Understanding the Aging of XLPE Cable Insulation Using Impedance Analyzer

The common problem of insulation failure is the root cause of concern for the aging of the equipment. The objective of this work is to use the Impedance Analyzer to investigate the electrical parameters of Cross-Linked Polyethylene (XLPE) insulation under various aging conditions. The electrical parameters of XLPE insulation are measured and compared for both aged and unaged samples. Aging of XLPE insulation is carried out at different values of Relative Humidity (RH), i.e., at 60°C & 50% RH, and 60°C & 80% RH. The samples are aged at a specified temperature and relative humidity under constant and cyclic stress in a thermal and humidity chamber. Frequency spectroscopy is performed between 4 Hz to 1000 Hz. The electrical parameters measured are dissipation factor, capacitance, and conductance. It is seen that aging modifies the XPLE samples' electrical parameters and relies on temperature and relative humidity.