| This study focuses on efforts to characterize degradation occurring in 15kV cross linked polyethylene (XLPE) insulated distribution cables for a hot and dry climate. The degradation has been quantified in terms of two parameters, namely the area of Fourier Transform Infra Red (FTIR) spectrum and the electrical breakdown strength using needle plane geometry. It has been shown that, degradation occurring in a hot and dry climate can be reproduced by a suitably planned accelerated thermal aging testing in the laboratory. The Arrhenius equation is used for establishing the accelerated aging test parameters. Different modes of statistical analysis namely analysis of variance (ANOVA), Andersen-Darling test for normality, F-test and t-test were performed to validate results from accelerated aging tests with field aging.; An aging model is also designed and validated to assess the future performance of the cable. It is based on a combination of theoretical aging models and diagnostic methods. New and field aged cables were evaluated in this study to validate the model. It has been shown that this approach can be used to prioritize cable replacement and optimize the maintenance schedule. The model uses the intermittent value of the identified degradation markers (available from the field) to assess the future performance. |
