Influence of materials and design alternatives to service reliability of MV cables with XLPE insulation

The authors describe the present state of experience with XLPE cables for medium-voltage in Germany. More than 20 years of operational experience with XLPE medium-voltage cables have proved the advantages during manufacture, laying, installation and operation. The well-known ageing processes could lead to an early failure of the dielectric system (insulation including semi-conductive layer) if neither design nor materials-related measures were taken. The operational experience in Germany and worldwide shows that other ageing processes which could influence the service life of XLPE cables are not likely to occur. Regarding the improved technology now available and quality awareness of manufacturers and users, that XLPE medium-voltage cables have the potential to reach the same service life as paper-insulated mass-impregnated cables