• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1425-1427
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• 1998

The thermal history of XLPE insulated cable during heating cycle voltage test specified by IEC 840 was examined by DSC(differential scanning calorimetry) method, of which the principal is on the basis of the phenomenon that the crystals in polyethylene are rearranged as it is annealed near/below the melting temperature. From the result, it can be estimated that XLPE insulation near the conductor was exposed at the temperature of about $100^{\circ}C$ with the electrical stress through the test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.88-88
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• 2010

High Voltage cross-linked polyethylene (XLPE) cables are widely used in a thermal power plant. These cables had been in service for 26 years. The insulation condition of six 6 kV XLPE cables was estimated by insulation diagnostic analyzer (IDA) with voltage amplifier. IDA was measured dissipation factor and capacitance of the whole cable as a function of frequency and voltage. This system measures in the frequency range from 0.1 to 10 Hz at each voltage level. Six XLPE cables are judged good condition, but three cables are analyzed at an aged condition.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.216-218
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• 1993

XLPE cable accessories are mainly consisted by the combination of various insulating materials such as XLPE cable insulation, rubber, epoxy, etc. It is important to investigate the dielectric and breakdown characteristics of the interfaces between various insulating materials. In this paper, by testing and measuring the breakdown strength, dissipation factor, volume and surface resistance and conduction current of specimens, we report the dielectric and breakdown characteristics of interfaces between various insulating materials.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.827-832
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• 2012

The crosslinked polyethylene (XLPE) is the most widely used insulating material for power cable. Due to its thermosetting characteristics, the XLPE can not be recycled, while the needs for the environmental friendly and recyclable insulator is rapidly increasing. In this paper, some important and basic electrical properties of non-crosslinked polyethylene such as conduction current characteristics, water the tree characteristics, AC breakdown test were experimentally investigated. It was shown that some of the tested samples had better performances from the application point of view for replacing current XLPE.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.318-319
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• 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 IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.136-140
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• 1999

Measurements of AE signals caused by partial discharges were performed by using an ultrasonic measurement technique to diagonise the electrical treeing deterioration in XLPE cable. We also examined the partial discharge magnitude and AE signals(peak-to-peak) with the increase of the deterioration time. From these results, it was found that AE signal due to partial discharge can be greatly detected at the peak value of positive polarities prior to the breakdown voltages, and the magnitude of AE signals was closely related to the current pulses by the increase of deterioration, and it appeared that AE signals(peak-to-peak) was proportional to partial discharge magnitude. Attenuation and time-delaying characteristics of ultrasonic signals propagated in various polymers sample by using ultrasonic oscillation and receiving systems are also reported as a basic data of ultrasonic measurements in XLPE cable.

• International Journal of Safety
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• v.7 no.1
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• pp.10-14
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• 2008

For evaluating the radiation degradation of cross-linked polyethylene (XLPE) cable insulation due to the irradiated oxidation, XLPE was irradiated with ${\gamma}$-ray. For each irradiated samples, TGA, DSC, FT-IR, and tensile tests were carried out. Regarding radiation degradation, oxidative process was predominant. TGA, DSC and FT-IR can be useful tools for evaluating the radiation degradation due to the irradiated oxidation because these analyses need only small amount of samples. The results of TGA, DSC and FTIR analyses showed the similar tendency for irradiated degradation. They can be useful tools for evaluating the oxidation of insulating material by non-destructive testing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.122-126
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• 2002

A diagnostic test of 15.4kV cross-linked polyethylene(XLPE) ultra high voltage power cables from generator in the Soyanggang hydro electric power plant was conducted over 3 months, beginning April 2001. According to the results, in the case of the power cables from generator 1, there was little possibility of proceeding rapid1y to failure or defect because the data from diagnosis doesn't indicate any failure, deterioration or partial discharge. However, in the case of the power cables from generator 2, the. polarization index show a slight abnormal condition of the insulator that is not severe, and the deterioration was also identified as not severe. However, the partial discharge had an abnormal condition which was severe.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1827-1829
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• 2002

This paper describes AC test for long delivered drum length of cable using pre-breakdown partial discharge detection(PPD) method, which can be applied to observe the causes of electrical breakdown of EHV XLPE insulation. This method is to de-energize applied voltage to cable rapidly using pre-breakdown partial discharge, and is able to prevent complete breakdown. By this effect, defects such as voids, metal particles and protrusion in cable can be observed clearly. AC resonant test set was used for PPD method. Localization of partial discharge was performed by time difference detection of the traveling wave. Accuracy of localization was 1% to the length of test cable. Through several experiments with XLPE cable, successful results of PPD method were obtained.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1782-1784
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• 2002

In this paper, the coefficient of friction betwee and sheath in 345kv XLPE cable was measured the simulated inclinated condition of You-Youngdeungpo transmission line. The phenomena of slipping down the simu inclination was investigated theoretically usin measured data and was analyzed from experim result. The measured and analyzed result were conside be as a reference data for real installation of XLPE Youngseo-Youngdeungpo transmission line.