A Novel Cooling Technique for the Windings of High-Torque-Density Permanent Magnet Machines

Hybrid vehicles require high torque for propel, hence permanent Magnet machines are highly suiting for the improvement in the torque density. The paper focus on designing built-in interior permanent magnet (IPM) synchronous machine for hybrid electric drive. With the permanent magnet switched from rotor to stator and the characteristics over a wide range of speed operation is studied. The results obtained though performance analysis shows that at 130 rpm high torque with power peaking at around 900 rpm. Both the inner and outer machine are studied using numerical study tool for performance analysis for the application mentioned above. The inner magnet rotor design has provide a better magnetic flux flow due to the larger flux linkage between the permanent magnet and stator pole. Both type of machines are evaluated for torque where the machine with inner magnet provide a higher torque density of 4.94% as compared to the outer magnet machines.

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High torque density and low torque ripple surface permanent magnet machines with sinusoidal plus third harmonic shaped magnets

2017 IEEE International Electric Machines and Drives Conference (IEMDC) ◽

10.1109/iemdc.2017.8002094 ◽

2017 ◽

Cited By ~ 2

Author(s):

Zhentao S. Du ◽

Thomas A. Lipo

Keyword(s):

Permanent Magnet ◽

Torque Ripple ◽

Permanent Magnet Machines ◽

Third Harmonic ◽

Torque Density ◽

High Torque ◽

Low Torque

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High torque density magnetically-geared switched flux permanent magnet machines

2015 Tenth International Conference on Ecological Vehicles and Renewable Energies (EVER) ◽

10.1109/ever.2015.7112948 ◽

2015 ◽

Cited By ~ 4

Author(s):

C. C. Awah ◽

Z. Q. Zhu ◽

Z. Wu ◽

D. Wu

Keyword(s):

Permanent Magnet ◽

Permanent Magnet Machines ◽

Torque Density ◽

High Torque

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Influence of unequal stator tooth width on the performance of outer-rotor permanent magnet machines

Open Physics ◽

10.1515/phys-2020-0175 ◽

2020 ◽

Vol 18 (1) ◽

pp. 432-438

Author(s):

Aimeng Wang ◽

Dashuang Li

Keyword(s):

Permanent Magnet ◽

Permanent Magnet Machines ◽

Efficiency Improvement ◽

Machine Model ◽

Element Analysis ◽

Torque Density ◽

Output Torque ◽

Tooth Width ◽

Outer Rotor ◽

High Torque

AbstractOuter-rotor permanent magnet machines for low-speed and high-torque applications have been used due to their high moment of inertia and torque density. In this paper, the 12-slot/10-pole outer-rotor fractional-slot permanent magnet machine model is established by finite element analysis, the influence of unequal stator tooth width and tooth tip width is investigated for the PM machine, and five different schemes of stator tooth and tip width are designed and analyzed. Detailed comparisons of the performance characteristics of the machines are presented including important issues such as output torque, magnetic field distribution, and tooth flux density. It is shown that the torque density and cogging torque and efficiency can be effectively improved by choosing reasonable tooth and tip width, which lays a foundation for further optimum design and efficiency improvement of the machine.

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Flux-Modulated Permanent Magnet Machines: Challenges and Opportunities

World Electric Vehicle Journal ◽

10.3390/wevj12010013 ◽

2021 ◽

Vol 12 (1) ◽

pp. 13

Author(s):

Qingsong Wang ◽

Xing Zhao ◽

Shuangxia Niu

Keyword(s):

Permanent Magnet ◽

Electric Vehicle ◽

Hybrid Electric Vehicle ◽

Permanent Magnet Machines ◽

Torque Density ◽

Rotating Speed ◽

Current State ◽

Desirable Feature ◽

Challenges And Opportunities ◽

High Torque

High torque density is a desirable feature of electrical machines used in traction applications, such as electric vehicle (EV)/hybrid electric vehicle (HEV) propulsion, wind turbines, more electric aircrafts, etc. The flux-modulated permanent magnet (FMPM) machine is considered as one of the most promising candidates to achieve high torque density. The incorporated gearing effect is ideal in reducing the rotating speed and amplifying the output torque of the FMPM machines. This paper aims at a comprehensive review of the topology evolution of the FMPM machines. Based on different structures, the FMPM machines are grouped into four categories: surface-type FMPM machines, spoke-type FMPM machines, partitioned stator FMPM machines, and bidirectional FMPM machines. The operating principles, advantages, drawbacks, and major applications of the FMPM machines are discussed in detail. In the end, the current state of the art, opportunities, challenges, and future trends of the FMPM machines are discussed. Therefore, this paper offers a systematic guidance on the selection and design of the FMPM machines.

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Study and design of dual stator permanent magnet machine with spoke-type configurations using phase-group concentrated-coil windings

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209457 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 1381-1389

Author(s):

Dezhi Chen ◽

Chengwu Diao ◽

Zhiyu Feng ◽

Shichong Zhang ◽

Wenliang Zhao

Keyword(s):

Permanent Magnet ◽

Permanent Magnets ◽

Low Cost ◽

Dynamic Performance ◽

Torque Ripple ◽

Permanent Magnet Machine ◽

Torque Density ◽

Phase Group ◽

High Torque ◽

Simulation Results

In this paper, a novel dual-stator permanent magnet machine (DsPmSynM) with low cost and high torque density is designed. The winding part of the DsPmSynM adopts phase-group concentrated-coil windings, and the permanent magnets are arranged by spoke-type. Firstly, the winding structure reduces the amount of copper at the end of the winding. Secondly, the electromagnetic torque ripple of DsPmSynM is suppressed by reducing the cogging torque. Furthermore, the dynamic performance of DsPmSynM is studied. Finally, the experimental results are compared with the simulation results.

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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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