Studies on the effects of temperature on XLPE cable insulation through Polarization and Depolarization Current (PDC)

Cross-linking Polyethylene (XLPE) insulation cable is most preferable power cable in underground transmission and distribution system. Power cables are operated for several years undergrounded and many factors like moisture, temperature can affect cable insulation over the years which may leads to insulation failure. The maintenance & detection of cable insulation status is thus very important as any kind of failure leads to economic losses and lot of problems. Dielectric response analysis is one of the advanced tool for condition monitoring of cable insulation. This paper is aimed to address the effect of temperature on thermally aged cable within its maximum operating temperature. To study the effect of temperature, PDC is performed on thermally aged cable at a temperature ranging between 25°C to 70°C. Based on the PDC results R-C parallel branch parameters of Debye model and Aging factor for different temperatures are calculated.