Motor-CAD E-magnetic example script

This example provides a Motor-CAD E-magnetic script. This script creates a partial custom winding pattern to change parameter values, run the analysis, and plot results. To create a full winding pattern, parameters must be specified for all coils.

Set up example

Setting up this example consists of performing imports, specifying the working directory, launching Motor-CAD, and disabling all popup messages from Motor-CAD.

Perform required imports

import os

import matplotlib.pyplot as plt

import ansys.motorcad.core as pymotorcad

if "QT_API" in os.environ:
    os.environ["QT_API"] = "pyqt"

Specify working directory

working_folder = os.getcwd()

if os.path.isdir(working_folder) is False:
    print("Working folder does not exist. Choose a folder that exists and try again.")
    print(working_folder)
    exit()

Launch Motor-CAD

print("Starting initialization.")
mcad = pymotorcad.MotorCAD()

Starting initialization.

Disable popup messages

mcad.set_variable("MessageDisplayState", 2)
print("Initialization completed.")
print("Running simulation.")

Initialization completed.
Running simulation.

Create analysis

Creating the analysis consists of showing the magnetic context, displaying the Scripting tab, setting the geometry and parameters, and saving the file.

Show the magnetic context.

mcad.show_magnetic_context()

Display the Scripting tab.

mcad.display_screen("Scripting")

Set the geometry.

mcad.set_variable("Slot_Number", 24)
mcad.set_variable("Tooth_Width", 6)
mcad.set_variable("Magnet_Thickness", 4.5)

Set parameters for creating the custom winding pattern.

The following code creates only a partial winding pattern.

Set the winding type to custom: mcad.set_variable('MagWindingType', 1)

Set the path type to upper and lower: mcad.set_variable('MagPathType', 1)

Set the number of phases: mcad.set_variable('MagPhases', 3)

Set the number of parallel paths: mcad.set_variable('ParallelPaths', 1)

Set the number of winding layers: mcad.set_variable('WindingLayers', 2)

Define a coil’s parameters: set_winding_coil(phase, path, coil, go_slot, go_position, return_slot, return_position, turns)

Set the stator/rotor lamination materials.

mcad.set_component_material("Stator Lam (Back Iron)", "M250-35A")
mcad.set_component_material("Rotor Lam (Back Iron)", "M250-35A")

Set the torque calculation options.

points_per_cycle = 30
number_cycles = 1
mcad.set_variable("TorquePointsPerCycle", points_per_cycle)
mcad.set_variable("TorqueNumberCycles", number_cycles)

Disable all performance tests except the ones for transient torque.

mcad.set_variable("BackEMFCalculation", False)
mcad.set_variable("CoggingTorqueCalculation", False)
mcad.set_variable("ElectromagneticForcesCalc_OC", False)
mcad.set_variable("TorqueSpeedCalculation", False)
mcad.set_variable("DemagnetizationCalc", False)
mcad.set_variable("ElectromagneticForcesCalc_Load", False)
mcad.set_variable("InductanceCalc", False)
mcad.set_variable("BPMShortCircuitCalc", False)

Enable transient torque.

mcad.set_variable("TorqueCalculation", True)

Set the operating point.

mcad.set_variable("Shaft_Speed_[RPM]", 1000)
mcad.set_variable("CurrentDefinition", 0)
mcad.set_variable("PeakCurrent", 3)
mcad.set_variable("DCBusVoltage", 350)
mcad.set_variable("PhaseAdvance", 45)

Save the file.

filename = os.path.join(working_folder, "../ActiveX_Scripting_EMagnetic.mot")
mcad.save_to_file(filename)

Run simulation

Run the simulation.

mcad.do_magnetic_calculation()

Export results to CSV file

Export results to a CSV file.

exportFile = os.path.join(working_folder, "../Export_EMag_Results.csv")
try:
    mcad.export_results("EMagnetic", exportFile)
    print("Results successfully exported.")
except pymotorcad.MotorCADError:
    print("Results failed to export.")

Results successfully exported.

Get and analyze results

Get torque and voltage data.

shaft_torque = mcad.get_variable("ShaftTorque")
line_voltage = mcad.get_variable("PeakLineLineVoltage")

Graph the torque data.

num_torque_points = points_per_cycle * number_cycles
rotor_position = []
torque_vw = []

for n in range(num_torque_points):
    (x, y) = mcad.get_magnetic_graph_point("TorqueVW", n)
    rotor_position.append(x)
    torque_vw.append(y)

Graph the airgap flux density data.

loop = 0
success = 0
mech_angle = []
airgap_flux_density = []

Keep looking until you cannot find the point.

while success == 0:
    try:
        (x, y) = mcad.get_fea_graph_point("B Gap (on load)", 1, loop, 0)
        mech_angle.append(x)
        airgap_flux_density.append(y)
        loop = loop + 1
    except pymotorcad.MotorCADError:
        success = 1

Graph the harmonic data.

num_harmonic_points = (points_per_cycle * number_cycles) + 1
data_point = []
torque = []
for n in range(num_harmonic_points):
    try:
        (x, y) = mcad.get_magnetic_graph_point("HarmonicDataCycle", n)
        data_point.append(x)
        torque.append(y)
    except pymotorcad.MotorCADError:
        print("Results failed to export.")


print("Simulation completed.")

Simulation completed.

Plot results

Plot results from the simulation.

plt.subplot(211)
plt.plot(mech_angle, airgap_flux_density)
plt.xlabel("Mech Angle")
plt.ylabel("Airgap Flux Density")
plt.subplot(212)
plt.plot(rotor_position, torque_vw)
plt.xlabel("Rotor Position")
plt.ylabel("TorqueVW")
plt.figure(2)
plt.plot(data_point, torque)
plt.xlabel("DataPoint")
plt.ylabel("Torque (Nm)")
plt.show()

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Exit Motor-CAD

Exit Motor-CAD.

mcad.quit()

If you want to continue working with this instance of Motor-CAD, rather than using the preceding command, use this command: mcad.set_variable('MessageDisplayState', 0)