高压电缆大截面分割导体焊接后的机械性能及缓冲阻水层设计

A Study on Mechanical Property of Large Section Welded Milliken Conductor and Design of Water-Blocking Buffer Layer for HVAC Cable

结合国网南京供电公司"秋藤-高旺"220 kV电缆线路工程,介绍了导体截面为2 500 mm^2的220 kV高压陆缆大长度的设计与生产情况。采用整体焊接法完成2 500 mm^2分割铜导体焊接,根据电缆生产过程中导体的受力情况设计试验验证导体焊接后的机械性能,通过绝缘线芯热膨胀试验确定膨胀程度与缓冲层厚度配合情况,并进行了缓冲层的纵向透水试验。焊接后2 500 mm^2分割导体在300 k N拉力作用下未破断,试验后焊接点无明显损伤;焊接导体在100 kN下的张力弯曲试验过程中经受了三次弯曲循环,焊接点无开裂情况;成品电缆样品在热膨胀试验后未出现绝缘线芯的明显形变,缓冲层的纵向透水距离为0.7 m。通过上述研究充分说明了本产品分割导体焊接方式及采取的缓冲层设计可应用于大长度高压陆缆的生产。

This paper introduced the design and manufacture of 220 kV-2 500 mm2 land cable based on ＂QiutengGaowang Power Transmission Project＂built by Nanjing Electric Power Company. 2 500 mm2 conductor was welded in whole section in according to the stress condition during the manufacture of cable,then tensile strength test and tensile bending test was carried out. Simulating the cable actual running state through the thermal expansion test to make sure that the thickness of buffer layer match the expansion of cable,and testing the water-proof capability of buffer layer by vertical permeability test. The welding conductor samples went through tensile force test under 300 kN without exception on sample,and tension bending test under 175 kN for three times with no crack. After thermal expansion test,there was no indentation in the surface of insulation conductor. Vertical permeability test showed the permeable distance was 0. 7 m on the condition of 1 m water column and 10 thermal cycle.