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Choke setup

This example shows how to use PyAEDT to create a choke setup in Maxwell 3D.

Keywords: Maxwell 3D, choke.

Prerequisites

Perform imports

import json
import os
import tempfile
import time

import ansys.aedt.core  # Interface to Ansys Electronics Desktop

Define constants.

Constants help ensure consistency and avoid repetition throughout the example.

AEDT_VERSION = "2025.2"
NG_MODE = False  # Open AEDT UI when it is launched.

Create temporary directory

Create a temporary working directory. The name of the working folder is stored in temp_folder.name.

Note: The final cell in the notebook cleans up the temporary folder. If you want to retrieve the AEDT project and data, do so before executing the final cell in the notebook.

temp_folder = tempfile.TemporaryDirectory(suffix=".ansys")

Launch Maxwell3D

Launch Maxwell by creating an instance of Maxwell3d.

project_name = os.path.join(temp_folder.name, "choke.aedt")
m3d = ansys.aedt.core.Maxwell3d(
    project=project_name,
    solution_type="EddyCurrent",
    version=AEDT_VERSION,
    non_graphical=NG_MODE,
    new_desktop=True,
)

PyAEDT INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr  5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)].
PyAEDT INFO: PyAEDT version 0.22.dev0.
PyAEDT INFO: Initializing new Desktop session.
PyAEDT INFO: Log on console is enabled.
PyAEDT INFO: Log on file C:\Users\ansys\AppData\Local\Temp\pyaedt_ansys_b8744447-a5cd-41f0-8a14-ae1bd256c740.log is enabled.
PyAEDT INFO: Log on AEDT is disabled.
PyAEDT INFO: Debug logger is disabled. PyAEDT methods will not be logged.
PyAEDT INFO: Launching PyAEDT with gRPC plugin.
PyAEDT INFO: New AEDT session is starting on gRPC port 53298.
PyAEDT INFO: Electronics Desktop started on gRPC port: 53298 after 11.352928161621094 seconds.
PyAEDT INFO: AEDT installation Path C:\Program Files\ANSYS Inc\v252\AnsysEM
PyAEDT INFO: Ansoft.ElectronicsDesktop.2025.2 version started with process ID 3240.
PyAEDT INFO: Project choke has been created.
PyAEDT INFO: No design is present. Inserting a new design.
PyAEDT INFO: Added design 'Maxwell 3D_7HN' of type Maxwell 3D.
PyAEDT INFO: Aedt Objects correctly read

Model Preparation

This example uses a custom create_choke() method to create a common-mode choke in Maxwell 3D. The geometric parameters are passed to the method as a dict instance.

Choke Geometric Parameters

The dictionary values contain the different parameter values of the core and the windings that compose the choke. You must not change the main structure of the dictionary. The dictionary has many primary keys, including "Number of Windings", "Layer", and "Layer Type", that have dictionaries as values. The keys of these dictionaries are secondary keys of the dictionary values, such as "1", "2", "3", "4", and "Simple".

You must not modify the primary or secondary keys. You can modify only their values. You must not change the data types for these keys. For the dictionaries from "Number of Windings" through "Wire Section", values must be Boolean. Only one value per dictionary can be True. If all values are True, only the first one remains set to True. If all values are False, the first value is chosen as the correct one by default. For the dictionaries from "Core" through "Inner Winding", values must be strings, floats, or integers.

Descriptions follow for the primary keys:

• "Number of Windings": Number of windings around the core.

• "Layer": Number of layers of all windings.

• "Layer Type": Whether layers of a winding are linked to each other

• "Similar Layer": Whether layers of a winding have the same number of turns and same spacing between turns.

• "Mode": When there are only two windows, whether they are in common or differential mode.

• "Wire Section": Type of wire section and number of segments.

• "Core": Design of the core.

• "Outer Winding": Design of the first layer or outer layer of a winding and the common parameters for all layers.

• "Mid Winding": Turns and turns spacing (Coil Pit) for the second or mid layer if it is necessary.

• "Inner Winding": Turns and turns spacing (Coil Pit) for the third or inner layer if it is necessary.

• "Occupation(%)": An informative parameter that is useless to modify.

The following parameter values work. You can modify them if you want.

choke_descriptor = {
    "Number of Windings": {"1": False, "2": False, "3": True, "4": False},
    "Layer": {"Simple": False, "Double": False, "Triple": True},
    "Layer Type": {"Separate": False, "Linked": True},
    "Similar Layer": {"Similar": False, "Different": True},
    "Mode": {"Differential": True, "Common": False},
    "Wire Section": {"None": False, "Hexagon": False, "Octagon": True, "Circle": False},
    "Core": {
        "Name": "Core",
        "Material": "ferrite",
        "Inner Radius": 100,
        "Outer Radius": 143,
        "Height": 25,
        "Chamfer": 0.8,
    },
    "Outer Winding": {
        "Name": "Winding",
        "Material": "copper",
        "Inner Radius": 100,
        "Outer Radius": 143,
        "Height": 25,
        "Wire Diameter": 5,
        "Turns": 2,
        "Coil Pit(deg)": 4,
        "Occupation(%)": 0,
    },
    "Mid Winding": {"Turns": 7, "Coil Pit(deg)": 4, "Occupation(%)": 0},
    "Inner Winding": {"Turns": 10, "Coil Pit(deg)": 4, "Occupation(%)": 0},
}

