• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.187-189
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• 1997

Thermal and electrical breakdown phenomena in XLPE insulator of power cable were investigated. At high temperature the polymeric insulator was thermally deteriorated. Under the magnified high electric field, electrical tree was initiated at the sharp tip of needle electrode which was inserted to simulate the defects and impurities such as void, crack, metallic particles, dusts, and so on.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.365-366
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• 2015

This paper describes the analysis on thermo-mechanical characteristics of underground cable termination. Specially, the interface pressures between stress relief cone and XLPE insulation were analysed according to the change of conductor temperature and ambient temperature. This interface pressures were measured by real test with current transformer and chamber and the interface pressure was changed with conductor and ambient temperature. This paper will continue to perform the test with various cases, then the relation between low interface pressure and breakdown will prove with test results in the near future.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2014-2016
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• 2000

In order to meet recent increasing demand for electric power in large cities, plans are being made to introduce 345kV lines into large urban areas. Up to now, OF cables have been used for 345kV fines, but nowadays XLPE insulated cables are preferred as they are easier to maintain due to phenomenal advances in plastic insulation technology, therefore cable manufacturing companies are trying to improve the performance and reliability of UHV CV cables and their accessories. For the purpose, our company has developed facilities for testing UHV cables. In this paper, we describes the methodology adopted for the design and development of a test termination, conducted the electrical test of UHV cables. Based on detailed analytical studies for electrical field distribution, the internal electrical design for the testing end has been carried out.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.477-480
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• 2004

In other to estimate an electrical properties of the cross linked polyethylene cable, the partial discharge properties due to charge of electrode shape(needle and bar) and void size were investigated at room temperature. Fast trip and breakdown time were appeared by the closed of needle electrode. The trip and breakdown voltage depend on insulator thickness. As the result, confirmed larger effect of void size than effect of insulator thickness. The effect of voids size than influence of insulation thickness was dominated by internal an electrode of inner insulators.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.205-209
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• 2015

The economic losses resulted from the accident in the power cables at the power station is not only huge but also requires a great amount of time and expenses to restore to the former condition. In order to prevent these, it is necessary to invent and apply a technique to expect and prevent the accidents. In order to measure insulation resistances of power cables in operation, we derived the relations between load current and temperature. By analyzing data obtained from our measuring equipments, we showed the expected time to change deteriorated cables before accident occurs. We present a result of our study on the effects of the load current on lifetime of 6.6 kV cable systems in operation. With the current flowing through the load of the cable a heat is generated reducing the lifetime of the cable. In order to find out the effect of load current on the lifetime of cable systems, we applied the lifetime theory to the development of two equipments to measure insulation resistance and current of cable systems in operation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.205-211
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• 2014

With a development of modern industry, demand for electric power is rapidly increasing and the capacity of power transfer is required to become bigger and bigger. At power station, the high-voltage power cable is used as the only method in order to transfer electric power. In this paper, we have analyzed the deterioration characteristics of 6.6kV power cable systems in operation. For the time duration of 2000 days, we have measured the cable in operation in order to extract the data for the deterioration characteristics. By analyzing the data by means of several steps of filtering processes, we could obtain the linear relations of insulation resistances as a function of time. Furthermore, we can verify that the progress characteristics in deterioration process of 6.6kV power cable systems follows the process of heat deterioration.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.165-170
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• 2016

The XLPE(or CV) cables installed to deliver high electric power from generator at the power station have operating for the last 40 years in Korea. In 6-8 years from the time of initial operation, the cables in operation start a deteriorating process, depending on the installation and usage conditions. Some cables, even before 6-8 years from the installation, can cause accidents due to the faulty construction or other inadequate environments. In order to prevent cable accident in advance, the regular auditing of power cables are required. For a systematic realization of surveillance and prevention of accidents, we have invented a measuring device. In this paper, we present the device installed at Korean Western Power Co. Ltd., in order to detect the deterioration status of insulation resistances of dielectrics in the cables. We present that the measured results by the device we developed show the deteriorating processes in the cables in operation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.7
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• pp.414-420
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• 2003

The domestic needs for larger capability of power sources are increasing to cope with the expanding power load which results from the industrial developments & the progressed life style. In summer, the peak load is mainly due to the non-industrial reasons such as air-conditioners and other cooling equipments. To cover the concentrated peak load in stable, the power transmission lines should be more constructed and efficiently operated. The ampacity design of the underground cable system is generally following international standards such as IEC287, IEC60853 and JCS168 which regards the shape of 100% daily full power loads. It is not so efficient to neglect the real shapes of load curves generally below 60~70% of full load. The dynamic (real time) rating system tends to be used with the measured thermal parameters which make it possible to calculate the maximum ampacity within required periods. In this paper, the CTM(Conductor Temperature Monitoring) which is the base of dynamic rating systems for tunnel environment is proposed by a design of lumped thermal network ($\pi$-type thermal model) and distribution temperature sensor attached configuration, including the estimation results of its performances by load cycle test on 345kV single phase XLPE cable.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1497-1498
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• 2011

본 논문에서는 -50[$^{\circ}C$]환경에서 케이블 접속함의 극한지역 적용가능 여부를 확인하기 위해 접속함의 주재료인 Etylene Propylene Rubbe(EPR), Silicone Rubber(SR) 및 Epoxy의 물성 및 특성 평가 시험을 진행하였다. 실험방법은 DSC(Differential Scanning Calorimetry)를 사용하여 10[$^{\circ}C$]/min의 승온속도로 각각의 온도구간에서 샘플들의 Tg(Glass Transition Temperature)를 측정하였고, UTM(Universal Testing Machine)으로 -50[$^{\circ}C$]~ 상온에서 인장강도 및 신율을 측정하였다. 본 연구를 동하여, 극한지역의 전력계통 연계 안정성 및 신뢰성 향상을 위한 기초적인 Data-base를 구축했다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.455-458
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• 2002

In this paper, the physical and volume resistivity properties of cross-linked polyethylene (XLPE) for ultra-high voltage investigated due to temperature dependence, and the measurement of volume resistivity used to highmegohm meter is measured from 1 to 30 minutes when the each applied voltage, for example, DC 100[V], 250[V], 500[V] and 1000[V] is applied, according to the step voltage application method. From FT-IR spectrum as an analysis of physical properties, a strong absorption in wavenumbers 700 to 730[$cm^{-1}$ /], 1456[$cm^{-1}$ /] and 2700 to 3000 [$cm^{-1}$ /] observed by the methyl groups(CH$_2$). From the analysis of DSC, the crystalline melting points of the specimen observed in the temperature 60[$^{\circ}C$] and 106.58[$^{\circ}C$].