• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권12호
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• pp.592-600
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• 2005

In this paper, a low loss magnetic levitation(Maglev) system is suggested and tested. The suggested Maglev system includes four hybrid magnets which consist of permanent magnet and coil. In the steady state, the levitated module system can be supported by attraction force generated by permanent magnet. The coil current controls only dynamic loads due to external disturbances. The module systems are designed by using finite element method(FEM) software tools such as MAXWELL and ANSYS. Also, digital control systems are designed to keep the magnet airgap at a constant value. The control systems include a VME(versa module europa)-based CPU(central processing unit) board, AD(analog to digital) board, PWM(pulse width modulation) board, 4-quadrant chopper, and sensors. In order to estimate the vertical velocity of the magnet, we use second order state observer with acceleration and gap signals as input and output signals, respectively. The characteristics of the suggested low loss Maglev system are demonstrated by experimental results showing coil current of 0A in the steady state of 3m airgap and performance specifications are satisfied for reference gap and force disturbance.

• 한국초전도ㆍ저온공학회논문지
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• 제1권2호
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• pp.20-24
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• 1999

The study of HTS(High Temperature Superconducting) bulk in magnetic levitation system requires the calculation of currents distribution in HTS bulk is very important to determine this forces. We have made computer program to find this current distribution and levitation force. J-E relation in HTS bulk is extremely nonlinear, so iteration method must be used to determine the current distribution. We developed the method to determine the current distribution in the unifrom-field model and, using this method, calculated the levitation force in permanent-magnet-levitation model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.198-200
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• 2009

This paper presents the numerical simulation results on the moving type electrodynamic suspension (EDS) simulator. Superconducting EDS system is generated by the interaction between the magnetic field made by the induced the eddy current in the ground conductor and the moving magnetic field made by onboard superconducting magnet. The levitation force of EDS system, which is proportional to the strength of the moving magnetic field, becomes saturated according to the increase of the velocity Especially, the levitation force is influenced by the structure of HTS magnet and ground conductor. The 3-D numerical analysis with FEM was used to find the distribution of the magnetic field, the optimal coil structure, and the calculation of the levitation force.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.959-962
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• 2005

In the semiconductor and optical industry. a new transport system which can replace the conventional transport system is required. The Transport systems are driven by the magnetic field and conveyer belts. The magnetic field may damage semiconductor and the contact force may scratch the optical lens. The ultrasonic wave driven system can solve these problems. In this semiconductor and optical industry, the non-contact system is required for reducing the damages. The ultrasonic transportation is the solution of the problem. In this paper, the ultrasonic levitation system for levitation object are proposed. The 3D vibration profiles of the beam are measured by Laser Scanning Vibrometer for verifying the vibration characteristics of the system and the amplitudes of the beam and the levitation heights of object are measured fore evaluating the performance.

• 한국철도학회논문집
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• 제18권1호
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• pp.15-24
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• 2015

상전도흡인식 자기부상열차는 전자석의 전류를 조정하여 차량과 선로 사이의 간극(공극)을 일정하게 유지한다. 이러한 능동현가장치를 사용하는 자기부상열차에 있어서는 다양한 외란에도 불구하고 부상제어기를 이용한 부상공극을 허용하는 범위 내로 유지하는 것이 핵심기술 중의 하나이다. 특히 차량과 유연한 가이드웨이 사이의 동적상호작용에 의해 발생되는 진동은 저속 및 정지상태에서 부상안정성을 방해하는 중요한 요인으로 작용한다. 본 논문에서는 가이드웨이의 유연성에도 강인한 부상제어기를 개발하기 위하여 차량과 유연 가이드웨이 사이의 연성 동역학 모델을 개발하고, 전자석 및 부상제어기도 포함시키는 통합모델링을 제안하였다. 개발된 통합동역학 모델을 이용하여 가이드웨이의 유연성을 고려한 부상공극 시뮬레이션을 수행하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1019-1020
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.741-742
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• 2010

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.418-420
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• 2007

When the magnetic levitation system(MAGLEV) initially rise, The MAGLEV has a weak point that is very large variation of the electric current. In this paper, The author applied the multi-loop-control to stably control the magnetic levitation system(MAGLEV). The gains of the control algorithm were selected based on pole locations formulated from a prototype Bessel transfer function model. The design incorporate tradeoffs in DC-to-DC converter hard-ware para-meters and pole locations. In order to confirm the superiority of the proposed pole selection and controller, MATLAB simulation and experiment results are presented.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.61-64
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• 2001

Levitation force of a new magnetic levitation system using a super-conducting bulk magnet(SBM) and a permanent magnet(PM) was numerically calculated. The non-linear J-E relation of a SBM was modeled using a critical state model and iteration method, and demagnetization of a PM was considered using a demagnetization curve of a real PM. The maximum limitation of levitation force was found according to increasing the trapped field in a SBM. Finite element method was used for numerical calculation.

• International Journal of Railway
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• 제9권2호
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• pp.41-45
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• 2016

In this paper, a study on the efficiency improvement of the magnetic levitation train using the LIM (Linear Induction Motor) was presented. The maglev train has the advantage of being environmentally friendly since much less noise and dust is produced. However, due to structural limitation, compared to a rotating induction motor, linear induction motor, the main propulsion engine of the maglev train has a relatively greater air gap and hence has the lower operation efficiency. In this paper, the relationship between the operating condition of the train and the slip frequency has been investigated to find out the optimum slip frequency that might improve the efficiency of the magnetic levitation train with linear induction motor. The slip frequency is variable during the operation by this relationship only within a range that does not affect the levitation system of the train. After that, the comparison of the efficiency between the conventional control method with the slip frequency fixed at 13.5[Hz] and the proposed method with the slip frequency variable from 9.5[Hz] to 6.5[Hz] has been conducted by simulation using Simplorer. Experiments of 19.5[ton] magnetic levitation trains owned by Korea Institute of Machinery and Materials were carried out to verify the simulation results.