The alternative motor without rare-earth minerals was developed by Toyota Motor, If this motor can be produced in large amount, Toyota Motor doesn’t need at risk of supply disruptions in the future. The alternative motor was called induction motor which is lighter and more efficient than the magnet-type motor. It has been used in Toyota Prius and Tesla Model S.1
Induction motors, except not requiring rare-earth materials, induction motors also can offer higher efficiency and durability than permanent-magnet motors in some applications. Induction motors operate by inducing electrical currents in conductors in the motor’s rotor. these currents in turn give rise to a magnetic field in the rotor and thus produce torque. As a result, when switched off, these motors are inert, producing no electrical voltage or current, no losses and no cogging torque. These machines can produce high levels of performance using modern and well understood vector control techniques.2
References
1. Toyota Reading Motors That don’t use rare earths. http://www.bloomberg.com/news/articles/2011-01-14/toyota-readying-electric-motors-that-don-t-use-rare-earths
2. J. D. Widmer, R. Martin, M. Kimiabeigi. Electric vehicle traction motors without rare earth magnets. Sustainable Materials and Tecnologies. Volume 3, April 2015, Pages 7–13
