• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.10-10
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• 2016

• Proceedings of the Korean Magnestics Society Conference
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• 2016.05a
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• pp.4-4
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• 2016

• Proceedings of the Korean Magnestics Society Conference
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• 1992.03a
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• pp.10-10
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• 1992

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.873-878
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• 2012

Putting a conductive rod between rotating axial electrodynamic wheels composed of repetitive permanent magnets, three-axial magnetic forces generate on the conductive rod. It is possible to levitate and transfer the rod on space with the forces. However, the forces vary in direction and magnitude for a position of the rod between the electrodynamic wheels. Thus, the position influences the stability of the rod also. To guarantee the stability of a levitated object, the force acting on the object should have negative stiffness like a spring. So, we analyze the stable operating range of the conductive rod levitated by the axial wheels with the commercial finite element tool in this paper. Specially, as the pole number and the radial width of permanent magnets has much influence on the generated force and thereby the stable region, their sensitivities are analyzed also. The analytic result is compared with experimental result.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.200-206
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• 2014

This paper describes magnetically levitated vehicle with hybrid magnets, which have been studied by the authors in place of streetcars or conveyance system. An experimental vehicle of 20kg was magnetically levitated by using a small number of dry-cell batteries, which consisted of 10 Ni-MH cells of 1900mAh in series. The magnets were activated sequentially, because the internal resistance of the batteries suppressed the maximum current. The vehicle was kept levitating for about 2 hours and was stable against disturbance due to instantaneous external force. In this paper, dynamic characteristics of the magnetically levitated vehicle using a small number of dry cell batteries are presented.

• 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 Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.318-321
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• 2002

Superconductivity has various applications in the whole industry such as the generation of high magnetic field for medical care and diagnosis, the lossless power transmission, environment-friendly vehicles and clean energy storage systems. This paper deals with the High-Tc superconducting(HTS) power supply using heater-triggered switch for the charging of the superconducting magnets. HTS superconducting power supply consists of two heaters, an electromagnet, and Bi-2223 solenoid and Bi-2223 pancake is used as a superconducting load, similar to real HTS magnet. The timing sequential control of two heaters and an electromagnet is an important factor to generate pumping- current in the Bi-2223 load. The thermal analysis of switching parts of the Bi-2223 solenoid according to the heater input was carried out. Based upon the analysis, the 0.8A of heater current were optimally derived. The maximum pumping current reached 1.7A.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.92-94
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• 2008

The interest in permanent magnet synchronous motor is present in a wide area of applications, ranging from high-performance servo drive to line-start application[1]. The are mainly two reasons for this trend: first low rotor losses and second the foiling prices of high-energy magnets. In this paper the dynamic characteristic of the line-start permanent magnet synchronous motor are described and compared with those if the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bar in the line-start permanent magnet synchronous motor.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.5
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• pp.167-172
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• 1984

This paper describes the finite element analysis of magnetostatic field problems with permanent magnets. Two kinds of algorithms, one using the magnetic vector potential and the other using the magnetic scalar potential, are introduced. The magnetization of the pemanent magnet is used as the source instead of the magnetic equivalent current in both of the formulations using the magnetic vector potential and the magnetic scalar potential. A simple functional, which has only the region integral instead of the region integral and boundary integral, is derived in the formulation using the magnetic scalar potential. These make the formulation of the system equations simpler and more convenient than the conventional methods. The numerical results by the two proposed algorithms for a C-type permanent magnet model are compared with the analytic solutions respectively. The numerical results are in good agreement with the analytic solutions.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.756-760
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• 2001

Two different designs of permanent magnet motors as direct wheel-set drive for the German high speed train ICE 3 are designed, one with surface mounted magnets (SM) and one with buried rotor magnets (BM). The surface magnet motor has $17\%$ less mass and a slightly higher efficiency and was therefore chosen for further investigations. Compared with the conventional drive system of the ICE 3, consisting of geared inverter fed induction machines, the gearless permanent magnet direct drive yields about $16\%$ lower losses. This calculation is based on the route parameters of the high speed track between Frankfurt/Main and Cologne in Germany, which is currently under construction.