Healing of water tree aged cables using rejuvenation nanofluid

Abstract

The insulation of high voltage power cables is aged due to the impact of water treeing. The voids created due to water treeing can be filled with the injection of nanofluids and restore the insulation of cables. In this work, cross-linked polyethylene (XLPE) cable insulation is restored with the help of tetraethyl orthosilicate (TEOS) rejuvenation nanofluid. The morphological changes in aged and rejuvenated samples are analyzed with the help of scanning electron microscopy (SEM). Moreover, the molecular changes in the aged and rejuvenated samples are detected using Fourier transform infrared (FTIR) spectroscopy. Both the samples are also tested with the help of electrical breakdown tests. The results indicate a positive recovery in the insulation of cables with the injection of TEOS nanofluid. The tanδ results showed a decrease in values after the injection of nanofluid in the aged sample. Moreover, the tanδ values of rejuvenated samples are even better than the unaged cables. SEM results also showed a recovery in the voids of the aged sample due to the injection of nanofluid. FTIR results confirmed that the nanofluid penetrated in the insulation of the cable and the peaks of silicone and alumina bonds are seen in the spectrographs.

Keywords

• High voltage power cables
• Cable insulation
• Nanofluid
• Tetraethyl orthosilicate (TEOS)
• Rejuvenated sample
• SEM