• Proceedings of the KSR Conference
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• 2005.05a
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• pp.415-420
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• 2005

Korea High Speed Railway of which wheels have been excessively worn during the trial operation prior to opening was additionally applied with solid lubricant besides the existing oil lubricant in order to overcome such excessive wear. Therefore, it was shown that wear status has been improved in the test by which railway system including vehicles and tracks was stabilized during a year's commercial operation, comparing to that with excessive wear in the trial operation prior to opening to the public. In this connection, wheel's wear per mileage was analyzed, based on vehicles in service in order to make out the wheel's wear at present, from which the useful data relating to wheel maintenance could be obtained.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.645-650
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• 2003

Wheel/Rail geometric constraint relationships, such as effective conicity and gravitational stiffness, strongly influence the lateral dynamics of railway vehicles. In general, these geometric contact characteristics are nonlinear functions of the wheelset lateral displacement. There is a need to develop a wheel/rail contact simulation program for wheels and rails with arbitrary profiles for the prediction of the dynamic behavior of railway vehicles. An algorithm to simulate any combination of wheels and rails is employed and a GUI for easy analysis is constructed. The simulation program is applied to KTX which will run on both KTX and conventional rails, two rail standards having different rail profiles. The results show that the two rail systems have different geometric contact characteristic

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.747-754
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• 2003

In this paper, a new evaluation system was developed for ride comfort test and vibration level test on railway vehicles. Combining two tests carried out by different test equipment seperately before, the developed system is capable of ride comfort test and vibration test by one system. Also, the assessment algorithm of ride comfort and vibration was compared and verified by simulation results with VAMPIRE software. With the developed system, the comfort in a passenger coach and the vibration in a freight car were evaluated through field test.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.344-351
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• 2000

Recently, the microprocessor with network function based-controlled systems instead of conventional microprocessors is widely used to industrial applications, and also those technologies are widely adopted for train control and monitoring in modern rapid transit systems such as railway vehicles. The purpose of this paper is to propose a high quality data transmission line of railway vehicle system controlled by a microprocessor, which was designed and realized through SMG 7＆8 and ISA project. Noise, distortion and attenuation are always present in data transmission system and strictly limit performance. This paper describes a method to calculate the propagation constant, attenuation constant, phase velocity and length of stub.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.434-439
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• 2002

The researches on the direct drive system, which directly transfers axle load of the traction motor to wheels, have been developed as a next generation drive system in Japan and Europe. As a result of excluding couplings and gear units, the direct drive system has advantages on the bogie mount space to be smaller sized, lower noisy, more efficient and less weighted than the conventional drive system - indirect drive system. Since the simplification of the direct drive system design depends on the design of the traction motors, the researches on the direct drive system with focusing on the traction motors get started. The advantages/disadvantages of direct drive system, types, structures, cooling systems and interfaces of the traction motors are presented on this paper. Furthermore, the development of other countries on the electric equipments of the next generation railway vehicles are discussed and the necessity ＆ requirement for developing new concepts of traction motors are assured.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.882-887
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• 2014

In this paper, the water cooling method among the forced coolant cooling methods is considered to be applied to the 110kW-class IPMSM for railway vehicles. First, basic thermal property analysis of the IPMSM is conducted using the three-dimensional thermal equivalent network method. Then, based on the results of the basic thermal property analysis, some design requirements for the water cooling jacket are deduced and a basic design of the water cooling jacket is carried out. Finally, thermal equivalent circuit of the water cooling jacket is attached to the IPMSM's 3D thermal equivalent network and then, the basic thermal and effectiveness analysis are conducted for the case of applying the water cooling jacket to the IPMSM. In the future, the thermal variation trends inside the IPMSM by the application of the water cooling jacket is expected to be quickly and easily predicted even at the design step of the railway traction motor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.1-7
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• 2021

In this study, MIG welding was performed on extruded 6005A-T6 material, which is used in the base panel of railway vehicles. The material was considered as the experimental base material, and argon shielding gas and ER5356 and ER4043 filler metals were used as the consumable welding materials. Welding coupons were prepared under various welding conditions by using an auto-welding system that various welding conditions applied 2.5Hz and 4.5Hz the pulse frequency of SynchroPuls function of welding machine and 1.0mm and 1.5mm of root face affect the weld penetration of welding joint. The welding current and voltage were also varied for this testing. On the basis of the results obtained, optimum welding conditions are proposed.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.478-485
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• 2017

Urban DC railways have played an important role in urban transportation, and railway operation and energy management have been emphasized to be important to achieve maximum efficiency from existing infrastructure. Fast, accurate DC railway power flow analysis is required to operate a DC railway efficiently, and this paper proposes a novel methodology to analyze the DC railway power network by implementing the participation factor (PF). The PF concept consists of a correlation between the vehicle and the substation, as explained using zones based on the position of the vehicles running on the route. Then, the DC railway powerflow is calculated using the PF concept. Finally, the usability of the proposed method was validated via case studies with actual railway operation data, and we discuss some of the advantages of the suggested methodology.

• Journal of the Korean Society of Safety
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• v.26 no.6
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• pp.111-117
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• 2011

Risk-based railway safety management has been mandatory in Korea as by relevant laws and regulations enacted since the Railway Safety Act 2004. In particular, the Railway Vehicle Safety Guidance came into effect on Jan 1, 2008 specifies the details of methodology for hazard analysis, risk assessment and safety verification and validation. Fundamentals for success of the risk-based safety management are systematic hazard identification and risk assessment by use of reasonable risk assessment criteria, but the principle of risk-based safety management has not been applied in an effective way to introduction and maintenance of railway vehicle systems because definite risk assessment criteria have not been set down for each railway system or railway network. The purpose of this study is to suggest a risk matrix development principle for risk assessment of domestic urban metro vehicles by analyses of relevant rules and railway operating environment of Korea.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.613-618
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• 2004

Is confirming safety of derailment when wish to develop new vehicles or upgrade running speed of vehicles. This means the measure of wheel load and lateral force that act between wheel and rail. So far, problem in continuous measuring method of derailment coefficient was sensitivity decline and noise growth. This research supplemented these problems by composition of new bridge circuit.