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지중배전케이블 준공시험 관련 국제규격 동향과 국내기준 개선 방안
李載奉(Jae-Bong Lee),鄭蓮賀(Yeon-Ha Jung),宋一根(Il-Keun Song),趙誠勳(Soung-Hoon Cho) 대한전기학회 2008 전기학회논문지 Vol.57 No.11
XLPE insulated power cables are introduced in Korea in 1980s. The cable installation test has been carried out according to the Korean Technical Reference of Electrical Facilities. But recent research results shows DC Hipot test cannot detect the serious defects in XLPE insulated cables. VLF test is recommended as a installation test of XLPE insulated cables by CENELEC and IEEE standards in 1996 and 2001 respectively. We suggest to apply VLF test as an installation test for XLPE insulated MV cables in Korea.
XLPE 절연케이블의 열화진단 정확도 향상을 위한 VLF tanδ 판정기준 개선
이재봉(Jae-Bong Lee),정연하(Yeon-Ha Jung) 대한전기학회 2010 전기학회논문지 Vol.59 No.9
VLF tanδ diagnosis technology is introduced in IEEE Std 400 and proposed as evaluation criterion in an effective way of detecting water tree which mainly causes the failure of XLPE insulated cables. In order to inspect the accuracy of the VLF tanδ method for XLPE insulated power cables in Korean distribution system, diagnosis for 41 cables which were being serviced in the fields has been carried out and they were removed for AC breakdown voltage test after. Regarding the 41 cables, it was hard to confirm any relation between the VLF tanδ values and AC breakdown voltages and also water tree in the insulation was not detected. However, the other cables were failed several days after the diagnosis of the 41 cables. Water trees were found and their VLF tanδ values were also much higher than the criterion of IEEE standard. It has been ascertained that we need to change the IEEE criteria in order to improve the accuracy of detecting water trees by additional analyzing of field examples of failure and case studies from overseas countries and therefore amended VLF tanδ test voltage and evaluation criteria have been proposed.
자동운전 도시철도차량의 운전특성을 고려한 절연구분장치 이론적 고찰
이재봉(Jae-Bong Lee),김재문(Jae-Moon Kim) 대한전기학회 2013 전기학회논문지 Vol.62 No.10
In this paper, proper length of neutral section and neutral section system configuration is proposed to minimize accidents if ATO urban railway vehicle stops maintaining the leading vehicles in air section at regular intervals. When considering the minimum voltage sensing of power conversion unit in the urban railway vehicle, the effective length of 14,280[mm] with neutral section can be minimized damage due to high current because the urban railway vehicle is very little present chance compare neutral section with pantograph interval installed on a unit vehicle. In addition, uplift of catenary line and contact wire consider to minimize damage. The result of theoretical review, as the proposed neutral section shorter, isolated neutral section is effective than the integrated neutral section.