• Proceedings of the KSR Conference
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• 2003.10c
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• pp.467-472
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• 2003

Of those off-road diesel engines, the railroad diesel rolling stocks (RDRS) for passenger and freight transportation become a growing issue since they are emitting enormous amounts of various air pollutants. Furthermore, up to the present time, emissions from these sources are not well controlled. One of main purposes in this study is to develop emission factors for the RDRS and to estimate a total amount of major air pollutants from the RDRS in Korea. Prior to develop a Korean mode emission factor, the emission factor from the USEPA was simply applied for comparative studies. As a conclusion, based on the emissions calculated from both the USEPA mode and the KoRail mode, the RDRS is considered as one of significant mobile sources of major air pollutants including NOx and CO, and thus management plans and control strategies for the RDRS must be established to improve air quality near. future in Korea.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.806-812
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• 2008

Many kinds of rolling-stocks that have various control methods are being operated by Seoulmetro which is a history of a city railroad rolling-stock. Seoulmetro is being faced with a wheel management comparing of other lines with a perpendicular wear of wheel and a side damage, and so on, by operating several cars at a loop line. This is causing maintenance expenses increase and deteriorating a fusibility of rolling-stock, for it has an effect on a rolling-stock using. A cutting pattern of wheel and a wear form affect the expected span of a wheel. A wheel cutting cause is classifed into cutting for reprofiling of a flange wear of wheel and for removing every kind defect which originates from wheel wear. In this study, Seoulmetro exhibit a stable rolling-stock use method and a reasonable management method of wheel, analysing wheel exchange condition and cutting management of wheel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.277-278
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.1033-1034
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• 2010

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1897-1902
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• 2008

The computer system is used in many application domains and any system error in these domains may either cause critical loss or threaten environment or human life. Though examples of these domains can be found in many areas, the system, which is used in domains for carrying passengers including rolling stocks in particular, is expected to show satisfactory operation all the time. The relay control logic, which is used in rolling stocks, is complex in hardware and occupies considerably large volume. Nevertheless, it has been used for a long time, to let the system safely operate even in the occurrence of an error in the computer system. However, the relay control logic circuit is so complex that the analysis of proper circuit operation and interlocking tends to be dependent only on the designer's experiences instead of being systematically performed. Especially, the analysis following a change, addition and deletion of a previous circuit according to the requirements from a source of demand is significantly limited. In this paper, the accuracy of relay control logic is verified by the use of properties of Petri Net model. In addition, how main circuit breaker (MCB) control circuit is modeled and analyzed by the design methodology is shown.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1117-1124
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• 2009

Under frame side sill of rolling stock structure is designed for preventing corrosion in order to meet mechanical requirements. However during long operation time more than 20 years, there are corrosion in the under frame side sill caused by environmental effect, vibration and etc. So, detection and evaluation of the corrosion ill the under frame nondestructive is one of important issues to extend their life time. Most of nondestructive methods are not easy to apply for detecting corrosion in the under frame side sill, since the under frame side sill consist of there layered with different material (stainless steel - stainless steel - mild steel) and each layer is connected by spot weld and plug weld. Fortunately, pulsed eddy current method claimed that it can be measured not only thickness change but also corrosion under their insulation layers. So, in this study, we have investigated performance of pulsed eddy current testing method by measuring thickness variation of fabricate of mock-up specimens. The investigation results obtained from mock-up specimens and the corrosion evaluation results of the aged rolling stocks will be presented.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1357-1365
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• 2011

Reliability analysis-based maintenance system has the merit than elapsed time-based preventive maintenance system. First, it is possible to active handling of rolling stocks failures. In the past, Failure handling activities began when after increase failures rapidly. But if we can continuous manage of reliability than changing of failure tendency can know more quickly. Second, It is possible to using maintenance resources effectively. We can look forward to cost reduction to distributing of much less failures parts's maintenance resources. KORAIL builds reliability system called KTX-RCM for operating high-speed rolling stocks. But existing rolling stocks have not reliability system from the past. Fortunately, KORAIL started ERP system called KOVIS at 2007. KOVIS includes maintenance data for reliability analysis. So in this study analysis failure data for getting reliability number about existing passenger car. And we desire to maintenance connection plan.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1479-1485
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• 2012

The development of a technique for the real-time sensing of a curve section is very important for active rolling-stocks in order to improve the curving performance. However, conventional methods using expensive track inspection equipment or various complex sensors are not practicable to be applied to commercial vehicles. Therefore, we have proposed a new method to estimate the curve radius of a curve section. This method uses the relative displacements occurring between the body and the bogie when the rolling-stock is running on a curve. To verify the validity of this method, we conducted a vehicle dynamics simulation and test using a real vehicle on a test line. The results confirmed the validity of the proposed method. We expect that this method will be effectively applied in studies of active rolling-stocks to increase the curving performance using active control technology.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.38-45
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• 2016

The power transformation system of High Speed rolling stocks like KTX-Sancheon has shown excellent control capacities in the areas of riding comfortability, switching efficiency, safety and energy consumption due to technical developments in power-electronics, high speed & large scale integrated semiconductors and microprocessors. However, harmonics from IGBT, a high speed switching device used in the Convertor & Invertor equipment of rolling stocks have given rise to various problems in transformer substations, signaling systems, data transmission systems and facility monitoring systems. Especially, TI21 non-insulated track circuits have malfunctioned due to the influence of returning current harmonics which were generated at around of integer times of the number of power transformation equipment in the frequency domain. This paper, measures and analyzes various schemes to analyze the traveling path of the returning current harmonics generated due to the relationship between the rolling stocks and track circuits on site. Ultimately, theseschemes will be used to design high speed rolling stocks, AF track circuits and a common grounding network.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1286-1291
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• 2004

This paper was showed evaluation method and technical items for measurement test of new catenary system of Honam(Daejeon - Mokpo) conventional railway electrified. This line have tested by three type new electric rolling stocks in order to test construction quality and operation safety of a new catenary system with speed-up than conventional speed. We have some important experiences through measurement test of catenary system by new device installed on train roof.