank



Uncheck Polygon Geometry and check it again to make all bodies visible.

Figure 41: Make all bodies visible

Click 3D Tetrahedral from Home|Mesh tab. Select the coil pieces as Objects to Mesh. Set Element

Size=30 mm, Surface Curvature Based Size Variation=70. Uncheck the “Minimum Two Elements

Through Thickness” option and keep all other settings. Create a mesh collector “Coils” with

Copper as Solid Property.

Figure 42: 3D Mesh Settings for coils

Click Apply to keep the 3D Tetrahedral Mesh window open with the same settings. After finishing the mesh processing, the Coils is listed under 3D Collectors in the Simulation Navigator.

Figure 43: Mesh Collector Settings for coils



Select the core as Objects to Mesh. Set Element Size=70 mm, keep all other settings. Create a mesh

collector “Core” with CoreSteel as Solid Property.

Figure 44: 3D Mesh Settings for core

Click Apply to keep the 3D Tetrahedral Mesh window open with the same settings. After finishing the mesh processing, the Core is listed under 3D Collectors in the Simulation Navigator.

Figure 45: Mesh Collector Settings for core

Select the inner air as Objects to Mesh. Keep all other settings that were set for core. Create a

mesh collector “Inner air” with Air as Solid Property.

Figure 46: 3D Mesh Settings for inner air



Click Apply to keep the 3D Tetrahedral Mesh window open with the same settings. After finishing the mesh processing, the Inner air is listed under 3D Collectors in the Simulation Navigator.

Figure 47: Mesh Collector Settings for inner air

Select the outer air as Objects to Mesh. Keep all other settings as set for Inner air. Create a mesh

collector “Outer air” with Air as Solid Property.

Figure 48: 3D Mesh Settings for outer air

Click OK. After finishing the mesh processing, the Outer air is listed under 3D Collectors in the Simulation Navigator.

Figure 49: Mesh Collector Settings for outer air



To obtain a better view of the mesh, click Home|Utilities|More and select Model Display

Preferences. In Model Display window, under Element page, select Mesh Collector for Color Basis and click Set Mesh Colors button.

Figure 50: 3D Mesh of the model


4. Simulation Set‐Up The simulation set‐up involves creating coils, circuits, motion components and assigning boundary conditions, which can only be done in the sim file.

Right‐click “Transformer 100MVA assembly_3D_Tutorial_fem1.fem” in the Simulation Navigator, select Display Simulation and then “Transformer 100MVA assembly_3D_Tutorial_sim1.sim”. This will make the sim the work part.

Figure 51: Make sim the work part

4.1. Create Coils Coils are implemented as simulation objects and are associated to a solution. Before creating coils, at least one solution should be created.

Right‐click “Transformer 100MVA assembly_3D_Tutorial_sim1.sim” in the Simulation Navigator, select New Solution.

Figure 52: create a new solution



In the Solution window, set Solution Type to Time Harmonic.

Click OK; the new solution is listed in the Simulation Navigator.

Figure 53: Create Time Harmonic solution

To obtain a better view, make the polygon bodies of Coils visible only and change to Top view

Figure 54: Make Top view

From the Low Frequency EM ribbon, under the Coils command group, click Create Coil.

Figure 55: Launch Create Coil tool

In the Coil window, select Body Coil method. Then set the name as LV.

Figure 56: Select coil method and set coil name



Select the inner right‐most body as Select Object. An arrow will show the current flow direction. Reverse Direction button can be used to change the direction. For this case, keep the direction as shown.

Figure 57: Select coil object

In Coil Type section, select Stranded as Type, set Number of Turns=398.

Figure 58: Set Coil type and properties

In Pattern Definition section, select Linear as Type, set ‐XC as Specify Vector. Select Count and Pitch as Spacing method, set Count=3 and Span=1470 mm. Click Preview Pattern to show all coils.

Figure 59: Set LV Coil pattern definition



Click Apply to finish the coil definition and to keep the window open with the same settings.

Change the name to HV, and select the outer right‐most body as Select Object. Change Number of

Turns to 694. Keep other settings and then click Preview Pattern button to show all coils.

Figure 60: Set HV Coil pattern definition

Click OK to finish the coils definition. In the Simulation Navigator, two folders will be listed under

Simulation Object Container, which includes 3 coils each for a total of 6 coils. To display the coils,

click Display Coils from the Low Frequency EM ribbon.

Note: the coils are active and automatically added to the active solution that was created earlier.

