scholarly journals Magnetic field determination for different block permanent magnet systems

2010 ◽  
Vol 23 (3) ◽  
pp. 259-272 ◽  
Author(s):  
Ana Vuckovic-Mladenovic ◽  
Slavoljub Aleksic
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Analytical Method ◽  
Comsol Multiphysics ◽  
Magnetic Flux Density ◽  
Field Calculation ◽  
Arbitrary Direction ◽  
Magnetic Dipoles ◽  
Density Distributions

The paper presents magnetic field calculation of three characteristic permanent magnet systems, which component parts are block magnets homogeneously magnetized in arbitrary direction. Method used in this publication is based on a system of equivalent magnetic dipoles. The results obtained using this analytical method are compared with results obtained using COMSOL Multiphysics software. Magnetic field and magnetic flux density distributions of permanent magnet systems are also shown in the paper.

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 Effect of Pole Shoe Design on Inclination Angle of Different Magnetic Fields in Permanent Magnet Machines

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2437
Author(s):  
Jonathan Sjölund ◽  
Sandra Eriksson
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Field Strength ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Magnetic Circuit ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Inclination Angles

Electromagnetic modelling of electrical machines through finite element analysis is an important design tool for detailed studies of high resolution. Through the usage of finite element analysis, one can study the electromagnetic fields for information that is often difficult to acquire in an experimental test bench. The requirement for accurate result is that the magnetic circuit is modelled in a correct way, which may be more difficult to maintain for rare earth free permanent magnets with an operating range that is more likely to be close to non-linear regions for the relation between magnetic flux density and magnetic field strength. In this paper, the inclination angles of the magnetic flux density, magnetic field strength and magnetization are studied and means to reduce the inclination angles are investigated. Both rotating and linear machines are investigated in this paper, with different current densities induced in the stator windings. By proper design of the pole shoes, one can reduce the inclination angles of the fields in the permanent magnet. By controlling the inclination angles, one can both enhance the performance of the magnetic circuit and increase the accuracy of simpler models for permanent magnet modelling.

Analytical Method for Magnetic Field Calculation in a Low-Speed Permanent-Magnet Harmonic Machine

2011 ◽  
Vol 26 (3) ◽  
pp. 862-870 ◽  
Author(s):  
Linni Jian ◽  
Guoqing Xu ◽  
Chunting Chris Mi ◽  
K. T. Chau ◽  
C. C. Chan
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Analytical Method ◽  
Field Calculation ◽  
Low Speed

scholarly journals ALTERNATING MAGNETIC FIELD GENERATOR FOR THREE-DIMENSIONAL POSITION TRACKING OF MEDICAL TREATMENT EQUIPMENT FOR TRAINING

2021 ◽  
pp. 2140027
Author(s):  
MIN GYU PARK ◽  
SANG KWANG BANG ◽  
SEONG HWAL SHIN ◽  
KI WOONG SEONG ◽  
JYUNG HYUN LEE
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Alternating Magnetic Field ◽  
Magnetic Flux Density ◽  
Position Tracking ◽  
X Ray ◽  
3D Space ◽  
Magnetic Field Generator

In recent years, the incidence of cardiovascular disease is high due to the aging population and westernization of dietary habits, what encourages researching new methods. Most cardiovascular procedures use the catheter. In the procedure using a catheter, a long time of training is required to lower the procedure risk. So, a medical training simulator is being developed. In the actual procedure, the position of the catheter is confirmed by a C-arm using X-ray, but there is a risk of over exposure to radiation if the X-ray device is used until training. To solve this problem, in previous studies, the position of the catheter was tracked using a permanent magnet. However, the method of permanent magnet has a high error value due to the shape of the external magnetic flux density and the interference of environmental magnetic field. In this paper, an alternating magnetic field generator is proposed for 3D position tracking of medical equipment for training. An electromagnet with an optimal shape was designed through finite element analysis. The designed electromagnet is implemented and tested to confirm the performance. Through the location tracking experiment, an equation to estimate the distance between the electromagnet and the Hall sensor in 3D space was derived by linear regression recursive method. Through the derived equation, it was possible to track the position of the electromagnet at any position in the 3D space. Unlike previous studies using permanent magnets, the proposed alternating magnetic field generator has an isotropic shape with an external magnetic flux density according to the same distance. So, it is possible to reduce errors in position and distance, and minimize the effect of environmental magnetic fields by using an alternating magnetic field.

