• 한국안전학회지
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• 제25권2호
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• pp.18-23
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• 2010

This paper describes a cause of fire accidents on power system fire DC electric traction vehicles. We investigated fire scene of power line for DC electric traction vehicles. From analysis results, the cause of fire on power line turned out line to ground fault between a feeder of electric power services(pantagraph) and DC electric traction vehicle roof. Fire accident of DC electric traction vehicles be assumed that electric sparks had been produced between the pantagraph and the power line conductor by repetitively making contact and separation, maybe if some material like branches get in between connecting rod it makes progress line to ground fault. ZnO arresters are widely used to protect DC electric traction vehicles against overvoltages caused by lightning or switching surges. However, the arresters are deteriorated by commercial overvoltages and/or lightning one. The deteriorated arresters could lead power failures, such as line to ground fault by a thermal runaway resulting from the increases in leakage current even in a nominal power system voltage. Finally, the power failures would be causative of the fire accident.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1376-1378
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• 2004

When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the cathodic protection systems of buried pipelines and DC traction stray current influence on it using the simulation software CatPro. We can discuss the problems and mitigation of DC traction interference for protected pipeline.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.499-504
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• 2008

DC substation of urban transit supplies a suitable DC power on electricity vehicles by being supplied from KEPCO. DC substation is verified electrical safety of system through pre-operation inspection on electrical installations to be supplied power from KEPCO. However, because test items and method for DC traction system are unprepared on pre-operation inspection, the general safety and performance verification of DC traction system are very insufficient. Therefore this paper analyze the overseas test examples such as factory equipment tests, factory combined tests and railway tests for the safety and performance verification of DC traction system and present a suitable test items and test standard in domestic.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.241-247
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• 2008

This paper describes a cause of fire accidents on power system for DC electric traction vehicles. We investigated fire scene of power line for DC electric traction vehicles. From analysis results, the cause of fire on power line turned out line to ground fault between a feeder of electric power services(pantagraph) and DC electric traction vehicle roof. Fire accidents of DC electric traction vehicles be assumed that electric sparks had been produced between the pantagraph and the power line conductor by repetitively making contact and separation, maybe if some material like branches get in between connecting rod it make progress line to ground fault. ZnO arresters are widely used to protect DC electric traction vehicles against overvoltages caused by lightning or switching surges. However, the arresters are deteriorated by commercial frequency overvoltages and/or lightning one. Deteriorated arresters could lead power failures, such as line to ground fault by a thermal runaway resulting from the increases in leakage current even in a nominal power system voltage. The power failures, such as line to ground fault would be causative of the fire accidents.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.505-511
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• 2008

when electric traction system used DC 1500V runs on decline of rail road track and slows down, dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. This paper described a DC electric railway system, which can generate the excessive DC power form DC bus line to AC source in substation for traction system. The purpose of this study was the development of the regenerative inverter system which suppress extra DC-line voltage and regenerate the energy instead of using a resister. That is Developed regenerative inverter system returns the regenerative energy from the DC line voltage to the utility. In addition, the inverter can be compensate the harmonics caused by the power conversion devices used in the DC traction system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.282-284
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• 2005

When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the influence on lead wire method of distributed ICCP(impressed current cathodic protection) systems for mitigation of DC traction interference using the simulation software CatPro.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.285-287
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• 2005

When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the influence on parallel pipelines of distributed ICCP(impressed current cathodic protection) systems for mitigation of DC traction interference using the simulation software CatPro.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1660-1662
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• 2005

When an underground pipeline runs parallel with DC traction systems, it suffers from DC traction interference. Because the train is fed by the substation through the overhead wire and return current back to the substation via the rails. If these return rails are poorly insulated from earth, DC current leak into the earth and can be picked up by nearby pipeline. It may bring about large-scale accidents even in cathodically protected systems. In this paper we analyze the anode location of distributed impressed current cathodic protection systems for the mitigation of DC traction interference on buried pipelines using the simulation software CatPro. We can get a fix on the anode location.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.804-808
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• 2007

when electric traction system used DC 1500V runs on decline of rail road track and slows down, Dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. This paper described a DC electric railway system, which can generate the excessive DC power form DC bus line to AC source in substation for traction system. The proposed regeneration inverter system for DC traction can be used as both an inverter and an active power filter(APF). As a regeneration inverter mode, it can recycle regenerative energy caused by decelerating tractions and as an active power filter mode, it can compensate for harmonic distortion produced by the rectifier substation. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality. From the viewpoint of both power capacity and switching losses, the system is designed on the basis of three phase PWM inverters and composed of parallel inverters, output transformers, and an LCL filter.

• 전력전자학회논문지
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• 제13권4호
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• pp.247-256
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• 2008

직류철도의 회생제동 시 발생되는 회생에너지는 급전선로의 직류가선전압의 상승에 의해 시스템의 오동작이나 차량 정류기의 파손, 또는 급전 시스템의 전력변환 장치의 고장을 일으키는 원인이 될 수 있다. 슈퍼 커패시터를 이용한 회생에너지 저장장치는 직류가선전압을 안정화 하게하는 방법이다. 본 논문에서는 슈퍼 커패시터 뱅크를 이용하여 직류철도 시스템의 에너지 저장장치를 구현하였고, 지하철 2호선 N역과 S역의 실측값을 이용하여 가선전압이 전동차에 의한 회생에너지 발생에 따른 동작 특성과 슈퍼 커패시터의 충 방전 특성을 확인하였다. 본 논문을 통하여 직류철도 시스템에 설치된 회생에너지 저장시스템용 슈퍼 커패시터 뱅크의 동작 특성을 알 수 있고, 향 후 직류철도 모든 변전소의 직류 가선전압 실측 데이터를 이용한다면, 특정 직류철도 운행 구간에 대한 회생에너지 저장장치의 운전특성과 슈퍼커패시터의 용량 및 수명 예측으로 가격을 절감 할 수 있고 전체 시스템의 안정도 와 신뢰성을 향상시킬 수 있다.