Figure 61: Coil‐Pattern folder




4.2. Create excitation In place of creating the excitation in a circuit, it can be set through the Body Coil window instead.

Right‐click LV and select Edit from Simulation Objects Container.

Figure 62: Edit Coil

In the Body Coil window, select Current Driven from the type drop‐down list in Excitation section.

Figure 63: Set Excitation type

Click Create Modeling Object button beside Coil Excitation cell.

Figure 64: Create an excitation



In the Coil Excitation‐Current window, set Name to Coil Excitation‐LV, change the source type to

AC, set Magnitude (RMS)=437.38 A, and Phase=‐120. Then click OK. The Coil Excitation‐LV appears

in Coil Excitation cell. Click OK to finish the excitation settings.

Figure 65: Excitation settings

The created current excitation Coil Excitation‐LV is stored as Modeling Object and listed under

Modeling Objects in the Simulation Navigator.

Figure 66: Excitation Modeling Object

Follow the same steps to create another 5 current excitations as below:

LV (2): Coil Excitation‐LV (2), AC, Magnitude (RMS)=437.38 A, and Phase=0.

LV (3): Coil Excitation‐LV (3), AC, Magnitude (RMS)=437.38 A, and Phase=120 The high voltage coils in this demo are all short‐circuited. So, one Voltage Driven type excitation

with 0 voltage can be applied to all three HV coils. Right‐click Modeling Objects and select

Modeling Objects.

Figure 67: Create an excitation from Modeling Objects



In the Modeling Objects Manager window, select Coil Excitation‐Voltage from the type drop‐down

list. Set Name as Coil Excitation‐Voltage HV and click Create button.

Figure 68: Modeling Objects Manager

In the Coil Excitation‐Voltage window, change the type to AC and keep 0 for the magnitude. Click

OK. The Selection table in the Modeling Objects Manager window lists all the excitations. Click OK to

finish the voltage excitation creation.

Figure 69: Create a voltage excitation modeling object

Right‐click HV coil under Simulation Objects Container, select Edit. In the Body Coil window, select

Voltage Driven from the type drop‐down list in Excitation section. Then select Coil Excitation‐

Voltage HV for Coil Excitation.

Figure 70: Assign voltage excitation to coil

Follow the same steps to set Coil Excitation‐Voltage HV to HV (2) and HV (3).




4.3. Setup Boundary Conditions The faces on XY plane should be assigned a Field Normal boundary condition.

Change the view to Bottom.

Figure 71: Make Bottom View

Select Field Normal from Constraint Type in Home|Loads and Conditions menu ribbon.

Figure 72: Select Field Normal Boundary condition

In the Field Normal window, click Stack Smart Selector Methods button in Faces section. In Smart

Selector Methods window, select Tangent Faces as method. Set Tangent Angle Tolerance=0, uncheck

Stop at Non‐manifold Junctions.

Figure 73: Smart Selection



In the view window, click the face of outer air, then click Commit method button.

Figure 74: Set Tangent Faces method

All 29 faces on the XY plane are selected. Click OK twice to finish the definition of the Field Normal

boundary condition.

Figure 75: Apply Field Normal Boundary condition

The created Field Normal boundary condition is listed under Constraint Container in the Simulation

Navigator

Figure 76: Constraint Container

For the structural parts, such as Tank and Frame, Surface Impedance (SI) boundary condition are

assigned. Note that the SI is applied to the Body. Make core, coil and air bodies invisible. Select

Surface Impedance from Constraint Type in Home|Loads and Conditions menu ribbon.

Figure 77: Select Surface Impedance boundary condition



In the Field Normal window, change Name to SI Frame, select the frame from view window as

Select Object and keep the default Impedance setting as Calculated Value. Follow the same steps

to create SI for the 4 pieces of tank. As a result, 5 Surface Impedance conditions are created and

listed under Constraints

Figure 78: Set Surface Impedance boundary condition for frame and tank


4.4. Setup solving options The solving related options are setup by editing the solution.

Right‐click Solution 1 and select Edit.

Figure 79: Edit Solution 1

In the Solution window, change the solution Name to Solution 1‐TH with Shunts. In General tab, set

Default Source Frequency=50 Hz

Note: The setting Default Source Frequency is specific to AC source type that is assumed to be cosine in Low Frequency EM

Figure 80: Edit solution name and source frequency

Keep the default settings in all the other tab and click OK to finish the solution editing. Click File|Save|Save all to save the files.



4.5. Solve

Right‐click the active solution Solution 1‐TH with Shunts, and select Solve. In the Solve window, click OK to start the solve

Note: click Edit Solver Parameters, and uncheck the option Run Solver in Foreground will allow the users continue working on the sim when starting solve.

Figure 81: Launch active solution solve

When starting solve, a solver monitor will pop up to show the solving progress.

Figure 82: Solver monitor

4.6. Clone solution and solve Since we have unchecked the Run Solver in Foreground option, we can continue working on the sim during the solving process. Now, we will create another solution by cloning solution 1. The clone will keep the same settings as the source solution. This solution is to solve the same model but without shunts on the tank wall. Here the mesh attributes overridding feature will be used to replace the shunt material with air.

Right‐click Solution 1‐TH with Shunts and select Clone; a new solution is created.

Figure 83: Clone a solution



Right‐click Copy Solution 1‐TH with Shunts and select Edit. Change the solution name to Solution 2‐

TH without Shunts and click OK

Figure 84: Edit solution 2

Right‐click Shunt under 3D Collectors and select Edit Attribute Overrides.

Figure 85: Edit mesh collector Shunt

In the Override Mesh Collector Attributes window, click the button beside Type and select Apply Override. From the drop‐down list of Solid Property, select Air and click OK.

Figure 86: Edit mesh collector attributes override

Note ‐‐ the color of Shunt becomes red, which indicates that the attributes have been overridden.

Figure 87: Attribute overridden mesh collector

Right‐click the active solution “Solution 2‐TH without Shunts”, and select Solve.



5. Results The post‐processing of results is available through a separate tool (i.e. Low Frequency EM ‐ Results Viewer)

that can be launched directly from Simcenter.

Click Open Results Viewer from the Low Frequency EM ribbon. This will open the results of the

active solution.

Figure 88: Launch Results Viewer from Low Frequency EM ribbon

5.1. Results for Solution 1

Note In version 2020.1 of the Results Viewer:

TreeView panel has been renamed Datasets and Solutions.

Component has been renamed Object.

Functionality has not changed.

From the Simulation Navigator, double‐click Solution 1 to make it the active solution, then click

Open Results Viewer from the Low Frequency EM ribbon. The results viewer will popup. In Datasets

and Solutions, the default datasets are listed: Solution mesh and the B field.

Figure 89: Low Frequency EM Results viewer

Right‐click Vector magnitude filter under B field, and select Delete. Right‐click Object, select New

Filter and RMS. Follow the same steps, add another two filters Vector magnitude and Phasor

magnitude as shown below.

Figure 90: Add filters for RMS |B| field of solution 1



Right‐click Object and select Properties. In Object Filter Properties window, check Include for Selection mode and select all the SI Objects from Selected objects drop‐down list.

Figure 91: Edit Object filter properties

Click OK. Checking the Phasor Magnitude filter displays the RMS |B| plot in the Field view; this may take a

minute. To obtain the below view, right‐click the Field View and select Plane Views/Bottom.

Figure 92: RMS |B| field plot

Close and save the Results Viewer and return to Simcenter 3D.



5.2. Results for Solution 2

From the Simulation Navigator, double‐click “Solution 2‐TH without Shunts” to make it the

active solution, then click Open Results Viewer from the Low Frequency EM ribbon. The results

viewer will popup. In Datasets and Solutions, the default datasets are listed: Solution mesh and the B

field.

Figure 93: Low Frequency EM Results viewer of Solution 2

Right‐click Vector magnitude filter under B field, and select Delete. Right‐click Object, select New

Filter and RMS. Following the same steps, add another two filters Vector magnitude and Phasor

magnitude, as shown below.

Figure 94: Add filters for RMS |B| field plot of solution 2



Right‐click Object and select Properties. In Object Filter Properties window, check Include for Selection mode and select all the SI objectsts from Selected objectss drop‐down list.

Figure 95: Edit Object filter properties

Click OK Checking the Phasor Magnitude filter displays the RMS |B| plot in the Field view; this may take a

minute. To obtain the below view, right‐click the Field View and select Plane Views/Bottom.

Note: The right image below is the field plot of solution 2, in which the shunt material is overridden by air, effectively making it non‐existent. The image to the left shows the field of solution 1. Because of the shield effect of the shunts, the fields in the structural objects, such as tank and frame, are reduced significantly. This leads to a reduction in stray losses.

Figure 96: RMS |B| field plot comparison between solutions 1 and 2

3d low frequency em tutorial #2 transformer · assembly_3d_tutorial_fem1.fem”. this will make the...

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