• 전기학회논문지
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• 제62권3호
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• pp.424-430
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• 2013

This paper presents a new design works for the braking chopper system which is included in the propulsion system of KTX high speed train. Due to the current fed type synchronous motors used in the propulsion system, some different behaviors are shown comparing to the voltage type other chopper systems. Specially this chopper system acts either braking controlling or regenerative power controlling system with a parallel resistive load in the propulsion system. In this paper, an improved simple high power IGBT brake chopper system has proposed which is able to be replaced with an existing complicated GTO chopper system. The analytical approaches to the parallel load type current chopper system and the propper snubber circuits calculation were explained in this paper to control new chopper system. In addition, the thermal resistance of the cooling system for power dissipation of IGBT modules was calculated also. Finally several PC simulations have been done to clarify its availability.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.445-450
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• 2017

ZPP(Zirconium Potassium Perchlorate)는 산화제 potassium perchlorate, 금속원료 zirconium, 결합제 Viton 조성의 점화제이다. ZPP는 항공우주산업, 추진제 점화원, 자동화 산업에 사용되고 있다. 본 연구에서는 PMD(Pyrotechnic Mechanical Device)에 사용되는 ZPP의 제조공정 및 형상/열량/압력값과 같은 특성을 연구하였다. ZPP 제작 시, 원료들을 고속으로 교반하여 ZPP가 균일한 입자크기 및 형상으로 제작될 수 있도록 혼화공정을 설계하였다.

• 대한조선학회논문집
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• 제56권1호
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• pp.34-46
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• 2019

This paper provides the numerical results for the self-propulsion performance in waves of a car ferry vessel with damage in one of its twin-screw propulsion systems without flooding the engine room. The numerical simulations were carried out according to the Safe Return to Port (SRtP) regulation made by the Lloyd's register, where the regulation requires that damaged passenger ships should have an ability to return to port with a speed of 6 knots in a Beaufort 8 sea condition. For the validation of the present numerical analysis study, the resistance performance and the self-propulsion performance of the car ferry in intact and damaged conditions in calm water were calculated, which showed a satisfactory agreement with the model test results of Korea Research Institute of Ship and Ocean engineering (KRISO). Finally, the numerical simulation of self-propulsion performance in waves of the damaged car ferry ship was carried out for a normal sea state and for a Beaufort 8 sea state, respectively. The estimated average Brake Horse Power (BHP) for keeping the damaged car ferry ship advancing at a speed of 6 knots in a Beaufort 8 sea state reached about 47% of BHP at MCR condition or about 56% of BHP at NCR condition of the engine determined at the design state. In conclusion, it can be noted that the engine power of the damaged car ferry ship in single propulsion condition is sufficient to satisfy the SRtP requirement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.637-641
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• 1992

This paper presents a fundanental method to analyze and design a Single-sided Linear Induction Motor(SLIM) as a propulsion system for magnetic levitation vehicles of DAEJEON EXPO'93 in Korea. The performance characteristics of the designed SLIM are examinated by the thrust force, the normal force, the efficiency and the power factor according to the change of input frequency. The dimension of the SLIM is 1792mm long ${\times}$ 200mm width ${\times}$ 58mm high and the rated thrust is 1300 Newtons at the operating speed of 40 Km/h.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1376-1382
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• 2010

The propulsion Motor system has changed from the DC motor system to the induction motor system. Although the induction motor system has almost reached the stage of maturity, this system also need changed to the IPMSM system for direct drive without reduction gear. Thus, the IPMSM(Interior buried Permanent magnet synchronous Motor) has been adopted to meet the driving specification. In this paper, loss characteristic analysis of IPMSM has been performed using adopted F.E.M.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.37-40
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• 1987

In transverse flux linear induction motors(TFLIM), The loops of the working flux lie in planes transverse to the direction of motion. With a poly-phase primary winding, The TFLIMs has both electro-magnetic propulsion and levitation force. Thus, TFLIM a will be useful in high speed ground transportation systems. In this paper, The characteristics of a single aide TFLIM are analysed by using electromagnetic field theory.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.90-94
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• 2001

A Waterjet has been widely used for the propulsion of various speed range of marine vehicles due to its many advantages compared with the conventional screw propellers. In this paper, a power prediction based on momentum flux method is presented for the preliminary estimation of required power and selection of propulsion system for the waterjet driven craft. A theoretical basis of the mechanism of the waterjet is given and some of the empirical formulas are given as well. Finally the influence of intake type and nozzle exit velocity on the efficiency will be discussed.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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• pp.126-131
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• 2004

Pressure-based 알고리듬을 기반으로 한 cavitation 현상의 수치해석 코드를 개발하였다. Wall function을 사용한 k-\varepsilon$ 난류모델을 사용하였으며, cavitation 모델에는 volume transport equation을 사용하였다. 유동장은 저속이기 때문에 압축성 효과는 고려하지 않았다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.226-232
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• 1998

In this pager, we present IGBT VVVF inverters as a 1C1M propulsion system for electric car. This inverters are composed of high power IGBT's and controlled by compact control units. The control unit performs full digital control by using 32bit DSP and microconteroller. By using CAN-bus, high speed network is constructed within tow control units. The stack is simplified and optimized by using plate bus and IGBT driver units of hybrid-type.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3007-3018
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• 2011

This paper describes how to apply to commutate of thyristor efficiently. Thyristor is used for the high power system, as the research to secure domestic technology of the Current Source Inverter(CSI) for the synchronous motor operation which is used for the propulsion system of KTX. It has been composed to be available for the stable switching operation of the thyristor by supplementing problem of load commutation method, according to small Counter ElectricMotive Force(EMF) at low speed area of synchronous motor, via auxiliary commutation circuit using forced commutation method. We also have verified through the simulation using the Matlab.