Convert dictionary to JSON file

Convert the dictionary to a JSON file. PyAEDT methods ask for the path of the JSON file as an argument. You can convert a dictionary to a JSON file.

choke_fn = os.path.join(temp_folder.name, "choke_example.json")

with open(choke_fn, "w") as outfile:
    json.dump(choke_descriptor, outfile)

Verify parameters of JSON file

Verify parameters of the JSON file. The check_choke_values() method takes the JSON file path as an argument and does the following:

• Checks if the JSON file is correctly written (as explained earlier)

• Checks equations on windings parameters to avoid having unintended intersections

choke_descriptor_2 = m3d.modeler.check_choke_values(
    input_dir=choke_fn, create_another_file=False
)
print(choke_descriptor_2)

PyAEDT INFO: Modeler class has been initialized! Elapsed time: 0m 1sec
PyAEDT INFO: Materials class has been initialized! Elapsed time: 0m 0sec
PyAEDT WARNING: Inner Radius of the winding is too high. The maximum value has been set instead.
PyAEDT WARNING: Outer Radius of the winding is too low. The minimum value has been set instead.
PyAEDT WARNING: Height of the winding is too low. The minimum value has been set instead.
[True, {'Number of Windings': {'1': False, '2': False, '3': True, '4': False}, 'Layer': {'Simple': False, 'Double': False, 'Triple': True}, 'Layer Type': {'Separate': False, 'Linked': True}, 'Similar Layer': {'Similar': False, 'Different': True}, 'Mode': {'Differential': True, 'Common': False}, 'Wire Section': {'None': False, 'Hexagon': False, 'Octagon': True, 'Circle': False}, 'Core': {'Name': 'Core', 'Material': 'ferrite', 'Inner Radius': 100, 'Outer Radius': 143, 'Height': 25, 'Chamfer': 0.8}, 'Outer Winding': {'Name': 'Winding', 'Material': 'copper', 'Inner Radius': 86.25, 'Outer Radius': 156.75, 'Height': 52.5, 'Wire Diameter': 5, 'Turns': 2, 'Coil Pit(deg)': 4, 'Occupation(%)': 13.333333333333334}, 'Mid Winding': {'Turns': 7, 'Coil Pit(deg)': 4.0, 'Occupation(%)': 46.666666666666664}, 'Inner Winding': {'Turns': 10, 'Coil Pit(deg)': 4.0, 'Occupation(%)': 66.66666666666667}}]

Create choke

Create the choke. The create_choke() method takes the JSON file path as an argument.

list_object = m3d.modeler.create_choke(input_file=choke_fn)
# print(list_object)
core = list_object[1]
first_winding_list = list_object[2]
second_winding_list = list_object[3]
third_winding_list = list_object[4]

PyAEDT INFO: CHOKE INFO: {'Number of Windings': {'1': False, '2': False, '3': True, '4': False}, 'Layer': {'Simple': False, 'Double': False, 'Triple': True}, 'Layer Type': {'Separate': False, 'Linked': True}, 'Similar Layer': {'Similar': False, 'Different': True}...
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 3 Objects: Winding,Winding_1,Winding_2.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 7 Objects: Winding,Winding_1,Winding_2,Winding_3,Winding_4,Winding_5,Winding_6.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 10 Objects: Winding,Winding_1,Winding_2,Winding_3,Winding_4,Winding_5,Winding_6,Winding_7,Winding_8,Winding_9.
PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: Refreshing bodies from Object Info
PyAEDT INFO: Bodies Info Refreshed Elapsed time: 0m 0sec
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec
PyAEDT INFO: Deleted 3 Objects: Winding_2,Winding_1,Winding.
PyAEDT INFO: Creating triple linked winding
PyAEDT INFO: Choke created correctly

Assign excitations

first_winding_faces = m3d.modeler.get_object_faces(
    assignment=first_winding_list[0].name
)
second_winding_faces = m3d.modeler.get_object_faces(
    assignment=second_winding_list[0].name
)
third_winding_faces = m3d.modeler.get_object_faces(
    assignment=third_winding_list[0].name
)
m3d.assign_current(
    assignment=[first_winding_faces[-1]],
    amplitude=1000,
    phase="0deg",
    swap_direction=False,
    name="phase_1_in",
)
m3d.assign_current(
    assignment=[first_winding_faces[-2]],
    amplitude=1000,
    phase="0deg",
    swap_direction=True,
    name="phase_1_out",
)
m3d.assign_current(
    assignment=[second_winding_faces[-1]],
    amplitude=1000,
    phase="120deg",
    swap_direction=False,
    name="phase_2_in",
)
m3d.assign_current(
    assignment=[second_winding_faces[-2]],
    amplitude=1000,
    phase="120deg",
    swap_direction=True,
    name="phase_2_out",
)
m3d.assign_current(
    assignment=[third_winding_faces[-1]],
    amplitude=1000,
    phase="240deg",
    swap_direction=False,
    name="phase_3_in",
)
m3d.assign_current(
    assignment=[third_winding_faces[-2]],
    amplitude=1000,
    phase="240deg",
    swap_direction=True,
    name="phase_3_out",
)

PyAEDT INFO: Boundary Current phase_1_in has been created.
PyAEDT INFO: Boundary Current phase_1_out has been created.
PyAEDT INFO: Boundary Current phase_2_in has been created.
PyAEDT INFO: Boundary Current phase_2_out has been created.
PyAEDT INFO: Boundary Current phase_3_in has been created.
PyAEDT INFO: Boundary Current phase_3_out has been created.

