Motor-CAD Therm

Thermal performance predictions and advanced cooling system design.


The Motor-CAD Therm module is the industry-standard tool for thermal analysis of electric machines, with over 20 years of inbuilt experience.

Motor-CAD Therm allows designers to calculate the temperature of the motor components in steady-state and transient operating conditions, enabling accurate modelling of thermal behaviour within seconds of calculation. Understanding the main heat transfer paths gives motor designers opportunities to significantly improve motor efficiency and output, and make design decisions with confidence.

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.


Key Features

  • Calculates the temperature of the motor components in steady-state and transient operating conditions.
  • Thermal and flow network is generated automatically.
  • 3D network includes radial and axial heat transfer.
  • Detailed visualisation and calculation of the slot cross section.
  • CFD, FEA and empirical correlations are behind all calculations.
  • Experience built into the software assists users in selecting appropriate manufacturing factors.
  • Enables accurate modelling of thermal behaviour within seconds of calculation.


Cooling Methods

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.

Machine Types

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

  • IM: Induction motors
  • SRM: Switched Reluctance motors
  • SYNCREL: Synchronous Reluctance motors
  • SYNC: Synchronous machines
  • PMDC: Permanent Magnet DC motors
  • IM1PH: Single Phase Induction motors
  • CLAW: Claw pole machines.

Learn more:

  • Motor-CAD EMag – Electromagnetic and electrical analysis
  • Motor-CAD Mech – Mechanical analysis
  • Motor-CAD Lab – Efficiency mapping and duty cycles


The Motor-CAD software is distributed worldwide. Our carefully selected partners are experts in the use of the software and can provide support and training.

To find a distributor near you, click on the link below.