scholarly journals Analysis and Optimization of Axial Flux Permanent Magnet Machine for Cogging Torque Reduction

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1738
Author(s):  
Hina Usman ◽  
Junaid Ikram ◽  
Khurram Saleem Alimgeer ◽  
Muhammad Yousuf ◽  
Syed Sabir Hussain Bukhari ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Three Dimensional ◽  
Latin Hypercube Sampling ◽  
Air Gap ◽  
Axial Flux ◽  
Element Analysis ◽  
Cogging Torque ◽  
Basic Source ◽  
Three Dimensional Finite Element ◽  
Torque Ripples

In this paper, a hexagonal magnet shape is proposed to have an arc profile capable of reducing torque ripples resulting from cogging torque in a single-sided axial flux permanent magnet (AFPM) machine. The arc-shaped permanent magnet increases the air-gap length effectively and makes the flux of the air-gap more sinusoidal, which decreases air-gap flux density and hence causes a reduction in cogging torque. Cogging torque is the basic source of vibration, along with the noise in PM machines, since it is the main cause of torque ripples. Cogging torque is independent of the load current and is proportional to the air-gap flux and the reluctance variation. Three-dimensional finite element analysis (FEA) is used in the JMAG-Designer to analyze the performance of the conventional and proposed hexagonal-shaped PM AFPM machines. The proposed shape is designed to reduce cogging torque, and the voltage remains the same as compared to the conventional hexagonal-shaped PM machine. Further, optimization is performed by utilizing an asymmetric overhang. Latin hypercube sampling (LHS) is used to create samples, the kriging method is applied to approximate the model, and a genetic algorithm is applied to obtain the optimum parameters of the machine.

scholarly journals Design and Analysis of a Dual Airgap Radial Flux Permanent Magnet Vernier Machine with Yokeless Rotor

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2311
Author(s):  
Mudassir Raza Siddiqi ◽  
Tanveer Yazdan ◽  
Jun-Hyuk Im ◽  
Muhammad Humza ◽  
Jin Hur
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Flux Linkage ◽  
Element Analysis ◽  
Cogging Torque ◽  
Torque Density ◽  
Stator Windings ◽  
Radial Flux ◽  
Torque Ripples

This paper presents a novel topology of dual airgap radial flux permanent magnet vernier machine (PMVM) in order to obtain a higher torque per magnet volume and similar average torque compared to a conventional PMVM machine. The proposed machine contains two stators and a sandwiched yokeless rotor. The yokeless rotor helps to reduce the magnet volume by providing an effective flux linkage in the stator windings. This effective flux linkage improved the average torque of the proposed machine. The competitiveness of the proposed vernier machine was validated using 2D finite element analysis under the same machine volume as that of conventional vernier machine. Moreover, cogging torque, torque ripples, torque density, losses, and efficiency performances also favored the proposed topology.

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 Noise Reduction Design with Trapezoidal Back-EMF and Asymmetric Air-Gap for Single-Phase BLDC Refrigerator Cooling Fan Motor

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5467
Author(s):  
Jin-Hwan Lee ◽  
Sang-Yong Jung
Keyword(s):  
Single Phase ◽  
Three Dimensional ◽  
Torque Ripple ◽  
Air Gap ◽  
Manufacturing Cost ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Novel Method ◽  
The Dead ◽  
Three Dimensional Finite Element

In this study, a novel method for reducing the noise generated by single-phase claw-pole motors employed as refrigerator fan blowers is proposed. A single-phase claw-pole motor has the advantages of low manufacturing cost, easy manufacturing, and a high number of turns. However, in such motors, current delays occur owing to a high inductance; therefore, it is necessary to merge the back-electromotive force and current phases into the same phase using the phase advance method. Additionally, a single-phase motor exhibits dead torque and zero torque at an electrical angle of 180° owing to its electrical characteristics, and the dead torque deteriorates the average torque and torque ripple characteristics of the motor. In this study, a novel method is proposed to make the air gap asymmetrical by tilting the claw to reduce the noise generated by single-phase claw-pole motors. An asymmetric air gap allows the cogging torque to eliminate the dead torque caused by alignment torques, causing the torque ripple to decrease. To validate the effectiveness of the proposed method, the proposed model is compared with a base model via three-dimensional finite element analysis. Furthermore, the two models are manufactured and a noise test is conducted in an anechoic chamber to compare the noise difference between the two models.

scholarly journals Design and Analysis of a Permanent Magnet Vernier Machine with Non-Uniform Tooth Distribution

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7816
Author(s):  
Fei Zhao ◽  
Mengzhu Cao ◽  
Encheng Tao ◽  
Liyi Li
Keyword(s):  
Permanent Magnet ◽  
Uniform Design ◽  
Three Dimensional ◽  
Torque Ripple ◽  
Uniform Structure ◽  
Direct Drive ◽  
Cogging Torque ◽  
Dimensional Finite Element ◽  
Aerial Vehicle ◽  
Three Dimensional Finite Element

To improve the torque performance of the permanent magnet vernier machine in the direct-drive system for Unmanned Aerial Vehicle (UAV), this paper proposes the topology of non-uniform tooth distribution. This distribution, considering the additional flux harmonics, aims to contribute to torque improvement, whereas the cogging torque also increases at the same time. A phasors method is proposed to solve the issue caused by the non-uniform structure, adjusting the mechanic angle of each tooth reasonably to restrict the cogging torque. In addition, the non-uniform design is illustrated in detail, which includes the method of grouping the teeth, considering the factors of series pole ratio and winding layout. By using the three-dimensional finite element method, torque is significantly increased without additional torque ripple, which satisfies the desired design target.

A Nonlinear Magnetic Circuit Analysis of a Permanent Magnet Biased Homopolar Bearing

1999 ◽  
Author(s):  
Andrew Kenny ◽  
Alan Palazzolo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Analytical Methods ◽  
Magnetic Circuit ◽  
Three Dimensional ◽  
Magnetic Bearing ◽  
Axial Flux ◽  
Element Analysis ◽  
Good Agreement

Abstract A magnetic circuit model for a homopolar magnetic bearing is presented. This model connects the fore and aft circumferential flux paths with axial flux paths through the rotor and back iron. The bias flux is provided by a circumferential permanent magnet in the back iron. Results for an analysis using the nonlinear Hyperco50 B-H curve are presented. These results are compared to the results of a three dimensional magnetostatic finite element analysis. The two analytical methods are in good agreement and show that the control flux in this type of bearing follows both circumferential and axial paths.

Structure Design and Torque Characteristics Analysis of a Novel Transverse Flux Permanent Magnet Motor

2015 ◽  
Vol 719-720 ◽  
pp. 644-651
Author(s):  
Yu Feng Zhuang ◽  
Ze Yan Hu ◽  
Kai He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Three Dimensional ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Output Torque ◽  
Dimensional Finite Element ◽  
Transverse Flux ◽  
Three Dimensional Finite Element

A new type of transverse flux permanent magnet motor with surface-type permanent magnet rotor structure and silicon steel stator structure was designed. According to the new structure of transverse flux permanent magnet motor, the operating principle of the motor was given. The relationship among motor output torque, torque density, magnetic poles and winding parameters are deduced, and a reasonable method of designing motor size parameters was proposed. A three-dimensional finite element model of the motor was created and the model grid division was done using ANSYS finite element analysis software. According to different winding current values and different positions of stator and rotor, the motor magnetic flux density distribution, the output torque and inductance parameter were given through calculating the three dimensional finite element models. Finite element analysis results show that the new motor structure is reasonable.

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