scholarly journals Effect of Slot Opening Width on the Air-Gap Magnetic Field of a Direct Drive Permanent Magnet Motor

2019 ◽  
Vol 9 (21) ◽  
pp. 4649
Author(s):  
Yaofei Han ◽  
Shaofeng Chen ◽  
Caixia Gao ◽  
Mengzhen Gao ◽  
Jikai Si ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Air Gap ◽  
Direct Drive ◽  
Permanent Magnet Motor ◽  
Slot Opening ◽  
Air Gap Magnetic Field ◽  
Opening Width

The direct drive permanent magnet motor (DDPMM) is a promising candidate for applications because of its high efficiency, high power density, and low maintenance costs. This study focused on the effect of slot opening width on the air-gap magnetic field of a DDPMM. An exact analytical model based on Fourier analysis was established to calculate the air-gap magnetic field. The analytical general solution of the air-gap magnetic field shows that the slot opening greatly affects the air-gap magnetic field distribution when the amount of the permanent magnet is constant. Then, the air-gap magnetic fields of the DDPMM with closed and open slots were compared at different positions. Furthermore, several finite-element models of motors composed of different numbers of unit motor were established based on the different slot opening widths to study the effect of slot opening width on the air-gap magnetic field. The results obtained using the finite element method verify that the slot opening width greatly affects the air-gap magnetic field.

scholarly journals Analysis of the Rotor Magnetomotive Force of Built-In Radial Permanent Magnet Generator for Vehicle

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Huihui Geng ◽  
Xueyi Zhang ◽  
Tao Si ◽  
Lanian Tong ◽  
Qingzhi Ma ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
High Efficiency ◽  
High Reliability ◽  
Air Gap ◽  
Magnetomotive Force ◽  
Analytical Expression ◽  
Output Performance ◽  
Air Gap Magnetic Field ◽  
Permanent Magnet Generator

Permanent magnet generator (PMG) for vehicles has attracted more and more attention because of its high efficiency, high power density, and high reliability. However, the weak main air-gap magnetic field can affect the output performance and the normal use of electrical equipment. Aiming at the problem, this paper took the rotor magnetomotive force (MMF), the direct influencing parameter of the main air-gap magnetic field, as the research object, deduced the analytical expression of rotor MMF of the built-in radial PMG in detail, and analyzed its main influencing factors in analytical expression, including the permanent magnet steel (PMS) material, the thickness of PMS in magnetizing direction, the vertical length of the inner side of PMS, and the effective calculation length of PMS. Based on this, the rotor parameters were optimized to obtain the best values. After that, the finite element simulation and prototype test of the optimized generator were carried out. The comparative analysis results showed that the optimized rotor parameters could effectively improve the rotor MMF and optimize the output performance of the generator.

Comparative study of thrust of U-shaped ironless permanent magnet synchronous linear motor based on analytical method and finite element analysis

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1091-1101
Author(s):  
Zhihui Yang ◽  
Ren Liu ◽  
Bin Xia
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Edge Effect ◽  
Three Dimensional ◽  
Linear Motor ◽  
Air Gap ◽  
Element Analysis ◽  
Air Gap Magnetic Field

Due to the large transverse edge effect for U-shaped ironless permanent magnet synchronous linear motor affect the distribution of air gap magnetic field is large, it will reduce the no-load back electromotive force and thrust. This paper proposes a novel method to evaluate the effect of transverse edge effect based on Kriging surrogate model. By comparing the results of the two-dimensional and three-dimensional finite element analysis of the air gap magnetic field of the motor, it can be seen transverse length of the motor, air gap height and thickness of the permanent magnet are the main influencing factors.

Research on the Field of New Type Rotor Structure Permanent Magnet Synchronous Motors

2011 ◽  
Vol 143-144 ◽  
pp. 154-158
Author(s):  
J.K. Si ◽  
M. Si ◽  
Hai Chao Feng
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Flux Density ◽  
Amplitude Distribution ◽  
Air Gap ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor ◽  
Permanent Magnet Synchronous Motors ◽  
New Type ◽  
Air Gap Magnetic Field

For each characteristic of surface-mounted permanent magnet motor and built-in permanent magnet motor, this paper presents a new rotor hybrid topologies structure of both the permanent magnet motors. Surface Mounted, built-in and hybrid permanent magnet motor topology model were established using the finite element method for to calculate the static magnetic field three structures of the motor. Comparative analysis of their contour distribution of the pole from the amplitude distribution within the air gap flux density and the flux density of the cloud were done. Air-gap magnetic field distribution in permanent magnet motor proposed new structure is more close to the sine, which is basis on the motor design, operation and so on.

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.

Torque ripple optimization for synchronous reluctance motors based on a virtual permanent magnet harmonic machine model

2021 ◽  
Vol 67 (3) ◽  
pp. 327-338
Author(s):  
Yixiang Xu ◽  
Chong Di ◽  
Xiaohua Bao ◽  
Dongying Xu
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Torque Ripple ◽  
Air Gap ◽  
Analysis Model ◽  
Machine Model ◽  
Asymmetric Rotor ◽  
Rotor Flux ◽  
Air Gap Magnetic Field ◽  
Intermediate Variables

The torque ripple is affected by both the stator and the rotor magnetic field harmonics. In synchronous reluctance motors (SynRM), there are only rotor permeance harmonics existing on the rotor side for the absence of the rotor windings. Since the asymmetric rotor flux barriers are widely applied in the SynRM rotor, it is difficult to calculate the rotor permeance accurately by the analytical method. In this article, the effects of the rotor permeance harmonics on the air-gap magnetic field are studied by a virtual permanent magnet harmonic machine (VPMHM), which is a finite-element (FE) based magnetostatic analysis model. The air-gap flux density harmonics produced by the SynRM rotor are extracted from the VPMHM model and used as the intermediate variables for the torque ripple optimization. The proposed method does not need to solve the transient process of motor motion. Hence, the time of the optimization process can be significantly shortened. Finally, a full electric cycle is simulated by dynamic FE simulation, and the torque ripple is proved to be effectively reduced.

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