• 한국철도학회논문집
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• 제18권3호
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• pp.232-240
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• 2015

고속철도 차량기지에는 고전압임펄스(HVITC)와 AF 궤도회로를 사용하고 있다. HVITC는 열차의 위치검지 및 궤도 절손검지 기능을 하고, AF궤도회로는 열차제어 정보를 전송하여 고속열차의 이상 유무를 검지하는 출발 전 시험에 사용한다. 두 궤도회로는 별도로 구성되어 있고, 같은 레일을 사용하여 제어신호를 스위칭에 의해서 전송하고 있다. AF 궤도회로는 루프케이블을 궤도 안쪽에 설치하는 방법으로 구성할 수 있다. 그러면 스위치를 제거할 수 있고, 상시 시험용 제어신호를 전송할 수 있다. 이 경우에 두 궤도회로는 상호간섭이 발생할 수 있다. 본 논문에서는 두 궤도회로를 동시에 동작하는 경우에 발생되는 간섭을 두 회로의 모델링을 통하여 규명하였다.

• 전기학회논문지
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• 제62권1호
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• pp.70-75
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• 2013

The electrical separation joint as a filter circuit distributes the track circuit frequency. The electrical separation joint is classified into the interval where reinforcing bars are insulated and not insulated through the length of track circuit. In case of incorrectly setting up the length of electrical separation joint, the amplitude of current on the track circuit is not over standard current which is the standard of current on the track circuit and it effects on the close frequency on track circuit. Then, it makes an accident or makes a train not receive information for train control. In this paper, the electrical separation joint model is suggested and parameters are numerically calculated in the model. Moreover, the length of electrical separation joint is analyzed and is demonstrated by uisng Matlab and PSpice program.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1709-1715
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• 2011

A track-circuit device exploits two rails as a conductor of an electrical circuit. It detects the presence or absence of the trains with variation of received level when wheel sets of the train shunt rails together. So, it plays an important role in train operation. Non-insulated audio frequency(AF) track-circuit device can separate the rails into tracks by insulated joints without physically cutting the rails. And it transmits AF signals at track boundary, of which frequency is different between adjacent tracks. It has been employed at station-to-station section of domestic high speed rail, general rail, and subway. But It was not used at station yard of complicated general railway where lots of branches exist. In this paper, we consider current development status of non-insulated AF track-circuit device for the use of station yard.

• 전기학회논문지
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• 제60권6호
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• pp.1146-1151
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• 2011

There are two methods for train control in information transmission by using track circuit system and installing wayside transmitter. Information signal is transmitted to the on-board antenna by using rails. Continuous information about train intervals, speed and route is received by on-board antenna in AF track circuit system. The information signal is included with carrier wave and received by magnetic coupling in the on-board antenna. Therefore, it is important to define standard current level in the AF track circuit system. When current flowed to rails is low, magnetic sensors are not operated by decreasing magnetic field intensity. Hence, SNR is decreased because electric field intensity is decreased. When the SNR is decreased, there is the serious influence of noise upon demodulation. So, the frequency of information signal is not extracted in frequency response. Thus, it is possible to happen to train accident and delay as the information signal is not analyzed in the on-board antenna. In this paper, standard energy density is calculated by using Parseval's theory in UM71c track circuit. Hence, detection time of information signal is presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1701-1706
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• 2007

Jointless AF(Audio Frequency) Track Circuit is more comfortable than exist joint track circuit. This electrical circuit's function is detection train on rail, and transmit information between wayside and vehicle. 'Korea Railroad Corporation' proposed for revision of the Korean railway standards(KRS SG 0038-06 R, 2006.5.16) "Non-insulated AF Track Circuit". This proposal equipment developed to extend use for station of National Railway exist line. According to test standards Korean railway safety law and its ordinances, which were committed to Korea Railroad Research Institute, the professional committee 'Railway facility sector II' have helded on January in 2007. In this investigation, the changed test norm will be review the difference of important function test standards of new version to conform effectivity and safety test procedure according to the KS A 1025.

