Motor-CAD - electromagnetic and thermal analysis of electric machines

Motor-CAD is a unique software package dedicated to the electromagnetic performance of motors and generators and the optimisation of their cooling. Developed in 1998, Motor-CAD is used by major motor manufacturers and universities worldwide.

Motor-CAD provides the ability to quickly and easily perform electromagnetic and thermal performance tests on electric motor designs, using an integrated systems of software packages: EMag, Therm and LabAccurate electromagnetic and thermal calculations can be done in minutes. The results are presented in an easy to understand format and allows design decisions to be taken efficiently.

The software has a carefully constructed user interface that makes for easy data input and interpretation of results. Many of the features that make Motor-CAD the perfect optimisation tool have been developed in close consultation with customers to meet the needs of the industry.

EMag: Offers a fast 2D finite element module for accurate electromagnetic and electrical performance predictions.

The new Motor-CAD BPM-EMag module works with the existing Motor-CAD thermal design modules for brushless permanent magnet machines (BPM), with inner and outer rotor configurations, enabling motor designers to produce optimum designs for performance, energy efficiency, size and cost reduction. Motor-CAD makes the best use of the latest modelling techniques to provide the fast and accurate analysis tool for machine designers.

Motor-CAD has a user friendly interface that allows the user to enter the geometry, winding data, control strategy, materials and cooling details. The standard industrial tests for BPM machines are modelled as electromagnetic performance tests that take into account the thermal aspects of the machine.

Motor-CAD Emag – available motortypes:

- BPM – brushless PM machine
- BPMOR – brushless outer rotor PM machine
- IM - 3-phase induction machine
- SYNCREL – syncronous reluctance machine

The thermal model in Motor-CAD is based upon analytical lumped-circuit analysis making it extremely fast to calculate. This allows the user to perform ‘what-if’ calculations in real time. Alternative numerical methods typically require days or even weeks to model and several hours to calculate a solution.

All the thermal resistances and capacitances in the Motor-CAD model are calculated automatically from geometric dimensions and material properties. The user does not need to be familiar with complex heat transfer phenomena such as dimensionless analysis correlations for convection. Motor-CAD automatically selects and solves the most appropriate formulation for a given surface and the cooling type selected. Motor-CAD features efficient, accurate and robust mathematical algorithms for forced and natural convection, liquid cooling, radiation and conduction. An extensive library of proven laminar and turbulent convection correlations are used to give accurate models for all internal and external surfaces. The airgap model includes laminar, vortex and turbulent convection.

The software is used to optimise the cooling of a wide variety of motor types and cooling methods. The fast calculation speeds are huge benefit when modelling complex duty cycles, such as traction motor drive cycles, and applications such as elevator load cycles.

Motor-CAD modules are available for the following motor types:

- Brushless permanent magnet motors (BPM)
- Outer rotor BPM motors
- Induction motors
- Permanent magnet DC machines
- Switched reluctance motors
- Synchronous reluctance motors
- Synchronous machines
- Claw pole machines
- Universal motors

There are many different motor types, housing types and cooling types available in Motor-CAD.

Motor-CAD models are available for the following cooling methods:

- natural convection (TENV)- forced convection (TEFC)- through ventilation- water jackets (several configurations)- submersible- flooded- wet rotor and wet stator- spray cooling- radiation- conduction

Users are also able to include various mounting configurations in the model that can provide heating or extra cooling to the machine.

Motor-CAD uses powerful analytical methods to calculate the performance of electric machines and cooling systems.

MDL’s FE-Therm add-on module provides increased detail on conduction heat transfer in various components. For example this allows visualisation of the hotspot in the winding.

It can be used to analyse conduction heat transfer for complex geometries such as multi-layer interior magnet motor rotors.

FE-Therm can be used to calibrate analytical lumped circuit models, thus improving accuracy.

It is fully automated and takes only a few seconds to calculate.

With Lab, engineers can create efficiency maps, plot torque/speed characteristics, study the continuous and peak thermally constrained operational envelope and analyse performance over driving cycles. It is fast, easy to use and the techniques have been experimentally verified.

Motor-CADLab has an intuitive user interface: data is produced in a simple format that can easily be exported to Matlab, Microsoft Excel and other applications. A wide variety of graphs can be generated and a number of publication-quality output formats are supported.


For further information, please contact: