Thermal Aging Assessment of XLPE Cables Using Polarization Current Measurements & Hamon Approximation

Thermal aging is a crucial factor affecting the performance and reliability of cross-linked polyethylene (XLPE) insulated cables. This paper examine the effects of thermal aging on 11 kV XLPE cables through an accelerated thermal aging experiment combined with polarization current measurements under direct current excitation. Four XLPE cable sample were exposed to varying durations of thermal aging, and polarization current measurements were performed on them. From this data, imaginary permittivity characteristics were evaluated using the Hamon approximation to compute the degree of thermal aging. The results showed that the average imaginary permittivity of each sample, corresponding to different aging time, can be mathematically modeled using an exponential equation. This method work effectively in evaluating the thermal aging of the XLPE cable sample. Moreover, parameters such as imaginary permittivity at different frequencies were shown to be effective for evaluating the thermal aging condition over time. Therefore, this methodology can easily determine the degree of thermal aging in XLPE cables, offering insights into their long-term performance.