Time-Domain Dielectric Response Characteristics Of Xlpe Cable Insulation Under Different Water Content

The dampness problem of distribution cables is one of the most concerned issues for power companies. However, traditional power cable diagnostic methods such as voltage withstand tests cannot quantitatively determine the moisture content of cables. In recent years, polarization/depolarization current (PDC) method shows great advantages in moisture diagnosis [1]. Therefore, XLPE samples are prepared with different water contents and then measured them by PDC method in this paper. According to the PDC results, the extended Debye model was applied to extract the insulation characteristics parameters, including the value of steady conduction current, polarization time constant tau(i) and aging factor Q. The correlation between the factors above with water content was also analyzed to study the dielectric response of XLPE cable under different water content.