• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1187-1192
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• 2003

The railroad noise has been considered as one of environment pollution and complaints about it have been increasing every you. Therefore, the establishment of railroad noise monitoring network is necessary. It will be designed for monitoring railroad noise, storing data of railroad noise continuously and providing the fundamental knowledge for the measures of railroad noise. For this, we investigated the actual condition of railroad noise and status of noise level by floor in apartments around the capital region, Daejeon, Daegu, Gwangju, and Busan. Additionally, we present the basic data that will be used for predicting the noise level near railroad in the environmental impact assessment

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1295-1297
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• 2002

This paper describes the pantograph design result for tilting train at conventional railway. EMU(Electrical Multiple Unit) Tilting Train is important tilting pantograph. Tilting train pantograh should be operated to commercial service speed 180Km/h of 200Km/h at KNR upgrade railroad. This specification pantograh tested using catenary-panto dynamic simulation

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1069-1070
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• 2008

At the coupling area linking high speed line and conventional line, according to distance between trains due to speed limit of conventional line, the power load of substation supplying to this conventional line increase. At the coupling area between Kimcheon SS and Kyoungsan SS, train operation have problems caused by instantaneous voltage drop. So, this paper propose evaluation method of maximum load capacity at current normal feeding condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1176-1181
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• 2003

As the delay of the Kyungbu High Speed Railroad, HST should use conventional line through Daegoo to Pusan until the new railroad build. High speed railroad noise is one of the main causes of environmental impact. Whenever HST on conventional railroad line is planned or HST service into the urban center is proposed, an estimate of the relevant noise levels is usually required. For this, it is necessary to quantify those parameters that affect the railroad noise. This paper deals with an estimation of high speed railroad noise in urban center.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.128-136
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• 2005

The reinforcing subgrade, which first introduced Korea for the highspeed subgrade construction, has the many advantages to maintain the quality of ballast track as well as to prevent the softening of subgrade by mud-pumping. It causes the subgrade soil to spout into the ballast on many lines. Therefore, the application of reinforcing subgrade will be expected to increase in the future. This paper introduces the reinforcing subgrade as a maintenance-free technology f3r the railroad operation and the method f3r the determination of reinforcing subgrade depth. The criteria on reinforcing subgrade depths of highspeed and conventional railroad were verified from the calculation results based on an elastic analysis method.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.627-632
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• 2005

The reinforcing subgrade has the many advantages to maintain the quality of ballast track. It has also the function to prevent the softening of subgrade by mud-pumping. Therefore, active application of it is being expected for the future constructions of Korean railroad. In this paper, behaviors of the reinforced subgrade applied to conventional railroad were investigated through 3-D numerical analyses. The applicability of the reinforced subgrade to conventional railroad was evaluated by analyzing the distributions of the settlements and vertical stress of reinforced subgrade.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1173-1177
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• 2004

The high investment is necessary for the new high speed lines. So the KRRI was interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The tilting train system has been developed because the reconstruction of railway for the cant compensation costs very high. The purpose of the tilting system is to compensate the centrifugal acceleration in order to reduce the lateral acceleration of the passenger at high speed on the curves.The pantograph of the tilting train is indispensable in order to supply the electrification equipments with power in safe. The dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force and the contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the active control of pantograph and presents the LQ-servo controller to reduce the contact force variation.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.357-361
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• 1998

A new current controlled PWM technique for a 3-level inverter has been proposed and described in the paper. The proposed current control has the simple structure without needing to calculate the switching angles of the voltage vectors. The output in the proposed inverter contains less harmonic content than that of a conventional current controlled PWM controller, since the current control can be applied to the 3-level inverter. In addition, the proposed current controlled PWM technique has lower switching frequency than that of a conventional current controlled PWM technique at the same current limit. The control method and the performance for a proposed 3-level inverter has been discussed and investigated by the computer simulation.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.592-596
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• 2005

This study analyzed changes of train operation between Seoul~Cheonan after the introduction of new electrified rail in 2005. As expected number of passengers were reduced at specific service section and several railroad stations which were served by the Mugunghwa. Also, the statistic shows that passenter demand concentrated in a specific time, so train service frequency and level of service need to be modified to meet with changed demand pattern. The purpose of this paper is to identify critical demand pattern, especially, in several section of the railroad system. This studies provide a railroad transportation system that is significantly more efficient, with far greater capacity, by providing solutions to the problems of congestion impact.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.202-203
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• 2007

Induction Motor is important at tilting train. Tiling train induction motor should be operated to commercial servicespeed 180km/h at Korea Conventional Line upgrade railroad. As the induction motors are without commutators, maintenance is easy and it is far lighter than the conventional motors with the same capacity. The induction motor, however, posed problems in use as its motor torque is not large enough compared with DC motors. With the recent advances in power semiconductors, it is possible to apply the induction motors to trains by applying VVVF inverter control method to the traction motor. In this study, we realize the stable measurement AC motor temperature characteristic of TTX train.