Growth of lamellar crystalline at the semicon-interface in XLPE power cables

The authors have conducted a research work to improve the break-down strength by improving the crystallinity of the XLPE insulation at the semicon-interface and succeeded to some extent based on the idea using additives mixed into the semicon-layer. From the transmission electron micro-scope analysis, it was found that the lamellar region at the semicon-interface grew larger in the cable specimen with higher breakdown strength. To find out the best condition to improve the lamellar growth at the interfacial region, theoretical and experimental considerations were carried out in terms of the surface energy effect on crystallization at the interface. It was found that a larger surface energy material for the semicon-layer brings about better growth of the lamellar region at the interface