• 한국철도학회논문집
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• 제13권5호
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• pp.500-503
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• 2010

지금까지 궤도회로는 레일을 전기회로의 일부로 사용하여 열차의 위치 검지용으로만 사용하였으나 철도차량이 고속화 되면서, 지상신호의 한계를 극복하기 위하여 차상신호시스템의 사용이 일반화 되어가고 있다. 궤도회로의 전원은 직류나 고전압 임펄스를 사용하던 방식에서 가청주파수를 사용하는 고주파 교류궤도회로의 사용이 일반화 되고 있다. 철도도상도 환경과 궤도의 유지보수성 개선을 위하여 철근콘크리트 도상의 사용이 증대되고 있다. 철근 콘크리트 도상에서 고주파 교류궤도회로를 사용할 경우 도상의 내구성 향상을 위하여 사용되는 수많은 격자모양의 철근들로 인하여 전기적 절연에 의한 누설전류가 아닌 자기결합에 의한 손실로 인한 궤도정수의 변화를 초래할 수 있다. 본 논문은 철근콘크리트도상에서 AF(Audio Frequency)궤도회로를 사용하였을 경우 도상 철근에 의한 궤도회로신호의 영향과 손실을 시뮬레이션을 통하여 알아보고 이를 방지할 수 있는 방안을 제시하였다.

• 전기학회논문지
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• 제60권3호
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• pp.552-559
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• 2011

There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials of spray on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of the coating material of spray, researches are required about variation of flux density and resistivity by using the coating material of spray. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity and resistivity in the AF track circuit. Standard permeability of the coating material of spray is proposed. Also, standard resistivity of the coating material of spray is presented by analyzing short current.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1656-1662
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• 2010

Automatic train control systems are divided into ATC, ATP and ATS systems etc. The ATP and ATS systems offer discontinuous information for train control. While the ATC systems provide continueous information for train control. There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of ceramics, researches are required about variation of flux density by the ceramics. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity in the AF track circuit. Standard permeability of ceramics is proposed by analyzing the variation of magnetic field intensity. It is demonstrated by using Maxwell and Matlab program.

• 전기학회논문지
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• 제58권2호
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• pp.308-313
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• 2009

This paper presents a reliability analysis of S-bonds for AF track circuits, which detect train movement and transmit a speed control signal to the train. Field survey shows that S-bonds are exposed to very large vibrations transferred from rail, and suffer from frequent failures when they were installed on ballasted track. We collected the time-to-failure data of S-bonds from the maintenance field of Seoul metro line 2, and made a parametric approach to estimate the statistical distribution that fits the time-to-failure data. The analysis shows that S-bonds have time-to-failure characteristics described by Weibull distribution. The estimated shape parameter of Weibull distribution is 1.1, which means the distribution has constant failure rate characteristics like exponential distribution. The reliability function, hazard function, percentiles and mean lifetime are derived for maintenance support.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3594-3599
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• 2009

경부고속선에서 사용하는 열차제어시스템은 ATC, IXL, CTC로 분류되며, 열차 속도 제어 및 간격 제어에 관련된 ATC 정보는 UM71 AF 궤도회로와 BSP Loop를 통해 지상에서 차상으로 전송된다. 궤도회로를 통해 전송되는 정보는 주로 열차 운행에 직접적인 영향을 주는 운영 정보로 구성된다. 특히 BSP Loop를 통해 전송되는 정보는 터널, 차축온도 검지장치, 또는 절연구간과 같이 특수한 선로변 환경에 대해 추가적인 정보 전송을 필요로 하는 구간에서 사용된다. 본 논문에서는 경부고속선 개통 이후부터 현재까지 기존선과 고속선 연결 구간에서 주로 사용되는 UM71 AF 궤도회로의 BA형 동조 유니트 특성을 기준값과 측정값을 비교하여 분석하였다. 이러한 분석을 통해 BA형 동조 유니트가 설치된 구간의 궤도회로 장애와 같은 문제 발생시 원인규명 및 유지보수를 보다 쉽게 이룰 수 있을 것이다.