• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권11호
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• pp.514-519
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• 2006

To improve the mean-life and the reliability of power cable, we have investigated specific heat (Cp) and thermal conductivity of XLPE insulator and semiconducting materials in 154[kV] underground power transmission cable. Specimens were made of sheet form with the seven of specimens for measurement. Specific heat (Cp) and thermal conductivity were measured by DSC (Differential Scanning Calorimetry) and Nano Flash Diffusivity. Specific-heat measurement temperature ranges of XLPE insulator were from $20[^{\circ}C]\;to\;90[^{\circ}C]$, and the heating rate was $1[^{\circ}C/min]$. And the measurement temperatures of thermal conductivity were $25[^{\circ}C],\;55[^{\circ}C]\;and\;90[^{\circ}C]$. In case of semiconducting materials, the measurement temperature ranges of specific heat were from $20[^{\circ}C]\;to\;60[^{\circ}C]$, and the heating rate was $1[^{\circ}C/min]$. And the measurement temperatures of thermal conductivity were $25[^{\circ}C]\;and\;55[^{\circ}]C$. From these experimental results both specific heat and thermal conductivity were increased by heating rate because volume of materials was expanded according to rise in temperature. We could know that a small amount of CNT has a excellent thermal properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1881-1883
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• 2002

Recently, 345kV XLPE Cable and Accessories have been developed and will be applied for Youngseo$\sim$Youngdeungpo project in Korea. So, let this project and the process of development introduce on this paper. The cable type and length of this project is 345kv XLPE 1C*$2000mm^2$ 66km and all cable will be pulled on cable tunnel. The diameter of cable insulation was designed as 27mm, we could reduce it by appling for hi-tech and super-clean system. Joints were developed by a pre-fabricated type which considered high safety and economic issues. We had also done Pre-Qualification test for verifying the reliance of cable and accessories before construction. As we developed this 345kV XLPE cable system including its accessories at the same time, we can have higher technologies and contribute safe power in transmission lines. In adtionally, we can have a stable status for suppling EHV cable systems to a variety foreign customers by ourselves.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2268-2270
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• 1999

The underground transmission line have been consistently developed to increase its voltage level for satisfying the customer's demand through supplying the high reliability power. The underground XLPE cable and its accessories of 500kV level have been already developed internationally, but the XLPE cable have been installed 154kV level in Korea up to now. Thus, our company has developed 230kV XLPE cable and its accessory in 1998 for preparing 345kV level system in Korea and being qualified as international cable maker of developing oversea markets. In this paper, newly our developed 230kV system will be introduced using the type test result according to IEC 840 and additional specification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1608-1610
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• 1998

An oil-filled paper-insulated power cable and a XLPE-insulated power cable have been mainly applied as an extra-high-voltage underground power cable. But in recent the XLPE cable has been applied more widely than the OF cable, because of its advantages, such as the low-cost and simple installation. In general two types, molded and prefabricated, of straight joints are applied for the XLPE cables. For a tape-molded joint, one of molded joints, its electrical properties are excellent, but it has some disadvantages, such as a long working time. high skill of workers and the high cost of jointing equipments. For a prefabricated joint, developed and applied in Europe and Japan, its working time is short, its jointing procedures are simple, and its quality control is easy, but its prices are very high. In Korea the development of a compression-type PJ will be finished in the near future, and studies of its jointing techniques and equipments is actively going on. This paper describes the design and construction of the PJ, the jointing procedures and techniques for the PJ, and its future trends.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1954-1956
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• 2000

In this paper, when void of XLPE was existed, electrical tree was growth in branch-type, and it was growth in bush-type when void of XLPE was not existed. Moreover, charge magnitude of partial discharge by deterioration time of XLPE sample was about proportion to output voltage of AE signals. When void was existed, charge magnitude of partial discharge, the output voltage Vp-p value of AE signals were increased with increasing deterioration time. However, when void were not existed, charge magnitude of partial discharge, the output voltage Vp-p value of AE signals were increased in fast deterioration time, but it were decreasing at after in middle deterioration time. Frequency spectrum response of AE signal was about 100-250[kHz].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2268-2270
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• 2005

전력계통분야에서 송전전압의 초고압화는 꾸준히 연구가 진행되는 과제중의 하나이다. 국내에서는 당사가 참여한 한전(KEPCO)의 영서${\sim}$ 영등포 345kV XLPE 지중T/L 건설공사가 2003년 6월 20일 국내 최초로 준공된 이후 현재까지 아무런 문제없이 운전중에 있으며, 향후 그 수요가 꾸준히 증대될 것으로 예상되고 있다. 전 세계적으로 살펴보더라도 400KV급 XLPE 케이블 및 부속재에 대한 수요가 꾸준히 확대되고 있다. 그러므로, 당사에서는 국내에서 345KV 케이블 및 부속재를 개발한 기술력을 바탕으로, 한 단계 업그레이드된 해외시장에서 세계의 업체들과 경쟁하기 위해, 400KV 2500sq.mm XLPE 케이블 및 부속재를 성공적으로 개발하였다. 이에 관해 소개하고자 한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.220-223
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• 2003

This paper is aimed at determining the e-field distribution by apply voltage of air void, which can be generate air void in the XLPE cable for ultra high voltage. E-field distribution had an effect in XLPE due to the type and position of void, compared and studied. This method of analysis is based on the quasi-static electromagnetic 3D simulation program by boundary element method (BEM): Applied AC 3[kV], discretization of 2000 elements, 4 angular periodicity, The result of experiment indicate that E-field distribution appeared the highest levels on the void position of electrode 2[nm] outer boundary and shape of the smallest inner angle in the void. This will serve to explain the XLPE cable degradation studied of possible, connected cable variation of position and shape of void effects to e-field concentration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.58-61
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• 1997

Effects of ionic impurities on the dielectric breakdown of the crosslinked polyethylene (XLPE) were studied using aqueous electrolytes. It was found that the AC breakdown strength of XLPE decreases considerably when the ions are present in the electrodes composed of aqueous electrolyte. Details of results were described.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.313-316
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• 1995

In this study, in case the lead sheath of XLPE cable (radius : 15cm, inner conductor radius : 5cm, insulation paper raidius : 6cm, dc voltage : 1MV) is harmed, so that breakdown process by inhomogeneous eletric field is simulated with Finite Element Method. The result of simulation showed that defect of lead sheath layer caused breakdown.