• 한국전기전자재료학회논문지
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• 제32권1호
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• pp.1-5
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• 2019

The overhead contact line (OCL) is a key piece of equipment for transmitting electrical energy to the pantograph of rail cars. Recently, a 400 km/h OCL was applied to the Honam high-speed line, and its performance was examined by running HEMU-430X. For the study, we analyzed the current of catenary wire concurrently while running HEMU-430X in the Honam high-speed line. Specifically, this study recorded the currents for each speed during operation of the railway vehicle. The analysis of the frequency of line current showed generation of third-harmonics, 15th-harmonics, 17th-harmonics, and 19th-harmonics. The current of catenary wire is a basic technology assessment used to determine the electrical safety of electric railway systems, and it can be used as a technology for analyzing circulating currents generated in the current configuration, as well as for analyzing electric fatigue of the OCL components.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.620-627
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• 2000

This paper presents a mettled to obtain line constants for a catenary system. To find them, voltages, currents and power factors according to frequencies were measured in short circuit and open circuit respectively. And front the measured data, resistances, inductances and capacitances were also calculated.

• 한국철도학회논문집
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• 제4권2호
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• pp.62-70
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• 2001

Pure copper, Cu-1.1wt%Cd and ACSR(Aluminum Conductor Steel Reinforced) have been used as catenary materials of the electric railway system. Since these materials may be exposed to the corrosive environments like polluted air, acid rain and sea water, it is important to investigate the corrosion rates in various corrosive environments. The aqueous corrosion characteristics of catenary materials in aerated acid, neutral and alkali solutions were studied by using immersion corrosion tests, electrochemical measurements and analytical techniques. In order to examine corrosion characteristics according to the dissolved oxygen content, pH, chloride ion concentration ion, and the addition of Cd to Cu, a series of tests such as potentiodynamic polarization, a.c impedance spectroscopy and galvanic corrosion tests were carried out with these materials. Results showed that the addition of Cd to Cu and chloride ion in the solution have an adverse effects on the resistance to corrosion. Additionally, Galvanic currents between Al and steel wires of ACSR were confirmed by using ZRA(zero resistance ammeter) method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1631-1633
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• 2005

This paper describes the measurement result of leakage current flowing arrestors connected in catenary line to propose an optimal management methods. 27 arrestors set in 7 locations were tested. The leakage currents are included a harmonics of electric train during the operation of electric train in feeding section and in case of feeding earthing system.

• 전기학회논문지
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• 제62권4호
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• pp.573-576
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• 2013

In this paper, analysis method for current collection performance based on real-time current of catenary system is proposed. An innovative method based on track-side of railway system is used for measurement of currents for overhead contact line during the collection with pantograph. The evaluation of a qualitative ratio for current collection performance were conducted using proposed algorithm under various conditions such as laboratory and track-side. To check the validity of our approach, we compared between calculation results from current of contact wire and measurement results from arcing of pantograph using simulator in laboratory conditions. The results show that the behavior of current collection performance were analysis from currents of overhead contact line in AC electric railway system.

• 전기학회논문지P
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• 제66권1호
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• pp.38-42
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• 2017

The wear of the third track power collector is one of the essential check factors for safe train operation. Rapid wear of the current collector accelerates the line of the catenary. In addition, the arc generated when the catenary line is turned off causes a malfunction in the minute portion of the catenary line, thereby shortening the life of the catenary line. In this paper, to analyze the mechanical wear of the current collector during driving according to the environmental factor of the Maglev(magnetic levitation train), it was divided into dry season and wet season. the wear of metallized collector, copper alloy collector and carbon collector were measured and compared with each other. The wear rate was measured according to the position of the wire, the position of the power collector and the position per hour. Microscopic photographs of the cross section and surface of the power collector were measured. The electrical currents of the metallized collector, copper alloy collector and carbon collector were measured.

• 한국철도학회논문집
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• 제14권5호
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• pp.404-410
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• 2011

AT 방식의 교류 급전시스템에서는 고장점 표정하기 위해 리액턴스 방식과 AT흡상전류비 방식을 채택하고 있다. 하지만 이 방식들은 여러 이유로 인해 표정 오차가 발생할 수 있다. 기존 방식의 이러한 단점을 해결하기 위해 전차선 전류 분류비를 이용하여 고장점을 표정하는 새로운 기법을 제안한다. 전차선 전류 분류비 방식은 기존에 전차선에 연결되어 있는 보호계전기를 사용하여 각 전차선의 전류를 측정하고 취합하여, 그 비(ratio)를 이용하여 고장지점을 표정한다. 이 방식은 기존의 기법보다 더 정확한 고장점을 표정할 수 있으며, 기존의 설치되어있는 계전기를 사용함으로써 추가 설비의 비용을 절감할 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.634-643
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• 2011

The neutral section was installed in order to prevent conflict with different phase angle source in electric railway catenary system. The speed of electric train reduced due to coasting operation by notch off when it passed the neutral section. And, the catenary wire was damaged and the accident might be happened because of the arc generation when the electric train passed the neutral section with notch off condition. The inrush current of main transformer installed tiling train is analyzed during the operation of MCB(main circuit break) passing through the neutral section. The instantaneous waveform of load current were analyzed in case of powering and regenerative braking. Inrush current waveform with run of AC railway train showed that inrush current waveform and harmonics, the inrush current generated from main transformer in train has bad effects on power quality problem. In order to reduce these inrush currents, the MCB is connected when the phase angle of voltage is 90 degree. This paper is to measure inrush current and harmonics in main transformer of high speed train in neutral section of electric railway. This measurement report is used to control minimum inrush current in algorithm and power phase angle.

• 전기학회논문지
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• 제63권6호
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• pp.850-854
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• 2014

Analyzing dynamic performance between pantograph and contact wire depends on mechanical and electrical conditions such as contact force, currents, aerodynamics of pantograph and tension of overhead contact wire. For the characteristic of dynamic performance between pantograph and overhead contact wire, various evaluation systems are used to measuring of the interaction of the contact line and the pantograph. Among the various methods, the contact force and percentage of arcing are intended to prove the safety and the quality of the current collection system on the train. However, these methods are only capable of measuring on the train which are installed measurement systems. Therefore in this paper, a track-side monitoring system was implemented to measure electrical characteristics from active overhead contact wire systems in order to constantly estimate current collection performance of railway operation. In addition, a method to analyze loss of contact phenomena was proposed. According to simulation results, the proposed system was capable of measuring abnormal electrical behavior of pantograph and contact wires on the track-side. The advantage of the proposed system is possible to detect loss of contact or any other electrical abnormalities of all types of trains within sections from sub to sub without the need to install any on-board equipment on trains.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1341-1346
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• 2004

Basic design for single-phase active power filter, which aims at railway applications provided with PWM-controlled converters, is comprehensively studided and its performance is presented in this paper, Active power filters are used to compensate railway signaling and public telecommunication interference due to the high-order harmonic currents generated in railway traction locomotives. A type of hybrid digital filter which is composed of low pass filter and high pass filter is proposed so that the desired harmonic reference current with accurate magnitude and phase shift can be extracted from catenary line current. A design criteria to determine input inductor L and output capacitor C is also described, considering voltage, current. PWM pattern, and switching frequency of the main converters, Finally, computer simulation and DSP-based experiments resulted from laboratory test are presented.