Prediction of future performance of in-service XLPE cables

This study examines the performance of 15 kV cross-linked polyethylene (XLPE) insulated new and aged cable (taken out of service after 10+ years) in context with electrical tree and electrical breakdown failure of cable. The breakdown tests are performed using needle plane geometry at room temperature as well as elevated temperature of 100°C. The statistical technique of regression analysis is utilized for analysis of the test results, as well as to predict the future performance and life expectancy of cables. The analytical technique, Fourier transform infrared (FTIR) spectroscopy is used to study the permanent changes in the XLPE material. This study identifies the permanent changes occurring in the material that lead to progressive degradation and/or failure in the long run.