• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.196-201
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• 2008

In DC traction systems, a part of feedback current returning through rails becomes leakage current, illumination on a metal laid underground results from the leakage current to ground. To prevent the leakage current on rails, feedback rails almost have insulated with the ground. Insulation between rails and the ground causes that the earth method changes a isolated method in DC traction systems. the rail potential rise results in the isolated method. the rail potential rise causes an electric shock when a person touches the ground and rolling stock. To decrease the rail potential rise and leakage current, there are methods for reducing the feedback resistance and current of rails, increasing the leakage resistance, decreasing the distance between substations. But it are necessary to forecast and analyze the rail potential and amplitude of leakage current. In this paper, we modeled DC traction systems and feedback circuit to simulate the rail potential and amplitude of leakage current using PSCAD/EMTDC that is power analysis program, forecasted the rail potential and amplitude of leakage current about changing various parameters in the electric circuit. By using the simulation model, we easily will forecast the rail potential and amplitude of leakage current in case of a level of basic design and maintenance in electric railway systems, valuably use basic data in case of system selection.

• 한국철도학회논문집
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• 제12권1호
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• pp.161-166
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• 2009

직류급전시스템은 주로 비접지방식을 사용하지만 레일과 대지간이 긴 거리를 평행하게 구성되어 레일저항과 레일-대지간 콘덕턴스가 존재하여 레일전위와 누설전류가 발생한다. 레일전위는 인체에 전기적 쇼크를 주고 누설전류는 인근 매설 철 구조물에 전해적 부식을 주게 된다. 그러므로 이러한 영향을 줄이고, 방지와 감시하는 설계기술이 현 직류급전시스템에서는 중요한 요소이다. 레일전위와 누설전류의 해석은 전파이론에 의해 이루어졌으며 레일저항과 레일-대지간 콘던턴스의 상태를 유지하기 위해 레일누설전류를 감시/제어하는 방안이 제안되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.236-241
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• 2007

DC feeding system is mainly floating but the rail potential and the leakage current are created because of long parallelism between rails and ground. Rail potential causes electric shock to human and leakage current causes electrolytic corrosion to nearby the buried metals. Therefore the design technologies to reduce, protect and monitor these effects are important recent DC feeding system. Normally during designing DC feeding system in terms of rail potential and leakage current, there are about 10 parameters. Four design parameters among those is analysed based on propagation theory that is utilized in order to simulate grounding system.

• 전기학회논문지
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• 제60권3호
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• pp.680-685
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• 2011

Nowadays, in metropolitan railroad, DC feeding system is being generally applied. In order to reduce damages of electro-chemical corrosion caused by stray current and leakage current, in DC feeding system, rail is used as negative-polarity return conductor for traction load current. However, it has problem of rail potential increase and there are no adequate measures to prevent it in domestic. In this paper, we presented fundamental theory and related standards about rail potential increase. And then, we analyzed field testing data and simulated a variety of operations by using PSCAD/EMTDC as an analysis program of power system. In addition, voltage control device is suggested to prevent accidents caused by rail potential increase.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.166-168
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• 2008

DC feeding system is mainly floating but the rail potential and the leakage current are created because of long parallelism between rails and ground. Rail potential causes electric shock to human and leakage current causes electrolytic corrosion to nearby the buried metals. Therefore the design technologies to reduce, protect and monitor these effects are important recent DC feeding system. Rail potential and leakage current are analysed based on propagation theory that is utilized in order to simulate grounding system. New measurement procedure is proposed based on this analysis in order to more be accurate in result.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.229-232
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• 1997

In this paper, we describe about the field test of polymeric long rod insulator for rail way. For the test, insulators were mounted at the feeder line system at Kuro base station and were exposed to environmental, electric, and mechanical stress. During the test service, the leakage current was been monitoring and stored the data by the leakage current measuring system that was specially constructed. After about 6 months, diagnostic tests for evaluation of the installed insulators were conducted. The test results developed that the developed polymeric insulator is valid to use for rail way.

• 전기학회논문지
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• 제61권3호
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• pp.485-490
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• 2012

Nowadays, in metropolitan railroad, DC feeding system is being generally applied. In order to reduce damage of electro-chemical corrosion caused by stray current and leakage current, in DC feeding system, rail is used as negative-polarity return conductor for traction load current. However, it has problem of rail potential increase and there are no adequate measures to prevent it in domestic. The rise of rail potential leads to damage for human and equipments. To solve the problems, this paper presents fundamental theory and related standards about rail potential increase. And then, we analyzed field testing data and simulated a variety of operations by using PSCAD/EMTDC as an analysis program of power system. In addition, this paper suggests rail potential limit device and addresses how to the device. To verify the effect, simulation of DC feeding system before and after the application of the device is carried out in various cases.

• 한국철도학회논문집
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• 제12권5호
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• pp.687-693
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• 2009

급전시뮬레이션과 함께 수행될 수 있는 '레일 전위 상승 분석을 위한 컴퓨터 알고리즘'이 제안되었다. 본 알고리즘에서 레일전위상승 분석은 2 단계로 진행된다. 첫 단계에서는 급전시스템의 조류해석을 수행하여 차량 및 변전소에서의 인젝션(injection) 전류를 구한다. 두 번째 단계에서는 급전시스템의 등가회로에서 변전소 및 차량을 전류 소스로 대치하고 레일의 대지로의 누설 저항이 삽입된 등가회로를 다시 구성한다. 새로 구성된 등가회로를 해석하여 변전소 및 차량 위치에서의 레일 전위를 구한다. 알고리즘의 타당성을 분석하기 위하여 컴퓨터 프로그램을 작성하여 레일전위상승을 구하였고 동일한 시스템을 대상으로 MatLab 사의 Simulink/SymPowerSystems 소프트웨어를 이용하여 레일전위를 구하였다. 2가지 방법에 의한 결과를 상호 비교 분석한 결과는 그 오차가 허용범위 내에 있음을 보여주었다. 본 알고리즘은 급전시뮬레이션과 연동하여 수행될 수 있는 장점을 가지고 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1885-1891
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• 2010

Recently metropolitan local governments is actively introducing urban railway's expand and light rail transit as a means of new transport system. DC electricity feeder system operating in the domestic urban railway is typically a feedback circuit consisted of the contact wire and electric railway vehicle via rail. But stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit with respect to a given structure. Stray current is generally results from the leakage of return currents from large DC traction systems that are grounded or have a bad earth-insulated return path. At the place where the current leaves the rail and metallic structures, electrolytic corrosion may take place. This paper presents comparison analysis of field test methods based on criteria of electrolytic corrosion protection of buried metallic structures adjacent to DC traction systems.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.91-96
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• 2006

This paper shows quantatively the cause of electric power induction that was occured by flowing current when high speed electric car travels and the investigation of earth potential upswing and animal damage example by rail leakage current.