Improvement of the XLPE-insulated distribution cables anddevelopment of the hot line cable monitoring systems

摘要

Crosslinked polyethylene insulated power cables (XLPE cables) werefirst used for 6 kV distribution lines in Japan in 1959. Since then,XLPE cables have been widely used in transmission and distributionsystems because of their many advantages in comparison with oil-filledcables, such as good electrical properties and easy-maintenance andhandling. XLPE cable, however, involves a problem of water treedeterioration. Water treeing began to be an actual problem in about1967, mainly with 6 kV XLPE cables for power distribution, and asolution has since been urged. The authors introduce actual instances ofwater tree deterioration and describe some improvements to the cablewhich may solve the problem. Development of an instrument that enableslive line diagnosis of the deterioration is also described in detail