• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1259-1260
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• 2007

In this paper, the inductive power collector using electromagnetic induction for vehicle such as the electric railway vehicle system is suggested and some ideas for power collector design to improve the power transfer performance are presented. The inductive power of secondary part is related to amount of linked flux to secondary part by the length of air-gap, which is expected by such a system parameter as mutual inductance. This paper will study for the transfer characteristic of power from input to output and equation including mutual inductance. And also, effect of leakage inductance variation of inductive power collector according to structure of winding was considered.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.210-215
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• 1997

Safety diagnosis on the driving system of electric train is performed using the vibration and noise signals of running railway train. Safety diagnosis is tried on the viewpoints of the appreciation of superannuation and the fault diagnosis of motor, reduction gear and boggie. The appreciation of superannuation is checked by the rms vibration levels of driving parts and the fault diagnosis is done by analyzing the frequencies of the vibration signals. The methods of measuring and analyzing the signals are decided on the basis of field 1-measured signals. The results shows that the vibration levels of each parts increase as the train goes older and each parts have their own frequency patterns of the vibration. As the results, the vibration and noise can be utilized successfully for the safety diagnosis of the driving part of electric train.

• 대한기계학회논문집A
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• 제38권7호
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• pp.817-822
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• 2014

경춘 복선의 일반 전동열차와 준 고속 열차인 ITX-청춘이 개통된 이래, 서울과 춘천을 오가는 유동인구가 급증하고 있다. 이는 대용량성과 저렴한 요금, 운행의 정시성 및 안전성 측면에서 다른 교통수단에 비해 철도 운송의 경쟁력이 높기 때문이다. 그러나 실내소음 측면에서는 전동 열차에 대한 승객들의 불만이 상당하다. 특히 터널 구간에서 실내소음은 급격히 높아져 대화에도 지장을 줄 정도이다. 본 연구에서는 경춘선 일반 전동 열차와 ITX-청춘 열차를 대상으로 정상 주행 중의 실내소음 특성을 비교 분석한다. 개활지, 터널 및 교량에서의 소음 레벨, 주파수 특성과 음질 지수를 분석하고, 실내 위치에 따른 소음레벨의 차이를 비교하여 소음의 전달 경로를 파악함으로써 향후 전동 열차의 실내소음 향상을 위한 기초 정보를 제공하고자 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1279-1286
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• 2010

This paper deals with the influence on the dynamic response of I-type girder railway bridge with high-speed electric multiple unit(HEMU) train load. This bridge system which has six I-girder and several cross beams, is modeled with plate and frame elements. And the upper slab is assumed to be fully connected with girders using rigid rinks. Span lengths, types of vehicle and running speeds are selected as parameters for analyses. For more exact analysis, it was adopted that 3-dimensional section of bridge models was produced by the assumed design wheel loads of HEMU vehicle at 200~350 km/hr speeds. Dynamic vertical deflections, dynamic amplification factors and vertical accelerations of bridges having 30 and 35 m span length were investigated and compared with the limit values specified in various national railway bridge specifications.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.169-174
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• 2012

Reduction unit is one of the most important components for railway vehicle because torque of motor must be transmitted to wheels of vehicle by reduction unit. However, According to advanced studies, it has been often broke down due to the damage, fatigue and wear of gear. To solve this problem, defect diagnosis methods of gear have been mainly using the vibration diagnosis technology through vibration waveform and frequency analysis. However, We should know vibration characteristics of normal state reduction unit prior to defect diagnosis. So in this paper, We had analyzed vibration characteristics of reduction unit in order to utilize monitoring system development. Comparison of targets is the vibration characteristics of normal state reduction unit about Electric Multiple Unit(EMU) and the High-speed trains(KTX, KTX II).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1407-1412
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• 2004

Impedance calculations of electric railway traction systems is essential to define characteristics and to design it. The self impedance is defined voltage drop rate per unit length, the mutual impedance is represented as a voltage induced to transmission line from transmission line. The self and the mutual impedance are influenced by ground return currents. The earth is considered as a semi-infinitely extended non-ideal conductor. The current of transmission line produces earth current induced magnetically and it flow through a path having minimum impedance. Carson proposed the impedance calculation formula using wave equations and magnetic field equations. Though the formula have an improper equation, that is still used as a standard impedance calculation method. This paper introduced an impedance calculation method that the complex depth of earth return method assumes that the current in conductor returns through an imagined earth depth path located directly under original conductor at a depth of. In this paper, we showed that this proposed method has a closed form and is easier than Carson's.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1097-1102
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• 2005

Non-Destructive Testing (NDT) is test method which finds the mechanical or natural or artificial defects of the interior or exterior of those without destructing materials and welded products. NDT is a means to assess the perfection of a component or system perfection. NOT images defects using scattered light, sound, electric current, magnetic fields and X-ray. Each NDT method has merits and demerits in the detecting ability of defects according to evaluated subjects. Defects can affect the serviceability of the material or structure, so NDT is important in guaranteeing safe operation as well as in quality control. In this review, we considered the methods of NDT applied to current railway vehicle manufacturing.

• Structural Engineering and Mechanics
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• 제23권2호
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• pp.163-175
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• 2006

In this paper, the dynamic response of a piezoelectric layer with a penny-shaped crack is investigated. The piezoelectric layer is subjected to an axisymmetrical action of both mechanical and electrical impacts. Two kinds of crack surface conditions, i.e., electrically impermeable and electrically permeable, are adopted. Based upon integral transform technique, the crack boundary value problem is reduced to a system of Fredholm integral equations in the Laplace transform domain. By making use of numerical Laplace inversion the time-dependent dynamic stress and electric displacement intensity factors are obtained, and the dynamic energy release rate is further derived. Numerical results are plotted to show the effects of both the piezoelectric layer thickness and the electrical impact loadings on the dynamic fracture behaviors of the crack tips.

• 한국철도학회논문집
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• 제7권3호
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• pp.173-179
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• 2004

This paper describes a low-cost single-phase active power filter, which consists of a half-bridge PWM inverter with a simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non-linear load. The active power filter has advantage of low implementation cost and compact size, using a half-bridge inverter and a simple control circuit with only one current sensor. So, it can be fabricated as a plug-in type. This paper shows the necessity and a good possibility to apply such advantage to the electric railway system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.500-501
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• 2007

The method of maintenance in railway is going to be changed to improve reliability on traction equipment. Partial discharge (PD) tests are useful to evaluate the insulation condition of stator winding. This paper describes the use of PD tests with 5 model coils which have the defects such as internal, slot discharge. The PD tests are performed with epoxy-mica coupler 500 pF at various AC voltages. The result of test shows PD pattern can correlate with the species of defects on 5 model coils.