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

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.

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Platform Design for Characterizing Shear Force Produced by Magnetized Magnetorheological Fluid

ASME 2019 28th Conference on Information Storage and Processing Systems ◽

10.1115/isps2019-7450 ◽

2019 ◽

Author(s):

Ping-Hsun Lee ◽

Jen-Yuan (James) Chang

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Yield Stress ◽

Flux Density ◽

Shear Force ◽

Permanent Magnets ◽

Magnetic Flux Density ◽

Finite Element Method Result ◽

Mr Fluid ◽

The Magnetic Field

Abstract In this paper we proposed a platform for measuring shear force of magnetorheological (MR) fluid by which the relationship of yield stress and magnetic flux density of specific material can be determined. The device consisted of a rotatable center tube in a frame body and the magnetic field was provided by two blocks of permanent magnets placed oppositely outside the frame body. The magnitude and direction of the magnetic field were manipulated by changing the distance of the two permanent magnets from the frame body and rotating the center tube, respectively. For determining the magnetic field of the device, we adopted an effective method by fitting the FEM (finite element method) result to the measured one and then rebuilt the absent components to approximate the magnetic field, which was hardly to be measured simultaneously as different device setup were required. With the proposed platform and analytical methods, the drawing shear force and the corresponding yield stress contributed by MR fluid could be evaluated in respect to the magnitude and direction of given magnetic flux density with acceptable accuracy for specific designing purposes without a large, complex, and expensive instrument.

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External Magnetic Field Control during EDM of a Permanent Magnet

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1017.806 ◽

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.

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Study on Magnetic Field for Navigation of Articulated Needle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.152-154.952 ◽

2012 ◽

Vol 152-154 ◽

pp. 952-957

Author(s):

Hua Fang Huang ◽

Yi Zhong Wang ◽

Zong Guo Zhou ◽

Yong Hua Chen

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Flux Density ◽

Permanent Magnets ◽

Dimensional Space ◽

Three Dimensional ◽

Magnetic Flux Density ◽

Variable Direction ◽

The Magnetic Field ◽

Three Dimensional Space

When the magnetic articulated needle is inserting, the magnetic field which can produce the magnetic force of variable direction is required in order to implement the magnetic navigation in three-dimensional space. The paper puts forward a method for generating three-dimensional magnetic field based on the rotaion and translation of multiple permanent magnets. In this method, multiple permanent magnets form a circumference array. Every permanent magnet can rotate around the spin axis of itself in the array plane and move along the direction vertical to the array plane. Thus, in the array center, a magnetic fied which can produce the uniform magnetic flux density is obtained. The direction of magnetic fied is controllable in three-dimensional space and the magnitude of magnetic flux density is variable in a certain range. The simulations by ANSYS verify the feasibility of the proposed method.

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Development of Magnetic Coupling Utilizing Magnetic Material Attached Magnetic-Flux Concentrated Surface Permanent Magnet Arrangement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.792.159 ◽

2014 ◽

Vol 792 ◽

pp. 159-164

Author(s):

Takuya Hirakawa ◽

Takashi Todaka ◽

Masato Enokizono

Keyword(s):

Magnetic Material ◽

Magnetic Flux ◽

Permanent Magnet ◽

Flux Density ◽

Vessel Wall ◽

Permanent Magnets ◽

Magnetic Coupling ◽

Air Gap ◽

Magnetic Flux Density

This paper presents a magnetic coupling for a large-sized mixer, which is separated by a vessel wall. In order to improve the transmission-torque, the magnetic material attached magnetic-flux concentrated surface permanent magnet (MCSPM) arrangement is applied to the magnetic coupling and the construction is optimized. The results show that the MCSPM arrangement is very effective to improve the air-gap magnetic flux density and the transmission torque even quantity of very few permanent magnets.

