• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.217-227
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• 2000

A rectangular ceramic dielectric antenna, placed on the top of a ground plane and fed by coaxial probe, is analyzed by using the finite element method. To verify the proposed code, a rectangular ceramic dielectric antenna was fabricated and the characteristics of antenna were measured. The numerical data obtained is in good agreements with experimental result. Thus we checked the validity of our FEM code, and it can be possible to extend the analysis of the arbitrary 3-D antenna on a ground plane fed by coaxial probe.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.1
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• pp.20-26
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• 2000

This paper deals with the modal analysis and the displacement of stator due to electromagnetic forces in Switched Reluctance Motor(SRM). A free-free model of the stator based on structural 3-dimensional Finite Element Method(FEM) is used for investigation the natural frequencies and the mode shapes of the stator. In addition, The displacement caused by magnetic force acting on stator pole is analyzed by the structural FEM coupled with the magnetic force. From these results, the resonance speed is obtained by the relation of the natural frequencies of the harmonic frequencies of magnetic force. And, the eccentricity with respect to rotor is predicted from the analysis result of the mechanical displacement of stator. The natural frequencies of stator are compared with experimental ones measured by modal testing.

• Journal of Magnetics
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• v.18 no.3
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• pp.260-267
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• 2013

In this paper a general 2-D model of a large air-gap synchronous machine either with non-magnetic or magnetic core rotor is investigated and electrical characteristics of the machine are analytically calculated. Considering the general model, analytical equations for magnetic field density in different regions of the large air-gap machine are calculated. In addition, self and mutual inductances in the proposed model of the machine have been developed, which are the most important parameters in the electromagnetic design and transient analysis of synchronous machines. Finite element simulation has also been performed to verify the obtained results from the equations. Analytical results show good agreement with FEM results.

• Journal of the Korean Magnetics Society
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• v.6 no.1
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• pp.40-47
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• 1996

In this paper, the optimal design rrethod of the electropermanent magnetic lifter is proposed. The electromag-netic performances at the states of attraction and release are calculated by the means of the equivalent magnetic circuit rrethod. The magnetic flux flow, the magneto-rrntive force and the aJronnt of lifting force correspond to the electromagnetic performances. As the optimization algorithm, the evolution strategy(ES) is applied for the maximization of the electromagnetic force at the state of attraction and for the minimization of the volume within the alJowable electomagnetic force range.[3] At this rrnrrent, the optimization satisfy the minimization of the electromagnetic force at the state of release. The validity of the proposed optimization rrethod is verified by the comparison between the optimization result and the FEM result (this FEM result is obtained from MAXWELL).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1321-1328
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• 2009

In this paper, an electromagnetic force driving actuator (EMFA) and three-link mechanism are proposed as a driving mechanism and connection device for low voltage air circuit breaker (ACB). As the result of dynamic characteristic analysis, the actuator and link mechanism are designed from the simulation and manufactured. The magneitc field of the EMFA is analyzed using the finite element method (FEM). The dynamic characteristic analysis with calculation of the circuit equation and kinetical equation is performed by the time difference method (TDM). Also, the result of the analysis is verified through the experiment of the fabrication model. In this paper, the EMFA size is smaller than the actuator for high voltage circuit breaker. Thus, the dynamic characteristic is analyzed with end-winding inductance that is calculated by the same method which is applied on the circle type end-winding of motors. The designed model for 1600 ampere-frame ACB and the three-link mechanism for connecting contact part with actuating part are manufactured. It is confirmed that the three-link mechanism is possible for improving the circuit breaker efficiency and reducing the size of the EMFA. It is proved that the improved 2-D analysis is more accurate than established method.

• Progress in Superconductivity and Cryogenics
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• v.21 no.3
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• pp.32-37
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• 2019

In various types of large-scale electrical applications, the number of coil turns in such machines is usually large. Electromagnetic simulation of large-scale superconducting coils (tens to hundreds of turns) is indispensable in the design process of superconducting electrical equipment. However, due to the large scale of the coil and the large aspect ratio of super-conducting material layer in HTS coated conductor, it is usually difficult or even unable to perform 3-D transient electromagnetic simulation. This paper introduces an effective 3-D electromagnetic simulation method for large-scale HTS coated conductor coil based on T-A formulation. The simulation and experimental results show that the 3-D model based on the T-A formulation using homogeneous strategy is more accurate than the traditional 2-D models. The memory usage is not sensitive to the number of turns and this model will be even more superior as the number of turns becomes larger.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.111-116
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• 2011

This paper deals with the electromagnetic clutch which stop the generator at emergency by using the engine power of generator. The electromagnetic field was analyzed using Flux-2d program with different conditions : voltage, air gap, coil locations. As a result, the maximum magnetic flux density of electromagnetic clutch occurred between the coil and wheel : 0.27[T], 0.41[T] at 12[V], 24[V]. The maximum flux density was at the center location of the coil.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.195-198
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• 1999

For the thixoforming process beside an existing solidus-liquidus interval, the reheating conditions to obtain the globular microstructure are very important. It relies on the control of globular microstructure of semi-solid alloys that contain non-dendritic particles. To obtain the globular microstructure in cross section of billet, the optimal design of the induction coil is necessary. Therefore, in this paper the optimal coil design to minimize electromagnetic end effect will be proposed. The results of coil design were also applied to the reheating process to obtain a fine globular microstructure. Finally, reheating data base of aluminum alloys for thixoforming and FEM model for induction heating based on the optimal coil design have been proposed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.965-966
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• 2011

본 논문은 이방성 등가 재질정수를 도입하여 roll타입 코어로 적층되어진 전류센서의 전자계 유한요소해석(FEM)을 이용하여 해석하였다. 철심의 roll 구조에 따른 전자계 현상을 고려하기 위해 등가 이방성 투자율모델을 유도하였으며, 유도된 모델에 대해 유한요소해석(FEM)을 수행하였고, 공극에서의 자속밀도 등의 특성을 분석하였다.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.181-183
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• 1997

In this paper the analysis and optimum design of ceramic insulator is studied. The finite element method (FEM) is used for the electromagnetic solution and the design sensitivity analysis is used for the optimization. The parameterization of design variables and movable points is introduced and the linear function is used as a interpolation function.