• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.5
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• pp.477-485
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• 2010

In this study, we suggested several approaches to evaluate the collision acceleration of a carbody under the article 16 of the Korean rolling stock safety regulations. There are various methods to evaluate the rigid body accelerations such as the displacement comparison method by double integration of filtered acceleration data, the velocity comparison method by direct integration of filtered acceleration data, and the analysis method of a velocity-time curve. We compared these methods one another using the 1D dynamic simulation model of Korean high-speed EMU composed of nonlinear springs or bars, dampers, and masses. From the simulation results, the velocity-time curve analysis method and the displacement comparison method are recommended to filter high frequency oscillations and evaluate the maximum and average accelerations of a carbody after a train collision.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.300-310
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• 2008

Through this study, a conceptual design for the next generation high-speed EMU has been derived to meet the crash worthiness requirements of the Korean rollingstock safety regulation. The crashworthiness regulations require some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 km/h, and a collision against a standard deformable obstacle of 15 ton at 110km/h. The complete train set will be composed of 2TC-6M with 13 ton axle load, which is different from KTX with the power car of 17 ton axle load. Using theoretical and numerical analyses, a crashworthy conceptual design was derived in terms of mean crush forces and energy absorptions for principal crushable structures and devices. The derived conceptual design was evaluated and improved using one dimensional dynamic simulations for the bar-spring-damper-mass model. It is shown from the simulation results that the suggested conceptual design can easily satisfy domestic crashworthiness requirements.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2198-2199
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• 2011

The sliding door and plug door are the main types of door system in the EMU(Electric Multiple Unit). The sliding door is widely used in Korea but has weak point in the noise problem. In the low operation speed, the noise coming from outer side of the EMU is not an important factor. As the speed is higher than before, noise is increased and make an issue. The main cause of noise is the imperfect air tightness in the EMU. The plug door system has advantages for the noise reduction characteristic in the high speed area. Actually the noise level is an important factor for the passenger comfort. In this paper, we will describe the characteristic of electric plug door and functions of sub component.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.239-242
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• 2005

This paper introduced an approach of improvement of performance of Electric device for EMU type Train like as TTX. The electric equipments are characterized by insulation, Noise, cooling system etc. and Their weight arc decided by these factors. There are two kinds of power source in EMU train. First, DC voltage source, 1500 volt, 750 volt is used for subway system. Second, AC power source 25000 volt is applied to high speed train and existing main lines. Composite material has the protection of inrush current and high frequency noise. We can use this material to minimize weight of train. Additionally we can get energy saving when operator service TTX.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.307-313
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• 2011

Hyundai Rotem Company has designed and manufactured the next generation high speed EMU bodyshell (M3-car). Korean Railway Safety Law specifies the loads vehicle bodies shall be capable of withstanding, identifies what material data shall be used and presents the principles to be used for design verification by analysis. Therefore, in order to fulfill the structural requirements, Hyundai Rotem Company has carried out Finite Element Analysis (FEA) and static load test to verify whether the carbody structure has enough strength to withstand the loads specified by Korean Railway Safety Law. This research contains the results obtained by the FE analysis and static load test. The FE analysis is carried out using NX I-DEAS 6.1 and specially designed test jigs and equipment are used for the load tests.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1873-1877
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• 2010

In the high-speed EMU, the modularized traction converter produces the significant harmonic currents caused from the switching behavior of a power converter. These harmonic currents bring the interference among the traction equipment. One way to minimize the interference is to design the secondary windings of a power transformer decoupled magnetically as possible. This paper presents a magnetic field analysis on a winding disposition to clarify an impact on magnetic decoupling between secondary windings, under a limited height of a train. Two winding dispositions for a single-phase shell-type transformer are constructed and simulated by a three-dimensional finite elements method (FEM) model. Two different winding dispositions are constructed and simulated by three-dimensional FEM model using Maxwell3D.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1182-1187
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• 2008

In this research, studied were performance improvements of the power conversion system for the high speed EMU. The object of this research is separated into two parts ; the one is the analysis of the designed transformer and the other is the switching improvement of a parallel PWM converter. The multi-outputs of a transformer must be balanced. However, the output of transformer is interfered and unbalanced in practical operation. To solve these problems, the electromagnetic analyzing model of a transformer is used to minimize the output interference. Also, the improvement of converter switching can reduce the unbalanced output and harmonics.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1995-2005
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• 2008

Recently, the smart sensors and USN (Ubiquitous Sensor Network) technologies are emerging. Smart sensors add the capability of storing local temporary data, processing instant operations, transmitting information outward, to the simple sensing devices. The USN is a wireless network of sensor/smart sensors that can collect data anywhere anytime and exchange the data within the network. In this research, case studies are performed on the smart sensors and USN applications. The cases were grouped in four categories, domestic private, domestic public, foreign private, and foreign public. Based on that survey, promising applications will be proposed and developed to be implemented to the next generation high-speed EMU.

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.235-243
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• 2005

Line constants of the catenary system are estimated. The harmonic current that the Korean Train Express (KTX) injects into the catenary is measured to precisely analyze the harmonic effects. The Korean high-speed railway system is modeled by estimated and measured results. The system model is applied for predicting the harmonic effects. The simulation results from the system model are compared to field test data concerning the total harmonic distortion (THD). The reliability of the system model is verified.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.259-264
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• 2009

This paper proposes a real-time estimation of the boost inductance in a single-phase AC/DC parallel PWM converter for high-speed EMU. The estimation procedure of the boost inductance is only based on the variation of input current and the input AC voltage measurement. The estimated boost inductance is optimized by the least square method. This estimation technique can improve the performance of current controller and reduce the harmonics of the input current in the feed-forward controller. The validity of proposed technique is verified through the MATLAB SIMULINK simulation results.