Microstructure Design of Surface Permanent Magnet and Tooth Surface Stator in Brushless DC Motor with Low Rare Earth Material

2013 ◽  
Vol 479-480 ◽  
pp. 427-430
Author(s):  
Hsing Cheng Yu ◽  
Bo Syun Yu
Keyword(s):  
Rare Earth ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Structure Design ◽  
Tooth Surface ◽  
Magnetic Flux Density ◽  
Cogging Torque ◽  
Brushless Dc ◽  
Earth Material

Permanent magnet (PM) brushless DC motors (BLDCMs) are widely applied in industrial drives. However, the price rising of rare earth resource resulted in country policy restriction, so it is detrimental for mass production of PM-BLDCMs. As a result, the design and manufacture tendency of PM-BLDCMs are smaller and slighter in adopting rare earth materials of PMs. Additional, the magnetic flux density of PMs are difficult to improve in the near future. The effective method is to decrease stator reluctance and to adjust magnetic flux distribution of the air gap in stator design. Hence, the surface permanent magnets (SPMs) and tooth surface stators (TSSs) are designed to improve the motor performance, and are calculated by finite-element analysis (FEA) software in this study. Various hemicycle groove microstructures of SPMs and TSSs for designing, analyzing and optimizing are considered to observe the magnetic field strength distribution and to reduce the cogging torque in PM-BLDCMs, and the FEA result can be regarded as important references of motor structure design. The cogging torque can be reduced 80.9% in SPM3-model and can be decayed 89.2% in TSS2-model versus original model separately, and the cogging torque of the optimal combination of SPM-BLDCM can be abated 62.4%. Furthermore, the usage amount of rare earth material volume in designed SPM-BLDCMs can be reduced 5.3% in average. Finally, a prototype of the SPM- BLDCM has been constructed to prove the simulation design.

scholarly journals Analysis of a Permanent-Magnet Brushless DC Motor with Fixed Dimensions

2010 ◽  
Vol 26 (1) ◽  
pp. 78-81
Author(s):  
Uldis Brakanskis ◽  
Janis Dirba ◽  
Ludmila Kukjane ◽  
Viesturs Drava
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Dc Motor ◽  
Magnetic Flux Density ◽  
Brushless Dc Motor ◽  
Outer Diameter ◽  
Zone Length ◽  
Brushless Dc ◽  
Permanent Magnet Brushless Dc

Analysis of a Permanent-Magnet Brushless DC Motor with Fixed DimensionsThe purpose of this paper is to describe the analysis of a permanent-magnet brushless DC motor with fixed outer diameter and active zone length. The influence of air gap, material of permanent magnets and their size on the magnetic flux density of the machine and magnetic flux is analyzed. The work presents the calculations of two programs, the comparison of the results and the most suitable combination of factors that has been found.

scholarly journals Influence of Material and Geometrical Properties of Permanent Magnets on Cogging Torque of BLDC

2018 ◽  
Vol 8 (2) ◽  
pp. 2656-2662
Author(s):  
M. Yildirim ◽  
H. Kurum ◽  
D. Miljavec ◽  
S. Corovic
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Cogging Torque ◽  
Geometrical Properties ◽  
Brushless Dc ◽  
Stator Current ◽  
2D Numerical Model

Aim of this study is to investigate the influence of both material and geometrical properties of surface mounted permanent magnets (PM) on cogging torque of a brushless DC motor (BLDC) by means of numerical modeling based on finite element method (FEM). To this end, a 2D numerical model of the BLDC motor is built by using the software package Ansys Maxwell. In this study, we analyze the machine properties in no excitation mode (i.e. no stator current is applied) and calculate the distribution of magnetic flux density within the entire motor, the magnetic flux density in the air gap, the cogging torque and the back electromotor force (EMF). Firstly, analysis is performed for four different magnets. It is seen that while cogging torque, back EMF, and magnetic flux density in the air gap for the strongest magnet material have the highest values, the lowest values of these are obtained for the weakest magnet. In the second part of the study, the effect of variation of magnet geometry on the cogging torque, magnetic field density and back EMF of BLDC is examined. Three magnet embrace values are handled in this study. When the magnet embrace increases, the value of the cogging torque reduces. Besides, the maximum values of the back EMF are approximately the same for different magnet embraces, while shapes of the back EMF only change based on the magnet embrace. According to the results, the cogging torque strongly depends on the material and geometrical properties of the magnets.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals The Air Gap and Angle Optimization in the Axial Flux Permanent Magnet Motor

