Sensitivity Analysis and Design of a High Performance Permanent-Magnet-Assisted Synchronous Reluctance Motor for EV Application

Permanent-magnet-assisted synchronous reluctance motors (PMa-SynRMs) have many advantages. This paper designs a PMa-SynRM and optimizes the machine structure to achieve high performance for electric vehicle (EV) application. Many variables such as width and length of permanent magnets, length of air gap, and length and shape of tilted flux barriers are created to study the effects of these variables on motor performance based on the finite element method (FEM). The results indicate that the variables have an influence on the d-q axis reluctances and inductances, and then affect the torque; the tilted flux barriers are helpful to produce a large torque and a low torque ripple. Finally, optimal values of the variables for the designed PMa-SynRM and an optimal machine structure are obtained as well as a prototype PMa-SynRM is fabricated for experimental verification.