• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2147-2150
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• 2003

Recently, many technologies of the P.L.C (Power Line Carrier) are introduced for an efficient communication. P.L.C communication sends information in the carrier signals by conduction over the power wire. An arc detector is proposed in this paper for the effective transmission. The Power Line Carrier has an advantage in low cost because it uses existent power line. It can be easily applied anywhere that a power line socket is available. But the P.L.C. is very noisy, because many electronic devices in generate electronic noise in modulated signals. This problem should be considered carefully in the design of the arc detector system using P.L.C in railway. The proposed system can be applied for monitoring the arc detector system and the arc locator system in railway. Hence the system will be able to exchange the arc information to be T.C.M.S. (Train Control Management System), bogies and even between a station and trains in railway and use to suspicion fire in train.

• 동력기계공학회지
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• 제11권1호
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• pp.134-139
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• 2007

A delivery ship is used to handle the cargo with the crane to/from the ships. The ship is inclined in the direction of a cargo which is hung on a crane. In this case, a arc shaped rail should be in the equilibrium state to get good anti-rolling performance. In this study, a device and control algorithm are developed to take accurate and quick equilibrium of the rail. The device is composed of a hinged immovable support, screw jack and damper. And the control system is based on I-PD control law to consider of control input saturation and overshoot. The controller is composed of integral controller of feedforward path and proportional-derivative controller of feedback path. The parameters of controller is designed to follow the reference signal and to remove overshoot. The simulation results show that the desirable control performance is achieved.

• 한국철도학회논문집
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• 제15권3호
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• pp.224-230
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• 2012

전동차의 집전장치용 주습판은 형태와 재질에 따라 마모현상에 상당한 차이가 있으며 특히, 강수량에 따른 이상마모, 아크에의한 급격한 이상마모는 전차선과 주습판의 수명을 결정하는 주요인자로 작용한다. 본 연구는 현차 실험을 통하여 우수한 전기전도도 및 내아크성을 가진 동계주습판의 마모현상을 정상마모 특성이 관찰된 동계주습판과 우천 시 국부적으로 이상마모 특성이 관찰된 동계주습판에 대하여 강수량, 주행거리 및 주습판의 교환 후 중량을 상호 비교하여 분석하였다. 트라이볼로지적 접근을 통하여 내마모성 등이 우수한 철계습판체의 적용 필요성을 본 실험적 연구를 통하여 제안하였다.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.216-225
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• 2006

This paper presents a new circuit topology of DC busline switch and snubbing capacitor-assisted full-bridge soft-switching PWM inverter type DC-DC power converter with a high frequency link for low voltage large current applications as DC feeding systems, telecommunication power plants, automotive DC bus converters, plasma generator, electro plating plants, fuel cell interfaced power conditioner and arc welding power supplies. The proposed power converter circuit is based upon a voltage source-fed H type full-bridge high frequency PWM inverter with a high frequency transformer link. The conventional type high frequency inverter circuit is modified by adding a single power semiconductor switching device in series with DC rail and snubbing lossless capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge inverter arms and DC busline can achieve ZVS/ZVT turn-off and ZCS turn-on commutation operation. Therefore, the total switching losses at turn-off and turn-on switching transitions of these power semiconductor devices can be reduced even in the high switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules is selected to be 60 kHz. It is proved experimentally by the power loss analysis that the more the switching frequency increases, the more the proposed DC-DC converter can achieve high performance, lighter in weight, lower power losses and miniaturization in size as compared to the conventional hard switching one. The principle of operation, operation modes, practical and inherent effectiveness of this novel DC-DC power converter topology is proved for a low voltage and large current DC-DC power supplies of arc welder applications in industry.

• Journal of Power Electronics
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• 제7권3호
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• pp.181-190
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• 2007

This paper presents a novel circuit topology of a DC bus line series switch and parallel snubbing capacitor-assisted soft-switching PWM full-bridge inverter type DC-DC power converter with a high frequency planar transformer link, which is newly developed for high performance arc welding machines in industry. The proposed DC-DC power converter circuit is based upon a voltage source-fed H type full-bridge soft-switching PWM inverter with a high frequency transformer. This DC-DC power converter has a single power semiconductor switching device in series with an input DC low side rail and loss less snubbing capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge arms and DC bus line can achieve ZCS turn-on and ZVS turn-off transition commutation. Consequently, the total switching power losses occurred at turn-off switching transition of these power semiconductor devices; IGBTs can be reduced even in higher switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules can be realized at 60 kHz. It is proved experimentally by power loss analysis that the more the switching frequency increases, the more the proposed DC-DC power converter can achieve a higher control response performance and size miniaturization. The practical and inherent effectiveness of the new DC-DC converter topology proposed here is actually confirmed for low voltage and large current DC-DC power supplies (32V, 300A) for TIG arc welding applications in industry.

