• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1154-1160
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• 2015

This paper describes the thermal characteristics of underground power cable system terminations according to the change of ambient temperature as well as operating temperature. Recently, the failure has been gradually increasing in outdoor termination during winter season because the power demand was increased by electricity heating system. The power demand and outdoor temperature is difference between day time and night time. The temperature difference has an influence on conductor extension and shrinkage due to conductor force as well as thermal mechanical characteristics. These phenomena have daily repeated during heating and cooling period of conductors. In these cases, the insulation of outdoor terminations might be degraded by the reduced interface pressure surrounding stress relief cone. Therefore, in this paper, the thermal characteristics are variously analysed by simulation considering power demand and ambient temperature condition during winter season at epoxy type termination as well as slip-on type termination

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.39-46
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• 2015

A outdoor termination installed at the outdoor substation is required to connect undergroud cables and overhead transmission lines. The joint box for AC transmission system is already developed and widely used to interconnect overhead and undergroud systems. But the development of the joint box for DC transmission system was only introduced from China and Japan, but theire developemnt staus and core technologies were not fully reported. In order to implement HVDC systems connecting ovehead transmission lines and undergroud cables, a outdoor termination should be developed, but the detailed specifications and information of this device were not reported. It is estimated that the development of the joint box for DC environment has some technical obstacles including insulating materials, electric field mitigation, thermal temperature rise, and space charge accumuations. Among this, the most important one is the DC elctrical insualtion design. Therefore, in order to investigate the DC elctrical insualton design of outdoor termination, the design of AC slip-on type outdoor termination is reffered, and DC electric field analysis performed to verify the possiblity of application of AC joint box into DC joint box. Especially for DC electric field analysis, temperature rise of insualting materials of a joint box was considered, because the conductivity of materials could be changed due to temperature rise. Furthermore, DC electric field analysis considering transinet state, and polarity reversal state were also investigated to verify which state is the most severe condition for the DC joint box. From the simualtion resulsts, it was shown that the value and the position of maximum electric field was obtained comparing AC state, DC state without temperaure rise, and DC state with temperaure rise. And it was confimred that severe DC electric field was observed considing temperaure rise. Finally, in order to reduce DC eletric field intensifation, different configuration of the joint box was applied and it was not possible to obtain satisfactory results. It means that the slight change of configuration of AC joint box was not the suitable soluton for DC joint box. It is essential to establish novel DC insulaton design skills and method for DC joint box to commercialze this product in the near future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.257-263
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• 2016

This paper describes the lightning arrester transients in cable head termination. The installation references of cable head tower and lightning arresters are firstly reviewed, then the performance of lightning arrester operation is also evaluated based on lightning overvoltage analysis by the change of grounding lead cable length. This paper finally proposes the optimal length of grounding lead cable at the cable head termination. The limited lightning current is also proposed according to the change of grounding lead cable length. The results will contribute to protecting insulation breakdown failure against lightning surge at the terminations and joints.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1216-1217
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• 2008

A description is given of impregnated silicone rubber used in accessories for application on outdoor termination (EB-A). We examines the effects of swelling and mechanical/electrical characteristics for impregnated silicone rubber to develop slip on type sleeve of silicone material. There are semi-conductive silicone rubber and insulation silicone rubber. This examination is monitored as a function of the viscosity and temperature of oil during 30hr. We measure elongation at breakdown and AC breakdown strength and volume resistivities of the oil-impregnated silicone rubbers. The measured values are compared to initial value as function of stress relief cone.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.623-624
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• 2007

This work examines the effects of swelling MI type HVDC cable oil on the semiconductive silicone rubber and silicone rubber as used in accessories for application on outdoor termination (EBA) slip on sleeve. The behavior of volume resistivity is monitored as a function of the amount of cable oil diffused into the material. Resistivities of semiconductive silicone samples up to the typical insulator range (${\sim}10^{10}{\Omega}-cm$) are observed as a consequence of swelling due to the presence of the diffused oil. The measured volume resistivities of the oil-impregnated semiconductive silicone rubber are compared to desired value as function of stress relief cone.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.594-597
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• 1993

With the increase of electric power demand in the downtown area. many problems, such as the difficulty in security of substation site and interference of the electromagnetic wave or damage to person due to outdoor type substation facilities has been occured. Therefore, the compaction of substation facilities is required and the gas insulated switchgear(GIS) has been adopted accordingly. However, much care should be taken of the interface problem between cable and GIS. This paper describes the failure analysis and a countmeasure for prevent ion from failure in the interface.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1629-1631
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• 1998

Crosslinked polyethylene (XLPE) insulated cables are now widely used all over the world for extra-high voltage underground transmission systems. Prefabricated type (compression type) joint has developed in order to shorten the assembly time and lower the possibility of contamination at site by many companies in the world. For outdoor termination, to control the electric field distribution as uniform as possible, especially for the use of extra-high voltage system. much of products are adopting the oil-impregnated condensor cone type instead of electric field control element which uses the permitivity of it only (not capacitance). For Gas-immersed termination, dimension of outer insulation bushing was determined by IEC Publication 859. The highest voltage of underground power cable system is 345kV now, in Korea. We have much of experiences of the development of prefabricated type accessories for CV cable systems (154kV, 161kV, 230kV level). So it was possible to inspect the proto type of accessories for 345kV CV cable system and seems that the need time for the development of products is reduced.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.192-192
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• 2010

DAPAS (Development of Advanced Power system by Applied Superconductivity technologies) program that the, superconductivity national program has been started one of the 21C frontier programs from 2001 in Korea. The 3rd phase of DAPAS program was started at April 2007, and the ultimate goal of HTS cable project is to develop 154kV, 1GVA class HTS cable. The structure of 154kV, 1GVA HTS cable is single core with cold dielectric insulation. The cable core consists of the former, conduction layer, electrical insulation layer, shielding layer. The cable cryostat consists of two corrugated seamless aluminum tubes as its high sealing reliability, the tubes separated through a spacer arrangement. Outdoor termination was developed by LS cable and cryogenic system by CVE for 154kV, 1GVA class HTS cable. The 154kV, 1GVA HTS cable will be installed and be tested in KEPCO Gochang Testing Center from June 2010.