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DESIGN OF A SINGLE-PHASE RADIAL FLUX PERMANENT MAGNET GENERATOR WITH VARIATION OF THE STATOR DIAMETER

Jurnal Teknologi ◽

10.11113/jt.v81.12889 ◽

2019 ◽

Vol 81 (4) ◽

Author(s):

Hari Prasetijo ◽

Winasis Winasis ◽

Priswanto Priswanto ◽

Dadan Hermawan

Keyword(s):

Magnetic Flux ◽

Permanent Magnet ◽

Flux Density ◽

Single Phase ◽

Air Gap ◽

Wire Diameter ◽

Terminal Phase ◽

Magnetic Flux Density ◽

Phase Voltage ◽

Radial Flux

This study aims to observe the influence of the changing stator dimension on the air gap magnetic flux density (Bg) in the design of a single-phase radial flux permanent magnet generator (RFPMG). The changes in stator dimension were carried out by using three different wire diameters as stator wire, namely, AWG 14 (d = 1.63 mm), AWG 15 (d = 1.45 mm) and AWG 16 (d = 1.29 mm). The dimension of the width of the stator teeth (Wts) was fixed such that a larger stator wire diameter will require a larger stator outside diameter (Dso). By fixing the dimensions of the rotor, permanent magnet, air gap (lg) and stator inner diameter, the magnitude of the magnetic flux density in the air gap (Bg) can be determined. This flux density was used to calculate the phase back electromotive force (Eph). The terminal phase voltage (V∅) was determined after calculating the stator wire impedance (Z) with a constant current of 3.63 A. The study method was conducted by determining the design parameters, calculating the design variables, designing the generator dimensions using AutoCad and determining the magnetic flux density using FEMM simulation. The results show that the magnetic flux density in the air gap and the phase back emf Eph slightly decrease with increasing stator dimension because of increasing reluctance. However, the voltage drop is more dominant when the stator coil wire diameter is smaller. Thus, a larger diameter of the stator wire would allow terminal phase voltage (V∅) to become slightly larger. With a stator wire diameter of 1.29, 1.45 and 1.63 mm, the impedance values of the stator wire (Z) were 9.52746, 9.23581 and 9.06421 Ω and the terminal phase voltages (V∅) were 220.73, 221.57 and 222.80 V, respectively. Increasing the power capacity (S) in the RFPMG design by increasing the diameter (d) of the stator wire will cause a significant increase in the percentage of the stator maximum current carrying capacity wire but the decrease in stator wire impedance is not significant. Thus, it will reduce the phase terminal voltage (V∅) from its nominal value.

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

Elektronika ir Elektrotechnika ◽

10.5755/j01.eee.110.4.280 ◽

1970 ◽

Vol 110 (4) ◽

pp. 25-29 ◽

Cited By ~ 1

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

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A Mathematical Model of a Modified Voice Coil Energy Harvester

Volume 4: Energy Systems Analysis, Thermodynamics and Sustainability; Combustion Science and Engineering; Nanoengineering for Energy, Parts A and B ◽

10.1115/imece2011-64354 ◽

2011 ◽

Author(s):

Alireza Hekmati ◽

Siamak Arzanpour

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Flux Density ◽

Peak Power ◽

Magnetic Field Intensity ◽

Magnetic Circuit ◽

Magnetic Flux Density ◽

Magnetic Conductor ◽

Magnetic Circuits ◽

The Magnetic Field

This paper presents a mathematical modeling of a modified voice coil generator, which consists of a moving coil within a fixed magnetic circuit. The simulation has been done with Comsol Multiphysics software, which is a powerful tool to demonstrate the pattern of magnetic field and calculate the induced current in the coil. In our simulations, the magnetic circuit consists of the magnetic conductor and the air gap. In this analysis, the magnetic flux density and the magnetic field intensity are calculated. Moreover, through calculation of the total reluctance of the magnetic circuit and employing the ohm’s law for magnetic circuits, the effect of the length and cross section of the total circuit on the magnetic flux are investigated. Finally, a pattern for the magnetic flux density are demonstrated and the simulation result indicates that the magnetic field is well concentrated on the coil area, therefore this prototype can capture and convert most of the kinetic energy to electricity. A prototype has been fabricated and tested on the shaker. The experimental results indicate that this setup is able to produce the maximum voltage of 0.326 V and the peak power equal to 2.605 mW in 35 Hz frequency and 1 mm peak to peak amplitude.