External Magnetic Field Control during EDM of a Permanent Magnet

2014 ◽  
Vol 1017 ◽  
pp. 806-811
Author(s):  
Hideki Takezawa ◽  
Nobuhiro Yokote ◽  
Naotake Mohri
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Electrical Discharge Machining ◽  
Magnetic Flux Density ◽  
Internal Temperature ◽  
Set Up ◽  
The Magnetic Field

The effect of changes in the magnetic field on the magnetic flux density during the electrical discharge machining (EDM) of a permanent magnet is reported. During EDM of the permanent magnet, a second magnet for the external magnetic field was set up, and the internal temperature and surface magnetic flux density on the opposite surface of the permanent magnet during machining were evaluated. It was found that even though the internal temperature of the magnet remained unchanged, the surface magnetic flux density changed when the external magnetic field was varied. In addition, the magnetic field generated by the magnet changed when a plate with high permeability was pressed onto the surface of the permanent magnet.

scholarly journals Analytical Study and Comparison of Electromagnetic Characteristics of 8-Pole 9-Slot and 8-Pole 12-Slot Permanent Magnet Synchronous Machines Considering Rotor Eccentricity

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2036
Author(s):  
Hoon-Ki Lee ◽  
Tae-Kyoung Bang ◽  
Jeong-In Lee ◽  
Jong-Hyeon Woo ◽  
Hyo-Seob Shin ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Synchronous Machines ◽  
Magnetic Flux Density ◽  
Permanent Magnet Synchronous Machines ◽  
General Solutions ◽  
Rotor Eccentricity ◽  
Electromagnetic Characteristics

In this study, a magnetic field is analyzed using an analytical method and compared with the electromagnetic characteristics of 8-pole 9-slot and 8-pole 12-slot permanent magnet synchronous machines considering rotor eccentricity. The magnetic flux density and back electromotive force (EMF) are derived using perturbation theory and electromagnetic theory. First, the Fourier modeling of a permanent magnet is performed through magnetization modeling, and two analysis regions are set based on several assumptions for applying the analytical method. Accordingly, the governing equations of the analysis regions are derived in the form of Poisson and Laplace equations. In addition, the undefined coefficients of the general solutions are calculated through general solutions and appropriate boundary conditions, and the magnetic flux density and back EMF of the air gap region are derived based on the definition of the magnetic vector potential. The results obtained using the analytical method are compared with the finite element method and experimental results. In addition, we perform a torque analysis considering rotor eccentricity and analyze the torque ripple based on rotor eccentricity for two cases involving the pole/slot combination.

scholarly journals Magnetic Field Analytical Solution for Non-homogeneous Permeability in Retaining Sleeve of a High-Speed Permanent-Magnet Machine

2018 ◽  
Vol 23 (4) ◽  
pp. 72 ◽  
Author(s):  
Gabriel Mendonça ◽  
Thales Maia ◽  
Braz Cardoso Filho
Keyword(s):  
Magnetic Field ◽  
Analytical Solution ◽  
Permanent Magnet ◽  
High Speed ◽  
Fourier Method ◽  
Load Condition ◽  
Magnetic Flux Density ◽  
Permanent Magnet Machines ◽  
Field Calculation ◽  
Saturation Profile

This work presents a novel solution for magnetic field calculation in two-dimensional problems in which one region is defined with space-varying magnetic parameter. The proposed solution extends the well-established Maxwell–Fourier method for calculating magnetic fields in surface-mounted cylindrical high-speed permanent-magnet machines. This contribution is effective to evaluate more realistic magnetic parameters, where measurements of a high-speed permanent-magnet generator prototype indicate saturation in the retaining sleeve due to pole-to-pole leakage flux. The saturation profile is a function of mechanical angle and can be modeled with the aid of a space-varying relative permeability, expressed in terms of a Fourier series. As an example, the presented solution has been applied to a surface-mounted PM machine at no-load condition. Magnetic field calculations show that a simple saturation profile, with low order space-varying permeability in the retaining sleeve significantly affects the magnetic flux density distribution in the air-gap. The analytical solution is confronted with finite-element method, which confirms validity of the proposed methodology.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

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