• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.528-538
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• 1996

A magent console is critical element since its homogeneity is essential to the performance of a nuclear magnetic resonance (NMR) based sensor. Geometry and properties of magnet materials determine the magnetic flux density and homogeneity of the console. This study is carried out to develop a design scheme of the magnet console using ANSYS to reduce the design error of the magnet console compared . To enhance the performance of the magnet console, corner steel was proposed and validated by simulation and manufactured one. The corner steel increased the magnetic flux density (B) by about 1% and enhanced homogeneity by approximately 3 times. There was about 3% difference between simulated and measured B values.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.660-662
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• 2002

The single phase line start permanent magnet motor has high efficiency and power factor when it operates synchronous speed. The rotor structure is composed of permanent magnet and cage bars. The motor is accelerated by rotor bars and synchronized by magnet and rotor saliency. but starting torque is disturbed by magnet braking torque so, to obtain good starting performance and synchronizing capability. the design of proper permanent magnet is required. This paper is represented performance of start ing and synchronizing by changing permanent magnet thickness

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.1
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• pp.36-43
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• 1986

Superconducting magnet can be employed in many fields, such as, magnet for strong field, superconducting rotating machine and superconducting energy storage system. In this paper, the solenoid magnet design procedure and materials used in construction are described in detail, and those are the fundamentals of superconducting magnet study. The fabrication and test procedure of 3 Tesla superconduting magnet are also described. Nb-Ti is used as a superconducting wire, GFRP and Kapton are used for electrical insulation. Inner diameter of the magnet is 10 cm. According to the test results, the field at the central point of the magnet was 3 Tesla, evaporation rate per hour was 2.7 litter and current at that case was 315 A.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.253-255
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• 1999

In this paper, a shape optimization algorithm of superconducting magnet using finite element method is presented. Since the superconductor loses its superconductivity over the critical magnetic field and critical current density, this material property should be taken into account in the design process. Trial and error approach of repeating the change of the design variables costs much time and it sometimes does not guarantee an optimal design. This paper presents a systematic and efficient design algorithm for the superconducting magnet. We employ the sensitivity analysis based on finite element formulation. As for optimization algorithm, the inequality constraint for the superconducting state is removed by modifying the objective function and the nonlinear equality constraint of constant volume is satisfied by the gradient projection method. This design algorithm is applied to an optimal design problem of a solenoid air-cored superconducting magnet that has a design objective of the maximum energy storage.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2209-2217
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• 2014

A permanent-magnet-assisted switched reluctance motor (SRM) having small excitation poles, where phase coils are concentrically wound on the poles and thin permanent magnets are inserted inside the poles, is proposed in this paper. The insertion of permanent magnets into the stator excitation poles has a significant influence on positive torque improvement leading to a boost in efficiency. Three key design parameters such as the thickness of permanent magnets, space between two adjacent permanent magnets, and the width of stator excitation poles are determined during a design procedure in terms of the enhancement of positive torque. Step-by-step design modification and a comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRM have been conducted by means of static torque comparison along with dynamic performance. The first prototype from steel laminations up to its physical assembly has been constructed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.1
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• pp.29-35
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• 2014

The purpose of this paper is the rotor design of a single-phase LSPM(Line-start permanent magnet) motor. A single-phase LSPM motor has a permanent magnet in the rotor that is same as induction motor. For that reason, magnet is operated by breaking torque in starting region and alignment torque in driving region. Therefore, we need the design process considering the trade-off relationship. In this paper, we propose the design process of a single-phase LSPM motor for a high starting torque and efficiency with FEM. And we use Taguchi Method for considering tolerance in manufacture. Finally, we compared the LSPM motor that is designed in this paper and conventional induction motor.

• Progress in Superconductivity and Cryogenics
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• v.10 no.4
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• pp.29-32
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• 2008

The design of a superconducting magnet system producing very high magnetic field is underway at Korea Basic Science Institute (KBSI) to accelerate three kinds of carbon irons (C+2, C+4, C+6) to 120 MeV. A quarter-scaled prototype will be manufactured in order to confirm the feasibility of our design. Magnet Inductances in the system have a great influence on the current ramping rates and contribute to the stored energy, which are usually considered to be unfavorable in magnet operation. The modeling and simulation scheme of a prototype superconducting magnet for the cyclotron K120 is described in this paper. The inductances are calculated by a numerical method with and without iron yokes, respectively. These calculation results will be used as engineering design details such as a current ramping rate and a quench protection design.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.121-129
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• 2008

This paper deals with the design of BLDC motor replacing ferrite magnet with rare earth magnet. Electric machinery system using ferrite magnet motor is already widespread in large numbers. Electrical appliance makers have a tendency to adhere to existing system using ferrite magnet motors because of redesigning the whole system. This paper designs the rare earth magnet motor untouching the external system dimension and motor outer size. To do the design simply, finite element package is used iteratively To reduce the cogging torque effect and magnetic saturation, stator yoke shape and the groove of the end face of yoke are redesigned.

• Journal of Magnetics
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• v.16 no.3
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• pp.312-317
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• 2011

NMR over 1 GHz (23.5 T) level has difficulties in design and fabrication with only low temperature superconducting (LTS) wire because of its material characteristics such as the decay of critical current under the magnetic field. Because High temperature superconducting (HTS) tape has a good performance under the extremely high magnetic field, it has been developed for high-field magnet over 23.5 T. In this paper, the LTS magnet was made for applying magnetic fields externally and the HTS coil was designed and fabricated. The electromagnetic field analysis has been done with respect to the structure and the operating current of the LTS and HTS coil. Considering to the field homogeneity and the center field, the design parameters which is suitable for the HTS coil were found. The HTS insert coil was impregnated with epoxy resin in order to prevent the movement of winding during energizing the magnet. The hybrid magnet (LTS/HTS) magnet was fabricated and tested based on the design parameters. The experimental result shows that the LTS background magnet and the HTS insert coil can be operated stable beyond 220 A and 210 A. The final value 4.32 T at the center was acquired.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.805-812
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• 1990

In this paper, a design on the superconducting monolith for superconducting pulse magnet is described. Both stability and AC loss parameters are used in the design process, which restricted various design parameters. Determined design parameters satisfy both stability and AC loss restrictions. Finally superconducting monolith is flattened, fitting for magnet and acquiring transposition effect.