A Novel Modular Permanent Magnet-Assisted Synchronous Reluctance Motor

Abstract

This paper proposes a novel modular permanent magnet-assisted synchronous reluctance motor (MPMA-SynRM) structure. The rotor is composed of two types of rotor modules that are axially combined. This article analyses and explains the combined angle of the axial assembly of different rotor modules. The MPMA-SynRM rotor module is optimized using a differential evolution algorithm and the MPMA-SynRM space vector diagram is established to give the torque calculation an analytical expression. Whether there is axial magnetic isolation between different rotors is analysed, and various segment numbers, pole arc coefficients, and length ratios are used for different rotor modules to affect the electromagnetic influence of the MPMA-SynRM's cogging torque. Detailed analyses of the MPMA-SynRM loss, efficiency, and permanent magnet demagnetization state are given. The no-load back EMF, power factor, efficiency, eddy current loss, and cogging torque of the MPMA-SynRM with traditional Nd-Fe-B permanent magnet motors and permanent magnet auxiliary synchronous reluctance motors are compared, and a prototype is made to prove the performance of this motor.

Keywords

• Permanent magnet motors
• permanent magnet-assisted synchronous reluctance motor
• rare earth magnets
• ferrite magnets
• finite element method
• design optimization