Screenshot of Motor-CAD electric motor design software, now available from ANSYS. (Image courtesy of Motor Design Limited.)

If you’ve ever designed an electric motor, you may have been assisted by a design software package called Motor-CAD. Developed by Motor Design Limited, Motor-CAD provides a toolkit for the multiphysics simulation of electric motors across the full torque-speed range.

Now, Motor Design Limited has signed an agreement with simulation provider ANSYS to distribute Motor-CAD alongside ANSYS’s existing multiphysics simulation tools. Motor-CAD joins ANSYS’s electric machine design workflow, which includes ANSYS Maxwell for electromagnetic field simulation, ANSYS Fluent for computational fluid dynamics (CFD) simulation, and ANSYS Icepak for electronics cooling simulation.

“The addition of Motor-CAD to the ANSYS electric machine design flow creates a complete end-to-end workflow for electric machine design,” said Steve Pytel, senior director of product management at ANSYS. “Its ease of use and single application focus allow ANSYS to expand the electric machine design workflow to the concept design engineering teams earlier in the development process.”

The Four Modules of Motor-CAD

Motor-CAD consists of four integrated modules that allow designers to iteratively evaluate motor topologies and lock in a final design:

EMag (for electromagnetic performance predictions)
Therm (for thermal performance predictions and cooling system design)
Lab (for efficiency mapping and performance across a duty cycle)
Mech (for mechanical analysis)

Motor-CAD is comprised of four modules: EMag, Therm, Lab, and Mech. (Image courtesy of ANSYS.)

EMag

EMag provides a 2D finite element environment combined with analytical algorithms to calculate electrical performance characteristics, including power, torque, losses, voltages, currents, inductances, forces and flux linkages. To define the motor, users can input their geometry with the built-in template editor by defining parameters such as tooth width and number of slots and poles. Users can also import custom geometry through a DXF file.

Screenshot of Motor-CAD’s EMag module. (Image courtesy of Motor Design Limited.)

Users lay out the coils of their motor with the EMag winding editor. Coils can be placed in a custom pattern or one that is automatically generated by Motor-CAD based on user specifications, including number of phases, coil pitch and layers. As a final step, users assign materials to their design from the existing material database or through a custom material specification.

EMag can run performance tests, including Back EMF, Cogging Torque, On Load Torque, Single Load Point, Locked Rotor, and Synchronous Speed, depending on the type of motor that is under analysis. EMag automatically meshes the model and sets boundary conditions. The results can be exported to ANSYS Maxwell for further finite element simulations.

Therm

Coupled to EMag is Therm, which allows users to iteratively solve thermal calculations in steady state and transient conditions. Users begin by specifying their electric motor’s cooling system from options that include water jackets, natural convection, forced convection, spray cooling, radiation and more. Users can set specific thermal properties for the impregnation, slot liner and housing, as well as manufacturing factors including the lamination-to-housing interface gap.

Screenshot of Motor-CAD’s Therm module. (Image courtesy of ANSYS.)

Therm generates an equivalent thermal network to calculate thermal performance. The module presents users with the calculated steady state and transient temperatures, losses, heat transfer coefficients, axial temperature distribution, and thermal resistances.

Lab

Motor-CAD’s Lab module allows users to analyze their electric motors over the entire operating range. The module outputs efficiency and loss maps, peak torque and speed, thermally constrained torque and speed, and the motor’s performance over complex driving cycles. Lab couples to both EMag and Therm.

Screenshot of Motor-CAD’s Lab module. (Image courtesy of ANSYS.)

Users specify inputs such as DC link voltage, control strategy, maximum inverter current, and maximum modulation depth to build their motor model and generate their performance characteristics. The results can be visualized and explored within Lab or exported for further analysis. The process can also be automated with MATLAB or Excel scripting.

Mech

The Mech module uses 2D finite element analysis (FEA) to determine the stress and displacement in rotors during a motor’s operation. This allows users to optimize rotor design for electromagnetic performance while remaining within the mechanical limits.

Users define the rotor geometry with the Mech parametrized template editor, specifying inputs such as number of poles and inner and outer diameters. As with EMag, material properties can be applied from the Motor-CAD database or specified by the user. Users can also specify Young’s modulus, density and Poisson’s ratio, as well as yield strength and tensile strength.

Mech automatically meshes the geometry, but users can adjust the mesh as desired (such as for high-stress regions, to improve the accuracy of the results). Mech outputs the FEA results, including von Mises stress and directional displacements, and can also perform what-if analyses on design variants.

Electric Motors End to End

After using Motor-CAD’s four modules to design and analyze an electric motor, users can transfer the Motor-CAD model to ANSYS’s additional simulation packages for further analysis and validation. ANSYS Maxwell allows users to compute more advanced electromagnetic phenomena. Combined with ANSYS Fluent for CFD and ANSYS Icepak for electronics cooling, users can determine demagnetization, hysteresis, core loss, and noise, vibration, and harshness (NVH) effects of their motor designs.

(Image courtesy of ANSYS.)

“For deep analysis and validation, the Motor-CAD model can be transferred to ANSYS solvers, delivering high-fidelity, 2D and 3D analysis capabilities,” Pytel said.

ANSYS Motor-CAD is available in versions tailored for specific motor types or as a single package, including all motor types. Available motor packages include Motor-CAD PM for permanent magnet motors, Motor-CAD IM for asynchronous motors with an induced rotor field, and Motor-CAD SYNC for synchronous electric motors. Motor-CAD Enterprise includes all three motor types.

James Goss, CEO of Motor Design Limited, believes the agreement between his company and ANSYS will benefit designers of electric motors.

“Motor-CAD is the world-leading tool for fast multiphysics design and sizing of electrical machines,” Goss said. “It allows users to efficiently calculate electromagnetic, thermal and mechanical performance of a machine over the complete operating cycle, making Motor-CAD ideally suited for iterative design space exploration and optimization of concept designs. Through our agreement with ANSYS, Motor-CAD will add these valuable up-front design capabilities to ANSYS’s industry-leading multiphysics simulation technology.”

To learn more about ANSYS and Motor-CAD, or to watch an introductory webinar on the software, visit the ANSYS website.

ANSYS has sponsored this post. All opinions are mine. --Michael Alba