<ansys.aedt.core.modules.boundary.common.BoundaryObject at 0x18316525cf0>

Assign matrix

m3d.assign_matrix(
    assignment=["phase_1_in", "phase_2_in", "phase_3_in"], matrix_name="current_matrix"
)

PyAEDT INFO: Infinite is the only return path option in EddyCurrent.
PyAEDT INFO: Boundary Matrix current_matrix has been created.

<ansys.aedt.core.modules.boundary.maxwell_boundary.MaxwellParameters at 0x18316526050>

Create mesh operation

mesh = m3d.mesh
mesh.assign_skin_depth(
    assignment=[first_winding_list[0], second_winding_list[0], third_winding_list[0]],
    skin_depth=0.20,
    triangulation_max_length="10mm",
    name="skin_depth",
)
mesh.assign_surface_mesh_manual(
    assignment=[first_winding_list[0], second_winding_list[0], third_winding_list[0]],
    surface_deviation=None,
    normal_dev="30deg",
    name="surface_approx",
)

PyAEDT INFO: Mesh class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Mesh class has been initialized! Elapsed time: 0m 0sec

<ansys.aedt.core.modules.mesh.MeshOperation at 0x18316526260>

Create boundary conditions

Create the boundaries. A region with openings is needed to run the analysis.

region = m3d.modeler.create_air_region(
    x_pos=100, y_pos=100, z_pos=100, x_neg=100, y_neg=100, z_neg=0
)

Create setup

Create a setup with a sweep to run the simulation. Depending on your machine’s computing power, the simulation can take some time to run.

setup = m3d.create_setup("MySetup")
print(setup.props)
setup.props["Frequency"] = "100kHz"
setup.props["PercentRefinement"] = 15
setup.props["MaximumPasses"] = 10
setup.props["HasSweepSetup"] = True

sweep = setup.add_eddy_current_sweep(
    sweep_type="LinearCount",
    start_frequency=100,
    stop_frequency=1000,
    step_size=12,
    units="kHz",
    clear=True
)

{'Enabled': True, 'MeshLink': {'ImportMesh': False}, 'MaximumPasses': 6, 'MinimumPasses': 1, 'MinimumConvergedPasses': 1, 'PercentRefinement': 30, 'SolveFieldOnly': False, 'PercentError': 1, 'SolveMatrixAtLast': True, 'UseIterativeSolver': False, 'RelativeResidual': 1e-05, 'NonLinearResidual': 0.0001, 'SmoothBHCurve': False, 'Frequency': '60Hz', 'HasSweepSetup': False, 'UseHighOrderShapeFunc': False, 'UseMuLink': False, 'Name': 'MySetup'}
PyAEDT INFO: Parsing C:\Users\ansys\AppData\Local\Temp\tmpy8jnobzl.ansys\choke.aedt.
PyAEDT INFO: File C:\Users\ansys\AppData\Local\Temp\tmpy8jnobzl.ansys\choke.aedt correctly loaded. Elapsed time: 0m 0sec
PyAEDT INFO: aedt file load time 0.015883922576904297

Save project

m3d.save_project()
m3d.modeler.fit_all()
m3d.plot(
    show=False,
    output_file=os.path.join(temp_folder.name, "Image.jpg"),
    plot_air_objects=True,
)

PyAEDT INFO: Project choke Saved correctly
PyAEDT INFO: Parsing C:\Users\ansys\AppData\Local\Temp\tmpy8jnobzl.ansys\choke.aedt.
PyAEDT INFO: File C:\Users\ansys\AppData\Local\Temp\tmpy8jnobzl.ansys\choke.aedt correctly loaded. Elapsed time: 0m 1sec
PyAEDT INFO: aedt file load time 1.3872628211975098
PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 2sec
PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Post class has been initialized! Elapsed time: 0m 0sec

<ansys.aedt.core.visualization.plot.pyvista.ModelPlotter at 0x1831645fd90>

Finish

Save the project

m3d.save_project()
m3d.release_desktop()
# Wait 3 seconds to allow AEDT to shut down before cleaning the temporary directory.
time.sleep(3)

PyAEDT INFO: Project choke Saved correctly
PyAEDT INFO: Desktop has been released and closed.

Clean up

All project files are saved in the folder temp_folder.name. If you’ve run this example as a Jupyter notebook, you can retrieve those project files. The following cell removes all temporary files, including the project folder.

temp_folder.cleanup()

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Download this example

Download this example as a Jupyter Notebook or as a Python script.