To increase the efficiency and power density of asynchronous machines (ASM) for traction

drives, the use of copper as a conductor material, as well as increasing the rotational speed,

are well known options. Therefore, enhanced mechanical requirements on cage and rotor

package must be considered.

In this presentation, the design and construction of asynchronous machines with different cage

materials (copper, aluminum, special copper alloys with optimized yield strength and

conductivity), as well as different electrical steel grades, are presented. The measurements

and test results shown here follow the publication at E-Motive 2019.

The behavior of the cage materials at maximum circumferential speeds (> 200 m/s) is

compared through mechanical investigations of different rotors. Furthermore, the impact of

different cage materials on the motor efficiency is considered based on measurement results.

The influence of the electric steel sheet thickness on the motor losses measured for machines

with 0.3 mm and 0.35 mm sheet thickness is shown. A comparison of measurements with

results of FEM Simulations demonstrate the impact of material deterioration as well as inverter

related losses in the motor.