1970 ◽  
Vol 110 (4) ◽  
pp. 25-29 ◽  
Author(s):  
C. Akuner ◽  
E. Huner
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Permanent Magnet Motor ◽  
Axial Flux ◽  
Flux Change ◽  
Torque Values ◽  
The Impact

In this study, the axial flux permanent magnet motor and the length range of the air gap between rotors was analyzed and the appropriate length obtained. NdFeB permanent magnets were used in this study. Permanent magnets can change the characteristics of the motor's torque. However, the distance between permanent magnets and the air gap will remain constant for each magnet. The impact of different magnet angles for the axial flux permanent magnet motor and other motor parameters was examined. To this aim, the different angles and torque values of the magnetic flux density were calculated using the finite element method of analysis with the help of Maxwell 3D software. Maximum torque was obtained with magnet angles of 21°, 26°, 31.4°, and 34.4°. Additionally, an important parameter for the axial flux permanent magnet motor in terms of the air gap flux was analyzed. Minimum flux change was obtained with a magnet angle of 26°. The magnetic flux of the magnet-to-air-gap is under 0.5 tesla. Given the height of the coil, the magnet-to-air-gap distance most suitable for the axial flux permanent magnet motor was 4 mm. Ill. 11, bibl. 4, tabl. 2 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.280

scholarly journals Mitigation Method of Slot Harmonic Cogging Torque Considering Unevenly Magnetized Permanent Magnets in PMSM

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3887
Author(s):  
Jeong ◽  
Lee ◽  
Hur
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Permanent Magnet Synchronous Motor ◽  
Harmonic Component ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Cogging Torque ◽  
Maxwell Stress Tensor ◽  
The Finite Element Analysis ◽  
Harmonic Components

This paper presents a mitigation method of slot harmonic cogging torque considering unevenly magnetized magnets in a permanent magnet synchronous motor. In previous studies, it has been confirmed that non-uniformly magnetized permanent magnets cause an unexpected increase of cogging torque because of additional slot harmonic components. However, these studies did not offer a countermeasure against it. First, in this study, the relationship between the residual magnetic flux density of the permanent magnet and the cogging torque is derived from the basic form of the Maxwell stress tensor equation. Second, the principle of the slot harmonic cogging torque generation is explained qualitatively, and the mitigation method of the slot harmonic component is proposed. Finally, the proposed method is verified with the finite element analysis and experimental results.

Non-Contact Actuation of Less-Invasive Bone Lengthening Device Using Embedded Cycloidal Motor Driven by Permanent Magnets from the outside

2012 ◽  
Vol 523-524 ◽  
pp. 722-726 ◽  
Author(s):  
Yuki Matsuzaki ◽  
Yoichi Kadota ◽  
Kazuo Uzuka ◽  
Hideyuki Suenaga ◽  
Ken Sasaki ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
The Body ◽  
Magnetic Flux Density ◽  
Bone Lengthening ◽  
Ring Gear ◽  
Actuation Mechanism ◽  
Surgical Device

This report proposes a miniaturized non-contact actuation mechanism for a surgical device for bone extension operation. The device is embedded inside the body, and the device controls the gap between the bones cut by operation. A small permanent magnet is attached to the outer gear of a cycloidal reducer that rotates a screw of the screw-nut mechanism. This magnet is forced by the external magnetic flux density controlled by the outer permanent magnets’ position. In this research, two pairs of permanent magnet bar were rotated by stepping motors outside the device. The outer gear is constrained in As a result, ring gear of the cycloidal reducer is driven in translational wobbling motion the inner gear is connected to the screw and the output nut position is driven linearly with screw rotation. The dimensions of the fabricated device were 7 mm in diameter and 39.7 mm in length. The output thrust of this device was 2 N.

scholarly journals Performance Optimization of a Differential Method for Localization of Capsule Endoscopes

2020 ◽  
Vol 2 (1) ◽  
pp. 31
Author(s):  
Samuel Zeising ◽  
Kivanc Ararat ◽  
Angelika Thalmayer ◽  
Daisuke Anzai ◽  
Georg Fischer ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Performance Optimization ◽  
Permanent Magnets ◽  
Magnetic Flux Density ◽  
Computational Domain ◽  
Localization System ◽  
The Mean ◽  
Position And Orientation

