• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.671-682
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• 1998

Chemical structure and electrical characteristics of 5 commercial crosslinked polyethylenes (XLPE) used as insulating materials for medium voltage distribution power cables in Korea were investigated. It was found that each XLPE shows different properties depending on the type of XLPE. Chemical structural irregularities of pellets change considerably by crossliking reaction, with some irregularities being disappeared after crosslikeng reaction. It was also found through a solvent extraction study that additives such as crosslinking agent and antioxidants act as major source retarding water tree growth. Low molecular weight polyethylene chains plays a different role in water tree growth of XLPE.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.3
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• pp.227-234
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• 2000

Electrical conduction characteristics of crosslinked polyethylene(XLPE) were investigated using an electrode made of semicon material containing a surfactant. When the semicon material is used as an electrode the conduction of XLPE obeys a space charge limited conduction(SCLC) mechanism which holds true for both control and surfactant-containing semicon electrodes. Conduction currents get higher with the addition of surfactant in the semicon electrodes while the charge mobility increases with the increase of surfactant content in the semicon electrode. The diffusion of surfactant molecules into the XLPE was confirmed via a $\mu$-FTIR analysis. It was found through a measurement of spatial charge distributions that the surfactant in the semicon electrodes enhances the injection of negative charge into the XLPE from the electrode. Experimental results and their origins are discussed in detail.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.77-80
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• 2000

In order to determine what influences the interfacial charge in EPDM/XLPE laminates, We used PEA (pulsed electroacoustic) method. Interfacial properties such as space charge accumulation and breakdown strength in crosslinked polyethylene (XLPE)/ethylene-propylene-diene monomer (EPDM) laminates were investigated. Interfacial charge develops when the EPDM is laminated with XLPE. It showed the positive polarity same as the simulation in case on intercase of EPDM/XLPE. In case of coupling agent added silicone oil, as increasing the content of coupling agent, the interfacial charge decreased. Details of the results are given and their origins discussed.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1493-1495
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• 2003

EVAOH (ethylene-vinyl acetate-vinyl alchol terpolymers) were prepared by using the transesterification reaction between ethylene-vinyl acetate copolymer and alchol. Structural and thermal analyses were accomplished with FTIR and DSC. XLPE (crosslinked polyethylene) and EVAOH were blended using a two-roll mill and their water tree and dielectric loss characteristics were investigated. It is found that the water tree characteristics of XLPE were improved by the addition of EVAOH. It was also found that the extent of improvement of water tree and dielectric loss characteristics of XLPE/EVAOH blends depends on the kind and concentration of EVAOH.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1028-1030
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• 1999

전 세계적으로 송전 용량의 증대 요구에 따라 송전 시스템이 초고압화 되어 가고 있으며 환경친화성 및 여러 특성에 있어 OF(Oii filled) 케이블에 비하여 우수한 성능을 지닌 XLPE(Crosslinked Polyethylene) 케이블의 사용이 급속하게 증가하고 있는 추세이다. 최근 345kV급 이상의 XLPE 케이블 시스템 개발이 해외 선진업체들에 의해 활발히 진행되고 있으며 이의 평가를 해외공인 인증기관에서 수행하여 개발된 제품의 디자인 검증 및 장기간 신뢰성을 입증하고 있다. 이러한 추세에 맞추어 LG 전선은 400kV 케이블 및 접속함의 사내 개발시험후 해외공인 인증기관인 네덜란드의 KEMA에서 IEC 62067에 따른 인증시험을 완료하여 개발된 제품의 높은 신뢰성을 인증 받았으며, 자사의 초고압 기술을 한 단계 상승시켜 세계 선진업체들과 경쟁할 수 있는 발판을 마련하였다.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.218-220
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• 1996

This paper was evaluated dielectric characteristics and temperature dependency in the XLPE with and without void. Each dielectric loss was $3.5{\times}10^{-4}$(%) and a little decreased with temperature's increase. Capacitance presented a contant value. According as the study is obtained results, loss in the XLPE increased in proportion to square of applied voltage. As a result of the study, it was knowed that dielectric characteristics had a great deal to do with degradation in the high voltage dielectric materials.

