Evolution of ac and impulse breakdown strength of HV XLPE cableafter long term test. Correlation with physical properties

摘要

Despite the good knowledge of actual materials for HV insulationcable, the influence of aging on dielectric properties is not wellknown. Recent 90 kV XLPE cable aged on site with load cycles has beeninvestigated just after fabrication, after 15 000 hours and 30 000 hoursaging. In addition, the thermal loop after 30 000 hours only stressedwith thermal cycles is also under investigation, allowing separation ofthermal and electrical stresses influence on insulation aging.Electrical and physical properties are followed with aging time andcompared with those of unaged insulation