• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.207-210
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• 2004

In oil-filled equipment such as transformers, partial discharge or local overheating will make insulating material(oil, kraft paper, proclain and wood) be stressed and generate many sort of gases($CO,\;CO_2,\;H_2,\;C_2H_4$) which are dissolved in transformer oil. The ratio of this gas can make diagnostic tecchniques of the lifetime of transfomer so, it is important to monitoring $H_2$ gas continuously. This paper developes a system of detecting about $H_2$ gas by using $H_2$ gas sensor, and we describe operation and performance of this system

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.574-574
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• 2005

To found out the degradation characteristic of transformer insulation, insulation material was depisited into transformer oil and heated. Due to the thermal stress which added to insulation, the density of carbon dioxide which included in transformer oil was mesured by using the gas density detection equipment of gas sensor and air circulation method. As a result, it didn't match with the transformer supervision standard. But it was found that as thermal stress increased, the density of carbon dioxide propertionally increased.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.10
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• pp.523-529
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• 2004

Faults of cellulosic insulations greatly affect the life span of oil immersed transformers because their performance recovery is impossible. Therefore, the reliable diagnosis technologies are needed for detection of the faults. Dissolved gas analysis technologies using CO and $CO_2$ gases have been widely used for fault diagnosis of cellulosic insulations. In this research, we described Degradation diagnosis of insulation paper CO and $CO_2$ gases in oil immersed Transformers using. We considered the distribution characteristics of CO, $CO_2$ gases' concentrations and ratios of $CO_2$/CO not only in serviced transformers but in experiments with typical fault causes such as heat, partial discharge and moisture. As result, the reliability of diagnosis results for the cellulosic insulations can be improved when the concentrations of CO, $CO_2$ and the ratio of CO/$CO_2$ satisfy each diagnosis criterion at a tim

• KEPCO Journal on Electric Power and Energy
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• v.3 no.1
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• pp.23-28
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• 2017

The life management technology becomes important as the failure risk of the aged power transformers increases. Asset management technology, therefore, has been developed to evaluate the remaining life and build replacement strategies of power transformers, which enables an optimal investment decisions based on reliability and economic feasibility. The remaining life assessment technology uses data related to such as installation, operation, maintenance, refurbishment, and disposed history of power transformers. The optimal investment decision additionally uses data related to failure and social costs. To develop the asset management technology in power transformers, it is important to find deterioration parameters directly indicating degradation of power transformers. In this study, 110,000 DGA data during the past 35 years have been analyzed in order to find the deterioration parameters related to the degradation of power transformers. The alarm rates of combustible gases ($H_2$, $C_2H_2$, $C_2H_4$, $CH_4$, $C_2H_6$), TCG CO, and $CO_2$ were analyzed as deterioration parameters. The origin of the gas was discussed in connection with discharge, overheating and insulation aging.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.137-138
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• 2008

가스절연변압기(GITr)는 우수한 절연내력과 높은 신뢰성을 장점으로 가지고 있기 때문에 운전 시 유지 보수가 불필요하도록 설계목표를 정하여 제작되고 있지만, 제작과 운전 단계에서 치명적인 결함이 발생할 수 있고, 이러한 결함들은 전력기기 사고의 원인이 될 수 있다. 따라서 사고발생 전 단계에서 대규모 전력 사고의 발생 요인 중 하나인 전력기기 내부의 결함에 대한 상시 진단 및 원인 분석이 반드시 선행되어야 하며, 이와 같은 진단 분석 기법의 하나로 전력 기기의 내부 결함의 위치 판별에 대한 연구의 필요성이 절실히 요구되고 있다. 따라서 본 논문에서는 일반적으로 Cubicle 구조체 위치의 판별에 사용되는 기법 중 하나인 상변측정법(Trilateration)을 적용함으로써, GITr Mockup(170kV 급)의 세 개의 센서를 이용하여 결함에서 발생되는 부분방전 신호를 3차원적으로 분석하기 위한 연구를 위해 3개의 센서가 구성하는 평면상에 인위적 결함을 위치시켜 결함의 위치를 2차원적으로 분석하는 연구를 수행하여 약 5cm 오차 범위 내에서 결함을 판별하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.5
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• pp.206-212
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• 2005

In this paper, criterion and algorithm for on-line dissolved gas of a Power transformer are studied. For the initial diagnosis of a power transformer, the on-line dissolved gas analysis is one of the most important and acceptable item to preventively diagnose a power transformer. But the criterion and algorithm of this item are not established yet in korea. In this paper, criterion and alarm level of the on-line dissolved gas analysis are based on the analysis of on-line data of operating transformers, Korea industrial standard and operation manual for a power transformer as well as accumulated data of the preventive diagnosis systems which have been operated at nine substations of Korea Electric Power Co.(KEPCO) since 1997, Therefore, the criterion and alarm level proposed in this paper are to be well suitable and are adaptable for the domestic operational environments and conditions of the power transformer. Considering that the conventional diagnosis system is capable only of accumulating and monitoring data of the power transformer operation, the criteria and the algorithms make it possible to accomplish an ultimate goal of the preventive diagnosis system. It is expected, therefore, that they will have a beneficial effect on broad applications of the preventive diagnosis system and the achievement of manless substation system in the future.

