• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.954-956
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• 1993

This paper describes the process of levitation melting of metals in an axisymmetric induction heating system. This process has advantages of low heat losses, heating with short times and clean operating conditions. The shape of molten metal is determined using sensitivity analysis and optimization technique. Electromagnetic, gravitational and surface tension energies are considered, and these energies are used as an objective function in optimization process. Electromagnetic field are calculated using the finite element method. The fact that volume is constant in the process is also considered as an equality constraint.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.850-853
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• 2009

통신선에 장애를 유발할 수 있는 전자유도 대책을 위해서 국가 기술기준에 의한 유도전압 한계치가 정해져 있고, 현장 유도 대책 상 이 제한치를 초과할 때에 필요한 것이므로 정부 고시의 기술 근거에 의해 유도전압을 계산하여 이에 대한 조치를 시행하고 있다. 전자유도 현상에 있어서 피유도원인 통신선간의 커플링 관계에 있어서 중간 차폐를 줄 수 있는 성분에 대한 계수치를 적용할 수 있다. 고시에 의하면 고속전철 시설 중 국내의 건설기반이 되는 고가의 교량구간에 의한 차폐 계수를 사용할 수 있고 그 수치가 제시되어 있는 바 이 수치에 대한 실증적 연구 소요에 의하여 교량구간이 아닌 노반 구간과 교량 구간의 경계점에서 비교 측정을 수행하였고 교량에 의한 차폐효과가 현재 고시에 주어진 수치에 근접함을 확인하였다.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.200-206
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• 2012

In order to develop a deep-underground great train express (GTX) in South Korea, the specifications decision and development of a traction control system (including an inverter and a traction motor), which considers a variety of route conditions, must be advanced. In this study, we examined the running resistance properties of a high-speed traction system based on a variety of tunnel types and vehicle organization methods. Then, we studied the power requirements necessary for the traction motor to maintain balanced speed in the high-speed traction system. From this, we determined the design criteria for the development of a high-speed traction system for use in the deep-underground GTX. Finally, we designed a linear induction motor (LIM) for a propulsion system, and we used the finite element method (FEM) to analyze its performance as it travelled through deep-underground tunnels.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.325-328
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• 2008

This paper presents a new conceptual electromagnetic induction eddy current-based stainless steel plate spiral type heater for heat exchanger or dual packs Heater in hot water system boiler steamer and super heated steamer, which is more suitable and acceptable for new generation consumer power applications. In addition, an active clamped quasi resonant PWM high frequency inverter using trench gate IGBTs power module can operate under a principle of zero voltage soft commutation with PWM is developed and demonstrated fora high efficient induction heated hot water system and boiler in the consumer power applications This consumer induction heater power appliance using active clamp soft switching PWM high-frequency inverter is evaluated and discussed on the basis of the simulation and experimental results.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.100.1-100.1
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• 2008

• Structural Engineering and Mechanics
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• v.37 no.4
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• pp.443-458
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• 2011

An extensive numerical investigation on the magnetorheological (MR) damper-based smart passive control system for mitigating vibration of stay cables under wind loads has been conducted. The smart passive system is incorporated with an electromagnetic induction (EMI) device for reducing complexity of the conventional MR damper based semi-active control system by eliminating an external power supply part and a feedback control part (i.e., sensors and controller). In this study, the control performance of the smart passive system has been evaluated by using a cable structure model extracted from a full-scale long stay cable with high tension. Numerical simulation results of the proposed smart damping system are compared with those of the passive and semi-active control systems employing MR dampers. It is demonstrated from the results that the control performance of the smart passive control system is better than those of the passive control cases and comparable to those of the semi-active control systems in the forced vibration analysis as well as the free vibration analysis, even though there is no external power source in the smart passive system.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.229-231
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• 1999

This paper deals with electromagnetic transient modelling of wind power system embedded in distribution networks. Wind power system consists of induction generator link reactor, distribution line, and controlled load unit. The introduction of embedded wind power system presents a new set of conditions to networks both with respect to power quantify needed to be transported and power quality such as sag swell, very short interruption, and flicker. This paper investigates the transient behavior of voltage, frequency, and load flow in wind driven induction generation system embedded in distribution networks.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.72-79
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• 2005

Compared with linear induction principle, the transverse flux circumferential induction principle is suggested as a driving mechanism of the revolving stage, which can rotate contactlessly without any supporting structure. The stage realizes the integrated motion of levitation, rotation, and planar perturbation, using the two-axis forces, normally directed force of the air-gap and tangential force, of the induction drivers mounted on the stator uniformly. In this paper, the force generating mechanism of the stage is described in detail. First, the various core shapes generating the transverse flux are analyzed to guarantee the proper thrust force. And the vector force intensity of the circumferential induction driver constituting the stage is compared with that of the linear induction driver. Especially it is shown that the magnetic force of the suggested system can be modeled with the linear equivalent model, including the test verification.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.3
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• pp.232-242
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• 1997

In this paper, we have designed an active radio frequency identification system solving the problems of moving transponder which is identification range expanding and low battery consuming of transponder. Developed radio frequency identification system is a bidirectional data transmission system which is composed of decoder data transmission of 120 kHz and transponder data carrier of 60 kHz which is a subharmonic frequency response with ASK modulation. The experimental results, designed system operating at 9600 bps, show good performances with detecting the 40 km/h moving transponder up to the range of 2 and 15 ${mu}A$ low consuming current.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2621-2625
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• 2007

This study aims at analyzing the flow characteristics of the electromagnetic pump using a linear induction motor (LIM) for transferring molten metals. The flow characteristics of the pump are simulated by magnetohydrodynamic(MHD) program. In this system, the LIM is used for transferring molten metal by electromagnetic force. The molten metal is treated as the secondary part of the LIM. Since the LIM produces an electromagnetic force in the duct, the molten metal can flow from the furnace to the reservoir. The flow characteristics of the pump are analyzed using MHD program for magnetic field of 0.1[T] in duct. In order to prove the analysis, we made a prototype electromagnetic pump using LIM.