• Polymer(Korea)
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• v.27 no.3
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• pp.249-254
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• 2003

The variation of chemical structure and physical properties of crosslinked polyethylene (XLPE) during thermal aging process was investigated. The formation of carbonyl functional group resulting from thermal oxidation reaction of XLPE was monitored using X-ray photoelectron spectroscopy and near infrared (NIR) spectroscopy. It was observed that the intensity of carbonyl peak observed at 1715 nm linearly increased with aging time in NIR spectroscopy. The linear relationship between NIR peak absorbance and aging time confirmed that NIR spectroscopy might be used as a proper tool for monitoring the aging process of polymeric materials. Also the formation of crosslinks during the aging process was monitored using thermal mechanical analysis, stress-strain test, and Shore hardness test. The change in the physical properties, such as the increase in the glass transition temperature from 110 to 132$^{\circ}C$, the decrease in the strain from 265 to 110%, as well as the increase in the shore D hardness from 32 to 50, was observed during the aging process.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1426-1427
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• 2011

전기적, 기계적으로 우수한 성능을 지닌 절연재료인 폴리에틸렌은 장기간 운전 중 열화에 의해 절연성능이 저하되고 시간이 지나면서 케이블의 사고 원인을 제공하게 된다. 본 논문에서 전력용 케이블의 절연체로 널리 사용되고 있는 가교폴리에틸렌(XLPE)를 대신하여 최근 주목을 받고있는 친환경 특성을 부여하기 위한 비가교 폴리에틸렌 재료에 대한 기초적 물성(워터트리성장특성, AC 절연파괴특성, 전도전류 특성)을 실험적으로 비교분석하였다.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1615-1617
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• 1997

절연재료로서 널리 쓰이는 XLPE(Crosslinked Polyethylene)의 경우, 내부에 발생하는 수트리에 의해 절연체로서의 성능 및 내구성이 많은 영향을 받게 된다. 이에 대한 연구가 진행되어 왔지만 수트리 발생과 진행에 관한 메커니즘은 아직까지 정확하게 알려지지 않은 상태이다. 이 논문에서는 몇 가지의 수트리 억제 컴파운드를 선정하여 시간과 온도에 따른 수트리 발생을 관찰하고, 컴파운드 내의 공간전하 및 전도전류가 수트리 억제에 미치는 영향을 조사하였다. 수트리가속을 위하여 주파수가속열화 방법을 사용하고 온도와 시간에 따른 발생 및 진전을 관찰하였다. 실험에서는 압축성형된 평판형 시편을 사용하였으며 상부전극으로는 $AgNO_3$ 수용액을, 하부전극으로는 금속전극을 사용하였다. 그리고 컴파운드 내부의 공간전하 분포 및 전도전류 측정을 하기위해 PEA(Pulsed Electro Acoustic) 방법을 이용하였다.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1629-1631
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• 1998

Crosslinked polyethylene (XLPE) insulated cables are now widely used all over the world for extra-high voltage underground transmission systems. Prefabricated type (compression type) joint has developed in order to shorten the assembly time and lower the possibility of contamination at site by many companies in the world. For outdoor termination, to control the electric field distribution as uniform as possible, especially for the use of extra-high voltage system. much of products are adopting the oil-impregnated condensor cone type instead of electric field control element which uses the permitivity of it only (not capacitance). For Gas-immersed termination, dimension of outer insulation bushing was determined by IEC Publication 859. The highest voltage of underground power cable system is 345kV now, in Korea. We have much of experiences of the development of prefabricated type accessories for CV cable systems (154kV, 161kV, 230kV level). So it was possible to inspect the proto type of accessories for 345kV CV cable system and seems that the need time for the development of products is reduced.