Selection of Magnet Wire Topologies With Reduced AC Losses for the Windings of Electric Drivetrains

Abstract

In high speed electrical machines, one of the main challenges that can be faced is the high frequency losses in the machine windings due to both skin and proximity effects. This paper studies the effect of using different types of magnet wires on the AC losses in the winding of high speed electric machines. Using finite element modelling (FEM), the conductors are subdivided into multiple strands to calculate the losses in each conductor and in each layer. Aiming at loss minimization, different arrangements are introduced and compared at a wide range of frequencies. Further, four coil designs are prototyped using different magnet wires or arrangements. Moreover, the design and performance are compared with highlighting the pros and cons of each case. Eventually, recommendations are provided based on the obtained results for a better selection of magnet wire.

Keywords

• AC losses
• electric machines
• electromagnetics
• magnet wires
• skin & proximity effects