• 한국BIM학회 논문집
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• 제7권2호
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• pp.1-7
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• 2017

Urban planning involves many different disciplines. In order for the related stakeholders to have better understanding and acceptable outcomes, planners are required to present a methodology that would properly reflect people's interest. In order to justify the demand and distribute people's interest, planners actively utilized the suitability analysis. Accordingly, a suitability analysis to find the optimal route for high-speed rail was performed in this paper. With ArcGIS and geographic data sets, simple map algebra could be used. The final product of this research was a map indicating the suitable routes for high-speed rail using the shortest path analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.281-283
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• 2006

This paper presents two new circuit topologies of DC bus lineside active edge resonant snubber assisted soft-switching PWM full-bridge DC-DC converter acceptable for either utility AC 200V-rms or AC 400V-rms input voltage source. All the active power switches in the full-bridge arms and DC busline can achieve ZCS turn-on and ZVS turn-off commutations and the total turn-off switching power losses of all active switches can be reduced for high-frequency switching action. The effectiveness of these new DC-DC converters topologies is proved for low voltage and large current high efficiency DC-DC power supplies as TIG arc welding machine from a practical point of view.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.51-56
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• 2007

Pantograph of the electric train is the important part receiving current by adhereing contact wire. Wearing rate of pantograph or contact wire is changed by the type of pantograph and material of adhering part. In special, the weather influences the relative wearing rate and wearing type of pantograph Slider and Contact wire with steep wearing in arc and life cycle of pantograph slider. Presently, the weather causes side-wearing and over-wearing of pantograph slide installed in electric train. So it is difficult to manage and operate the electric train. Although the quality of slide using in line4 vehicle was finished the test in line 2 vehicle experimentally, it has to apply after pantograph is installed in some electric trains and check the influence in it and contact wire. It is because line4 section is very different from line2 section. Experimental application is the sequence to certify the safety and abrasion resistance importantly by enlarging experimental application with increase of the experimental electric train. The lenth of line4 in Seoul Metro is 71.5[km]. It is long section. The line is mixed DC 1,500[V] section and AC 25,000[V] section. It has underground section of 41.5[km] and ground section of 30[km]. Ground section is about 42% and receives much influence in the rain during the rainy season. After experimental application we found that this pantograph slide has twice as much abrasion resistance despite a little deviation and found the occurrence probability of arc and side-wearing is decreased considerably.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.366-373
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• 2005

This paper presents two new circuit topologies of the dc busline side active resonant snubber assisted voltage source high frequency link soft switching PWM full-bridge dc-dc power converters acceptable for either utility ac 200V-rms or ac 400V-rms input grid. These high frequency switching dc-dc converters proposed in this paper are composed of a typical voltage source-fed full-bridge PWM inverter, high frequency transformer with center tap, high frequency diode rectifier with inductor input filter and dc busline side series switches with the aid of a dc busline parallel capacitive lossless snubber. All the active switches in the full-bridge arms as well as dc busline snubber can achieve ZCS turn-on and ZVS turn-off transition commutation with the aid of a transformer leakage inductive component and consequently the total switching power losses can be effectively reduced. So that, a high switching frequency operation of IGBTs in the voltage source full bridge inverter can be actually designed more than about 20 kHz. It is confirmed that the more the switching frequency of full-bridge soft switching inverter increases, the more soft switching PWM dc-dc converter with a high frequency transformer link has remarkable advantages for its power conversion efficiency and power density implementations as compared with the conventional hard switching PWM inverter type dc-dc power converter. The effectiveness of these new dc-dc power converter topologies can be proved to be more suitable for low voltage and large current dc-dc power supply as arc welding equipment from a practical point of view.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.399-402
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• 2006

This paper presents a new circuit topology of dc bus line switch-assisted half-bridge soft switching PWM inverter type dc-dc converter for arc welder. The proposed power converter is composed of typical voltage source half-bridge high frequency PWM inverter with a high frequency transformer link in addition to dc bus line side power semiconductor switching devices fer PWM control scheme and capacitive lossless snubbers. All the active power switches in the half-bridge arm and dc bus lines can achieve ZCS turn-on and ZVS turn-off commutation operation and consequently the total turn-off switching losses can be significantly reduced. As a result, a high switching frequency of using IGBTs can be actually selected more than about 20 kHz. The effectiveness of this new converter topology is proved for low voltage and large current dc-dc power supplies such as arc welder from a practical point of view.