White Papers

Accounting for AC Winding Losses in the Electric Machine Design Process

By Dr. Giuseppe Volpe, Senior E-Machine Specialist

The efficiency and power output capability of an electric machine is defined by the losses generated during the machine operation. Losses that are generated in a machine cause heating, which fundamentally limits performance and defines the maximum torque and power capability of a design. Large AC winding losses are often discovered at a late stage in the development process and this can result in significant additional costs, delays and a failure to meet the design requirements. Taking machine losses into account early on in the design process is, therefore, crucial to ensure that the design requirements are met.

In this paper, we compare the advantages and disadvantages of different approaches to modelling AC losses during the design process—including analytical calculations and finite element analysis (FEA)—and discuss a ‘hybrid’ approach to calculating frequency-dependent winding losses that combines the speed of analytical methods with the accuracy of FEA. Using the Motor-CAD EMag module, we analyse the AC losses of three electric machine types using the Full FEA and Hybrid FEA methods and compare the speed and accuracy of both approaches.

What will you learn?

  • Why it is important to calculate AC losses early in the design process
  • The advantages and disadvantages of different approaches to calculating AC losses
  • How different approaches to calculating AC losses compare using the Motor-CAD EMag module.
Download pdf (540kb)


Related Resources