Fault analysis of oil-filled power transformers using spectroscopy techniques

The power transformer plays a vital role in the power system network. Nowadays, the condition monitoring of oil-filled power transformer is greatest requirement for its reliable operations and quality power supply to the utility. The condition of such transformer can be indeed determined by knowing the ageing status of the dielectric liquid used for insulation and cooling. Though Dissolved Gas Analysis (DGA) has been well-acclaimed in the field of the transformer fault diagnosis, it has certain drawbacks like need of carrier gas, regular calibration. To overcome these drawbacks, in this proposed work, optical methods such as Ultra Violet-Visible (UV-vis) spectroscopy and Nuclear Magnetic Resonance (NMR) have been used. The obtain results of UV-vis spectroscopy demonstrate that all the characteristic peaks are covered and qualitatively analyzed within the wavelength region of 200-400 nm. Further, NMR spectroscopy results precisely identified the molecular groups present in the oil such as the methyl group, methylene group and the aromatic hydrocarbon groups. Moreover, this method is fast and reliable for determining the moisture content in the transformer oil. Overall, the obtained data confirms that UV-visible and NMR spectroscopy methods are highly efficient for analyzing the degraded transformer oils.