Advertisement

Detection of Methanol in Power Transformer Oil Using Spectroscopy

  • Qiang Fu
  • Lei Peng
  • Li Li
  • Musong Lin
  • Yaohong Zhao
  • Shengli LiEmail author
  • Chen Chen
Original Article

Abstract

Oil-paper insulation in transformers plays an important role in the operation of power grid. At present, the aging (life assessment) of transformers are mainly conducted based upon the degree of polymerization, concentration of furfural, and the gas analysis of CO and CO2 in the transformer oil. However, these techniques lack sensitive response, especially in the early aging of oil-paper insulation. Methanol as a new indicator to evaluate the aging of insulating paper, is getting more and more attention. An evaluation method based on the measurement of methanol concentration using ultraviolet–visible spectrometer was proposed in this work. After the extraction from transformer oils, the methanol was oxidized using potassium permanganate. Then, chromotropic acid was used to react with the oxidation products (formaldehyde) to form a mauve clathrate, finally, the methanol content was measured using the spectroscopy. Different from traditional spectroscopy which calculate only by absorbance at the characteristic wavelength, this paper use the partial least squares method, obtain the relationship between the absorbance at selected regions and the concentration of methanol. The minimum detection limit for the proposed method was 10 ppb, whereas the correlation coefficient for the relationship between the absorbance and the concentration of methanol was as high as 0.99.

Keywords

Transformer oil Aging Life assessment Ultraviolet–visible spectrometer Methanol 

Notes

Acknowledgements

The work was supported financially by the China Southern Power Grind (Grant No. GDKJQQ20152046) and National Natural Science Foundation of China (51507129).

