• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.57-63
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• 2007

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Fire Science and Engineering
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• v.22 no.1
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• pp.93-98
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• 2008

Full-scale fire extinguishment tests were conducted to develop loaded stream fire extinguishing systems for protecting underground transmission cables. The dimension of test mock-up was 5.5m height${\times}3m$ width ${\times}6m$ length, and six 154kV OF cables were piled up. Gasoline was used to ignite cates. Linear heat detection cables were installed on top of 154 kV OF cable and discharge nozzles were installed on the top and sidewalls, respectively. As a result, both surface fires and deap-seated fires were extinguished successfully within the specified 3 minutes by discharging loaded stream agent.

• Explosives and Blasting
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• v.16 no.3
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• pp.25-34
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• 1998

This area is covered in Andesite of high compression strength and located in PUSAN SEO-KU. There are many old houses around shaft site. So, we must have a cautious blasting operation. A total of 40 blasts were test at DAE-SHIN Shaft site to study the magnitude and frequency characterization of blast-induced vibration. The effect of viblating frequency on structual damage and site-specific scaling to define th empirical equations were also discussed. The result can be summarized as follows: 1. Some empirical equations were obtained. $V=K\{{\frac{D}{W}}1/3\}^{-n}$ where the values for n and K are estimated to be -1.407 to -2.202 and 643.3489 to 7283.2104 respectively. 2. Dominant frequencies at short distance are in the range of about 75.0 to 91.8 Hz, with some exceptions of about 50Hz, Frequencies observed at long distance are in the range of 10 to 2Hz. It is apparent the shift of dominant frequency down to lower levels at long distance.

• International Journal of Safety
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• v.7 no.1
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• pp.21-25
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• 2008

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154kV dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in l54kV power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method (FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.768-769
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• 2011

대용량 수도사업장 고압(6.6[kV]) 비접지 방식의 전력계통 사고는 3상 단락에 비해 1선 지락 사고가 대부분을 차지하고 있다. 1선 지락사고 발생 시 건전상 상전압이 $\surd$3배 상승하고, 공진현상 발생으로 수십배의 전압상승도 일어날 수 있으므로 운전 중인 전력기기 보호를 위해 신속한 지락점 제거가 필요하다. 그러므로 본고에서는 A,B 사업장 펌프기동반의 지락사고 발생을 분석하여 이를 토대로 비접지 계통의 지락보호협조에 대하여 학습하고자 한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.500-508
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• 2011

In the distribution systems, the maximum power transportation capacity is restricted within 40MW based on two lines, because of the thermal current limit of a distribution line. Recently it has been continuously required to expand the abilities of the power transportation in distribution systems, as the number of large scale industrial complexes and distributed generations are growing. In this paper, we suggested the five alternatives combining two methods, laying the two bundle lines and adding another voltage between the 22.9kV and 154kV in distribution systems. This paper implemented the economic evaluations of proposed alternatives from national and customer perspectives. And then we compare the results with those of 154kV transmission system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.146-147
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• 2007

초전도체는 일반도체와 달리 직류 전류 인가 시에 저항이 발생하지 않지만 교류 전류 인가 시에는 히스테리시스에 의한 교류 손실이 발생한다. 이러한 초전도 선재를 이용하여 제작한 초전도 변압기에서 발생하는 교류손실은 변압기의 효율 감소 및 온도 상승으로 인해 초전도 변압기의 안정성을 저하시키는 요인으로 작용한다. 본 논문에서는 외철형의 구조를 갖는 154 kV급 5 MVA 고온 초전도 변압기를 YBCOCC 선재를 사용하여 설계하였다. 또한 2차원 수치해석을 통해 YBCOCC 선재의 자화 손실을 계산하고, 이를 154 kV급 5 MVA 고온 초전도변압기의 권선부에서 발생하는 수직 방향의 자장에 적용하여 변압기의 교류손실을 계산하고 그 결과를 나타내었다.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.333-336
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• 1997

In generally, the TMj is widly used for the 154KV underground system. However it has been many trobles such that working time, quality. In this paper will discuss our first successfull service experience in KOREA. And practical results and experience gained from the electrical tests on site test.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.150-154
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• 1993

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.56-59
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• 2020

Porcelain insulators are typically exposed to surface discharge and lightning impulse in service. This study investigates the insulation characteristics of the external and internal discharges of a porcelain insulator with respect to its flashover for a 154 kV transmission line. The experiments are also conducted using a wet flashover test and an impulse test based on the external discharge and the internal penetration, to classify the flashover voltage-time curve of the porcelain insulator. When an impulse with a strength of 2,500 kV/㎲ was applied three times to 6.5 mm ceramic samples, electrical penetration of approximately 70% occurred. The impulse experiment confirmed that the electrical penetration inside the porcelain insulator coincided with the area where the electric field was concentrated. The wet flashover voltage test revealed that the flashover threshold voltage increases by approximately 7% after cleaning of the surface.