scholarly journals Lamination effects on a 3D model of the magnetic core of power transformers

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 997-1003
Author(s):  
Antonio Poveda-Lerma ◽  
Guillermo Serrano-Callergues ◽  
Martin Riera-Guasp ◽  
Manuel Pineda-Sanchez ◽  
Ruben Puche-Panadero ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Experimental Tests ◽  
Butt Joint ◽  
Magnetic Core ◽  
Magnetic Flux Density ◽  
Lap Joint ◽  
3D Fem ◽  
Average Value ◽  
Depth Direction

AbstractIn this paper the lamination effect on the model of a power transformer’s core with stacked E-I structure is analyzed. The distribution of the magnetic flux in the laminations depends on the stacking method. In this work it is shown, using a 3D FEM model and an experimental prototype, that the non-uniform distribution of the flux in a laminated E-I core with alternate-lap joint stack increases substantially the average value of the magnetic flux density in the core, compared with a butt joint stack. Both the simulated model and the experimental tests show that the presence of constructive air-gaps in the E-I junctions gives rise to a zig-zag flux in the depth direction. This inter-lamination flux reduces the magnetic flux density in the I-pieces and increases substantially the magnetic flux density in the E-pieces, with highly saturated points that traditional 2D analysis cannot reproduce. The relation between the number of laminations included in the model, and the computational resourses needed to build it, is also evaluated in this work.

Magnetic Flux Density under Single Harmonic Distortion

2021 ◽  
Vol 1034 ◽  
pp. 151-157
Author(s):  
Michał Kaczmarek ◽  
Ernest Stano
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Phase Angle ◽  
Harmonic Distortion ◽  
Magnetic Core ◽  
Magnetic Flux Density ◽  
Higher Harmonics ◽  
Secondary Voltage ◽  
Magnetizing Current ◽  
Higher Harmonic

In the paper the change of the magnetic flux density under single harmonic distortion is discussed. Presented results show the dependence of the value of the magnetic flux density in the toroidal magnetic core made from the Ni80Fe20 tape of the phase angle of higher harmonic in relation to the main harmonic of distorted magnetizing current. Moreover, the influence of higher harmonic depends from it frequency and it becomes undetectable above 15th higher harmonic, even if its level reaches 50% of the RMS value of the main harmonic of distorted magnetizing current. Laboratory tests were carried out for the magnetic toroidal core of iCT with a current ratio equal to 300 A / 5 A. The oscilloscope is used to measure waveforms of the excitation current and the secondary voltage through the voltage probes. Build in numerical integration is used to determine the magnetic flux density from secondary voltage. In the case of tested 5th higher harmonic the highest value of the magnetic flux density is obtained for phase angle equal to 90° between main and higher harmonics, while the lowest is obtained for 270°. This depends from the initial phase of the magnetic field strength and results from the integration of distorted secondary voltage with the particular content of higher harmonics.

Relationship between Magnetic Flux Density and Temperature Distributions of Permanent Magnets by EDM

2012 ◽  
Vol 523-524 ◽  
pp. 322-327 ◽  
Author(s):  
Yoshihiro Ichimura ◽  
Hideki Takezawa ◽  
Naotake Mohri
Keyword(s):  
Magnetic Flux ◽  
Magnetic Materials ◽  
Flux Density ◽  
Permanent Magnets ◽  
Electrical Discharge Machining ◽  
Magnetic Flux Density ◽  
Input Energy ◽  
Machined Surface ◽  
Depth Direction ◽  
Temperature Distributions