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The influence of conductive passive parts on the magnetic flux density produced by overhead power lines

Facta universitatis - series Electronics and Energetics ◽

10.2298/fuee1904555v ◽

2019 ◽

Vol 32 (4) ◽

pp. 555-569

Author(s):

Slavko Vujevic ◽

Tonci Modric

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Flux Density ◽

Biological Effects ◽

Research Work ◽

Power Lines ◽

Magnetic Flux Density ◽

Human Beings ◽

Overhead Power Lines ◽

The Magnetic Field

There has been apprehension about the possible adverse health effects resulting from exposure to power frequency magnetic field, especially in the overhead power lines vicinity. Research work on the biological effects of magnetic field has been substantial in recent decades. Various international regulations and safety guidelines, aimed at the protection of human beings, have been issued. Numerous measurements are performed and different numerical algorithms for computation of the magnetic field, based on the Biot- Savart law, are developed. In this paper, a previously developed 3D quasistatic numerical algorithm for computation of the magnetic field (i.e. magnetic flux density) produced by overhead power lines has been improved in such a way that cylindrical segments of passive conductors are also taken into account. These segments of passive conductors form the conductive passive contours, which can be natural or equivalent, and they substitute conductive passive parts of the overhead power lines and towers. Although, their influence on the magnetic flux density distribution and on the total effective values of magnetic flux density is small, it is quantified in a numerical example, based on a theoretical background that was developed and presented in this paper.

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Analytical calculation of magnetic field in surface-mounted permanent-magnet machines with air-gap eccentricity

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-07-2018-0284 ◽

2019 ◽

Vol 38 (2) ◽

pp. 893-914

Author(s):

Jawad Faiz ◽

Mohammadreza Hassanzadeh ◽

Arash Kiyoumarsi

Keyword(s):

Magnetic Field ◽

Permanent Magnet ◽

Field Distribution ◽

Analytical Calculation ◽

Air Gap ◽

Magnetic Field Distribution ◽

Magnetic Flux Density ◽

Content Type ◽

Air Gap Magnetic Field ◽

The Magnetic Field

Purpose This paper aims to present an analytical method, which combines the complex permeance (CP) and the superposition concept, to predict the air-gap magnetic field distribution in surface-mounted permanent-magnet (SMPM) machines with eccentric air-gap. Design/methodology/approach The superposition concept is used twice; first, to predict the magnetic field distribution in slot-less machine with eccentric air-gap, the machine is divided into a number of sections. Then, for each section, an equivalent air-gap length is determined, and the magnetic field distribution is predicted as a concentric machine model. The air-gap field in the slot-less machine with eccentricity can be combined from these concentric models. Second, the superposition concept is used to find the CP under eccentricity fault. At this end, the original machine is divided into a number of sections which may be different from the one for slot-less magnetic field prediction, and for each section, the CP is obtained by equivalent air-gap length of that section. Finally, the air-gap magnetic field distribution is predicted by multiplying the slot-less magnetic field distribution and the obtained CP. Findings The radial and tangential components of the air-gap magnetic flux density are obtained using the proposed method analytically. The finite element analysis is used to validate the proposed method results, showing good agreements with the analytical results. Originality/value This paper addresses the eccentricity fault impact upon the air-gap magnetic field distribution of SMPM machines. This is done by a combined analysis of the complex permeance (CP) method and the superposition concept. This contrasts to previous studies which have instead focused on the subdomain method.

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Magnetic Field Finite Element Analysis of Generator with Rotor Inter-Turn Short-Circuit Fault

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.707.343 ◽

2014 ◽

Vol 707 ◽

pp. 343-347

Author(s):

Yong Gang Li ◽

Bing Han

Keyword(s):

Magnetic Field ◽

Finite Element ◽

Magnetic Flux ◽

Flux Density ◽

Early Stage ◽

Short Circuit ◽

Air Gap ◽

Operating Conditions ◽

Magnetic Flux Density ◽

Short Circuit Fault

Rotor inter-turn short-circuit is a common fault in generator and it is a research hotspot to identify the fault at its early stage. Considering the disadvantage of circuit analytical method, this paper establishes a 2D transient finite element electromagnetic-circuit coupling model, and calculates the magnetic field at normal and fault situations through the powerful post-processing function of ANSOFT, then magnetic flux density cloud pictures and air-gap magnetic flux density curves of different operating conditions are got. Using MATLAB to analyze and deal with the air-gap flux density cures, we can get the differences of faults in different levels and different positions, which provide a basis for further study of rotor inter-turn short-circuit fault.

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