• Proceedings of the KIEE Conference
• /
• 2007.04b
• /
• pp.146-148
• /
• 2007

We studied the partial discharge detecting by sensing electromagnetic wave emitted from the partial discharge source in the MV XLPE cable with the new type of patch antenna sensor. In this study, we design new kind of Patch antenna and make many experiments compare with the existing HFCT sensor on MV XLPE cable in the laboratory. According to our experimental results our new sensor can defect pure PD and wider bandwidth 20MHz to 70MHz than HFCT and can easily localized manually on the cable.

• KEPCO Journal on Electric Power and Energy
• /
• v.7 no.2
• /
• pp.263-268
• /
• 2021

This paper statistically analyzes the time required for each failure cause and describes a diagnostic method for 159 reports of failure analysis of MV cables that occurred in the distribution system of KEPCO over the past 18 years. In addition, the manufacturer's failure rate compared to 100C-km was calculated using 381 cases of MV cable deterioration failure between 2008 and 2020. It is hoped that this paper will help those in charge of maintaining underground facilities at the business office to use the failure rate to prioritize facility diagnosis.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.11
• /
• pp.1933-1937
• /
• 2008

XLPE insulated power cables are introduced in Korea in 1980s. The cable installation test has been carried out according to the Korean Technical Reference of Electrical Facilities. But recent research results shows DC Hipot test cannot detect the serious defects in XLPE insulated cables. VLF test is recommended as a installation test of XLPE insulated cables by CENELEC and IEEE standards in 1996 and 2001 respectively. We suggest to apply VLF test as an installation test for XLPE insulated MV cables in Korea.

• Proceedings of the KIEE Conference
• /
• 1999.11d
• /
• pp.1105-1107
• /
• 1999

The purpose of termination for high voltage tests of XLPE power cable is to prevent flashover during the breakdown test of specimen as well as to withstand the specified voltage between its conductor and screen without failure. For easier treatment and simpler construction of testing termination, resistivity grading method using semi-conductive material was employed. Based on the fundamental theory, its failure characteristics by changing the resistivity of semi-conductive material on the insulation surface was investigated. With two layers construction by difference resistivity on their surfaces, much improved result than that of one resistivity was obtained through the experiment for MV cable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.313-316
• /
• 1995

In this study, in case the lead sheath of XLPE cable (radius : 15cm, inner conductor radius : 5cm, insulation paper raidius : 6cm, dc voltage : 1MV) is harmed, so that breakdown process by inhomogeneous eletric field is simulated with Finite Element Method. The result of simulation showed that defect of lead sheath layer caused breakdown.

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.1
• /
• pp.55-59
• /
• 2016

In Europe, polypropylene-insulated HV class cable with high temperature and no cross-linking was commercialized following the MV class. Our company also started a study of the polypropylene-insulated cable in 2013 and was carried out thermal, physical and electrical test. In addition, polypropylene-insulated cable was tested for compatibility with conventional joints and terminations in emergency condition and the accelerated life test for verifying their design life is in progress. The results of this study will be used to establish a standard specification and operation conditions of the polypropylene-insulated cable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.267-268
• /
• 2008

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

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1511-1512
• /
• 2006

In this paper, we measured PD signals from artificial surface defects and corona discharges under laboratory circumstances like the fields using both HFCT-sensor and UHF-sensor for MV grade XLPE cable with AMP, spectrum analyzer and oscilloscope. Also, detected signals were analyzed via PRPDA system in this paper. As a result, in this case of HFCT-sensor, the amount of background noise are larger than as compared to UHF-sensor. There is needed some hardware or software or software algorithm removing background noise effectively for diagnosis the underground power transmission cable in the case of HFCT-sensor.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.318-319
• /
• 2008

국내 지중배전선로에 XLPE 절연체를 사용한 전력케이블이 1980년대 중후반부터 사용되기 시작하여 20년 이상 사용경험이 축적되고 있다. 현재 국내는 전기설비기술기준에 의하여 직류내전압시험을 사용하여 준공시험을 수행하고 있다. 그러나 최근 20여년의 국제적 연구결과는 직류내전압시험이 XLPE 절연체의 결함을 발견하지 못하며 절연체 내에 장기 공간전하를 형성함으로써 케이블의 수명을 단축하는 역효과가 발생한다고 보고되고 있다. 2000년대에 XLPE 절연체를 사용한 전력케이블의 준공시험으로 초저주파(VLF) 내전압시험이 CENELEC과 IEEE 규격으로 제정되었다. 국내에도 전력케이블의 준공시험으로 초저주파 내전압시험을 도입하여 적용하는 것이 적절하며, 초저주파전압을 이용한 열화진단기술을 적용하는 것이 XLPE 절연 케이블의 고장예방에 효과적일 것으로 기대된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.04c
• /
• pp.27-31
• /
• 2008

In this study, The new type of loop antenna which detects the partial discharge was designed based on microstrip line technology. In diagnosis of power cable, partial discharge signal generally occurred at the frequency range lower than 100MHz because high frequency PD signals could be lost along the propagation path in the cable. The new type of loop antenna sensor has been studied by using Simulation software named CST microwave studio version 5.0. In partial discharge measuring experiments, commercial HFCT sensor was used as a reference sensor. Several experiments were made over HFCT sensor and loop antenna sensor in detection partial discharge on MV XLPE cable of 22.9kV. In this study, we have shown our loop antenna sensor can apply as a commercial HFCT sensor.