• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.99-103
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• 2013

In this paper, research on the thermal analysis method is reported for the characterization of heat generation while operating an Interior Permanent Magnet Synchronous Motor (IPMSM) for railway vehicles. Efficient cooling of the heat generated in the IPMSM is important because the excessive heat generated from the winding, core and permanent magnets increases the difficulty of continuously operating an IPMSM over long time periods. Therefore, in this study, in order to analyze the heat generation characteristics of the IPMSM for advanced research in the application of IPMSMs to cooling devices, the heat transfer coefficients for each component of the IPMSM were derived and the thermal equivalent circuit was configured to perform thermal analyses. Finally, the validation of the suggested thermal analysis method was performed through comparison with the heat experimental data of an IPMSM prototype.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1442-1447
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• 2006

Recently, According to rapid advancements in railway system and IT have enabled manless operation in urban transit system. Futhermore, development countries have been tried to develop unmaned operation system for reliability, safety, efficiency, and some ones already adopted. In this paper, we define system requirements and functionalities, and establish the system scenarios to handle the various accidents/faults in manless operation environment.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.535-542
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• 2002

This paper show communication network scheme problem for the railway is solved which were electrical noise and line break in wayside using rerouting communication line, Considering the availability and the maintainability based on the reliability in design of communication networks. At first, Self-Healing Ring algorithm is suggested in that solution which is satisfied with above requirements. And also, in the advanced type, Dual Master scheme is suggested that the problem which is occurred in line break of both main and sub line at the same time can be solved using DMSHR(Dual Master Self Healing Ring). Therefore total reliability in railway system is going to be advanced using DMSHR scheme.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.489-497
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• 2016

The rail fastening system, which provides a structural connection between the rail and the sleepers, is a main track component that plays an important role in retaining the rail gauge within acceptable tolerances, as well as in passing the train load to the roadbed through the sleepers. In this paper, a modal test was first performed to evaluate the dynamic characteristics (e.g., natural frequency) of the clips of the railway fastening system under the condition of rail corrugation in urban railway operation. The corrugation-induced passing frequency was then compared with the natural frequency of the clips to investigate any resonance effect during train passage. Furthermore, a field test under train passage was conducted to measure the accelerations on the rail and the rail fastening clips as well as the strains on the rail fastening clips in the rail corrugation condition. The field measurements indicated that the accelerations on the rail and the rail fastening clips have a close relationship with the rail corrugation, but they had a minimal effect on the strains of the rail fastening clips.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1418-1422
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• 2006

The project of advanced urban transit system development is developing the advanced vehicle and the core technologies for the cost down by system change, the transport safety and the environmental friendliness and the improvement of passenger service. The product data management system is installed for management of each project. Various data and informations producted from each project are made for database. Therefore, we develop the product data management system.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.376-380
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• 2012

A study on the iron-loss reduction of 110kW-class Interior Permanent Magnet Synchronous Motor (IPMSM) for Light Railway Transit (LRT) is conducted. In general, the iron loss of IPMSM depends on the characteristics of core material and non-oriented electrical steel is used as a core material of IPMSM. In order to reduce the iron-loss of IPMSM, both non-oriented electrical steel and grain oriented electrical steel are applied as core material. Iron loss of 110kW-class IPMSM can be reduced approximately 40% comparing to an existing IPMSM by applying grain oriented electrical steel to the stator teeth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.331-336
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• 2005

A lot of manufacturing knowledge and method have applied to increase manufacturing efficiency in industry field. DES(Discrete Event Simulation) is one of solution to deal with manufacturing problems in factory. Beginning of research, old maintenance system of KNR ( Korea National Railroad) and its technical problems are basically investigated. KNR has maintained railway vehicle with their own solution based on experience. Very advanced railway vehicles such as KTX (Korea Train Express) and TTX(Tilting Train Express) will be difficult to maintain with their old maintenance method. In order to apply knowledge of DES, maintenance field of railway must be considered. Imaginary maintenance machine are selected to variable of DES. Maintenance capability of each machine will be evaluated base on imaginary data from imaginary machine. The machine could be very expensive as well as difficult to replace. Target of research is minimization of number of machine in railway workshop. So basic knowledge of discrete event simulation is introduced. Then five essential stages of discrete event simulation are provided. Each maintenance case defined as event. Each event is discrete and simulated base on different case such as one maintenance line with one machine and one maintenance line with two machines in railway workshop. simple maintenance method, discrete event simulation, will be come out very powerful in complicate maintenance system and will be helpful to reduce maintenance cost as well as maintenance labor.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1168-1173
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• 2004

Bridges and tunnels mainly compose the structural system of Kyung-bu high-speed railway in Korea and the prestressed concrete box girder bridges are applied for the most part of bridge structures. Precast full span construction method was practiced in the construction of many prestressed concrete box girder bridges in Kyung-bu high speed railway for the high quality, great construction speed, low construction cost and construction safety. However, there have been no application of this method in continuous bridges until now. Therefore, a new advanced precast full span construction method is developed using pre-tensioning for precast and post-tensioning in alternating the simple span into a continuous bridge system. since the high-speed railway trains can cause dynamic problems in a continuous bridge. This study shows the structural behavior and the construction process of the new advance method.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.252-256
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• 2003

Smart materials can adapt to changes of environment like living organs in nature such that they can maximize the performance and minimize the maintenance expense of engineering systems. Such materials have been paid attention ten years ago and applied in the area of industry, aerospace, transportation and civil structures. This paper summarizes smart material technology and shows some application examples in railway vehicles. Also, its future of smart material technology in railway vehicle technology is envisaged based on its possibility and practical aspect.

• Journal of the Korean Society for Railway
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• v.3 no.4
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• pp.219-228
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• 2000

This paper presents an advanced approach to simulate AC electric railway system in steady-state. The algorithm consists of two parts. One is circuit modeling of elements of electric railway system, the other is an analysis on electric circuit. The modeling procedure has two steps, in the first step, proposed is the modeling method which is considered to be an internal impedance of the autotransformers and mutual impedances between the feeding systems. For the load(locomotives) modeling which is the second step, improved results are obtained as application to the proposed constant power model compared with constant impedance model. In the analysis on electric circuit, a generalized analysis method using the loop equation has been proposed and there is no limit in the number of trains between the ATs. In addition, the computer simulation by the proposed model was practiced. Simulation result seems very reasonable. It is therefore concluded that techniques for the electric circuit modeling and analysis have been established. Accuracy of the techniques will be further investigated.