• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권4호
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• pp.219-225
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• 2000

This paper presents the shape optimization considering the uncertainty of design variable to find robust optimal solution that has insensitive performance to its change of design variable. Stochastic finite element method (SFEM) is used to treat input data as stochastic variables. It is method that the potential values are series form for the expectation and small variation. Using correlation function of their variables, the statistics of output obtained form the input data distributed. From this, design considering uncertainty of design variables.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권11호
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• pp.749-756
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• 2000

Detent force develops generally undesirable effect that contributes to the output ripple of machine, vibration and noise. This paper proposes detent force minimization techniques for a Permanent Magnet Linear Synchronous Motor (PMLSM). In addition, thrust according to each minimization technique is estimated to observe the change of machine performance. A two-dimensional Finite Element Method is used to predict detent force and thrust due to structural factors and non-linearity. And moving node technique for geometric models is proposed to reduce modeling time and efforts.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권11호
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• pp.720-728
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• 2000

This paper describes the calculation of the equivalent circuit parameters and the characteristic analysis of a capacitor-run type single-phase induction motor by means of the finite element method in coupled with the conventional equivalent circuit model. The circuit parameters of the stator are calculated form the lumped parameter and the slot leakage reactance of the rotor with the closed slot can be obtained by the use of slot pitch boundary condition. From the analysis result this combined equivalent circuit and finite element method which is used slot pitch boundary condition is compared with the experimental results, the validity of the method is proved.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권8호
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• pp.408-416
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• 1999

The characteristics of permanent magnet synchronous motor are defined by airgap flux and circuit parameters. Interior Permanent Magnet Synchronous Motor(IPMSM) has a nonlinear characteristics due to structural speciality of rotor, so it is difficult to analyze circuit parameters and field-weakening characteristics of IPMSM. This paper presents the calculation of circuit parameters by using Finite Element Method(FEM) taken into consideration of nonlinear characteristics. Using the circuit parameters by FEM, IPMSM is analyzed to field-weakening characteristics and is compared with the Equivalent Magnetic Circuit(EMC) in which lumped parameter is consideration.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.11-12
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• 2014

차량용 양방향 DC/DC 컨버터에 적합한 새로운 토포로지 및 그 구성방법을 제안한다. 제안된 구성방식은 공통접지를 사용하는 새로운 양방향 공진형 충전펌프 토포로지와 기존 양방향 컨버터와 결합한 2단방식의 양방향 DC/DC 컨버터이다. 제안된 2배 승압 공진형 충전펌프는 전력변환 효율 증대와 병렬 구동 시 공진회로가 영향이 받지 않게 하기위해 출력 측으로 전력 전달시 인덕터가 입력전원과 직렬로 구성하게 하였다.

• 대한토목학회논문집
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• 제13권5호
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• pp.183-190
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• 1993

정확한 지오이드고(高)의 결정은 측위위성에 의한 위치해석시 3차원 측지좌표변환과 정표고 결정에 기본이 되므로 그 중요성이 강조되고 있다. 본 연구는 GPS에 의한 지오이드고(高) 결정에 관한 것으로 경도 $127^{\circ}{\sim}128^{\circ}$, 위도 $36^{\circ}{\sim}37^{\circ}$내 $5km{\times}5km$ 지역과 $60km{\times}60km$ 지역의 실측성과를 토대로 Bi-linear 방법과 GPS leveling 방법 및 OSU91A 방법으로 결과를 도출, 수준측량 성과와 비교하여 그 특성을 고찰한 것이다. 그 결과 Bi-linear 방법은 보간망의 형태와 크기 및 지형의 기복에 좌우되며 GPS leveling 방법은 수준측량의 성과가 양호하다면 이상적인 방법임을 알 수 있었다. 또한 OSU91A 방법의 경우 GPS leveling 방법과 평균 62cm의 차를 나타내므로 보다 정밀한 지오이드고(高) 결정을 위해서는 우리나라 지형에 적합한 지역적 지오이드 모델의 개발이 요망된다. 본 결과는 지오이드고(高)의 모델개발과 3차원 좌표변환체계의 연구에 한 참고 자료가 될 것이며 각종 건설공사의 3차원 위치결정에도 응용될 것으로 기대된다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권6호
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• pp.254-261
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• 2003

This study investigates magnetic circuit design of the Single-phase Line-start Permanent Magnet Synchronous Motor (LSPM) to develop the characteristics in steady state. In this paper, the saliency ratio, that is the ratio of q-axial inductance to d-axial inductance, and the inductance difference between q-axial inductance and d-axial inductance are increased. Design factor is selected permanent magnet position and rotor diameter. The analysis method of the synchronous motor on d-/q- axis coordinates is used for the positive component and the equivalent circuit of the induction motor is applied for the negative component analysis. Back-emf and d-q- axial inductance is analyzed by using 2 dimensional Finite Element Method (FEM). Characteristic analysis results with variation of design factor are reflected magnetic circuit design of LSPM. The characteristics of design model are compared with the characteristic of initial model.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권8호
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• pp.434-440
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• 2002

Switched Reluctance Motor (SRM) has been not commonly used because of the severe noise and vibration, although it has many advantages as solidity and economical efficiency. The origin of the acoustic noise and vibration in SRM's can be broadly classified into two types, mechanical and magnetic. Therefore this paper verifies the origin of vibration induced by radial magnetic forces from various experiments, and then studies the relationship between the output and vibration characteristics of SRM according to switch-on and off angles. Acceleration, torque and efficiency is measured by changing switching angles. From the comparison and analysis of the experimental results, a proper switching angle is presented for both satisfying electric performance and reducing vibration.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.403-410
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• 2000

This paper deals with a study to improve the performance of Moving Coil type Linear Oscillatory Actuator (MC-LOA) considering unbalanced magnetic circuit. MC-LOA has an unbalanced magnetic circuit due to its asymmetric structure. In this type of LOA, the airgap flux density tends to have different magnitude along mover's displacement and the current directions. The above property causes eccentric of displacement center and interferes with the proper oscillation of LOA. Therefore, this paper presents two models having the unbalanced magnetic circuit and the other balanced by the saturated core. In order to compare the characteristics between the two models, a characteristic analysis for both the basic model and the improved model is performed by their dynamic analysis composed of kinetic and electric equations and Finite Element Method (FEM). The propriety of the improved model is verified through the experimental results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권2호
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• pp.77-83
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• 2000

This paper deals with the design of a touch free eddy-current brake for high speed transportation systems by using 2-dimensional Finite Element Method (2-D FEM). The eddy current brake systems have to equipped with maximum braking force and deceleration at the given volume or mass, high braking force at small rate, attraction forces as small as possible and stable construction. The parameters, such as the number of pole, electric ampere-turns and slot width have influence on these braking characteristics. For the magnet to satisfy above-mentioned performance in high speed, the braking performance according to variation of the parameters are analyzed by the 2-D FEM. In addition, the magnet stack width is determined from equivalent stack width that is calculated by solution of the Field with scalar potential. From these results, the magnet of optimized configuration with maximum braking force and minimum attraction force is designed by the process of detail design.