• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2143-2145
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• 1999

Measurements of wind noise, generated by High-voltage overhead transmission lines placed in a uniform flow are carried out in the Anechoic windtunnel. High-voltage overhead transmission lines generates audible wind noise, which cause a serious environment problem. Accordingly, wind noise has become one of major concerns for design engineers and operations personnel. In the present research, tests were mainly performed with various configuration of transmission line with spiral wires. Remarkable noise reduction was observed for some of the spiral transmission lines, compared with the noise generated without the spiral wire.

• Journal of Magnetics
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• v.21 no.1
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• pp.102-109
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• 2016

In this paper, the theoretical and experimental characteristics of magnetic and electric fields in the vicinity of high voltage lines are investigated. To realize these measurements and calculations, we have developed some equations for two overhead power line configurations of 150 kV (single circuit, double circuit), based on Biot-savart law, image and Maxwell theories, in order to calculate the magnetic and electric fields. The measurements were done to a maximum distance from the tower of 50 m, at a height of 1m from the ground. These experiments take into consideration the real situations of the power lines and associated equipment. The experimental results obtained are near to that of the Biot-Savart theoretical results for a far distance from the tower; and for a distance close to the power line, the results from the image theory are in good agreement with the experimental results.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.421-426
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• 2003

Dropper which can get to suspend contact wire should be installed with a uniform distribution, so that electric locomotive can have good characteristics of current collection. Because dropper distribution is changed according to a circumstances in the construction field, it is hard to calculate and construct a overhead line. Therefore, in this study, a program was developed to calculate the dropper length in the normal and elevation section. Through the program, it is possible to perform a accurate construction of overhead line and contribute to a improvement of current collection as well.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.724-729
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• 2005

Winter weather condition can cause icing and ice coats on 25 kV overhead contact wire. This generates shocks at the mechanical interface of the collecting strips of the pantograph and the contact wire and extra electrical resistance, which may affect quality of current collection at the contact wire / collecting strips of pantograph interface. De-icing operations should he performed just before train operation to avoid the formation of another ice layer. Thus, the work in this paper is investigation and analysis of de-icing system which could be applied to the electric car line of railways.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.189-195
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• 2012

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.294-301
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• 2008

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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.871-879
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• 2008

Recently, as there are a rise in the standard of living and higher concerns of an electromagnetic wave and environment, undergrounding the aerial cables which are supported by large pylons and generally considered as the least attractive feature of an urban area is on an increasing trend to improve aesthetic benefits and electric reliability. This study applied Contingent Valuation Method (CVM) which is expected to become an effective tool to measure indirect benefit to estimate the substantial benefits of undergrounding overhead power line projects in an urban area. The tunneling construction project of the 345kV Shinsungnam electric power cable in Seongnam city was selected and a hypothetical scenario was given to respondents to determine their levels of Willingness to Pay (WTP) for undergrounding overhead power lines. The result from the estimation of the WTP of undergrounding overhead power lines in Seongnam city was calculated as approximately 17.1 billion won. Placing existing overhead lines underground is difficult to justify economically. Most undergrounding costs appear to be justified by aesthetic and public policy considerations. Therefore, considering the result of this study, undergrounding overhead power lines is of great benefit to public.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.67-78
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• 2005

In this paper, impedance characteristics of overhead medium-voltage (MV) power line for power line communication (PLC) is analyzed. For analysis, a two-port equivalent network model of MV power lines is derived. By applying the equivalent model and basic transmission line theory, input impedance at the signal induction part is calculated. And also calculated input impedance of power line itself that the medium voltage coupler and coaxial cable effect are removed. For verification, impedance of power lines is measured at a test field for an MV PLC. The results show that impedance of MV power line itself is between $200\;{\Omega}\;and\;300\;{\Omega}$ and converges to a half of their characteristic impedance with increasing frequency. And also measured data is very similar to calculated data.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.510-512
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• 2000

This paper describes the voltage induced at neutral line and the proper location of lightning arrester in combined 22.9 kV class distribution line jointed overhead line and cable each other Modeling is established in ATP Draw to perform simulation. Simulated distribution line at this paper consists of distribution line 4.2km and underground distribution line 2km. Overvoltage and induced voltage are analyzed at several point of combined line. Analysis results was compared to select the best point to install arrester. Such analysis technology will be applied to obtaining capacity and location of arrester in the similar combined distribution line.

• 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.