• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1105-1111
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• 2007

Because forest fire can give a serious damage to overhead conductors, the thorough understanding about aging behavior of burned conductor is very important in maintaining the transmission line safely. Therefore, a systematic investigation was carried out by heating method. As the heating temperature increases, drastic change of tensile strength of Al wire due to the softening of Al wire occurred. When Al wire is exposed to the flame(about $800\;^{\circ}C$) during only 13 seconds, the remained tensile strength of Al wire showed under 90 %. The detailed results will be given in the text.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.534-535
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• 2007

Because forest fire can give a serious damage to overhead conductors, the thorough understanding about aging behavior of burned conductor is very important in maintaining the transmission line safely. Therefore, a systematic investigation was carried out by heating method. As the heating temperature increases, drastic change of tensile strength of Al wire due to the softening of Al wire occurred. When Al wire is exposed to the flame(about $800^{\circ}C$) during only 13 seconds, the remained tensile strength of Al wire showed under 90%. The detailed results will be given in the text.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.566-569
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• 2018

A power line coupler that can apply high-frequency power to a railway overhead line structure was analyzed. It is difficult to supply auxiliary power to an overhead line in a high-voltage environment, and doing so requires a long-distance transfer. A method is proposed that utilizes the resonance on the Rogowski coil, which does not use a magnetic core. A simple overhead line structure was fabricated that consisted of a contact wire, messenger wire, and dropper. Couplers of various sizes were fabricated and deployed on the messenger wire, and the transfer characteristics of the two couplers were compared at a distance. As a result of applying the matching circuit to the coupler, the transmission efficiency was 53% at a distance of 2.5 m. The proposed method shows that it is possible to apply the auxiliary power by using the existing conductor in a special structure, such as the overhead line.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.518-518
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• 2008

We propose an optical-based measuring instrument of catenary system in electric railway. This system was made to utilize line scan camera as inspecting system to measure the stagger and height of overhead contact wire in railway and composed with optical type source and FPGA-based image acquisition system with PCI slot. Vision acquisition software has been used for the application to programming interface for image acquisition, display, and storage with a frequency of sampling. The proposed optical-based measuring instrument to measure the contact wire geometry shows promising on-field applications for online condition motoring. Also, this system can be applied to measure the hight and stagger or other geometry of different type of overhead catenary system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.740-744
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• 2017

Overhead Line is divided by two systems which are OCS (Overhead Catenary Line) and R-Bar (Overhead Rigid Conductor system). R-Bar has an advantage of maintenance and economic aspect comparing with OCS. R-Bar in Korea has developed for the max. speed of 120km/h, but it is evaluated up to the max. speed of 250 km/h in Europe. There are lots of mountains and underground sections in korea, it is really necessary to develop the R-Bar for a high-speed line. In the study, design parameters for the max. speed of 250 km/h of R-Bar was proposed. A bracket space, stiffness, and especially an installation tolerance of contact wire height at a bracket were considered as a parameter, and a dynamic behavior between a contact wire and pantograph was predicted by evaluated FEM simulation tool. The installation tolerance and bracket space are more important for the high-speed system. The proposed parameters was decided very conservative. Because the aerodynamic characteristics of a pantograph in tunnel is more severe than an open route and the simulation tool is not considered the such kind of aerodynamic characteristics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.474-481
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• 2013

It is anticipated that AC distribution system can be replaced by DC distribution system in the near future because of the operation of various distributed source or microgrid system. However DC distribution system replacing 22.9kV AC distribution line is not sufficiently studied still. This paper describes lightning overvoltage analysis among many research fields should be studied to realize DC overhead distribution systems. DC distribution system is modeled using EMTP and overvoltage is analyzed according to interval of arrestor location, earth interval of overhead grounding wire and grounding resistance. It is evaluated that analysis results can be effectively used to design of future DC distribution system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.886-890
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• 2013

Uplift of contact wire and dynamic characteristics between pantograph and contact wire are key interaction performance of OCS (Overhead Catenary System). These two evaluation items are the approval criteria for the performance between OCS and pantograph. A telemetry system or DAQ (Data Acquisition) System based on wireless communication make it monitor a dynamic behavior which is measured directly in a 25 kv like parts. While permissible working time is too short time to install is too long. In this paper, it is described that optimization the telemetry measurement system for OCS and increasing accuracy, easy adaptation, and faster handling can be also achieved through the study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.531-532
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• 2006

This paper presents the implementation of Real-time data acquisition system for dynamic characteristics of overhead contact wire in electric railway. The reconfigurable field-programmable gate array (FPGA) and LabVIEW graphical development tools have been used to Real-time monitoring system. The results from a field test show that the proposed technique and developed system can be practically applied to measure the assessment quantity or quantities on overhead contact lines for the online real-time process monitoring.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.482-487
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• 2013

The new recycling technology for aged aluminum wires in overhead conductor have been carried out. We are attempting to develop remanufacturing method for them for more effective way of recycling in stead of its conventional remelting process. The drawing process of aged aluminum wires play a role in remanufacture process. Drawing process was performed under lubricant. The speed of drawing was between 500 m/min and 1,000 m/min. These machines have 11 or 12 dies house for breakdown of the feedstock. Material of the die is tungsten carbide and they have generally 25% reduction ratio. The paper investigates the mechanical properties during drawing process of aged aluminum wire. The results of tensile tests and microscopic analysis were discussed to underscore the hardening features of drawing aluminum wire. Various graphs are presented accompanied by discussion about their relevance on the process.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.932-939
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• 2011

This paper deal with technique of tension length calculation for 350km/h high speed catenary system. Tension length affects in facility investment. Possibility of overlap increasing a tension length and the equipment investor decreases in order to decrease. Considers the parameter which specifies and the grudge which is possible long the fact that decides a tension length is the aim which is important plans overhead contact line. The element which decides a tension length with next following; (i) Operating range of tension device, (ii) Change of the horizontal tension which affects possibility of the effect which operates to the line and span, (iii) Tension of wire material the tensile force which is relation, (iv) Wire thermal expantion which relates with a standard temperature, (v) Curve radius, (vi) Wind velocity, (vii) Thermal range of overhead contact wire and mechanical design of tension mechanism etc.