Although capsule endoscopy is already used for diagnosis of the gastrointestinal tract, a method to precisely localize the capsules, important for accurate diagnosis, is lacking. Static magnetic localization is a promising solution for that purpose. In this paper, the simulation of a differential static magnetic localization system with dynamic geomagnetic compensation was optimized. First, a convergence-test for the position and orientation errors as a function of the dimension of the computational domain was conducted. Subsequently, the diameter-to-length ratio of a permanent magnet was varied and the corresponding position and orientation errors, as well as the mean magnetic flux density measured at the sensor positions, were compared. The results revealed that for a computational domain radius of 800 mm, the position and orientation errors converged to less than 0.1 mm and 0.1°, respectively. The position and orientation errors were also of that order, even with the smallest permanent magnet employed in the study. Furthermore, the mean magnetic flux density measured at the sensors of the proposed magnetic localization system would be detectable using state-of-the-art magnetometers. It is concluded that the differential localization method is also feasible for small permanent magnets, which is especially important considering the limited space within endoscopy capsules.

scholarly journals Development of Mathematical Models in Explicit Form for Design and Analysis of Axial Flux Permanent Magnet Synchronous Machines

2020 ◽  
Vol 10 (21) ◽  
pp. 7695
Author(s):  
Franjo Pranjić ◽  
Peter Virtič
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Input Data ◽  
Permanent Magnets ◽  
Synchronous Machines ◽  
Simplified Model ◽  
Magnetic Flux Density ◽  
Axial Component ◽  
Permanent Magnet Synchronous Machines ◽  
Axial Flux

This article proposes a methodology for the design of double-sided coreless axial flux permanent magnet synchronous machines, which is based on a developed model for calculating the axial component of the magnetic flux density in the middle of the distance between opposite permanent magnets, which also represents the middle of the stator. Values for different geometric parameters represent the input data for the mathematical model in explicit form. The input data are calculated by using a simplified finite element method (FEM), which means that calculations of simplified 3D models are performed. The simplified model consists of two rotor disks with surface-mounted permanent magnets and air between them, instead of stator windings. Such a simplification is possible due to similar values of permeability of the air and copper. For each simplified model of the machine the axial component of the magnetic flux density is analyzed along a line passing through the center of opposite permanent magnets and both rotor disks. Values at the middle of the distance between the opposite permanent magnets are the lowest and are therefore selected for the input data at different stator, rotor disks and permanent magnets (PM) thicknesses. Such input data enable the model to consider the nonlinearity of materials.

scholarly journals Finding the Optimal Size of Permanent Magnets for a Transverse Magnetic Flux Generator with a Disk Rotor

2021 ◽  
Vol 2(50) ◽  
Author(s):  
Oleksii Duniev ◽  
◽  
Andri Yehorov ◽  
Andrii Masliennikov ◽  
Mario Stamann ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Transverse Magnetic ◽  
Optimal Size ◽  
Cogging Torque ◽  
Negative Effect ◽  
Relative Design ◽  
Design Simplicity ◽  
Optimal Calculation

Based on the analysis of the transverse flux machine designs, they were found to have a relative design simplicity and a high-power density. The purpose of this work is to determine the optimal height of a permanent magnet and to define its effect on the induced EMF value in the stator coils and the cogging torque, as well as to define the picture of the magnetic flux leakage between the stator poles. To achieve these goals, the 3D model of a low speed generator was studied. The electromagnetic analysis was carried out using a modern software, which allows us to determine the magnetic field distribution in the 3D, as well as the induced EMF value and the rotor cogging torque. The criterion for the optimal calculation is the highest EMF value at the minimum value of the rotor cogging torque. The parameters of the permanent magnets, such as the width and length, remained unchanged, whereas, the height varied from 1 to 8 mm at a 1-mm step. The corresponding dependencies are obtained for each height. The most significant result of the work is the conclusion that the height of the permanent magnet should not exceed the 3-mm value. The significance of the obtained results is that the used methodology allowed finding the optimal height of the permanent magnet, since a further increase in its height leads to no growth in the EMF value, but rather significantly enhances the negative effect from the rotor cogging torque. In addition, the simulation results were supported experimentally.

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