• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.270-272
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• 2005

With the wide spread of direct current (DC) electric railroads in Korea, the stray currents from negative return rails become a pending problem to the safety of nearby underground infrastructures, such as gas pipelines, water distribution lines, heat pipelines, POF cables, etc. The mitigation of such interference, however, is mainly dependent on stray current drainage bond methods, which connect the underground metallic structures to the negative feeder cables attached to the rails with diodes (polarized drainage) or thyristors (forced drainage). Despite some merits of these methods, they increase the total amount of stray currents from rails and cause other interference problems. In this paper, we summarize the domestic conditions of stray current interference and describe a conceptual design of other mitigation methods for such interference.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.276-278
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• 2005

For over 25 years, the stray currents from DC electric railroads have caused serious interference problems with underground metallic infrastructures in Korea. The most serious interference is reported at the pipelines near the depot areas. Our field survey proves that this phenomena is mainly due to the missing of dedicated rectifiers for mainline, depot and/or workshop areas. Because it takes so much time and costs too much to replace the traction power system, we consider a stray current confinement method which collects the stray currents and drains them to the negative terminal of the rectifier. This can be realized by installing a stray current collecting wire along the depot boundary. Moreover, we found the stray current collecting reinforcement bar located beneath the rails of concrete slab tracks. Using this bar, we arc going to draing the stray currents from mainline rails. In this paper we show the result of field survey on railroad facilities and present the stray current confinement method under field test.

• Corrosion Science and Technology
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• 제11권3호
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• pp.77-81
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• 2012

Cathodic protection(CP) is widely used as a means of protecting corrosion for not only marine structures like ship hulls and offshore drilling facilities, but also underground structures like buried pipelines and oil storage tanks. The principle of CP is that the anodic dissolution of metal can be protected by supplying electrons to the cathode metal. When unprotected structures are nearby to CP systems, interference problems between unprotected and protected structures may be happened. The stray current interference can accelerate the corrosion of nearby structures. So far many efforts have been made to reduce the interference in the electric railway systems adjacent to the underground metal structures like buried pipelines and gas/oil tanks. During recent few decades the protection technologies against stray current induced corrosion have been significantly improved and a number of techniques have been developed. However, there is very limited information an marine environments. Some complex harbor structures are protected by two cathodic protection systems, i.e. sacrificial anode cathodic protection(SACP) and impressed current cathodic protection(ICCP). In this case, when the protection current from sacrificial anodes returns to the cathode through electrolyte, it passes through nearby other low resistance metal structures. In many cases the stray current of ICCP systems influences the function of SACP. In this study, the risk of stray current from the SACP system to adjacent reinforced concrete structures has been verified through laboratory experiments. Concrete and steel pile structures modeled a part of bridge have been investigated in terms of CP potential and current between the two. The variation of stray current according to the magnitude of ICCP/SACP has been studied to mitigate it and to suggest the proper protection criteria.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1083-1084
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• 2006

The wide spread of DC electric railway systems such as urban rapid transits including heavy rail and light rail transits has significant ramification as the stray currents from return conductor rails can cause the electrochemical interference, that is, the electrolytic corrosion of both rails and outside underground metallic infrastructures. The immature understanding of either the railway authority who is responsible for establishing the necessary provisions at the design stage or the affected parties makes it difficult to prepare the optimum range of solutions for the long-pending interference problem. In Japan, however, numerous assessment studies have been carried out on the stray current interference, by which protective guidelines are provided by "Electrolysis Committee". In this paper, we review a guide book from "Tokyo Electrolysis Committee", namely, "Protective Methods for Stray Current Corrosion".

