Experimental Study of the Amorphous Magnetic Material for High-Speed Sleeve-Free PM Rotor Application

Amorphous magnetic materials (AMMs) have been commercially available for decades. However, their application to electrical machines still lacks of breakthrough progress. This article proposes to use the AMM for a high-speed interior permanent-magnet rotor to avoid sleeves. In this application, advantages of the high mechanical strength, the low core losses, and the relatively low-saturation flux density of the AMM are fully taken. In order to ensure the success of the proposed application, three important aspects: slotting, electromagnetic properties, and mechanical strength of the AMM are experimentally studied. Since the electromagnetic properties of the AMM core are sensitive to the mechanical process, stress, and temperature, the AMM cores are tested and the tested data are used for the motor design. Finally, a prototype is built and tested.