• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.197-201
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• 2017

The demand for electric power is increasing every year in Korea. All the systems adopted at power stations in order to generate and transmit electric power should operate in perfect condition or reliability. The device for transmitting the generated high-voltage electric power is 6 kV CV single core cables. The manufacturing companies of the cables makes an official announcement that the operating lifetime of their cables is about 30years. But from the moment of operation the deterioration precesses of worsening the characteristics of cables starts. Since the reliability for the status of installed cables in deterioration has not been diagnosed, the cables can be broken at any unexpected moments. In order to prevent the abrupt cable accident by systematically monitoring the cable status, we have invented the first device in Korea. We have installed our device at Korea Western Power Co. Ltd. in order to diagnose the live cables. In this paper, we present our research results of measured temperatures of inner conductor and surface and the compared results of those data with other cable company. We also show that our results agree with those made by other company.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.239-244
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• 2017

The demand for electric power is increasing every year. All facilities operating at power stations and all facilities used in transmitting high volumes of electric power are therefore expected to operate with a high degree of reliability. 6.6 kV XLPE 100 SQ 1C cables are used to deliver high levels of generated electric power. Depending on the method of manufacture, installation environment, and usage conditions, the deterioration processes of power cables start from the instant of operation. Cable junctions may break down in three years from the start of operation due to manufacturing or construction defects. We have invented the first device in Korea to monitor the status of live cables and installed these at Korea Western Power Co., Ltd.. We have set the criteria to determine deterioration status and specified the degree of deterioration at which one should replace the cables. In this paper, we present the effect of insulation layer and sheath on the insulation resistance status in cables.

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.31-34
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• 2005

The 765kV transmission line will be maintained by live-line works for efficient operation, In order to maintain the 765kV transmission lines safely by live-line works, lineman have to know flashover characteristics of the insulator strings with damaged insulators. This paper suggests flashover characteristics of the 765kV insulator strings from experimental test results directly.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.9
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• pp.1632-1637
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• 2007

This paper analyses current densities induced inside human body of lineman for 765kV transmission line when he wears a protective cloth or not. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 15[cm], 30[cm], 50[cm], and 100[cm] far from a prefabricated jumper. As results of study, we find a maximum current density induced in all organs may be higher than $10[mA/m^2]$ if he does not wear protective clothes. We also know high permeability materials can lower current density more than high conductivity materials.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1239-1244
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• 2011

In our previous paper, we developed an insulator inspection robot system for a suspension insulator string in the 345kV power transmission line. However, this robot cannot be applied to a tension insulator string, because its constituent insulators are different in diameter and height from those of a suspension insulator string. To solve this problem, we developed a new live-line insulator inspection robot system that is applicable to both suspension and tension insulator strings. We confirmed its effectiveness through live-line performance tests.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.271-272
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• 2008

실선로 전력 케이블의 부분방전 측정은 주위 전력설비의 신호들이 혼합되어 검출된다. 본시험에서는 배전전력 케이블을 대상으로 부분방전 신호의 방향 추정 시험을 하였다. 시험 조건으로 모의 선로와 활선 현장선로에서 시행하였다. 2개 HFCT 센서를 사용하여 방전 펄스를 검출하였고 미소신호를 검출하기 위하여 AMP와 필터를 설계하였다. 신호 분석을 위하여 1GS/S의 스코프를 사용하였으며 자동 방향추정 S/W를 제작하였다. S/W의 특징으로는 2개의 채널에서 동일한 펄스의 시간차를 분석하여 방향을 분석하도록 하였다. 센서의 간격이 20CM일 때 약1nS의 시간차가 발생하여 신호의 방향을 추정할 수 있었다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.467-468
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• 2011

모든 설비에는 안전과 설비보호를 목적으로 전기적, 기계적으로 조건이 만족되지 않으면 이후 동작을 금지시키는 장치를 구비하는데 이를 "인터록 장치"라 한다. 일부 인터록장치가 미 구비된 선로에서 근무자의 착오로 사활여부를 판단하지 못하여 활선선로에 접지를 시행하여 대형사고로 이어졌으며 이를 방지하기 위하여 인터록 장치의 설치가 중요하게 대두 되었다. 그러나 송전선로로 연결된 원거리에 있는 설비간의 인터록 구성은 매우 어려운 상황이다 특히 선로의 사활여부를 판단하는 요소는 직접적인 전압을 측정하는 방법이 일반적으로 사용되고 있으나 용도에 비하여 설비구축을 위한 투자비가 과다함에 따라 간편하고 신뢰성이 우수한 인터록 장치를 개발, 적용하였다. 기존의 직접 또는 간접 전압측정 방법에서 상대단 변전소의 단로기 및 접지개폐기 접점상태에 대하여 통신회선을 이용 상호 확인하고 인터록을 구성한 연구이다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.349_350
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• 2009

가스개폐기의 고장을 예방하기 위해서는 열화상태를 진단하여 고장을 일으키기 전에 교체하는 것이 가장 바람직하다. 이를 위해서는 제품의 제조상태, 불량가능성 등 이력사항을 진단하고 활선 진단을 통한 내부 상태를 파악한 후 위험도를 평가할 필요가 있다. 본 연구에서는 국내 배전개폐기의 열화 및 수명인자를 이용하여 개폐기 고장 위험을 예측할 수 있는 기법을 제시하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1295_1296
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• 2009

The authors have published several technical reports on the deterioration of conductor due to forest fire in series so far. This is because even we have been experiencing hundreds of forest fires every year, no systematic research on conductor which is very vulnerable to fire have been fulfilled. This paper describes the sag-tension behavior of conductor under loading current normally when only partial area of a long conductor is exposed to fire. Temperaures of Overhead Conductor were different with measurement position. When the partial area of conductor was heated up to $500^{\circ}C$, 20 % of permanent tension loss was observed. This results in the increase of sag of 1.5 m when span is 300 m. The other results will be presented in the text.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.83-88
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• 2010

A new live-line insulator tester was developed to detect faulty insulators in 154kV power transmission lines. This paper is the first part of the two-part paper and deals with its tester development. The developed tester has the following characteristics. First, it automates parts of the insulator inspection process by using a sensor and an actuator, and secondly, it sustains its weight by itself, not by a lineman. Finally, it measures the insulation resistance of an insulator together with its distribution voltage to provide more information for its analysis and diagnosis. These leads to the improvement of its operation efficiency, measurement reliability and usability. Its effectiveness was validated by live-line field tests in actual power lines.