Optimization Design of PMSM With Hybrid-Type Permanent Magnet Considering Irreversible Demagnetization

Abstract

This paper proposes optimization design of permanent-magnet synchronous motor (PMSM) using hybrid-type permanent magnet (PM) considering irreversible demagnetization. Here, the hybrid-type PM is defined as using both of neodymium PM (Nd-PM) and ferrite PM (Fe-PM) in a rotor. First, irreversible demagnetization of Fe-PM occurring by reversed magnetic field of Nd-PM is analyzed by using a finite-element method, when a rotor is inside or without a stator in order to improve reliability of PMSM using hybrid-type PM. Second, the optimized design considering demagnetization phenomenon is suggested for analyzing exactly output characteristics of the motor using hybrid-type PM. Finally, the prototypes based on proposed design are developed for evaluating the performance and demagnetization phenomenon through experiment.