• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.585-590
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• 2014

A permanent vertical magnetization should be obtained to counteract induced vertical magnetization due to the earth's background field during the Flash D demagnetization process. A vertical susceptibility is needed to calculate a extra-permanent magnetization, which is needed to control the permanent vertical magnetization in stage 2 of Flash D demagnetization and added to the final vertical permanent magnetization. Two susceptibilities were found in this paper. One is obtained from the extra-magnetization. The other is obtained by magnetic field measurement from the scaled physical vessel when the vessel is excited by vertical magnetic field. The initial susceptibility by the extra-magnetization was 0.101~0.109 and the one from the measured magnetic field was 0.122. Two susceptibilities have a good agreement each other. From this paper, it is found that the susceptibility is able to appllied to calculate the extr-magnetization.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.104-106
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• 2003

In this paper, we study about the stator winding magnetization method and the magnetizing fixture magnetization method in post-assembly magnetization. Most of small electrical machine use the stator winding magnetization method but it is impossible to magnetize the permanent magnet by the stator winding magnetization method when the capacity of machine increases and the coercive force of magnet increases. And the eddy current disturbs the magnetization seriously in case of LSPM(Line Start Permanent magnet Motor) that have conductor bar in rotor. Hence, the magnetization fixture is required. So, in this paper we study about the post-assembly magnetization method that can use the stator winding magnetization method or must use the magnetization fixture magnetization method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.8
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• pp.373-380
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• 2003

This paper consists of a study in post-assembly magnetization of LSPM (Line Start Permanent Magnet Motor). Recently, LSPM is noted as an alternative to the induction motor because it offers a very high efficiency and unity power factor, And it is necessary for permanent magnets to be magnetized by means of post-assembly magnetization in LSPMS because of the manufacturing cost involved. The manufacturing process is also simpler in post-assembly magnetization than in pre-assembly magnetization. Generally, permanent magnet motors are magnetized by their own stator coil or by magnetizing fixtures. However, the permanent magnet in a LSPM is scarcely magnetized by using them because of the eddy current of the rotor bar. Hence, it is necessary to design a magnetizing fixture that overcomes this problem. In this paper, the author analyses the post-assembly magnetization of a LSPM and proposes a method for designing the magnetizing fixture. The method that the author proposes is to make the number of coil turns greater in order to reduce the effect of the eddy current of the rotor bars.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.12
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• pp.576-585
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• 2005

This paper deals with the electromagnetic field analysis of slotless brushless permanent magnet machines with three different magnetization patterns such as Halbach, parallel and radial magnetization. The magnetization modeling of Halbach, parallel and radial magnetization is performed analytically. And then, analytical solutions for open-circuit field distributions, armature reaction field distributions, flux linkages due to PMs and stator windings, torque, back-emf and inductance are derived in terms of magnetic vector potential and two-dimensional (2-d) polar coordinate systems. The analytical results are validated extensively by finite element (FE) analyses. The magnet volume required in order to produce identical flux density is compared with each magnetization. Finally, analytical solutions and derivation procedures of those presented in this paper can be applied to slotless and slotted brushless permanent magnet AC and DC machines.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.15-17
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• 2002

In this paper, we analyse the dynamic characteristic of 3-phase line start permanent magnet motor considering magnetization. Magnetization vector of NdFeB is obtained from the 2-D FEM magnetization analysis. And comparing the proposed analysis with conventional analysis method, we know that it is necessary to consider magnetization in dynamic analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.2051-2056
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• 2014

This paper investigated the separation of magnetic signal from a ferro-magnetic object. The magnetic signals were ILM(induced longitudinal magnetization) and IVM(induced vertical magnetization), which were induced by earth magnetic field and PLM(permanent longitudinal magnetization) and PVM(permanent vertical magnetization), which were due to a permanent magnetization of the object, respectively. Magnetic signal separation was based on the fact that magnetization vector could be analyzed according to longitudinal and vertical directions. Also the influence of non-uniform magnetic field from a rectangular coil on the separation was examined. A military vessel with a size close to rectangular coil has more errors on the magnetic signal separation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.469-475
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• 2014

This paper deals with the characteristics evaluations of PM magnetization using stator coil in a Post-Assembly Line Start Permanent Magnet Motor (LSPMM) using a coupled Finite Element Method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics analysis relative to magnetizing direction and quantity of permanent magnets due to the eddy current occurring in the rotor bar during magnetization of Nd-Fe-B.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1029-1031
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• 2005

A magnetic position sensor is a apparatus that detect the rotating position by measuring the value of the flux density of the rotating position. In this paper, the magnetization system of the permanent magnet in the magnetic position sensor which detects the rotating position was designed. The permanent magnet was magnetized for the flux density into the hole element to be sinusoidal distribution according to the rotating position. To make the sinusoidal distribution of flux density, the magnetization values according to the position in permanent magnet were varied by adjusting the air gap between the pole of the magnetization fixture and the surface of the permanent magnet.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.3
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• pp.103-107
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• 2004

Recently, greater attention has been paid to the high-speed generator for its many merits, such as ease of installation, high efficiency and high power density. However, due to their high fundamental frequency, careful consideration needs to be given to both electromagnetic and mechanical design issues. This paper deals with the comparison of two types of permanent magnet high-speed machines. Specifically, the effect of the permanent magnet magnetization pattern on the rotor losses is investigated. On the basis of analytical field analysis and the 2-D finite element method, this paper predicts the flux harmonics and rotor losses under the no-load condition. It is shown that the Halbach magnetization is superior to parallel magnetization in terms of producing rotor losses.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.9
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• pp.427-433
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• 2003

Permanent magnet movers with three different magnetization patterns were applied to a linear eddy current braking system. By using a two-dimensional analytical technique, this paper deals with the comparison of the design guidelines, magnetic field, required magnet volume, and force capability for three types of linear brakes. The analytical results are also verified by finite element analyses.