• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.243-248
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• 2009

The operation of KTX in Korea has launched since 2004, which brought about a great change in railroad industry. We have acquired lots of great know-hows, especially in railroad construction and operation field. Therefore, we have been building up numerous operation skills until now. However, it was necessary to investigate some of the equipment based on our own environment because the high speed train system were totally imported. In case of Toughened Glass Stem Insulator, it was totally new type in domestic. This paper introduces estimation method and result in three different field aspect, such as an electrical field, a physical field, and environmental circumstances. First, in case of an electrical field, amplitude and a number of time for switching surge voltage data were collected. Second, in case of a physical field, amplitude and trend of vibration in to the insulator were examined. Finally, in case of environmental circumstances, flying possibility of gravel and ice clod were investigated. Also shrink and expend characteristic according to temperature were reviewed. Through this basic data, suitability for Toughened Glass Stem Insulator using in domestic high speed railway have been accumulated and estimated.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.468-479
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• 2016

In order to supply power to online monitoring systems that are attached to high voltage catenary or overhead wires, a wireless power transfer system is required that is able to transmit power over the insulation gap. Such wireless power transfer systems have transmitter and receiver coils that have diameters of over 10cm. This paper focused on an investigation of the sources of loss in the coils when the coils are fabricated using printed circuit board technology. Using finite element simulation results, it has been shown that the dielectric loss in the substrate was the dominant source of the total loss. It has been demonstrated that the selection of a proper dielectric material was the most critical factor in reducing the loss. For further reduction of the loss, the distributed tuning capacitor method and the slotting of the inter-turn spaces have been proposed. For the evaluation of the proposed methods, four coils have been fabricated and their equivalent series resistances and quality factors were measured. Measured quality factors were greater than 300, which means that these devices will be helpful in achieving high coil-to-coil efficiency.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.906-911
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• 2006

Since railway system has been developed, the interface system which is interfaced with various sub-systems of railway including rolling stock, SIG, COM, catenary system came out more complicated and mixed-up. For the purpose of improving the management techniques about interface system among the sub-systems of railway, this paper proposes method of management by using of SE(system engineering) that makes structure of data system through describing and separating the user's requirements, functional analysis and interface of the train control system in its degree. This study is focused on the ATC signaling sub-system, a important part of SE, to analysis of the system.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.291-295
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• 2005

This paper presents the modeling of grounding system on Korean electric railway system. The system model is composed of the catenary system, the grounding-system, the sub-sectioning post, the fault point, the sectioning post, the autotransformer in the substation, and the electric vehicle. The increment of rail-ground voltage may be thought as an amplifier of danger on human body of equipment insulation. The rail-ground voltage on steady state and on fault condition should be under standard limit voltage. To analyze grounding system for steady state and fault condition on Korean railway, modeling for each railway system is performed by 10-port network model. Modeling and analysis of present grounding-system are important to protect human and electronic equipments. The examinations for systematic grounding-system are investigated.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.82-92
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• 2011

This paper presents a PFC(Power Factor Correction) system to control the power factor of input current of the converter system which is working in the propulsion system of KTX high speed train. In the KTX train system, initially introduced from ALSTOM, the thyristor converter with phase controlling technique is adopted in the current fed type powering system. The input current induces harmonic losses highly because the waveform becomes rectangular shapes according to the filter inductor current increased as the train speed increasing gradually. Especially the interference with the signalling systems is severe concerned due to high current harmonics on the catenary line. To protect this problem, a frequency trap filter(notch filter) is operating with the input converter system. In this paper, an analysis work and PC simulation have been done on the PFC system to upgrade its performance and maintenance efficiency.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.754-760
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• 2011

In the DC traction system, a large load current of electric railcar leads to a voltage drop when a vehicle starts, and the regenerative power generated by brake system increases the catenary voltage. To minimize the voltage fluctuation during the train operation and make use of the regenerative power, several types of energy storage systems are being studied. The energy storage system that is being recently introduced consists of the supercapacitors for energy storage and the bi-direction DC/DC converter for charge/discharge control. The efficiency of the energy storage system depends on the train operation pattern. In this paper, the operation efficiency of the energy storage system was quantitatively analyzed via simulation study taking consideration of the train operation patterns. The simulation was conducted changing the headway of trains with the energy storage system that uses the bi-direction DC/DC converter and supercapacitor. The simulation results showed that the operation efficiency of the energy storage system increases as the headway increase.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.342-348
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• 2015

In this paper, fuel cell power generation system that is being studied in recent railway field was applied to compensate for the voltage drop due to the load as driving electric vehicle. PSIM simulation program is to be used to implement the modeling of the electric railway for AC AT feeder system. For it, It was applied to the product-type single-phase PLL algorithm, step-down converter is controlled as power so as to have the fuelcell generation system. Based on it's result, a reactive power due to the catenary impedance in accordance with the current flowing is compensated as linked with fuelcell generation system which supplied the current to the power supply grid. and then its performance was confirmed that voltage compensation effect obtained at SubStation (SS), SubSectioning Post (SSP), Sectioning Post (SP).

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.71-74
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• 2005

At the neutral sections, There are neutral sections inserted in overhead contact line between the substations to divide different phase current sections of AC electrified lines. except convention line, a large stress occurs in the contact wire near the fittings under passing pantographs. So, in order to raise the train speed over 150km/h, a new type section has been adopted.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1161-1162
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• 2007

In year 2004 korea runs high speed train KTX for the 5th time in the world. And now the traction power system is quite stabilized. But still a lot of work to develop and abnormal voltage problem is one of them. In this paper, by actual measuring we have collected the abnormal data on the high speed train sub-staion for more than 15 days. The collected data has been evaluated. In the near future collected data will be used planing a countermeasure.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.241-248
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• 1998

The purpose of this study is to evaluate the harmonics generated from Korea High Speed Rail's trainset and to analyze the effect on the KEPCO power system. This study focuses on the test track of the high speed rail and analyzes 154㎸ transmission line, scott transformer, autotransformer and 27,5㎸ line. The trainset is modeled as a harmonic source attached to the catenary line of the test track. Then, harmonic distortion is calculated. This distortion is compared with the KEPCO's regulations in relation to harmonic.