New Efforts to Utilize Amorphous Foils in High Efficiency Electric Motors

Amorphous foils show extremely low losses and are commonly used in applications such as highly efficient distribution transformers. A brief review of soft magnetic amorphous alloys currently used in the market along their primary industrial applications will be discussed. However, these amorphous foils have not been widely used in an electric motor application. The barrier to commercial acceptance has primarily been related to the challenges fabricating stators and rotors from the thin amorphous laminations. Emerging trends in electrification are putting a premium on efficiency in electric motors and amorphous foil is widely being studied again.

Here we will discuss the approaches to incorporate amorphous ribbon into the motor components and the methods that have been industrially adopted. The Fe-based amorphous foils today are thicker (25 mm) with higher stacking factors (90%) and higher saturation levels (1.63T) than the historical foils. FeCo-based amorphous alloys further enhance the induction levels (1.8T) and can perform at the same operating conditions of conventional Si-steel at a fraction of the losses.