• Journal of Advanced Marine Engineering and Technology
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• 제38권1호
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• pp.70-77
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• 2014

In this work, we studied basic characteristics of transmission lines employing various PSS (periodic strip structure) on silicon substrate for application to a miniaturization of RF components. According to the results, the transmission lines employing various PSS showed wavelength shorter than conventional coplanar waveguide due to their strong wave characteristics. Especially, with-contact structure was most effective for a miniaturization of RF component. Concretely, the size of the transmission line employing with-contact was only 4.39 % of the conventional coplanar waveguide, According to the bandwidth extraction result, the bandwidth of the transmission lines employing various PSS structures were wider than 384 GHz. Above results indicate that the transmission lines employing various PSS can be effectively used for application to a broadband and miniature RF component, and especially, with-contact is most effective for a miniaturization of RF components.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제26권7호
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• pp.646-655
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• 2015

The purpose of this study was to evaluate the perceived distance from home to high-voltage power lines using a transmission and substation geographic information system(TGIS). Of the 725, 136 respondents reported that high voltage power transmission tower, power lines or substation was within visual field range from home. Among them, 114 respondents reported valid address, which could be used in the analysis of TGIS. Forty two respondents(36.8 %) estimated that the power lines were closer and 15 respondents(13.2 %) estimated that they were farther than they actually were. Our current findings suggest that the reported distance from home to high-voltage power transmission towers, power lines, and substations cannot be used as a proxy for exposure to electromagnetic fields due to the low validity.

• KEPCO Journal on Electric Power and Energy
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• 제4권2호
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• pp.115-123
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• 2018

Various types of robots running on power transmission lines have been developed for the purpose of line patrol monitoring. They usually have complex mechanism to run and avoid obstacles on the power line, but nevertheless did not show satisfactory performance for going over the obstacles. Moreover, they were so heavy that they could not be easily installed on the lines. To compensate these problems, flying robots have been developed and recently, multi-copter drones with flight stability have been used in the electric power industry. The drones could be remotely controlled by human operators to monitor power distribution lines. In the case of transmission line patrol, however, transmission towers are huge and their spans are very long, and thus, it is very difficult for the pilot to control the patrol drones with the naked eye from a long distance away. This means that the risk of a drone crash onto electric power facilities always resides. In addition, there exists another danger of electromagnetic interference with the drones on autopilot waypoint tracking under ultra-high voltage environments. This paper presents a patrol monitoring plan of autopilot drones for power transmission lines and its field tests. First, the magnetic field effect on an autopilot patrol drone is investigated. Then, how to build the flight path to avoid the magnetic interference is proposed and our autopilot drone system is introduced. Finally, the effectiveness of the proposed patrol plan is confirmed through its field test results in the 154 kV, 345 kV and 765 kV transmission lines in Chungcheongnam-do.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.155-158
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• 2004

This paper presents a CPW patch antenna with $\lambda/2$ CPW transmission lines. Through the full-wave simulation and the equations of gap capacitance, the dimensions of the CPW transmission lines and resonance circuit components are extracted. Using extracted dimensions, we designed and implemented CPW patch antennas in the range of frequency of 5GHz.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• 제3권2호
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• pp.3-9
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• 1992

The reponse of the angled two-strip transmission lines illuminated by an external electromagnetic field is estimated by using the circuit concept approach. Calculated terminal voltages reveal convergence to a fixed value as the number of discretization increases. The amplitude patterns of two terminal voltages to all the direction and polarization of the incident field are also calculated.

• Proceedings of the KIEE Conference
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.255-257
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• 2003

The reliability of power transmission lines depends on long-term performance of the suspension insulators used on the lines. The importance of such long-term performance of the insulators has been recently noted, but its evaluation method has not been established yet. In this paper, various causes of insulator deterioration are verified and laboratory test method for evaluating the long term performance of insulators are studied.

• Journal of the Korean Institute of Telematics and Electronics A
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• 제33A권5호
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• pp.65-74
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• 1996

in this paper, the propagation characteristics of the dominant modes in multiple coupled microstrip lines on a magnetized ferrite substrate are analyzed. The propagation constants and characteristic impedances are calculated by using the spectral domain method. With the numerical results, multi-port impedance parameters as well as scattering parameters are derived from nonreciprocal transmission line equations which are consistent with conventional transmission line theory. In additon, the numerical resutls of nonreciprocal characteristics for various values of structural, material parameters, and external magnetic fields are also presented.

• Journal of the Korean Society of Safety
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• 제12권1호
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• pp.44-50
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• 1997

As jumpers for overhead transmission lines increase In size, it Is necessary to take into the characteristics of jumper swaying space in order to determine jumper reinforcements adequately. From the theory of a structure made of beams, formulas for the sideway swaying of overhead transmission lines due to wind are modeled. And also natural frequency of the vibrated jumper is estimated to check the system resonance. The theoretical results can be led good suggestions to improve the economy and reliability of jumper structure.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제32권5호
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• pp.170-175
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• 1983

A simplified method for the estimation of lightning performance of transmission Lines is described. Only one stroke current wave shape was used and the potentials of tower top and crossarms were computed at the two time points to obtain the critical stroke current for insulator flashover. Variation of the critical stroke current due to power frequency voltage was also takes into account. An applied example on 345KV Line model was shown and the calculated result was compared with the estimating curve suggested by Clayton & Young.

• Proceedings of the KIEE Conference
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1734-1736
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• 1997

Insulator strings can be frequently damaged by fault currents occured by lightning strokes, overvoltages and contamination of the insulators. So the Insulator damages may lead to extensive damages to transmission lines as well as power outages that have caused dangerous situations to occur. This paper suggests the characteristics of arcing horn in relation to the protection of insulators and basic design concepts of the arcing horn for transmission lines.