• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.136-140
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• 1999

Measurements of AE signals caused by partial discharges were performed by using an ultrasonic measurement technique to diagonise the electrical treeing deterioration in XLPE cable. We also examined the partial discharge magnitude and AE signals(peak-to-peak) with the increase of the deterioration time. From these results, it was found that AE signal due to partial discharge can be greatly detected at the peak value of positive polarities prior to the breakdown voltages, and the magnitude of AE signals was closely related to the current pulses by the increase of deterioration, and it appeared that AE signals(peak-to-peak) was proportional to partial discharge magnitude. Attenuation and time-delaying characteristics of ultrasonic signals propagated in various polymers sample by using ultrasonic oscillation and receiving systems are also reported as a basic data of ultrasonic measurements in XLPE cable.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.491-493
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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 $25{\sim}100[^{\circ}C]$ and frequency $20{\sim}1[MHz]$ and volume resistivity at temperature $25{\sim}100^{\circ}C$, voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.193-196
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• 2001

XLPE is occasionally happened to deteriorate cable insulation characteristics. It is happened to do a breakdown state by the degradation of electrical characteristic and electrical breakdown strength. I prepared TR-XLPE (Tree-Retardant XLPE) as adding various additives to prevent its states. Various additives are treeing retardants, anti-oxidants. Treeing retardants three kinds of aromatic compounds as adding each additive. Anti-oxidants use quinone compound and cresol compound as adding each additive. In order to observe each electrical characteristics, I measured breakdown strength, relative dielectric constant$({\varepsilon}_r)$, dielectric loss tangent$(tan{\delta})$. TR-XLPE specimens as adding treeing retardants and anti-oxidants enhance breakdown strength, ${\varepsilon}_r$, $tan{\delta}$ than pure XLPE.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1330-1332
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• 1994

In order to investigate the properties of electrical conduction and space charge in crosslinked polyethylene film, we were observed the specimen with 200[${\mu}m$] thickness. The electrical conduction properties of specimen were measured temperature range from 30 to $110[^{\circ}C] $as well as $10^{-2}$ - 1 [MV/cm] of electric field. The investigations on influence of space charge were carried out at room temperature and $60 [^{\circ}C]$.

• 전기의세계
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• v.27 no.6
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• pp.76-83
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• 1978

This paper reveals the results of fundamental experiments with the breakdown strength- and treeing phenomena, by A.C voltage and impulse voltage, of cross-linked polyethylene insulator, respectively compared in each case of the various specimens; nonvoid, air void, water void, oil void and oil impregnated one, all articially made. In this research, the V-t and V-n characteristics are investigated by means of the Weibull distribution and are analysed the characteristics of fatigue breakdown caused by the A.C and impulse voltage. Based on numerous tests, treeing effect and treeing breakdown mechanism is investigated through microscopic photographs taken to clarify the shapes of each tree and treeing breakdown phenomena.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1377-1378
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• 2007

본 논문에서는 초고압 케이블에서 절연재료로 사용되고 있는 가교폴리에틸렌(Cross-Linked Polyethylene; xLPE)에 침전극의 기울기와 인가전압의 변화에 따른 전계분포와 방전특성을 경계요소법에 의한 3차원 시뮬레이션과 부분방전장치를 통하여 해석하여, 기울기가 $45^{\circ}$에서 전계가 집중되는 현상을 확인하였다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.6
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• pp.23-31
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• 1992

Charged particle in the polymers is supposed to affect the electrical conduction and to lead them th dielectrical breakdown finally. So we measured the space charge distribution made by application of high electric field and evaluated the polarity of the charged particle affected on electrical conduction and space charge formed in the insulating materials by using temperature gradient thermally stimulated current measurement method(TG-TSC measurement). As a result, in the cross-linked polyethylene, A-peak was caused from dipole polarization, C-peak was caused from ionic space charge polarization and D-peak was injected trap hole. Also we found it crossible the evaluated the polarity of injected trap carrier and electron(or hole) of carrier trap in the cross-lined polyethylene. We found that ${\gamma}$-ray irradiated low density polyethylene had a relation to the electronic trap and we also could get the value of electric field distribution in the samples of which evaluation was available.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.11-17
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• 1999

Aging characteristics of the crosslinked polyethylene have been measured after applying electrical, thermal and combined stresses. ICP and FT-IR measurements confirmed diffusion of low molecular weight components such as antioxidant and presence of carbonyl group. Carbonyl group of aged crosslinked polyethylene under combined stress was detected by FT-IR. As deterioration of the crosslinked polyethylene progresses, crystallinity degree and density decrease. Also, dielectric properties have been measured by tan $\delta$ and $\varepsilon$$_{r}$ measurements. The three-parameter Weibull distribution was found to be the best suited among other probabilistic distribution representing the dielectric breakdown strength of aged crosslinked polyethylene. The scale parameter and location parameter decreases as the applied stress increases. The shape parameter increases as the stress increases.s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.234-235
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• 2005

본 논문에서는 전력용 케이블에서 초고압으로 사용되고 있는 가교폴리에틸렌 내부(XLPE)에 침투된 침전극의 곡률반경변화에 따른 XLPE의 전계분포를 경계요소법에 의한 3차원 시뮬레이션 프로그램을 통하여 해석하여, 곡률반경이 작을수록 전계가 집중되는 현상을 확인하였다.

• Membrane Journal
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• v.27 no.5
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• pp.441-448
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• 2017

In this study, the effects of membrane characteristics on the power generation performance in reverse electrodialysis (RED) have been investigated with pore-filled ion-exchange membranes (PFIEMs) prepared by employing a porous polyethylene substrate and the mixtures of three cross-linking agents. As a result, it was confirmed through the correlation analyses that the cross-linking degree and free volume of the PFIEMs were effectively controlled by mixing the cross-linking agents having different molecular sizes, influencing complexly the electrochemical characteristics of the membranes and the power generation performance in RED. In particular, the pore-filled cation-exchange membranes at the optimum cross-linking conditions exhibited the power generation performance superior to that of the commercial membranes and the pore-filled anion-exchange membranes also showed the excellent performance close to that of the commercial membrane.