• JOURNAL OF ELECTRICAL WORLD
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• s.310
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• pp.67-72
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• 2002

미쓰비시(삼릉)전기 플랜트건설총괄부의 전력플랜트 건설공사는 수력$\cdot$화력플랜트 및 변전설비를 대상으로 하고 있으며, 수차$\cdot$수차발전기$\cdot$가스절연개폐장치(이하 ''GIS''라 한다), 변압기, 배전반 및 관련 제어기기 등의 설치 및 기기간의 배선공사 설계$\cdot$시공을 담당하고 있다. 최근의 전력플랜트를 둘러싼 일본의 시장환경은 신설 플랜트는 감소하고 갱신$\cdot$기기개수(개조, 수선) 공사의 비율이 커지고 있으며, 신설$\cdot$개보수 공사를 불문하고 공사품질의 유지와 공사비 저감을 위한 공법$\cdot$작업의 개선과 설계$\cdot$계획 업무의 합리화를 추진하여 왔다. (1) 기자재 개발에 의한 공법$\cdot$작업 개선 대형수력발전기의 로터조립용 다브테일키 박아놓기(타입)장치, 스테이터코일 분해(갱신)용 코일 엔드절단 및 코일뽑기공구, 터빈발전기 센터링용 유압잭, GIS 설치용 작업용발판을 개발하여 적용함으로써 공법 개선과 작업효율의 향상을 실현하였다. (2) 공사계획 방법의 개선 변전플랜트에서의 공기단축을 목적으로 하는 현지 설치 최적공정 책정방법의 개발$\cdot$적용, 또한 화력플랜트에서의 공사물량의 저감과 설계작업의 효율 향상을 목적으로 하는 케이블 배선 설계$\cdot$계획 방법의 개발 및 적용으로 설계업무의 개선, 공사비 저감을 도모하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.12
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• pp.578-584
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• 2005

This paper describes development of management software for transformers based on artificial intelligent analysis technology of dissolved gases in oil. Fault interpretation using the artificial intelligent analysis is performed by the artificial neural network and a rule based on the analysis of dissolved gases. The used gases are acetylene($C_{2}H_{2}$), hydrogen($H_2$), ethylene($C_{2}H_{4}$), methane($CH_4$), ethane($C_{2}H_{6}$), carbon monoxide(CO) and carbon dioxide($CO_2$). This software is mainly composed of gases input, fault's causes, expected fault's phenomena in detail, the decision on maintenance as well as report and gas trend windows. It is indicated that this is very powerful software for the efficient management of oil-immersed transformers using data analysis of gas components.

• Proceedings of the KIEE Conference
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• 2006.07e
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• pp.43-44
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• 2006

Characteristics of hydrogen sensors for realization of transformer diagnosis system was studied, sensors used in this work are commercialized for detecting hydrocarbons or hydrogen gases. Based on the experimental results, the sensing characteristics of A company showed the high value even at the lower concentration of 20ppm, and it showed a saturation tendency with increasing it above 500ppm. In the case of B company, it showed the linear characteristics from 20ppm to 7000ppm. In addition, the output acquired from C company was amplified by external circuits due to its low output, and its adequate operation region was above 500ppm. Therefore, it is likely that these sensors are possible to apply for realization of transformer diagnosis system due to the different sensing characteristics of these sensors.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.8
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• pp.6-14
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• 2006

This paper is a study about a proper method of plasma generation to cleaning method and a high frequency power equipment circuit to generation of plasma that used cleaning of chamber for TFT-LCD PECVD. The high density plasma required for cleaning causes a possibility of high density plasma more than $1{\times}10^{11}[EA/cm^3]$. It apply a ferrite core of ferromagnetic body to a existing ICP form. In case of power transfer equipment on 400[kHz] high frequency to generation of plasma it makes certain a stable switching operation in condition of plasma through using a inverter form for general purpose HB. And it demonstrates the performance of power transfer equipment using methods of measurement which use a transformer of series combination the density of plasma and the rate of dissolution of $NF_3$ in condition of $A_r\;and\;NF_3$.