• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.55-58
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• 1999

Crosslinked polyethylene/silane crosslinked polyethylene (XLPE/SXLPE) blends were prepared by a twin screw extruder and their water tree growing and electrical breakdown characteristics of XLPE were improved by the addition of SXLPE, when samples were crosslinked only by the thermorolysis of DCP (dicumyl perosxide). However, steam curing process was not good for water tree characteristics. It was also found that the rate of water tree growing of XLPE/SXLPE blend increased when the content of SXLPE was 50 %. AC breadown strength slightly increased by the addition of SXLPE to XLPE when samples were crosslinked only by the thermorolysis of DCP.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.400-405
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• 2000

In order to improve the reliability of XLPE cables, it is necessary to understand the mechanism of electrical and water tree degradation. Especially, electrical tree initiation and propagation are important in XLPE cable insulation. This paper deals with the changes of electrical properties of XLPE cable insulation with electrical tree degradation. To understand the electrical properties of XLPE insulation, specimens were prepared by 22.9kV distribution cable and made in a type of block. Ogura needles having tip radius of 10${\mu}{\textrm}{m}$ were inserted into each block pieces. AC voltages of 8kV, 10kV and 12kV at 60Hz were applied to needle. We investigated the relationship between electrical properties(PD quantity, tan$\delta$ and DC current) and the growth of electrical tree. The electrical properties of the specimens were measured from initiation of tree to breakdown and their characteristics were analyzed.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.50-55
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• 2003

Radiation degradation of crosslinked polyethylene(XLPE) was investigated using thermogravimetric analysis(TGA), The results of TGA were compared with FT-IR, melting temperature, oxidation induction time, and elongation at break on the XLPE exposed by $\gamma$-ray. 5% decomposition temperature of $\gamma$-ray irradiated XLPE showed similar tendencies with the case of elongation at break. Both properties agreed below 1000 KGy, however, did not show any remarkable characteristics above 1000 kGy, these properties can be useful to evaluate the radiation degradation of XLPE for only low irradiated region. Above 1000 kGy, the thermal decomposition activation energy showed decreased, on the contrary, increasing below 1000 kGy. Compared with FT-IR spectrum of irradiated XLPE, it was confirmed that the oxidation reaction was still occurring below 1000 kGy. Radiation degradation of XLPE was dependent upon the irradiation doses, TGA can be a useful tool to evaluate the degradation.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.73-77
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• 2022

Recently, as the number of years of operation has increased for more than 30 years, interest in evaluating the remaining life of major power facilities such as transformers and ultra-high voltage cables is increasing. In particular, the risk of failure is increasing because the underground transmission XLPE cable has been built since 1980 and has been operating in excess of 30 years of design life or close proximity. Therefore, it is necessary to develop an algorithm to evaluate the residual life of the XLPE cable considering the load to determine the risk of failure. Since load data is large amount of data, it is necessary to make the variable load information equivalent to the time unit first in order to calculate the remaining life of the system quickly. In overseas literature, transformers are reported to be standardized for variable load equivalent conversion formulas, but they have not been reported for ultra-high voltage cables. Therefore, in this paper, whether the equivalent conversion formula of a transformer can be applied to XLPE cables was reviewed through accelerated degradation tests under equivalent and variable temperature conditions, and considerations were studied when evaluating the remaining operating life of XLPE cables based on the experimental results.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1608-1609
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• 2011

In this study, in order to develop the evaluation method for XLPE materials for HVDC cables, DC/Impulse superposition testing system was builded up. Throughout the P-spice simulation, optimal values of the protection resistor for the DC generation system and the blocking capacitor for the Impulse generator were calculated. DC/Impulse superposition system showed good result maintaining their proper wave shapes and amplitudes. This system would be planned to apply to the evaluation of XLPE materials for HVDC cables.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.73.1-76
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• 2000

The performance of insulate materials gets worse with stress time in power system and because this causes lowering of function and accidents in equipment, development and performance improvement of excellent insulate materials are needed to make stable system. In this paper, to study the influence of degradation in XLPE, inner semiconducting layer and outer semiconducting layer, we studied dielectric characteristics at temperature 25~10$0^{\circ}C$ and frequency 20~1[MHz].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.207-210
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• 1998

Electrical properties such as space charge distribution and electrical conduction of XLPE/VLDPE blends were studied. When the VLDPE is blended, residual charge inside XLPE increases. In case of electrical conduction characteristics, there were no changes in electrical conduction mechanism, space charge limited conduction. XLPE/VLDPE blend including crosslinking coagent showed relatively small current density. It might be due to the carbonyl group in crosslinking coagent.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1801-1803
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• 2001

At present the under ground power transmission systems have installed until 154KV XLPE power cable in Korea But, the large capacity underground power transmission systems have been required gradually with the increasing demand of electric power. Therefore, our company has developed 345KV XLPE cable. This paper describes the estimate details of the insulation thickness according to weibull plotting for 345KV XLPE power cable.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2243-2244
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• 2008

In this paper, XLPE cable underneath a bridge is modelled using EMTP/ATPDraw. Bridge section is also modelled by mutually coupled parallel conductor with XLPE cable. This paper is analysed the overvoltge by structure change of bridge section when the lightning occurs on the system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.108-110
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• 1994

Decomposition products by crosslinking reaction of PE using Dicumylperoxide(DCP) should influence on the electrical properties in XLPE. This paper studies on Behaviors of Decomposition products and Electrical Treeing ding to Drying condition. We used the Gas Chromatography for Decomposition Gases analysis FT-IR for investigating the behaviors of Decomposition products remained in XLPE Break Down Voltage Tester for Electrical Treeing measurement.