• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1694-1700
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• 2007

In the electrified section, both of return current and signal current are flowing in the same rail in common. But signal current shall be allowed to flow in the specific track circuit and not in the other circuit while the traction return current shall come back to power sub-station. This paper presents measuring system that use both sensor and antenna. The aim of the system is to achieve the difference in current between the two rails and the presence of trimming capacitors. In order to improve the transmission level, trimming capacitors are connected between the two rails at constant spacing. To maintain the balance of traction return current, rails of both sides may be jointed by the so-called SVPMM. The traction return current is sometimes unbalanced owing to the ill-contact of SVPMM. In this paper, we propose a diagnosis method based on a short-circuited current(Icc), trimming capacitors and traction return current measured by Korail inspection vehicles. Whether Icc is good or bad depends not only on the presence of trimming capacitors but also on the unbalance of the traction return current.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2319-2344
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• 2010

Accumulated deficits resulting from managing the Korean Railroad and debts from the construction of the KTX (Korea Train Express which is a high-speed rail system) have left the Korean Railroad faced with great troubles. Since it changed into a public corporation Korail on January 1st, 2005, the Korea Railroad has been making unceasing efforts to overcome the troubles and improve its management. However, even these efforts haven't worked in the face of the improved conditions of other transportation methods such as better networks of land roads and air ways. The Korea Railroad had its revenue from its railway transportation limited, and has tried to expand its business to non-transportational areas. In some metropolitan cities, the Korea Railroad made investments in real estate by constructing station buildings based on private money. Yet, in small and medium size cities, the Korea Railroad has little particular strategic projects for business development. Recently certain small and medium size regional cities began to plan on business developments for the ex-railway land, and some small towns have developed real estate on the ex-railway land. Nevertheless, there have been no systematic case studies to classify these real estate developments.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.933-941
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• 2010

KORAIL has improved profitability through abolition of nonprofitable route and withdraw rolling stocks, operated at that route. as a part of that process, most sections of commuters' train are gone. presently, gyeongui-line and gyeongwon-line's commuter's trains are operated. Despite the abolition, there are demands for commuters' train. so, nonprofitable route operation policies are needed to meet the demands and connect seamlessly to KTX. In this study, we consider the overall operation policies and problems of commuters' train in the past. and then, we analyze foreign nonprofitable route, connected with high speed train, operation policies and search for the development suggestions for applying to the nonprofitable route between Iksan - jeonju section at Honam and joenra line.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.719-728
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• 2007

Recently the assurance of railroad safety is very important issue in KOREA because there are lots of changes in the railroad industries. The Railway Safety Act was established in order to cope with these changes effectively and prevent the railroad transportation accidents. According to this law, Korea Transportation Safety Authority (KOTSA) has been entrusted with 'Integrated Railroad Safety Audit (IRSA)' and has implemented the safety audit to the railroad operation agencies such as Korea Railroad (KORAIL) and the railroad facility management organization such as the Korea Rail Network Authority (KR Network). The target of IRSA is to establish the effective rail safety management system and to raise the safety level of the railroad operation and facility agencies by checking synthetically their performance of safety duties with sincerity according to the Railway Safety Act. The purpose of this paper is to improve the efficiency of IRSA by the comparative research between IRSA and other similar safety audit system. To study the efficiency of IRSA, we investigated the rail safety audit systems of EU system specially France, England where the big changes have happened for the rail operation concepts and Japan where government entity control the railroad safety. The international standards of Occupational Health & Safety Assessment Series (OHSAS 18001), Quality Management System (ISO 9001) and Guidelines for Quality and/or Environmental Management Systems Auditing (ISO 19011) are investigated.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.965-968
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• 2007

Two major parameters, i.e. carbon dioxide ($CO_2$) and particulate matters smaller than $10{\mu}m\;(PM_{10})$, were selected as the index pollutants in managing indoor air quality. The former pollutant, $CO_2$, is the index that shows the ventilation status and is exhaled by passengers when they breathe in train or subway. It is generally known that high $CO_2$ concentration in the vehicle may be decreased by insufficient air-tightening vehicle bodies and the air is ventilated when vehicles stop at the station and doors open. However, there is no established proof or quantitatively identified data on how much the $CO_2$ concentration is reduced when ventilation is done while doors are opened. In this study, $CO_2$ concentrations were measured in 6 lines of Korail and one line of Seoul Metro subway linesand a theoretical approach was takento predict the changing trend of $CO_2$ concentrations during the operation of vehicle by using $CO_2$ dilution factor through natural ventilation. As a result, the change could be quantified and it was found that app. 35% of indoor $CO_2$ was removed through natural ventilation.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1223-1228
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• 2007

