A Novel Modular Permanent Magnet-Assisted Synchronous Reluctance Motor

Zeyu Liu,Jiacheng Wu,Bingyi Zhang,Guihong Feng,Yan Hu

doi:10.1109/access.2021.3054766

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.

Highlights

Permanent magnet motors have many advantages, such as a high power, high efficiency, direct drive, etc
The inner rotor permanent magnet-assisted synchronous reluctance motor (PMA-SynRM) has many advantages. It has the benefits of an interior permanent magnet machine (IPM) and a reluctance synchronous motor (SynRM), such as a low cost, a low permanent magnet material consumption, and a high efficiency
The structure of the MPMA-SynRM rotor was presented in this paper

Summary

INTRODUCTION

Permanent magnet motors have many advantages, such as a high power, high efficiency, direct drive, etc. The comparison of the synchronous reluctance machine’s and the permanent Magnet-Assisted synchronous reluctance machine’s performance characteristics in references [17], [18] show that the PMA-SynRM motor has a higher efficiency, power factor, and torque density. It increases the material cost and manufacturing difficulty. Considering the above factors, this paper proposes an axial modular combined reluctance-assisted permanent magnet synchronous motor (MPMA-SynRM), where the different rotor modules are synchronous rotors. Because the motor performance will be analysed under different pole arc coefficients and core lengths, the optimized rotor parameters are not provided here because the optimal motor parameters are not the same under different pole arc coefficients

MPMA-SynRM ROTOR TORQUE MATCHING

EXPERIMENTAL VALIDATION

Findings

CONCLUSION