Dual Stator Permanent Magnet Vernier Machine With Yokeless Rotor Having Single Stator Winding for Torque Density Improvement

Mudassir Raza Siddiqi,Tanveer Yazdan,Yeol-Kyeong Lee,Jun-Hyuk Im,Jin Hur

doi:10.1109/access.2021.3125688

Mudassir Raza Siddiqi, Tanveer Yazdan + Show 3 more

Open Access

https://doi.org/10.1109/access.2021.3125688

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Abstract

This paper proposes a special design of a dual stator radial type permanent magnet vernier machine (PMVM) having a yokeless rotor to improve the torque density. The PMVM model is designed with winding only in the outer stator, while the inner stator is kept auxiliary without winding. The proposed model reduced the overall volume of the machine, which in turn improved the torque density of the machine. The proposed configuration makes the design free from thermal and manufacturing issues due to the absence of inner stator winding. The detailed specifications and analysis results of the proposed model, such as torque, back EMF, inductance, and other features, are presented in this paper. The model is analyzed and compared with the dual stator radial type PMVM having a yokeless rotor and dual stator winding using the 2D-Finite Element Method (FEM) as well as 3D Co-simulation with Ansys Mechanical.

Highlights

With increasing concerns over various developing applications such as electric vehicles and wind power generation, high-torque density machines, such as dualrotor PM machines [1], harmonic machines [2], pseudo-PM machines [3], and transverse flux machines are gaining popularity in the industry as well as in academia
This paper proposed a novel topology of dual stator permanent magnet vernier machine (PMVM) with a yokeless rotor having a single stator winding to improve the torque density and overcome the thermal and manufacturing issues due to inner stator winding in the dual air gap model
A special topology of dual stator radial flux (DSRF)-PMVM is proposed in this paper to improve the torque density of the machine

Summary

INTRODUCTION

With increasing concerns over various developing applications such as electric vehicles and wind power generation, high-torque density machines, such as dualrotor PM machines [1], harmonic machines [2], pseudo-PM machines [3], and transverse flux machines are gaining popularity in the industry as well as in academia. A consequent pole PMVM was presented in [13] to decrease the flux leakage and improve the torque density of the machine This machine produced almost 20% higher back EMF and 40% reduced magnet usage as compared to the conventional PMVM. The rotor iron yoke in dual stator structures caused the reduced flux linkage between inner and outer stator windings, which affects the machine's overall performance This issue was addressed in [20] and was overcome by removing the iron core from the rotor. The structure, working principle, and design concept of the dual stator PMVM model having a yokeless rotor and single stator winding (SSW) are presented. The machine is analyzed using the 2D finite element method (FEM) and the results are compared with the reference DSW model having the same outer diameter

TABLE I COMPARISON OF DIFFERENT DUAL AIRGAP PMVM TOPOLOGIES

DSW model SSW model

DSW Model SSW model

Yokeless Cartesian

Findings

CONCLUSION