Electrical characteristics of the XLPE/EPDM double layered interface at the power cable joint

The main fault in the interface is that power cable insulating materials are mainly composed of a double layered structure, XLPE/EPDM laminates in cable joint. In this paper, an interface of XLPE/EPDM laminates was produced and the breakdown and conduction characteristics were investigated as a function of heat treatment time. The results showed that breakdown strength and conduction current were influenced by volatile crosslinking by-products (e.g. acetophenone, cumyl alcohol, /spl alpha/-methyl styrene) which remained inside the insulating material during the production of XLPE and EPDM, especially during the heat treatment process. The breakdown strength and conduction current of XLPE/silicone oil (12500 cSt)/EPDM was more stable than XLPE/Grease/EPDM over long heat treatment times.