• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2051-2053
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• 1999

In this work, PD patterns and electrical trees are observed by use of the XLPE cable insulation. and the tree initiation voltage related to the contamination are also measured in order to calculate the electric stress necessary for the design of cable insulation. Throughout these works, correlation between the PD pattern and the shape of electrical tree has been observed that there may exist three distinct pattern of PD dependence on the stage of tree propagation, Such correlation could bring a basic information in connection with the partial discharge of cable system. It was also found that the electrical stress necessary for the initiation of electrical tree was measured to the 290kV/mm for the 154kV XLPE cables manufactured in KOREA.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.179-182
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• 2002

XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.558-562
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• 2003

In this paper, neural networks is studied to apply as a PD source classification in XLPE power cable specimen. For treeing discharge sources in the specimen, three defected models are made. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different models of discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for three PD sources.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.114-120
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• 2008

XLPE cable is using insulator for Cross Linked Polyethylene(XLPE), because insulation Performance is superior and easy comparatively. Need systematization of accident transaction for electrical equipment accident, It is no disposal standard for defect of manufacture and second to accidents. in this paper deals with the change of XLPE cable insulation. To understand the electrical properties of XLPE insulation. Made of XLPE block sample, Penetration fracture Sample and flashover sample. Ogura needles having tip radius of $10[{\mu}m]$ were inserted into each sample. AC voltage of 1[kV/sec] increased at 60[Hz] were apple to breakdown sample and flashover sample. AC voltages of 12[kV], 17[kV] at 60[Hz] were a lied to XLPE block sample. The electrical properties of specimens were measured were measured from initiation of tree and breakdown to their characteristics were analyzed.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.73-77
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• 2022

Recently, as the number of years of operation has increased for more than 30 years, interest in evaluating the remaining life of major power facilities such as transformers and ultra-high voltage cables is increasing. In particular, the risk of failure is increasing because the underground transmission XLPE cable has been built since 1980 and has been operating in excess of 30 years of design life or close proximity. Therefore, it is necessary to develop an algorithm to evaluate the residual life of the XLPE cable considering the load to determine the risk of failure. Since load data is large amount of data, it is necessary to make the variable load information equivalent to the time unit first in order to calculate the remaining life of the system quickly. In overseas literature, transformers are reported to be standardized for variable load equivalent conversion formulas, but they have not been reported for ultra-high voltage cables. Therefore, in this paper, whether the equivalent conversion formula of a transformer can be applied to XLPE cables was reviewed through accelerated degradation tests under equivalent and variable temperature conditions, and considerations were studied when evaluating the remaining operating life of XLPE cables based on the experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.93-93
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• 2010

We developed friction welded bimetallic sleeve for 220kV aluminum conductor XLPE cable. Not only friction welded bimetallic sleeve for Termination(EB-A, EB-G) but also friction welded sleeve for Joint of Al to Cu conductor was developed regardless of this project. Generally, friction welded sleeve used to connect Al conductor cable to Cu conductor cable and used for improvement of mechanical property of terminal by offer the copper side of friction welded bimetallic sleeve at the Termination. Connection method for Al-Cu conductor has mainly used friction welding at the solid state, because it is difficult to connect by using conventional welding method. this investigation introduces development of friction welded bimetallic sleeve by friction welding and test result of 220kV Al conductor XLPE cable and accessories using friction welded sleeve.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.225-228
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• 1997

The main fault in this interface is that power cable insulating materials are mainly composed of a double layered structure, XLPE/FPDM laminates in cable joint. In this parer, we instituted the interface of XLPE/EPDM laminates and then investigated the breakdown and conduction characteristics as a function of heat treatment time. The results showed that conduction current was influenced by volatile crosslinking by-products which remained inside the insulating material during the production of XLPE and EPDM, especially during heat treatment process. And conduction current of XLPE/Oil 12500cSt/EPDM was more stable than XLPE/Grease/EPDM from the long heat treatment time. AC breakdown strength of silicone oil itself from the heat treatment was changed during the 4∼12 hour heat treatment time.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.90-95
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• 2004

This paper simulated partial discharge caused by 22.9[kV] power cable using XLPE(Peroxide Crosslinkable Polyethylene) insulation having the outside damage. As one of the insulation diagnostic method a radiated electromagnetic waves were measured by an UHF method using a BiconiLog antenna(EMCO-3142) and a spectrum analyzer used to measure EMI, EMC. From results of this study, It was confirmed that discharge Ogress were possible to be estimated by the proposed method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.75-81
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• 2018

In this study, the simulation of partial discharge pulse waveform have been performed for the typical joints such as EBA and PMJ in the HV underground transmission XLPE cable system in order to improve the understanding of partial discharge pulse waveform and the on-site measurement accuracy of partial discharges. FDTD simulation technique was adopted for the simulation and has been shown to be suitable for partial discharge simulation of power cables in terms of pulse propagation characteristics and waveform formation. The simulation results for the EBA showed that the second not-so-large opposite polarity peak appeared after the first negative polarity peak and the measurement sensitivity was the highest near the bottom of the EBA copper box. In the analysis results for PMJ, the magnitude of the second opposite polarity peak was large enough to compare with the first peak, and the measurement sensitivity at the end of the PMJ copper box was the highest. These simulation results show considerable similarity with the on-site measurement, and it would be very useful for the partial discharge measurement of HV XLPE cable systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.138-141
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• 2004

In this paper, we Investigated effects on impurities and water of semiconductive shield through a thermal, mechanical, and absorption experiment to estimate performance of insulating materials in power cable. Specimens had been prepared 22[kV], 154[kV] XLPE power cables and then were made of sheet form with XLPE and semiconductive shield with dimension of 0.4[mm] ~1.2[mm] of thickness from power cable. Heat capacity $({\Delta}H)$ and glass trasition temperature (Tg) of XLPE sheet were measured by DSC (Differential Scanning Calorimetry). We could know that thermal stabilities of 154[kV] are more excellent than 22[kV] from this experimental result. The strain of mechanical properties in 22[kV] and 154[kV] XLPE was 486[%], 507[%] and stress was 1.74$[kgf/mm^2]$, 1.80$[kgf/mm^2]$. The absorption contents of existing semiconductive shield were measured 710[ppm] to 1,090[ppm], and semiconductive shield of 22[kV] cable was measured 14,750[ppm] to 24,780[ppm]. We thermal and mechanical properties of 154[kV] could know more excellent than 22[kV] from this experimental result.