Quality control of extruded HVDC cables: Low frequency endurance testing of model cables with contaminations

This paper presents results from laboratory experiments preformed in order to evaluate different methods for quality assurance of polymeric insulated HVDC cables. Samples of model cables were prepared, equipped with 1.5 mm thick XLPE insulation, containing insulating and conductive spherically shaped particle inclusions with diameters of 250, 140 or 80 μm, distributed at the inner semi-conductor interface. The results indicates that the 0.1 Hz VLF test voltage needs to be 2 to 3 times higher than at 50 Hz power frequency in order to eliminate the same defects within a comparable time.