Evaluation of Partial Discharge Aged Transformer Oil Using Optical Spectroscopy Techniques

In recent times, optical spectroscopy techniques are being widely accepted for chemical analysis of transformer oil. These techniques gained popularity because of the advantages like they are quite simple to perform, give results very quickly, outcome is reliable, and they are economical. Unlike traditional methods, these can also be carried out online with cost effective equipments. In this work, breakdown voltage test is done and then, UV - Visible (UV - Vis) spectroscopy and Fourier transform Infrared (FTIR) spectroscopy techniques have been used to investigate the condition of the transformer oil. To replicate the actual aging of oil in field, partial discharge (PD) in the laboratory environment has aged oil samples. Test results obtained from UV-Vis spectroscopy gives the qualitative analysis of transformer oil and FTIR spectroscopy evaluates the functional group present in it. The analysis is done precisely by relating the optical spectra obtained by spectroscopy techniques with the duration of aging. The results obtained justify that the optical spectroscopy techniques used, can accurately analyze the condition of aged transformer oil.