It is difficult to machine permanent magnets by traditional machining such as turning, milling and grinding, because of magnetic force. However, electrical discharge machining (EDM), which is a non-contact thermal machining method, has been used for shape machining of magnetic materials. In the EDM process, non-magnetic materials such as copper and graphite are typically used for electrodes. Magnetic materials have a Curie point; therefore, their magnetic flux density reduces when they are heated to a high temperature. Because EDM is a thermal process, it has the potential to control the magnetic flux density of a machined surface. In this study, to clarify the relationship between magnetic flux density and temperature distributions in depth direction of permanent magnest by EDM, internal temperatures of magnets were investigated using a K type thermo couple during EDM. Neodymium magnets were used as work-pieces. The magnetic flux density of a machined neodymium magnet was measured. In addition, the effects of duty factor (D.F.) were also examined. The results showed that the average temperature inside of the magnet is determined by the input energy, depending on the discharge conditions. A decrease of surface magnetic flux density after EDM is affected by the magnitude of the area and the amount of decrease is due to the increase of the internal temperature of the magnet. Therefore, it isn’t determined by the magnitude of the simple input energy.

Relationship between F Value and Slag Entrapment in Mold with Electromagnetic Brake

2012 ◽  
Vol 182-183 ◽  
pp. 462-466
Author(s):  
Zhen Qiang Zhang ◽  
Zuo Sheng Lei ◽  
Zhan Yu ◽  
Zhong Ming Ren ◽  
Kang Deng
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Liquid Steel ◽  
Magnetic Core ◽  
Magnetic Flux Density ◽  
Level Fluctuation ◽  
Occurrence Probability ◽  
Electromagnetic Brake ◽  
Steel Flow ◽  
Slag Entrapment

An experimental device is designed to control slag entrapment of molten steel with ElectroMagnetic Brake(EMBR). Mercury was taken to simulate the liquid steel flow in the mold. The factors which affect slag entrapment with EMBR are studied, such as position of magnets, distribution of magnetic flux density and submerged depth of Nozzle. Experimental results show that the posibility of power entrapped by liquid steel was smallest as magnetic flux density B=0.3T, meanwhile, it was found that F value decreases with increasing immersion depth. Indeed, the occurrence probability of the slag entrapment decreases while d=45 mm (d is distance from the centre of SEN to the centreline of magnetic core.) instead of d=25 mm. The submerged depth within 30~50 mm are suitable to the level fluctuation in EMBR conditions in this experiment.

scholarly journals Magnetic field of a radial tire after puncture caused by ferromagnetic elements

2018 ◽  
Vol 3 (21) ◽  
pp. 183-194
Author(s):  
Agnieszka Szegda ◽  
Stanisław Radkowski ◽  
Sebastian Brol
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Rotation Angle ◽  
Distance Estimation ◽  
Magnetic Flux Density ◽  
Data Series ◽  
Measuring Device ◽  
Differential Signal ◽  
Average Value

Tire, an element of wheel, is made in a sophisticated vulcanization process of many components and some of which such as: bead wire, belt and carcass exhibit ferromagnetic properties. Such components create variable in direction and intensity magnetic field, which expands around tire and the complete wheel. Since the layout of magnetic field is exceptional for every single wheel many of information might be obtained on the basis of it alteration. The reported since now application concentrates on rotational speed measurement, wheel rotations counting and therefore also vehicle linear speed and distance estimation. However up to the present the known solutions did not describe changes in magnetic field in case of damage induced by e.g. puncture caused by ferromagnetic elements. This paper’s aim is to test the thesis that it is possible to detect puncture in tire made by ferromagnetic element by using measurement and analysis of changes of magnetic flux density around tire. The tests were executed using original measuring device, designed especially for such experiments. It registers a magnetic profile, which consists of data series of magnetic flux density measured in this investigations 55 mm above tire’s tread and arranged along with rotation angle. Tire magnetic properties were assessed by using of circumferential magnetic profiles and parameters such as: minimum value (Mmin), maximum value (Mmax), peak to peak value (Mm), average value of ordinates of profile (Mb), skewness of ordinate distribution (Ms) and kurtosis of ordinate distribution (Mk). Magnetic profiles before after puncture were analysed as well as the parameters. Moreover differential signal caused by puncture were determined. It turned out that detected changes are directly related to tire damage and showing in rotation angle where puncture occurs.

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.

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