• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1369-1374
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• 2014

Most accidents of medium-voltage cables installed in nuclear power plants result from the initial defect of internal insulators or the initial failure due to poor construction. However, as the service years of plants increase, the possibility of cable accidents is also rapidly increases. This is primarily caused by electric, mechanical, thermal, and radiation stresses. Recently, much attention is paid to the study of cable diagnoses. To date, partial discharge and Tan${\delta}$ measurements are known as reliable methods to diagnose the aging of medium-voltage cables. High frequency partial discharge measurement techniques have been widely used to diagnose cables in transmission and distribution systems. However, the on-line high frequency partial discharge technique has not been used in the nuclear power plants because of the plant shutdown risk, degraded measurement sensitivity, and application problems. In this paper, the partial discharge measurement with a portable device was tried to evaluate the integrity of the 4.16kV and 13.8kV cable lines. The test results show that the high detection sensitivity can be achieved by the high frequency partial discharge technique. The present technique is highly attractive to diagnose medium voltage cables in nuclear power plants.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.178-181
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• 2003

For many years, testing laboratories, research institutes and manufactures try to find a reliable water tree accelerated ageing test that is able to show whether a polymer Medium Voltage cable os susceptible to water treeing or not. Test on laboratory samples, model cable designs, and fell size cable are presented Apart form aging, another important aspect of any accelerated aging test is the right choice of th preconditioning method. This paper is the analysis of weibull distribution method after an accelerated aging test of MV(Medium Voltage) cable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.149-152
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• 2001

In this work, we have conducted insulation aging assessment and maintenance for submarine medium voltage power cable systems to discriminate and maintain bad cables economically. We have found that aging status of submarine cable systems are very poor and in progress. We have found that insulation status were improved with the replacement of cable terminations. We have confirmed with the electrical and structural analysis of terminations, that the poor aging status of cables are mainly caused not by the cable insulations but by the aging of cable terminations. From the above results, we have also confirmed that the domestic diagnostic system is successful and convenient for the discrimination and maintenance of the damaged cables economically.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.145-150
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• 2015

This paper described the medium voltage high temperature superconducting cable thermal simulation and its application. New simulation method for HTS cable modeling using PSCAD/EMTDC is introduced in this paper. The developed simulation method consists of electrical model part and thermal model part. In electrical model part, power loss and thermal capacitance can be calculated in each layer, then the temperature of each layer can be calculated by power loss and thermal capacitance in thermal model part. This paper also analyzes the electrical and thermal characteristic in the case of normal operating condition and transient including single line to ground fault and line to line ground fault using new simulation method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.7-11
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• 2003

for many years already, testing laboratories, research institutes and manufactures try to find a reliable water tree accelerated ageing test that is able to show whether a polymer Medium Voltage cable os susceptible to water treeing or not. Test on laboratory samples, model cable designs, and fell size cable are presented. Apart form aging, another important aspect of any accelerated aging test is the right choice of th preconditioning method. THTS paper is the analysis of weibull distribution method after an accelerated aging test of MV(Medium Cable) cable.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.295-295
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• 2008

Water tree experiments were done for several types of cross-linked polyethylenes. Test method is followed by ASTM D6097. Polyethylene is divided for four subgroup. First One is chemically cross-linked general XLPE, and second one is chemically cross-linked tree-retardant XLPE, and the third one is silane cross-linked polyethylene made by monosil process, and the last one is silane cross-linked polythylene made by copolymer. Tree retardant XLPE shows the shortest water tree length. Cahemcally cross-linked general XLPE shows the longest water tree length. Silane cross-linked polyethylene by copolymer is similar to tree retardant XLPE and similar breakdown strength. So silane cross-linked XLPE by copolymer could be used for the the medium voltage cable which should have tree retardant characteristics.

• 조명전기설비학회논문지
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• 제17권2호
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• pp.66-72
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• 2003

본 연구에서는 국내 배전계통에 사용 중인 전력케이블에 대한 평균열화평가시스템을 개발하였다. 절연진단의 최소한의 목적은 전력공급의 중단을 초래할 수 있는 열화 즉, 사고가능성이 논은 전력케이블을 효율적으로 선별하고 경제적으로 관리하는데 있다. 따라서 이러한 최소한의 진단 목표를 달성하기 위한 가장 효율적인 진단원리로 열화시정수법을 채택하고 감쇠전압을 측정변수로 하여 진단설비를 개발하였다. 현장적용성 시험 및 파괴강도 시험 결과 열화상태 평가결과와 파괴강도의 상관관계를 확인하였으며 본 연구를 통해 개발된 진단장치는 사고를 초래할 수 있는 열화의 효율적이고 경제적인 선별 및 관리에 유용한 설비가 될 수 있음을 알았다.

• 조명전기설비학회논문지
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• 제17권3호
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• pp.80-86
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• 2003

본 논문에서는 육상의 지중전력케이블에 비해 유지보수가 힘들고 사고의 파급효과나 사고복구에 큰 어려움이 따르는 해저케이블을 대상으로 진단시험 및 유지보수에 대한 연구를 수행하였다. 본 연구의 목적은 사고위험이 높은 해저선로에 대한 경제적이고 효율적인 열화진단 및 유지보수에 있다. 진단시험 결과, 해저케이블의 열화정도는 매우 심각하며 열화가 계속 진전되고 있음을 확인하였다. 단말부 교체시공 후 재 진단시험을 실시한 결과, 전체적인 열화상태가 개선되었음을 확인하였으며 단말부 및 케이블 절연부에 대한 전기적 특성시험과 화학구조분석 시험 결과, 전체 케이블 시스템의 열화는 주로 단말부 열화에 기인함을 알았다. 상기 결과에 따라 본 연구에 사용된 진단기법 및 유지보수 절차가 해저케이블시스템의 경제적인 관리에 매우 효과적임을 학인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1634-1636
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• 2001

We have developed the global assessment system for medium voltage power cable systems. Our purpose of diagnostic activity is the economic discrimination and maintenance of bad cables which is likely to cause cable system failure. We have atapted the Voltage Decay Method to construct the power cable assessment system for our diagnostic purpose. From the field application test results, we have concluded that our system is successful and convenient for the discrimination and maintenance of the damaged cables economically.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.422-429
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• 2008

This paper presents compact low frequency ultra-wide band (UWB) sensor design and study of the partial discharge diagnosis by sensing electromagnetic pulse emitted from the partial discharge source with the newly designed UWB sensor. In this study, we designed a new type of compact low frequency UWB sensor based on microstrip antenna technology to detect both the low frequency and high frequency band of the partial discharge signal. Experiments of offline PD testing on medium voltage (22.9kV) underground cable mention the comparative results with the traditional HFCT as a reference sensor in the laboratory. In the series of comparative tests, the calibration signal injection test provided with the conventional IEC 60270 method and high voltage injection testing are included.