• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.278-282
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• 1996

Electrical properties of acrylic acid and n-butyl acrylate grafted polyethylene were investicated. Charge accumulation characterist-ics of acrylic acid grafted PE are changed by graft ratio, but it remains not changed in n-butyl acrylate grafted PE. It was also observed that anti-treeing and AC breakdown strength of grafted PE were increased due to the graft ratio. The change of electrical properties of grafted PE were attributed to the polar group introduced by the graft reaction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.173-176
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• 1999

Crosslinked Decree is an important 7actor to determine dielectric property of crosslinked polyethylene(XLPE) used for the insulation material in Power cables. Recently, though it is necessary to investigate electrical properties according to crosslinked degree as a Part of the whose characterization of cable. it is not examined closely. In this study. crosslinked degree of samples were measured according to temperature and holding time of crosslinking. electrical tree characteristics of these characteristics of these samples were analyzed by crosslinked degree and applied temperature that was chanced from normal temperature to operating temperature of power cables. As a result. when the crosslinked degree was low, dielectric properties were decreased and influence of temperature was increased. but the crosslinked degrees were high, initiation voltages of treeing were increased and dielectric properties were improved. It is proved that the optimum crosslinked degree was one of most important factor for aging time and residual lifetime of Power cable.

• 전기의세계
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• v.25 no.6
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• pp.36-39
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• 1976

폴리에틸렌 절연 전력케이블, 특히 가교폴리에틸절연 케이블이 고분자 재료분야의 발달에 수반하여 급속히 실용화되어 전압의 계급도 11-23KV급으로 부터 66KV급 이상으로의 개발이 요망되고 있는 실정이다. 미국등 선진국에 있어서는 이미 이에 대한 충분한 연구가 진행되어 시험법이 제정되어 상위전압계급의 케이블 제작을 위한 연구가 활발히 진행되고 있는 상태이다. 따라서 앞으로 우리나라 고전압 분야에 있어서도 상기 분야의 개발을 위한 기초작업으로서 케이블의 사용조건, 케이블의 성능, 케이블의 열화성능, 시험기술등에 대한 조사, 연구, 분석이 필요함은 물론, 관계연구자들의 공동실험등 적극적인 참요가 요망되는 바이다. 본문에 있어서는 현재까지 진행되어 온 외국에 있어서의 합성수지절연체에 대한 여러가지 실험결과에서 판단한 앞으로의 연구과제 및 조사보고를 집약하여 간단히 소개코자 한다.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.40-43
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• 2000

Our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD(partial discharge) and AE(acoustic emission) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation, using statically operator such as the center of gravity (G), the gradient of the discharge distribution(C), we have analyzed for the prediction of life which we can be obtained the time, occurred of many pulse of small discharge amplitude.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1992-1994
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• 1999

Dicumyl peroxide (DCP) is used for crosslinking agent in general. And the correlation between polyethylene and DCP is significant in particular radiation environment. On this paper, The effects on $Co^{60}{\gamma}$-ray irradiation of polyethylene doped dicumyl peroxide(DCP) were investigated. We experimented on electrical properties as following; electrical tree inception and growing type for applying AC step voltage, AC breakdown strength, volume resistivity, capacitance and dissipation factor at high frequency as increasing dosage. Also, chemical analysis was performed TGA, gel content.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.215-216
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• 2006

Solid insulation exposed to voltage is degraded by electrical tree process. And the degradation of the insulation is accelerated by voltage application. For this experimental, specimen of e1ectrical tree model is made by XLPE (cross-linked polyethylene). And the size of the specimen is $7*5*7\;mm^3$. Distance of need1e and plane is 2 mm. Voltages applied for acceleration test are 12 kV to 15 kV. And distribution characteristic of degraded stage is studied too. As a PD detecting and data process, discharge data acquire from PD detecting system (Biddle instrument). The system presents statistical distribution as phase resolved. Moreover the processing time of electrical tree is recorded to know the speed of degradation according to voltage.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1476-1477
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• 2006

Solid insulation exposed to voltage is degraded and by electrical tree process. And the degradation of the insulation is accelerated by voltage application. For this experimental, specimen of electrical tree model is made by XLPE(cross-linked polyethylene). And the size of the specimen is 7*5*7 $mm^3$. Distance of needle and plane is 2mm. Voltage applied for acceleration test are 12kV. And distribution characteristic of degraded stage is studied too. As a PD detecting and data process, discharge data acquire from PD detecting system(Biddle instrument). Their results of PD distribution show good present and are good discriminating skill.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.60-66
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• 2001

Because of internal voids in insulators give rise to partial discharge(PD), which cause local breakdown and even entire insulation breakdown. Treeing due to PD is one of the main causes of breakdown of the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation has become important. From this viewpoint, our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD and acoustic emission(AE) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation, We analyzed the PD pulse and AE pulses by regression analysis, compared to these obtained the correlation coefficient and determination coefficient by T-distribution and saw that PD and AE pulses show a similar pattern on the whole. This is in agreement with the results of the research by Yoshimura and Fujita.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.39-45
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• 1999

Because of internal voids in insulators give rise to partial discharge(PD), which cause local breakdown and even entire insulation breakdown. Treeing due to PD is one of the main causes of breakdown of the insulating materials and nrluction of the insulation life. 1berefore the necessity for establishing a rrethod to diagnose the aging of insulation materials and to predict the breakdown of insulation has becorne irrportant. From this viewpoint, our studies diagnose insulation degradation using the rrethod of computer sensing system, which has PD and acoustic emission(AE) sensing system. To use advantages of these two methods can be used effectiveiy to search for treeing location and PD in sorre materials. In analysis rrethod of degradation, we analyzed the PD and AE pulses by regression analysis, corrpared to these obtained the correlation coefficient and retermination coefficient by T-distribution and saw that PD and AE pulses show a similar pattern on the whole. This has a similar teIlrency to the results of the research by Yoshimura and Fujita.Fujita.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.261-261
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• 2009

층상실리케이트 나노입자를 포함한 에폭시수지인 나노콤포지트를 장시간 트리절연내력을 평가하기 위하여 제조하였다. 층살실리케이트를 포함하지 않은 경우보다 월등하게 긴 트리잉파괴 시간을 나타내었다. 더욱이 층상실리케이트 나노입자와 에폭시수지 계면의 효과를 연구하기위해 silane coupling agent을 나노입자에 표면처리하여 장시간 트리잉 파괴에 초점을 맞추었다. 에폭시수지와 층상실리케이트 나노입자사이 커플링 의한 계면결합은 단시간 절연파괴강도와 장시간 트리잉파괴 시간에 중요한 역할을 하고 있음을 알았다. 그 결과는 침선단에 교류 전계강도가 781.42kV/mm(교류 15kV, 침선단 곡률반경 $5{\mu}m$) 절연파괴시간을 측정한 결과 나노입자가 충진된 경우 트리개시시간이 24,726분이었고, 파괴에 이르는 시간은 29,213분이 걸렸다. 반면에 실란을 처리하지 않은 경우 파괴시간은 11,591분 이었다. 충진된 층살실리케이트 나노입자의 함량은 3wt%로 하였으며, 이와같은 파괴시간 지연 결과의 향상이 152%향상된 결과는 계면의 결합력이 크게 향상되어 나타낸 경우로 사료된다.