scholarly journals Design and Analysis of Outer Rotor Permanent-Magnet Vernier Machines with Overhang Structure for In-Wheel Direct-Drive Application

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1238 ◽  
Author(s):  
Dong Yu ◽  
Xiaoyan Huang ◽  
Lijian Wu ◽  
Youtong Fang
Keyword(s):  
Permanent Magnet ◽  
Magnetic Composite ◽  
Direct Drive ◽  
Soft Magnetic ◽  
Axial Flux ◽  
Element Analysis ◽  
Torque Density ◽  
Outer Rotor ◽  
Flux Modulation ◽  
Conventional Machine

This paper presents a novel outer rotor permanent-magnet vernier machine (PMVM) for in-wheel direct-drive application. The overhang structures of the rotor and flux modulation pole (FMP) are introduced. The soft magnetic composite (SMC) was adopted in the FMP overhang to allow more axial flux. The 3-D finite element analysis (FEA) was carried out to prove that the proposed machine can effectively utilize the end winding space to enhance the air-gap flux density. Hence the PMVM can offer 27.3% and 14.5% higher torque density than the conventional machine with no overhang structure and the machine with only rotor overhang structure, respectively. Nevertheless, the efficiency of the proposed machine is slightly lower than the conventional ones due to the extra losses from the overhang structures.

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

Energies ◽  
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.

Analytical sub-domain model for predicting open-circuit field of permanent magnet vernier machine accounting for tooth tips

2016 ◽  
Vol 35 (2) ◽  
pp. 624-640 ◽  
Author(s):  
Y. Oner ◽  
Z.Q. Zhu ◽  
L.J. Wu ◽  
X. Ge
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Open Circuit ◽  
Air Gap ◽  
Domain Model ◽  
Direct Drive ◽  
Element Analysis ◽  
Cogging Torque ◽  
Content Type ◽  
Flux Modulation

Purpose – Due to high electromagnetic torque at low speed, vernier machines are suitable for direct-drive applications such as electric vehicles and wind power generators. The purpose of this paper is to present an exact sub-domain model for analytically predicting the open-circuit magnetic field of permanent magnet vernier machine (PMVM) including tooth tips. The entire field domain is divided into five regions, viz. magnets, air gap, slot openings, slots, and flux-modulation pole slots (FMPs). The model accounts for the influence of interaction between PMs, FMPs and slots, and radial/parallel magnetization. Design/methodology/approach – Magnetic field distributions for slot and air-gap, flux linkage, back-EMF and cogging torque waveforms are obtained from the analytical method and validated by finite element analysis (FEA). Findings – It is found that the developed sub-domain model including tooth tips is very accurate and is applicable to PMVM having any combination of slots/FMPs/PMs. Originality/value – The main contributions include: accurate sub-domain model for PMVM is proposed for open-circuit including tooth-tip which cannot be accounted for in literature; the model accounts the interaction between flux modulation pole (FMP) and slot; developed sub-domain model is accurate and applicable to any slot/FMP/PM combinations; and it has investigated the influence of FMP/slot opening width/height on cogging torque.

scholarly journals Investigation of an Inset Micro Permanent Magnet Synchronous Motor Using Soft Magnetic Composite Material

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4445
Author(s):  
Da-Chen Pang ◽  
Zhen-Jia Shi ◽  
Pei-Xuan Xie ◽  
Hua-Chih Huang ◽  
Gia-Thinh Bui
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Torque Ripple ◽  
Synchronous Motor ◽  
Silicon Steel ◽  
Magnetic Composite ◽  
Soft Magnetic ◽  
Tile Type ◽  
Torque Density ◽  
Soft Magnetic Composite

This paper presents the world’s smallest inset permanent magnet synchronous motor (PMSM) with a soft magnetic composite (SMC) core, providing ease of manufacturing for micromachine applications without silicon steel laminations. The inset motor can offer an additional reluctance torque and higher torque density with a lower usage amount of permanent magnet. A 15 mm diameter inset motor was developed with the thickness of a tile-type permanent magnet which is limited to 1 mm by the manufacturer. The motor was designed with high torque density and low torque ripple by varying the interpole iron width for the rotor. Two inset motors were made using both SMC and silicon steel materials for comparison. The performance of the SMC motor was inferior to the silicon steel motor, but it still meets the specifications of the commercial market. If the thickness of the tile-type permanent magnet is further reduced, the micro inset motor with a SMC core can be easily mass-manufactured using powder sintering.

Application of Soft Magnetic Composite Material in the Field of Electrical Machines

2013 ◽  
Vol 380-384 ◽  
pp. 4299-4302
Author(s):  
Xiao Bei Li ◽  
Jing Zhao ◽  
Zhen Chen
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Electric Machine ◽  
Magnetic Composite ◽  
Applied Potential ◽  
Soft Magnetic ◽  
Axial Flux ◽  
Permanent Magnet Machine ◽  
Soft Magnetic Composite ◽  
Radial Flux

The property of the soft magnetic composite (SMC) material is introduced. Take the traditional material used for electric machine, i.e. the silicon steel lamination, as the reference, this paper summarizes the application advantages of SMC in the typical electric machine, such as tubular permanent-magnet liner machine, high-speed permanent-magnet machine, claw-pole machine, axial flux permanent-magnet machine and radial flux permanent-magnet machine. SMC material has much applied potential in the field of electric machine.

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