References

  1. 1.
    Li J, Wang Y, Bao L (2014) Space charge behavior of oil-impregnated paper insulation aging at AC–DC combined voltages. J Electr Eng Technol 9(2):635–642CrossRefGoogle Scholar
  2. 2.
    Qian Y, Xiao H, Nie M et al (2018) Lifetime prediction and aging behaviors of nitrile butadiene rubber under operating environment of transformer. J Electr Eng Technol 13(2):918–927Google Scholar
  3. 3.
    Liao R, Yang L, Xu Z (2015) The investigation on thermal aging characteristics of oil-paper insulation in bushing. J Electr Eng Technol 10(3):1114–1123CrossRefGoogle Scholar
  4. 4.
    Zhou YX, Huang M, Chen WJ et al (2015) Space charge behavior of oil-paper insulation thermally aged under different temperatures and moistures. J Electr Eng Technol 10(3):1124–1130CrossRefGoogle Scholar
  5. 5.
    Kim J, Kim W, Park HS et al (2017) Lifetime assessment for oil-paper insulation using thermal and electrical multiple degradation. J Electr Eng Technol 12(2):840–845CrossRefGoogle Scholar
  6. 6.
    Rodriguez-Celis EM, Duchesne S, Jalbert J et al (2015) Understanding ethanol versus methanol formation from insulating paper in power transformers. Cellulose 22(5):3225–3236CrossRefGoogle Scholar
  7. 7.
    Setnescu R, Badicu LV, Dumitran LM et al (2014) Thermal lifetime of cellulose insulation material evaluated by an activation energy based method. Cellulose 21(1):823–833CrossRefGoogle Scholar
  8. 8.
    Norazhar AB, Abu-Siada A, Islam S (2014) A review on chemical diagnosis techniques for transformer paper insulation degradation. In: Power engineering conference. IEEE, pp 1–6Google Scholar
  9. 9.
    Laurichesse D, Bertrand Y, Tran-Duy C et al (2013) Ageing diagnosis of MV/LV distribution transformers via chemical indicators in oil. In: Electrical insulation conference. IEEEGoogle Scholar
  10. 10.
    Kes M, Christensen BE (2013) Degradation of cellulosic insulation in power transformers: a SEC–MALLS study of artificially aged transformer papers. Cellulose 20(4):2003–2011CrossRefGoogle Scholar
  11. 11.
    Jalbert J, Duchesne S, Rodriguez-Celis E et al (2012) Robust and sensitive analysis of methanol and ethanol from cellulose degradation in mineral oils. J Chromatogr A 1256(18):240CrossRefGoogle Scholar
  12. 12.
    Tang S, Peng G, Zhong Z (2016) Quantitative spectral analysis of dissolved gas in transformer oil based on the method of optimal directions. In: Control conference. IEEE, pp 4425–4429Google Scholar
  13. 13.
    Jalbert J, Gilbert R, Denos Y et al (2012) Methanol: a novel approach to power transformer asset management. IEEE Trans Power Deliv 27(2):514–520CrossRefGoogle Scholar
  14. 14.
    Pahlavanpour B, Duffy G (1993) Development of a rapid spectrophotometry method for analysis of furfuraldehyde in transformer oil as an indication of paper ageing. In: Conference on electrical insulation and dielectric phenomena, 1993 report. IEEE, pp 493–498Google Scholar
  15. 15.
    Kóréh O, Torkos K, Mahara MB et al (1998) Extraction and quantitation of furanic compounds dissolved in oils. J Radioanal Nucl Chem 228(1–2):47–52CrossRefGoogle Scholar
  16. 16.
    ASTM D5837-2005 (2005) Standard test method for furanic compounds in electrical insulating liquids by high-performance liquid chromatography (HPLC)Google Scholar
  17. 17.
    Okabe S, Kaneko S, Kohtoh M et al (2010) Analysis results for insulating oil components in field transformers. IEEE Trans Dielectr Electr Insul 17(1):302–311CrossRefGoogle Scholar
  18. 18.
    Arroyo OH, Fofana I, Jalbert J et al (2016) Relationships between methanol marker and mechanical performance of electrical insulation papers for power transformers under accelerated thermal ageing. IEEE Trans Dielectr Electr Insul 22(6):3625–3632CrossRefGoogle Scholar
  19. 19.
    Schaut A, Autru S, Eeckhoudt S (2011) Applicability of methanol as new marker for paper degradation in power transformers. IEEE Trans Dielectr Electr Insul 18(2):533–540CrossRefGoogle Scholar
  20. 20.
    Gilbert R, Jalbert J, Tétreault P et al (2009) Kinetics of the production of chain-end groups and methanol from the depolymerization of cellulose during the ageing of paper/oil systems. Part 1: standard wood kraft insulation. Cellulose 16(2):327–338CrossRefGoogle Scholar
  21. 21.
    Gilbert R, Jalbert J, Duchesne S et al (2010) Kinetics of the production of chain-end groups and methanol from the depolymerization of cellulose during the ageing of paper/oil systems. Part 2: thermally-upgraded insulating papers. Cellulose 17(2):253–269CrossRefGoogle Scholar
  22. 22.
    Matharage SY, Liu Q, Wang ZD et al (2018) Aging assessment of synthetic ester impregnated thermally non-upgraded kraft paper through chemical markers in oil. IEEE Trans Dielectr Electr Insul 25(2):507–515CrossRefGoogle Scholar
  23. 23.
    Bruzzoniti MC, Maina R, Carlo RMD et al (2014) GC methods for the determination of methanol and ethanol in insulating mineral oils as markers of cellulose degradation in power transformers. Chromatographia 77(15–16):1081–1089CrossRefGoogle Scholar
  24. 24.
    Matharage SY, Liu Q, Wang ZD (2016) Ageing assessment of kraft paper insulation through methanol in oil measurement. IEEE Trans Dielectr Electr Insul 23(3):1589–1596CrossRefGoogle Scholar
  25. 25.
    Molavi H, Yousefpour A, Mirmostafa A et al (2017) Static headspace GC/MS method for determination of methanol and ethanol contents, as the degradation markers of solid insulation systems of power transformers. Chromatographia 80(7):1129–1135CrossRefGoogle Scholar
  26. 26.
    Matharage SY, Liu Q, Davenport E et al (2014) Methanol detection in transformer oils using gas chromatography and ion trap mass spectrometer. In: IEEE, international conference on dielectric liquids. IEEE, pp 1–4Google Scholar
  27. 27.
    Chen S, Ma Y, Qu CT et al (2011) Improvement of chromotropic acid spectrophotometry for determining methanol content in gas production wastewater. J Xi’an Shiyou Univ 26:70–74Google Scholar
  28. 28.
    Guo Q, Small GW (2013) Quantitative determination of methanol and ethanol with synthetic calibration spectra in passive Fourier transform infrared remote sensing measurements. Appl Spectrosc 67(8):913–923CrossRefGoogle Scholar

Copyright information

© The Korean Institute of Electrical Engineers 2019

Authors and Affiliations

  • Qiang Fu
    • 2
  • Lei Peng
    • 2
  • Li Li
    • 2
  • Musong Lin
    • 2
  • Yaohong Zhao
    • 2
  • Shengli Li
    • 1
    Email author
  • Chen Chen
    • 1
  1. 1.Huazhong University of Science and TechnologyWuhanChina
  2. 2.Electric Power Research Institute of Guangdong Power Grid Co., LtdGuangzhouChina

Personalised recommendations