Since KHSL 2nd phase was adapted as a main track design, the interests of concrete slab track system have been gradually increased in the division of rail track engineering and many engineering companies have been trying to adapt a concrete slab track system at this moment. Advantages of this system proved in advanced country, japan and Germany etc. are excellent maintenance, track stability and increasing of buckling resistance This developed turnout is same with the KHSR 1st phase's design and applications rules, components and signaling system since it observes KTX specification. Comparing it with the former turnout, High-elasticity pad, lubrication-free roller slide plate and Rheda2000 PC sleeper are only different. The purpose of this study is the development of high speed turnout on concrete slab track and its application on site. Now these studies are going to show the verification and confidence about the interface between ballast-track and concrete slab track by finding and solving the possible problems when it is installed on site and to make these turnouts applied perfectly and completely on concrete slab track. Its first trial construction in korea had been successfully completed at Sangju-station on July 20th ,2007 thanks to KORAIL and KR. Hereunder Sampyo E&C trys to introduce all of turnout technologies on concrete slab track system with Rheda 2000 sleeper

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1370-1376
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• 2015

Generally, an autotransformer(AT) feeding system consists of double tracks, up and down, with the trolley wire and feeder wire of the up and down tracks connected in the sectioning post(SP). Consequently, load current or fault current flows on two tracks based on catenary impedance characteristics, making it difficult to estimate catenary impedance accurately. This paper presents a technique for the estimation of catenary impedance using boosting current compensation based on the current division characteristics of an AT feeding system to improve the operation performance of impedance relay. To verify the technique, we model an AT feeding system through a power analysis program (PSCAD/EMTDC) and simulate various operation and fault conditions. Through the simulation, we confirmed that the proposed technique has estimated catenary impedance with a similar degree of accuracy to the actual catenary impedance

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1609-1610
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• 2015

국내 철도 변전소의 부하전력은 부하인 철도차량의 부하특성에 의해 고조파와 역률이 매우 좋지 못한 실정이다. 이러한 이유에서 철도변전소에는 고조파를 보상하기위한 고조파 저감설비와 역률을 개선시키기 위한 역률보상용 콘덴서와 같은 전력품질개선설비(FACTs) 들이 설치되고 있다. 본 논문에서는 이러한 철도차량 부하의 차량별 고조파 특성을 살펴보고, 이를 효과적으로 제어할 수 있는 방법을 제안하였다. 제안된 알고리즘은 고조파저감설비의 위상제어를 통한 역률 향상을 도모하기 위한 것으로 일반적인 밴드패스 필터를 사용한 고조파 전류성분 검출에 따른 제어방식과 달리 고조파 전류에 대한 Lyapunov 안정도에 기반을 둔 제어방식을 적용하여 빠른 전류제어 동특성을 같도록 제안하였고 시뮬레이션과 실 부하 계통에 설치하여 운용함으로 그 타당성을 입증하였다.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.512-517
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• 2009

Extruded aluminium panels have been widely used for railway vehicle structures because -of their light specific weight and other merits. In the past, GMAW (Gas Metal Arc Welding) and GTAW (Gas Tungsten Arc Welding) were mainly used to join aluminium panels. But recently friction stir welding (FSW) is widely used due to its lots of advantage. In this study aluminium A6005 which is used for car body structures was chosen. The influences of main parameters on mechanical properties such as: pin (tool) rotating speed, pin transition speed, shoulder, diameter, pin length and tilting angle were examined. Optical microscope and scanning electron microscope (SEM) observation, micro hardness tests, and tensile tests were carried out.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2139-2144
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• 2008

There are eight kinds of railroad vehicles such as KTX, PP(Push-Pull), NEL(New Electric Locomotive), EL(Electric Locomotive), DL(Diesel Locomotive), CDC(Commuter's Diesel Car), VVVF(Variable Voltage Variable Frequency) and Resistance Control Car that Korail corporation presently runs, and a variety of vehicles just like EMU(Electric Multiple Unit) and DMU(Diesel Multiple Unit) currently developed and accepted are running in the near future. However, There is still no design standard of the control stand of cockpit and the same compatibility of forms and control unit arrangements for locomotive engineers because no one has tried to approach in an ergonomic way. It can cause Locomotive engineers to make errors using the machinery. when the new vehicles are adopted, The efficiency of operation will quite fall down due to the separate training of the engineers. Therefore, We'd like to improve the accuracy of manipulating the machinery used by the engineers at all times according to the design standard of ergonomic technology and safety engineering and increase the operational efficiency and the safety of railroad vehicles in order to handle the problems as quickly as we can in an emergent situation.