DEVELOPMENT OF PREFABRICATED JOINT 275-KV XLPE CABLE

Application of XLPE cables to extra-high-voltage (EHV) transmission li nes is expanding due to its excellent electrical properties and ease o f maintenance, and 275-kV long-distance underground transmission lines are reaching the stage of practical utility. Extrusion molded joints (EMJs) are widely used as the XLPE cable joint for EHV transmission li nes. However, EMJs have presented problems because of their insulation , which are formed on site through extruding and molding of crosslinka ble PE as like as the cable, need for long time installation on site, and higher jointing technique. The prefabricated joints (PJs), which a re already applied for 154-kV transmission line, are installed on site by using the parts manufactured and tested in the factory, they requi re shorter installation environment. This report introduces the result s obtained regarding the improvement of electrical property, workabili ty and the performance of PJs, designed for 275-kV XLPE cable. These j oints are planned to be used for 275-kV transmission lines from 1995.