• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.8
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• pp.893-897
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• 2004

In this paper, we studied the mechanical and thermal properties on slice XLPE sheet from 22 kV and 154 kV power cables. Interface structures are XLPE/semiconductor and XLPE/water/semiconductor. We evaluated mechanical property, thermal analysis, moisture analysis. Based on mechanical and thermal properties of the 22 kV XLPE sheet, elongation, mechanical strength, and melting point were evaluated to be 485.48 %, 1.74 kgf/$\textrm{mm}^2$ and $102.48^{\circ}C$, respectively. It was also evaluated from the mechanical and thermal properties of 154 kV XLPE sheet that elongation, mechanical strength, and melting point are 507.81 %, 1.8 kgf/$\textrm{mm}^2$, $106.9^{\circ}C$, respectively. A region shows a rapid increase in tension strength, and B region only shows increase in elongation under 1.0 kgf/$\textrm{mm}^2$, C region shows increase in both elongation and tension strength. Difference of melting point came from the chain of XLPE polymer and the difference of crystallization. Moisture density of semiconductor showed 800 ∼ 1200 ppm before extrude, 14000 ∼24000 ppm after extrude. These values were higher than the moisture density of XLPE (300∼560) ppm.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.271-272
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• 2008

실선로 전력 케이블의 부분방전 측정은 주위 전력설비의 신호들이 혼합되어 검출된다. 본시험에서는 배전전력 케이블을 대상으로 부분방전 신호의 방향 추정 시험을 하였다. 시험 조건으로 모의 선로와 활선 현장선로에서 시행하였다. 2개 HFCT 센서를 사용하여 방전 펄스를 검출하였고 미소신호를 검출하기 위하여 AMP와 필터를 설계하였다. 신호 분석을 위하여 1GS/S의 스코프를 사용하였으며 자동 방향추정 S/W를 제작하였다. S/W의 특징으로는 2개의 채널에서 동일한 펄스의 시간차를 분석하여 방향을 분석하도록 하였다. 센서의 간격이 20CM일 때 약1nS의 시간차가 발생하여 신호의 방향을 추정할 수 있었다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1503-1504
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• 2015

배전용 케이블은 수트리 억제, 화재예방, 경제성 등을 고려하여 구조와 재질이 지속적으로 변경되고 있다. 변경되는 추세를 살펴보면 경제성 측면에서 도체의 재질은 동에서 알루미늄으로 변경되었고, 수트리 억제를 위해 절연체의 재질은 XLPE에서 TR-XLPE로 변경되었다. 또한 외피의 재질도 난연성을 강화하고 수분침투를 억제하기 위하여 난연성 PE로 개선하였다. 중성선도 외부반도전층 위에 올려진 구조에서 외피 내부로 들어가는 충실형 구조로 변경되었다. 이와 같이 외피구조가 변경되면서 외부반도전층의 두께가 증가되었고 이로 인해 접속재 시공시 삼각형 모양의 공극이 커지게 되었는데, 본 논문에서는 케이블의 외부 반도전층 두께 증가가 접속재 부분방전에 미친 영향을 고찰하였다.

• 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.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.357-364
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• 2005

The prefabricated type used generally in Korea to join cable runs on new installations or to repair broken Cable runs on existing installations, because installation is very simple and save time. This type is a permanent, shielded and submersible cable joint for direct burial or vault application. It confirms to the requirements of IEEE std. 404-1993 by factory testing, but many problems of insulated cable systems are caused by internal defects of the joint part which have to be mounted ensile. Faults arise from impurities or voids. A suitable solution for a monitoring of cable joints during the after-laying test and service is partial discharge detection. Specimen obtained 1mm thickness from the insulation of real power cable and cable joint. <중략>The partial discharges are measured to determine their time dependence for 60 minutes and the influence of applied electrical stress under 30kV. $\Phi-q-n$ properties were measured using detection impedance, high pass filter and computerized data acquisition system. Statistic Value like maximum charge, repetition rate, average charge, etc. are calculated. It is possible to quantitative analysis of $\Phi-q-n$ properties from this statistic value and pattern analysis.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.279-286
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• 2005

The prefabricated type used generally in Korea to join cable runs on new installations or to repair broken Cable runs on existing installations, because installation is very simple and save time. This type is a permanent, shielded and submersible cable joint for direct burial or vault application. It confirms to the requirements of IEEE std. 404-1993 by factory testing, but many problems of insulated cable systems are caused by internal defects of the joint part which have to be mounted ensile. Faults arise from impurities or voids. A suitable solution for a monitoring of cable joints during the after-laying test and service is partial discharge detection. <중략> $\Phi-q-n$ properties were measured using detection impedance, high pass filter and computerized data acquisition system. Statistic Value like maximum charge, repetition rate, average charge, etc. are calculated. It is possible to quantitative analysis of $\Phi-q-n$ properties from this statistic value and pattern analysis.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.579-588
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• 2003

There are many unfavorable conditions that lead to shortening life of cable by causing dielectric breakdown and aging such as field concentrations occurring in intermediate materials linking each cables, penetration of various impurities, and undermining of cable insulation layers. This paper simulated investigated partial discharge properties of XLPE which is widely used for ultra high voltage cable insulation materials and EPDM which is being used as insulation layer of cable joint materials kit, using Boundary Element Method. The result of computer simulation showed that inner-Void defect caused silicone oil to weaken the E-field effect. and we also found that E-field distribution in EPDM remained relatively lower than that in XLPE.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1475-1476
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• 2015

국내에서 XLPE 지중케이블이 처음 포설된 지 30년이 경과하였으며, XLPE 케이블의 수명은 일반적으로 30~40년 정도이기 때문에 케이블의 교체시기에 대한 문제가 대두되고 있다. 본 연구에서는 국내의 지중케이블 잔존수명평가 알고리즘의 장단점을 분석하고 국외의 잔존수명평가 알고리즘에서 국내 잔존수명평가 알고리즘의 단점을 보완할 점을 분석하였다. 또한 잔존수명 평가 알고리즘을 개선하는 것 외에 알고리즘에 사용되는 데이터의 통합 관리방안을 제시하였다.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2271-2273
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• 1999

The manufacturing technology of XLPE power cable ( e.g. gas curing, triple common extrusion, clean room, super-clean compound, etc.) had been developed in 1960's and the design parameter of insulation thickness for EHV XLPE power cable at present was determined in 1960's. But, the quality of XLPE power cable has been improved up to now. The re-evaluation of design parameter for insulation thickness reductions is required and so we performed weibull plotting test using model cable. This paper describes the evaluation details of the insulation characteristics according to weibull plotting test.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1617-1619
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• 1998

In the nation, 154kV XLPE cable with an insulation thickness of 23mm have been used for transmission lines. The thickness is designed by old parameters which were determined by Kreuger, Oudin et al. in 1960s. By the way, the manufacturing technology has been developed. Especially in extruding and curing process we are using a triple common extruding head and applying gas-curing process. It allows the quality of XLPE cable improved. The paper evaluates the AC minimum insulation breakdown strength of XLPE power cable using model table. We can verify the uplifted insulation quality. And we expects the cable insulation thickness to be reduced applying the new parameter to the cable insulation design.