Rare Earths: Tesla extends EV range using permanent magnets

Tesla has opted to install a permanent magnet motor in its 2019 Model S and Model X electric vehicles (EVs), as the company had already done for its Model 3. The switch from induction motor to permanent magnet motor increases the motor efficiency by 4%, which allows for an improved driving range. As reported by InsideEVs, the overall drivetrain efficiency of Tesla’s EVs is improved by an average of 10%, gaining further technical benefits related to the use of permanent magnet motors. While the range of highway driving increased approximately 5%, the greatest improvement is a 14% increased range for city driving.

Roskill view:

Permanent magnets that offer the best performance and optimisation potential in electric motors are rare earth neodymium-iron-boron (NdFeB) magnets. Over 90% of EV models currently use NdFeB-based permanent magnet motors as part of the EV drivetrain. In 2017, Tesla released its Model 3 EV in which the rear axle motor was changed from an induction motor, as used in previous models, to a permanent magnet switched reluctance motor. This change allowed Tesla to optimise performance, battery cost and driving range in order to move the Tesla Model 3 into the larger automotive class D (compact executive car) rather than remaining in the smaller luxury car category of the Model X.

Roskill’s Rare Earths: Global Industry, Markets & Outlook report was published in December 2018 and a second quarterly update for subscribers is due to be published in June 2019. Click here to download the brochure or to access further information.