Analysis of transformer oil degradation due to thermal stress using optical spectroscopic techniques

Abstract

Summary The power transformers are continuously under the impact of electrical and thermal stresses. These stresses are primarily responsible for the occurring incipient faults such as partial discharge, arcing, and pyrolysis. The incipient faults, if not taken care at the earliest, cause the insulating transformer oil to degrade and transformer failure over a period of time. Therefore, monitoring and diagnosing the power transformer have become an inevitable task for its effective functioning. In this proposed work, thermal analysis on different transformer oil samples has been performed by using optical methods such as ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy and Nuclear magnetic resonance (NMR) spectroscopy. The obtained results with UV‐visible spectroscopy method exhibit proportional degradation of the oil samples with temperature rise. The Fourier transform infrared method identifies the dissolved gases (ie, CH4, C2H6) released during the decomposition of hydro carbon present in the transformer oil. Finally, NMR spectroscopy method also confirmed that it has the potential to monitor the decomposed oil by investigating the region under an NMR signal which is proportional to the number of absorbing protons. The employed photo‐spectroscopic methods can be best alternative next to so called dissolved gas analysis method.

A Review on Oil-Based Nanofluid as Next-Generation Insulation for Transformer Application

“…The natural ester oil and both nanoparticles react positively in the electrical breakdown value for all ranges of concentrations as illustrated in Figure 6 [88]. According to the researchers, the outcome may be due to the contribution of nanoparticles that leads to the formation of a shallow trap [89] and eventually results in the reduction of the existence of a breakdown mechanism.…”

Performance studies on dielectric and physical properties of eco‐friendly based natural ester oils using semi‐conductive nanocomposites for power transformer application

“…The results prove that use of ester oil-based NCFs serves as a compromising insulation medium and will be the best alternate for traditional mineral oil. The detailed degradation analysis [35] may be carried in future with an accelerated ageing process with different semiconductive nanopowder under various concentrations.…”

Transformer oil diagnostic by using an optical fibre system: a review

“…Throughout their lifetimes, transformers are subject to the effects of chemical, electromagnetic, electrical, mechanical and thermal changes under normal or transient loading conditions. These effects induce a gradual deterioration in the performance of a transformer and a decrease in its operational lifetime [47]. Transformer insulation is severely affected by the rise in temperature [48], and transformer losses are amongst the foremost drivers of the increases in top oil temperature and hotspot temperature (HST) rise [49].…”