Improvement in reliability of extrusion type molded joint for 275 kV XLPE cable

In the construction of a 275 kV long-distance power transmission line, the reliability of the extrusion-type molded joint (EMJ) is of utmost importance. To improve the reliability of EMJs, a study was undertaken to establish the control value and margin by computer simulation; verify the quality tolerance, variability, and control margin by ascertaining the characteristics of numerous samples; and confirm the properties of EMJs assembled under simulated typical trouble conditions obtained by determining assumed trouble patterns, through failure mode analysis. It was found that improved quality control measures based on the quality control data obtained during assembly permitted jointing work to be performed with greater reliability.<>