Post-Assembly Magnetization of Rare-Earth Permanent Magnet Materials in Permanent Magnet Assisted Synchronous Reluctance Motors

This paper discusses the post-assembly magnetization of rare-earth permanent magnet materials used in permanent magnet assisted synchronous reluctance motors. Firstly, the motivation behind post-assembly magnetization is given and challenges of embedding pre-magnetized magnets into the rotor flux barriers of synchronous reluctance motors are introduced. Magnetization computation across the magnets' surfaces is performed. Unfeasibility of using the original stator of the motor as a magnetizer is proven. Afterwards, a new tooling stator is designed to be utilized as a magnetizer. The proposed magnetizer structure and computational approaches are verified by finite element analysis (FEA) simulations on a sample permanent magnet assisted synchronous reluctance motor and the results are compared against the pre-magnetized case.