• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.551-556
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• 2017

The cross-linked polyethylene(XLPE) has been most widely used for the power cable insulating layer because of its outstanding properties such as electrical and mechanical properties. However, XLPE is unrecyclable when disposed after replacement and demolishing because it becomes thermosetting through cross-linked process. Recently, because of growing social awareness of recycling and eco-friendly, there is growing need for the development of recyclable insulating materials that can replace XLPE. Therefore, the purpose of this study is to compare the electrical properties of XLPE and recyclable thermoplastic insulating materials. To this end, we compared and analyzed the electrical properties of XLPE and group N2 through AC breakdown test, accelerated water treeing test and accelerated life test(ALT).

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1129-1135
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• 2011

Recently, In Korea region becoming subtropical climate, freezing index values have been increasing in winter. The climate condition in Korean became polarized. Since freezing index is increased recently, track heaving from frost is often occurred, which is ignored in past couple of years. Methods to prevent frost-heaving are circumfusion of calcium chloride and replacement of gravel ballast in usual. The effects of those methods are minimal, incontinuous, and not eco-friendly. Therefore, maintenances are performed repeatedly every year. This study discussed utilizing the waste-tire-chips and insulators in the small structures(bridge and box etc) for prevention of frost-heaving. In order to prove effect of waste-tire-chips, laboratory and field tests were conducted with CBR and measurement of frost-heaving amount to prove and verify effect of insulators.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.603-609
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• 2015

Dry air is an excellent alternative to $SF_6$ gas and is used as an insulation gas in Eco-friendly Gas Insulated Switchgears (EGISs), which has gained popularity in industry. Solid insulators in EGIS play an important role in electrical insulation. On the other hand, surface discharge can occur easily when solid insulators are used. This paper explored the surface discharge characteristics on the structure of three-layered laminated solid insulators to elevate the flashover voltage. A laminated solid insulator was inserted after the quasi-uniform electric field was formed in the test chamber. Dry air was then injected to set the internal pressure to 1 ~ 6 atm, and the AC voltage was applied. When identical solid insulators were stacked, the surface discharge characteristics were similar to those of a single solid insulator. On the other hand, the flashover voltage rose when the middle part was thicker and had lower permittivity than the top and bottom parts in the laminated solid insulator. Based on experimental results, when stacking a solid insulator in three layers, the middle part of the solid insulator should be at least four times as thick as the top and bottom parts and have lower permittivity than the others. In addition, the flashover voltage increased with increasing gas pressure on the surface of the laminated solid insulator due to the gas effect. This study may allow insulation design engineers to have useful information when using dry air for the insulation gas where the surface discharge can occur.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1165-1166
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• 2015

현재 가장 널리 사용되고 있는 전력용 지중케이블의 고분자 절연재료인 가교 폴리에틸렌(XLPE)은 전기적, 기계적으로 특성이 우수하다는 장점을 가지고 있지만 열경화성으로 인해 재활용이 어렵다. 본 연구에서는 환경친화적인 전력용 케이블을 개발하기 위해 열경화성인 XLPE를 대체할 수 있는 열가소성의 고분자 절연재료를 개발하는 것이다. 이를 위해 후보군의 재료들에 대한 단기적인 특성인 교류절연파괴 시험을 시행하였다. 또한, 중장기 특성을 평가하기 위해 가속수명시험(accelerated life test: ALT)을 수행하였다. 신뢰성있는 실험결과를 위하여 교류절연파괴시험과 가속수명시험에는 McKeown 전극계를 제작, 사용하였다.