• 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.

• 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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• 제62권4호
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• pp.584-590
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• 2013

Depending on the operating characteristics, track circuit is installed for the purpose of control directly or indirectly of the signal device, point switch machine and other security device. These are mainly used for train detection, transmission of information, broken train detection and transmission of return current. Especially, the return current is related to signal system, power system and catenary line, and track circuit systems. It is one of the most important component shall be dealt for the safety of track side staff and for the protection of railway-related electrical system according to electrification. Therefore, an accurate analysis of the return current is needed to prevent the return current unbalance and the system induced disorder and failure due to an over current condition. Also, if the malfunction occurred by the return current harmonics, it can cause problems including train operation interruption. In this paper, we presented measurement and analysis method at return current and it's harmonics by train operation. By the test criteria, we evaluated for safety. Hereafter, it is expected to contribute to the field associated with it.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1264-1269
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• 2008

We designed a track circuit of Tag in-tag out type that can be used for light rails and monorails. This method is called RFID-Tag and it literally uses RFID-Tag and replaces a fixed track circuit and implements a moving block. The distance between RFID-Tags is set to the length of a train and thus a train is always in contact with one of the tags. A train runs in RFID-Tag in -RFID-Tag out type at all times and the distance between trains can be precisely controlled through the application of a moving block combined with the basic principle of a fixed block, which enables the continuous speed control and enhances the satisfaction of passengers. When constructing a track circuit using RFID-Tag the Tag in-tag out brings us the cost reduction and is more economical than the existing fixed track circuit in that sense and easy for installation and maintenance. The wireless communication between onboard and wayside makes the continuous control possible and can improve the control capacity of ATP/ATO by the implementation of a moving block on top of a fixed one.

• 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.

• 한국통신학회논문지
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• 제42권5호
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• pp.1110-1116
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• 2017

동작 특성에 따라 궤도회로 장치는 신호기 장치, 선로전환기 및 기타 안전과 관련된 장치의 직접 또는 간접 제어를 위해 설치되며, 주로 열차의 검지, 지상에서 차상으로 제어정보 전송, 궤도 깨짐 검지 및 귀선 전류 전송에 사용된다. 특히 귀선 전류는 신호시스템, 전력시스템 및 전차선 및 궤도회로장치와 관련이 있다. 신호시스템에서 가장 중요한 구성 요소 중 하나인 귀선 전류는 선로변 유지보수자의 안전 및 전철화에 따른 철도 관련 전기시스템의 보호를 위해 적합하게 처리되어야 한다. 따라서, 과전류 상태로 인한 귀선 전류 불평형과 시스템 유도 장애 및 고장을 방지하기 위해서는 귀선 전류의 정확한 분석이 필요하다. 또한, 귀선전류 고조파에 의해 오동작이 발생하면 열차 운행 중단 등의 문제가 발생될 수 있다. 본 논문에서는 이러한 귀선 전류 측정 및 분석 방법을 제시하고 고속열차 운행에 따른 호남고속철도 노선에서의 귀선전류 고조파 시험 결과를 제시하고 있다.

• 한국산학기술학회논문지
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• 제16권9호
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• pp.6214-6220
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• 2015

열차위치 검지시스템에는 일반적으로 궤도회로장치가 거의 100여년을 안정적으로 사용되어 왔으나, 일반철도 구간의 역 구내, 측선, 해안선 구간 및 열차운행 빈도가 적은 지선 구간의 건널목 등에서는 녹 발생으로 궤도회로 단락불능에 따라 해소방안이 필요하다. 국내에서는 고속철도의 차축온도검지시스템과 통신기반열차제어시스템 분기부 일부에 차축카운터시스템이 사용되고 있으나, 해외의 경우 많은 국가에서 차축카운터 시스템이 없는 간선 및 지방 철도를 상상하는 것은 이제 불가능하고 지하철, 전차, 그리고 산업철도에서 상당한 증가가 확인되었다. 본 논문에서는 일반철도 구간의 역 구내 측선의 본선 및 분기부에 시험적용을 위해 기존 설치되어 있는 궤도회로와 병렬로 설치하여 로그분석을 하여 차축카운터시스템의 동작상태를 확인하였다. 그리고 오봉기지역 및 청주역 운행선 상 설치하여 연동장치와의 인터페이스 시험 및 이를 실용화하기 위한 시험결과를 분석하고, 시스템 안전측 설계, 제작 및 시스템 요구조건 등을 정립하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.737-747
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• 2011

5678SMRT has installed various sensor for operating conditions(field of electric, facilities, signal, communication equipment and track) and environment of Every Function Room for remotely detecting and monitoring. Installed sound sensor for analyzed after remotely heard the noise of every equipment at Every Function Room and temperature sensor for check the temperature condition of Every Function Room. Additional installed voltage sensor in signal equipment room for monitoring RF track-circuit's voltage condition. Installed displacement sensor at The Chungdam bridge's railway for measuring and monitoring track displacement caused by temperature change and Pan/Tilt camera at sub-station and drainage for remotely field monitoring. Installed sensor for each equipment's operating condition and failure at Every Function Room then periodic check of workforce turned to around-the-clock surveillance by sensor therefore improvement of operating equipment. SMRT is lots of prevent a failure by Immediately detect of precondition of equipment failure by analyzed the sensor data. If the occurrence of an failure, become detected Immediately so possibility correct diagnosis and order by remotely field check by installed camera and sound sensor at field.

• 전자공학회논문지B
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• 제31B권3호
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• pp.53-59
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• 1994

A new fully differential sample-and-hold circuit which can effectively compensate the offset voltage of an operational amplifier and the charge injection of a MOS switch is presented. The proposed circuit shows a true sample-and-hold function without a reset period or an input-track period. The prototype fabricated using a 1.2$\mu$m double-polysilicon CMOS process occupies an area of 550$\mu$m$\times$288$\mu$m and the error of the sampled ouput is 0.056% on average for 3V input at DC.

• 전기학회논문지
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• 제64권12호
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• pp.1659-1665
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• 2015

In general, AT(Auto-transformer) is used to improve voltage sag and inductive interference in power lines and communication lines in AC electrical railway feeding system. Especially, Korean AT feeding system has different composition compared to other countries like Japan or France, so that it has some special characteristics. However, relays imported from other countries have been used in Korea, and settings of these relays should be modified and reflect distinct characteristics of Korean AT feeding system. Therefore, study about fault analysis based on modeled AT feeding system is important. In this paper, we modeled a single track AT feeding system by using PSCAD and analyzed fault current flow in case of trolley-rail short circuit fault. Finally, we presented current magnitude of each branch expressed by boosting current of AT.