High Performance Rare-Earth Free Interior Permanent Magnet Motor Enabled by Carbon Fiber Sleeve and Iron Nitride Magnets

Interior Permanent Magnet (IPM) motors equipped with rare-earth permanent magnets (PMs) are the primary option in Electric Vehicles (EV). Despite the superiority of electromagnetic performance for these motors and resistance against demagnetization, price fluctuations and unsustainable supply are posing challenges to continue producing EV motors with that type of PM. Iron Nitride (FeN) PM, rare-earth free, developed by Niron Magnetics can be an alternative option especially when design issues are tackled. This paper presents FeN+Ferrite IPM motor with Carbon Fiber sleeve to enable the use of thick rare-earth free PMs without penalizing the motor performance as in conventional retention methods relying on bridges and center-posts.