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1075-1076
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• 2006

The wide spread of DC electric railway systems such as urban rapid transits including heavy rail and light rail transits has significant ramification as the stray currents from return conductor rails can cause the electrochemical interference, that is, the electrolytic corrosion of both rails and outside underground metallic infrastructures. The immature understanding of either the railway authority who is responsible for establishing the necessary provisions at the design stage or the affected parties makes it difficult to prepare the optimum range of solutions for the long-pending interference problem. In advanced countries, however, numerous assessment studies have been carried out on the stray current interference, by which protective standards and regulations are provided under the collaboration and agreement of the related parties. In this paper, we introduce a european standard from IEC, namely, "IEC 62128-2:2003 railway applications-fixed installations -part 2: protective provisions against the effects of stray currents caused by d.c. traction systems" and a "Code of Practice" produced by Victorian electrolysis committee (VEC) based on "Electricity Safety Act 1998" and "Electricity safety (stray current corrosion) regulations 1999" of Victoria state, Australia.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1817-1818
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• 2006

In present, most of metallic structures (gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway in Seoul and Pusan.In this case, subway system make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential, amplitude of stray current, point of source of stray current and so on. In this paper, results of development about Wireless Remote Monitoring and Control System on Underground Pipeline in Stray Current Conditions are presented. And also field test data should be reporting.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.731-734
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• 2003

In present, most of metallic structures(gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway and power line in seoul. Moreover subway system and power line make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential, amplitude of stray current, point of source of stray current and so. In this paper, results of development about data logger apparatus for measurement stray current of subway and power line are presented.

• 한국가스학회지
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• 제10권3호
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• pp.41-47
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• 2006

가스배관, 상수관, 송유관 등의 지중 매설배관이 직류 전기철도와 인접해 있는 경우, 전기철도 시스템의 귀선 회로로 사용되는 레일에서 누설되는 표유전류에 의해 이들 금속배관에는 전기적 부식, 즉 전식이 발생할 수 있다. 전식에 의한 집중 부식은 전기방식으로 보호되는 배관에 있어서도 지속적인 재료의 열화와 이에 따른 파손을 일으킬 수 있어 대형사고로 발전할 소지를 가지고 있다. 국내에서는 이러한 표유전류에 대한 대책으로 배관과 레일을 전기적으로 접속하는 배류법이 적용되고 있는데 특히 가스배관을 중심으로 한 강제배류법의 급속한 증가에 의해 간섭문제가 매우 복잡해지고 있다. 본 논문에서는 직류전기철도시스템과 매설배관 사이의 전기적 간섭 문제를 서울과 부산 지역에서 수행한 현장 실태조사의 결과를 통해 살펴본다.

• 한국가스학회지
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• 제12권4호
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• pp.8-13
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• 2008

전기철도의 궤도 누설전류는 주변 시설물 뿐 만 아니라 궤도 및 부속물의 전식을 일으킬 우려가 있다. 최근에는 누설전류의 영향을 감소시키기 위한 많은 노력이 기울여지고 있다. 본 연구에서는 수치해석 방법을 통하여 궤도와 매설배관의 이격거리, 토양비저항, 배관의 피복저항율, 궤도의 접지저항 등의 요인에 따른 간섭영향을 정량적으로 평가하였다. 이러한 정량적 연구결과를 토대로 주요 변수에 따른 간섭현상의 변화 방향을 예상할 수 있었으며 향후 대책의 수립과 수치해석에 있어서 각 변수의 민감도를 예상할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.217-219
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• 2007

With the wide spread of direct current(DC) electric railroads in Korea, the stray current or leakage currents from negative return rails become a pending problem to the safety of nearby underground Infrastructures. The most widely used mitigation method for this interference is the stray current drainage method, which connects the underground metallic structures to the rails with diodes (polarized drainage) or thyristor (forced drainage). This method, however, inherently possesses some drawbacks such as an increase of total leakage torrents from rails, expansion of interference zone, etc. In order to resolve these drawbacks, we developed a rapid potential-controled rectifier and applied to a depot area where stray current inference is very severe. The effect of this method was analyzed from the field tell data and we suggest this method can be an excellent alternative to the drainage-bond-based mitigation methods.