• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.171-173
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• 1997

This paper presents analysis of the radial force density in brushless DC motor of which distribution is not uniform in the axial direction. The analysis considering 3D shape of teeth and overhang is not only important but essential to calculate the radial force density that acts on the teeth of stator, because it is frequent source of vibration and changes at the end of teeth. For the analysis, a new 3D equivalent magnetic circuit network method taking into account movement of the rotor without remesh is proposed. The radial force density is calculated by Maxwell stress tensor and analyzed by discrete Fourier transform.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권5호
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• pp.325-331
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• 2004

The multiobjective optimization (MO) problem usually includes the conflicting objectives and the use of conventional optimization algorithms for MO problem does not so good approach to obtain an effective optimal solution. In this paper, genetic algorithm (GA) as an effective method is used to solve such MO problem of brushless DC motor (BLDCM). 3D equivalent magnetic circuit network (EMCN) method which enables us to reduce the computational burden is also used to consider the 3D structure of BLDCM. In order to effectively obtain a set of Pareto optimal solutions in MO problem, ranking method proposed by Fonseca is applied. The objective functions are decrease of cogging torque and increase of torque respectively. The airgap length, teeth width and magnetization angle of PM are selected for the design variables. The experimental results are also shown to confirm the validity of the optimization results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.918-920
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• 2003

This paper presents the analysis of the permanent magnet overhang effect for permanent magnetic actuator. Generally, The overhang is often used to increase the force density in permanent magnet machineries. The overhang is especially profitable to reduce the volume after increasing the force density per volume when using the overhang effect of the permanent magnet. Therefore, 3D Equivalent Magnetic Circuit Network Method (3D EMCNM) has been used in this paper. According to the plunger position, flux distribution per the overhang length, and the holding force are quantitatively compared. Furthermore, an appropriate length of the overhang has been proposed. To confirm the accuracy of the analysis method, the results of 3D EMCNM and FEM(2D, 3D) are compared for the basic model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.271-273
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• 2000

This paper presents the dynamic characteristics Linear DC Motor(LDM) using 3 Dimensional Equivalent Magnetic Circuit Network Method(3-D EMCN) by voltage driven. The movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series. The Dynamic characteristics are carried out from coupling the electrical circuit equation and mechanical kinetic equation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.773-775
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• 2002

This paper deals with 3 Dimensional(3D) analysis of magnetic flux density of High Temperature Superconducting(HTS) motor using 3D Equivalent Magnetic Circuit Network (EMCN). When the Finite Element Method (FEM) is applied to an analysis of 3D models, it takes much time to the pre-process work required for 3D modeling and to solve the differential equation. Compare with 3D FEM, the result of 3D EMCN by using the magnetic resistance and magnetomotive force is exact and rapid. The accuracy of 3D EMCN is verified by comparing the 3D EMCN analysis with that of 3D FEM in HTS motor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.876-878
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• 2000

In this paper, the characteristic of the Linear DC motor(LDM) are analyzed by using 3 Dimensional Equivalent Magnetic Circuit Network (3D EMCN), the movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series, thrust characteristic analysis is performed and the appropriateness of analysed result is verified by comparing with the results of 2 Dimensional Finite Element Method (2D FEM) and experiment.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권4호
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• pp.229-236
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• 2004

In this paper, the effect of permanent magnet overhang structure on the characteristics in Brushless DC motor has analyzed quantitatively. We classified the overhang structure as symmetric and asymmetric. 3D equivalent magnetic circuit network (EMCN) method which uses the permeance as the distributive variable is used for the efficient analysis of magnetic field. The overhang effect which increases the linkage flux at the stator is verified by comparison between overhang and no overhang structure. In addition, it is known that no load back electro motive force (EMF) is also increased due to the overhang effect. In case of asymmetric overhang structure, the ratio effect of the upper to lower overhang length on the magnetic forces is analyzed. Form the analysis results, the variation of the asymmetric overhang ratio has a significant effect on the axial magnetic force except the radial and tangential magnetic forces. The validity of the analysis results is also clarified by comparison between calculated results and measured ones such as back EMF and cogging torque.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.592-594
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• 2002

Hybrid stepping motor(HSM) has very small airgap and teeth. These bring out the saturation in the teeth easily. In this paper. the 3 dimension equivalent magnetic circuit network method (EMCNM) based on the trapezoidal element is used for the accurate and efficient nonlinear analysis of HSM. and the validity of the analysis results by the proposed method is verified by comparison with the experimental results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권3호
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• pp.138-144
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• 2000

The detent force caused by the interaction of magnets with the teeth of a armature core deteriorates the driving performance of a permanent magnet linear synchronous motor. In this paper, we analyze the fields and forces of a linear synchronous motor with segmented or skewed magnet arrangement according to lateral overhang length of permanent magnets. For the analysis, the 3-dimensional equivalent magnetic circuit network method is used. The detent force and the static thrust are analyzed according to the segmented or skewed angle and the overhang length of permanent magnets, and the optimal angles that the detent force is minimized are found out in each case. The analysis results are compared with the experimental ones and shown a reasonable agreement.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2605-2614
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• 2002

This paper describes an analysis method based on the experimental parameter for the 0.9kW starter motor of vehicle with permanent magnet and pole core, and analyzed the influence by the effect of pole core of starting motor by using the 2D-FEM analysis technique to reflect the structural characteristic of 3D. A starter motor consists mainly of armature, yoke and permanent magnet with the pole core. Additionally, there is different the axial length of each part. Therefore, the effective of analysis method is needed to improve the characteristic of it. This paper approached the 2D-FEM analysis estimated by the 3D-EMCN(Three Dimensional Equivalent Magnetic Circuit Network) instead of the 3D-FEM analysis to minimize parameters. As a result, this paper is proposed the validity of 2D-FEM analysis and obtained reasonable results for improving a performance.