A study of the GK transformer oil using the EPR and NMR methods

Turanova, O. A.; Sharipova, A. R.; Суханов, А. А.; Гнездилов, О. И.; Козлов, В. К.; Туранов, А. Н.

doi:10.1134/s0965544110060113

Cited by 9 publications

(7 citation statements)

References 6 publications

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“…Between 0.5 to 1.9 ppm, more strong lines are acknowledged and between 1.9 and 3 ppm, signals which authorize the formation of alkoxyl groups are identified owing to transformer oil aging due to heat treatment given to the samples. Finally, between 6.5 and 7.5 ppm, the lines confirm the aromatic groups, which are generally indicative of the result of the process of the degradation of the oil . Though all the graphs seem to be same, there is significant variation based on the type of the sample oil.…”

Section: Resultsmentioning

confidence: 67%

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

Kalathiripi

Karmakar

2017

Int Trans Electr Energ Syst

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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.

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Section: Resultsmentioning

confidence: 67%

“…The NMR for the 48 hrs heating period at 120°C is chosen to show how NMR can be a useful technique to investigate the deteriorated oil samples. Indeed, the results show that the vitality of this method for degraded oil analysis …”

Section: Resultsmentioning

confidence: 90%

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

Kalathiripi

Karmakar

2017

Int Trans Electr Energ Syst

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“…The T 2i and p i values of the TMD-decomposition components of the samples investigated, which were determined with a correlation coefficient |R 2 | > 0.95, are presented in Table 1. The presence of two Lorentz components with relaxation times T 2a = 164 ± 17 msec and T 2b = 53 ± 8 msec in the TMD of the TO samples correlates with results of these same samples by high-resolution 1 H NMR spectroscopy [14], in the spectra of which the widths at the half heights of the two most intense lines are matched up as 1:3. The signals of these components pertain to the profiles of the liquid-phase molecules.…”

Section: A(t) Absolute Unitsmentioning

confidence: 60%

“…The one-order intensification of the effect of nonlinear optical absorption is inexplicable in sample III, since the content of aromatic hydrocarbons in the liquid phase of these oils does not differ so significantly [14].…”

Section: A(t) Absolute Unitsmentioning

confidence: 99%

Investigation of transformer oil by nuclear magnetic relaxation and Z-scanning

Arkhipov

Gizatullin

Shkalikov

et al. 2013

Chem Technol Fuels Oils

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G K -g r a d e t r a n s f o r m e r o i l i s i n v e s t i g a t e d b y m e t h o d s o f n u c l e a r m a g n e t i c r e l a x a t i o nand Z-scanning. The size of the heterogeneous structures in the oil increases during its service. The solid-particle content in the liquid phase, however, remains essentially unchanged, and the excess particles precipitate. The feasibility of quantitative determination of the heterogeneous-structure/liquid ratio in oil samples investigated is discussed.Heterogeneous structures -colloidal, micelle-like, and solid particles -affect the properties of transformer oils (TO), and may substantially reduce the breakdown voltage, and alter the viscosity and other TO characteristics critical to power transformers, and, consequently the power systems on the whole [1, 2]. Owing to the physical and chemical processes that take place under the action of temperature, electric fields, and circulation of oil, the composition of the heterogeneous structures is altered over the life of the TO. These processes are currently being monitored by an obsolete method [3], which, in our opinion, is unreliable due to insufficient accuracy.Investigations [4][5][6][7] have indicated that heterogeneous structures always exist in TO. A method of determining the percentage of solid particles in oil products with use of nuclear magnetic (NM) relaxation is described in the literature [8]. We have been unable, however, to find information on the applicability of this method to TO. The Z-scanning method is sensitive to nonlinear optical absorption of delocalized electrons, occurring most frequently in the heterogeneous particles [9]. This study described results of TO investigation by NM-relaxation and Z-scanning methods.

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“…This had previously been repeatedly demonstrated by methods of 1 H and 13 C nuclear magnetic resonance, and ultraviolet spectroscopy [7,10,11].…”

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confidence: 79%