Comparison of high-speed induction motors employing cobalt-iron and silicon electrical steel

This paper presents the design of 20 kW cage rotor induction machines operating at speeds above 20.000 rpm employing different kind of electrical steels. One machine is designed using cobalt-iron laminations of 0.2 mm thickness. For the second machine 0.35 mm silicon electrical steel of low-loss grade has been used. Both machines are compared in terms of the materials influence on lamination layout, mechanical behavior and thermal loading. Measurements of both machines underline the presented facts.