• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.272-274
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• 2003

Distribution system reliability evaluation estimates by approach methods such as Makove modelling or Monte Carlo simulation, equation of state and failure rate that is on one basic data used to these assessment technique is described as probability of average value. because average failure rate equipment device is aged as time goes by but there is shortcoming that such used failure rate does not evaluate thing which is correct in reliability change hereafter. In this paper, failure rate displayed that apply aging to basis equipment device by passing time using Weibull distribution one of life evaluation method and for express aging of component from utility's failure database.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1800-1802
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• 2003

This paper describes a study on gas dissolved distribution in oil for simulated transformer thermal faults. Experimental chamber was setup for simulation of transformer thermal faults or discharge in oil with or without insulation paper. The experimental results showed that dissolved gases in oil excluding the paper did not evolved upto $150^{\circ}C$. Hereafter the planned gas dissolved analysis will be continuously carried out for transformer fault conditions with or without insulation paper related to water absorption, arc and partial discharge.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.171-173
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• 2003

This paper presents a new fault location algorithm for 3 phase underground cable based on distributed parameter circuit analysis, by which we establish the basic equations for each of core and sheath currents and voltages considering cross-bonding sheaths. The proposed algorithm need simulate by EMTP, and then the EMTP data need be compared with the calculation result in Matlab.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.24-27
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• 2004

This paper proposes a new algorithm of underground cable fault location based on the analysis of distributed parameter circuit. The proposed method firstly makes voltage and current equations for each of cores and sheathes respectively, and then establishes an equation of the fault distance according to the analysis of the fault conditions. Finally the solution of this equation is calculated by Newton-Raphson iteration method. The effectiveness of this proposed algorithm has been proven through PSCAD/EMTDC simulations.

• 한국정밀공학회지
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• 제26권9호
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• pp.96-102
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• 2009

In this study, performs analysis of the life of parallel opening type pneumatic chucks that are usually applied in the factory automation line. Pneumatic chucks have complicated failure cause because they are organized as a complex of various elements. Therefore, we analyzed the main failure mode of pneumatic chuck, and then performed life test and performance test according to the international standards. On the basis of these processes, shape parameter of pneumatic chuk is proposed that is the main factor for the calculation of zero failure test time for the reliability of pneumatic chuck and their data analysis of life distribution.

• 동력기계공학회지
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• 제10권4호
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• pp.127-132
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• 2006

Pneumatic cylinders that are usually applied in the factory automation line have complicated failure cause because they are composed of various elements. In this study, we performed life test and performance test of double acting pneumatic cylinders according to the international standards and then analyzed the life and the main failure mode of the cylinders in the same load condition. On the basis of these processes, we can estimate shape parameter for the reliability estimation of pneumatic cylinders and their data analysis of life distribution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.412-414
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• 2004

In this paper, a novel algorithm of underground cable fault location based on the analysis of distributed parameter circuit is proposed. The proposed method makes voltage and current equations about core and sheath, and then establishes a function of the fault distance according to the analysis of fault conditions. Finally gets the solution of this function through Newton-Raphson iteration method. The effectiveness of proposed algorithm has been verified by Matlab program, and the cable parameters such as impedance and admittance are from EMTP simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.79-81
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• 2004

본 논문에서는 전력시스템의 정적 안전도수준(Steady-state Security Level)을 평가할 수 있는 안전도 지수를 전력시스템의 영향을 반영하는 가중치를 고려하여 보다 개선된 안전도 지수를 제안한다. 먼저, N-1선로사고를 가정하여 각 선로가 계통에 미치는 영향과 각 선로의 사고로 인해 모선 전압의 변동량을 분석하여 각각 안전도 지수들의 가중치를 산정한다. 이때, 가중치의 표준화를 위해 분포도(Distribution Chart)를 활용한다. 가중치가 적용된 안전도 지수는 이를 고려하지 않은 안전도 지수보다 더욱 계통상황을 잘 반영할 것이며, 전력계통 운영 상태를 나타내는 중요한 지표로서 활용될 수 있을 것이다.

• 풍력에너지저널
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• 제4권1호
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• pp.46-52
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• 2013

The wind generally includes turbulence characteristics in nature. So the yaw errors between wind turbine direction and wind direction occur due to turbulence fluctuation. The yaw errors affect the fatigue load of wind turbine system and power reduction. The components of turbulence intensity are different from those of each site where the wind turbines are installed. We studied that the fatigue load and power efficiency are improved by controlling yaw motions. In this study, we controlled the averaged yaw error time according to site conditions by turbulence intensity.

• 조명전기설비학회논문지
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• 제21권5호
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• pp.90-98
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• 2007

본 연구의 목적은 고장 케이블(LV URD(low voltage underground) cable)의 원인을 밝히는데 있다. 분석방법은 외형패턴, 열패턴, 표면구조 분석, 열분석, 성분분포 등 다양한 분석기기를 이용하여 분석되었다. 국제기준과 사고케이블 제작회사가 제시하고 있는 규정이 일치하는지의 여부를 분석하였으며, 국내산 케이블과의 비교분석하였다. 그 내용을 요약하면 다음과 같다. (1) 사고케이블 자체의 절연성능을 저하시키는 요인으로 IEC 60502-1과 IEC 60811-1-1에 의한 절연피복의 최소 두께가 시방(specification)과 일치하지 알음을 확인하였다. (2) 적외선분광기에 의해 적외선흡광피크가 동일 재료에서 일치하지 않는 것으로 나타났다. (3) PVC bedding 부분이 열적으로 취약하여 장시간 현장에 노출되어 사용되는 경우 이와 유사한 패턴의 사고를 유발할 것으로 판단된다.