Optimal design and torque analysis considering eddy-current reduction of axial-flux permanent magnet couplings with Halbach array based on 3D-FEM

Background/Objectives: This study proposes and verifies a design method that considers the permanent magnet (PM) loss reduction of axial flux permanent magnet coupling (PMC), to replace mechanical coupling.Methods/Statistical analysis: In this study, the design of an axial magnetic flux PMC is performed using a three–dimensional (3D) commercial finite element (FEM) analysis program, and an optimum design is performed through parametric analysis. In addition, we designed a PMC that minimizes loss by analyzing the PM eddy current loss when using divided magnets.Findings: We found that some parameters (thickness of the PM, number of poles, ratio of inner radius to outer radius) act on the magnetic torque of the axial flux coupling. Using these results, we could obtain the design point. Further, to reduce the PM eddy current loss in the designed coupling, we used the PMs divided radially and circumferentially to obtain the magnet shape to minimize the loss. In addition, the fabricated coupling proved that the design results of the 3D FEM matched with the experimental results.Improvements/Applications: We propose an optimal design method of an axial flux PMC using 3D FEM, and a method to reduce eddy current loss using divided magnets

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Performance analysis of magnetic gear with Halbach array for high power and high speed

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209410 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 959-967

Author(s):

Se-Yeong Kim ◽

Tae-Woo Lee ◽

Yon-Do Chun ◽

Do-Kwan Hong

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

High Power ◽

High Speed ◽

Torque Ripple ◽

Eddy Current Loss ◽

Element Analysis ◽

Current Loss ◽

Halbach Array ◽

Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

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3-D Magnetic Field and Torque Analysis of a Novel Halbach Array Permanent-Magnet Spherical Motor

IEEE Transactions on Magnetics ◽

10.1109/tmag.2008.922782 ◽

2008 ◽

Vol 44 (8) ◽

pp. 2016-2020 ◽

Cited By ~ 61

Author(s):

Changliang Xia ◽

Hongfeng Li ◽

Tingna Shi

Keyword(s):

Magnetic Field ◽

Permanent Magnet ◽

Spherical Motor ◽

Halbach Array ◽

Torque Analysis

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Design and Analysis of a Novel Axial-Radial Flux Permanent Magnet Machine with Halbach-Array Permanent Magnets

Energies ◽

10.3390/en14123639 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3639

Author(s):

Rundong Huang ◽

Chunhua Liu ◽

Zaixin Song ◽

Hang Zhao

Keyword(s):

Permanent Magnet ◽

Permanent Magnets ◽

Torque Ripple ◽

Axial Flux ◽

Element Analysis ◽

Torque Density ◽

Axial Forces ◽

Halbach Array ◽

Radial Flux ◽

High Torque

Electric machines with high torque density are needed in many applications, such as electric vehicles, electric robotics, electric ships, electric aircraft, etc. and they can avoid planetary gears thus reducing manufacturing costs. This paper presents a novel axial-radial flux permanent magnet (ARFPM) machine with high torque density. The proposed ARFPM machine integrates both axial-flux and radial-flux machine topologies in a compact space, which effectively improves the copper utilization of the machine. First, the radial rotor can balance the large axial forces on axial rotors and prevent them from deforming due to the forces. On the other hand, the machine adopts Halbach-array permanent magnets (PMs) on the rotors to suppress air-gap flux density harmonics. Also, the Halbach-array PMs can reduce the total attracted force on axial rotors. The operational principle of the ARFPM machine was investigated and analyzed. Then, 3D finite-element analysis (FEA) was conducted to show the merits of the ARFPM machine. Demonstration results with different parameters are compared to obtain an optimal structure. These indicated that the proposed ARFPM machine with Halbach-array PMs can achieve a more sinusoidal back electromotive force (EMF). In addition, a comparative analysis was conducted for the proposed ARFPM machine. The machine was compared with a conventional axial-flux permanent magnet (AFPM) machine and a radial-flux permanent magnet (RFPM) machine based on the same dimensions. This showed that the proposed ARFPM machine had the highest torque density and relatively small torque ripple.

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