Electric Motor Cooling

Correct simulation of an electric motor will help reduce cost and increase efficiency. As motors continue to get smaller and work harder, excess heat is produced, and efficiency is greatly reduced. In some extreme cases, permanent magnets can even reach their limit and become demagnetized. Thermal management is a big challenge that needs to be analyzed early in the design process.

Using ANSYS solutions to optimize your electric motor will help you to be first to market in demanding applications, including:

  • Electric/Hybrid electric vehicles
  • Electric aircraft
  • Wind turbines
  • Solar tracking panels

Simulating all aspects of a motor from electromagnetic fields and their loss distribution to structural integrity from thermal stresses will help with early design tradeoffs and considerations. A simulation to show electromagnetic fields and the power losses associated with them in ANSYS Maxwell is the first step to perform the temperature analysis.

Power losses are automatically mapped as a 3D time-averaged input in ANSYS Fluent. These results will be analyzed to reveal the critical areas for thermal performance and optimize design for cooling. Under certain circumstances, when it is not sufficient to consider single physics, Fluent and Maxwell can be coupled: Fluent will simulate different cooling methods and pass the temperature information back to Maxwell. These values are used to adjust temperature-dependent material properties and perform corrections to the electromagnetic field, to pass back to Fluent for further evaluation.

Electric motor cooling: Optimized temperature distribution on an electric motor

Optimized temperature distribution on an electric motor using water jacket and oil spray cooling in Fluent.
Courtesy of Lucid Motors.

Fluent can be used to simulate many different methods of motor cooling, including:

  • Natural or forced air cooling
  • Water cooling
  • Spray cooling

Once proper cooling is achieved, thermal stresses can be calculated by coupling Fluent and ANSYS Mechanical. As the materials heat up, they can deform. Deformation will increase noise, vibration and harshness (NVH), which is not only unpleasant for users, but also greatly impacts safety.

Using ANSYS Twin Builder, the entire motor can be simulated using reduced order models from the ANSYS physics solvers along with the embedded software controlling the motor, created with ANSYS SCADE. This systems simulation enables you to make design decisions early in the process without creating a physical prototype. Additionally, you can use Twin Builder to create and connect the virtual asset or digital twin to the physical asset in the field, so you can understand different operating conditions of the motor, perform diagnostics and predict the ideal maintenance schedule, reducing warranty costs.

Simulation: Oil spray cooling process on an electric motor

ANSYS Fluent simulation of the oil spray cooling process on an electric motor that increased efficiency by 12 percent.
Courtesy of Lucid Motors.

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