Journal of Electrical Engineering and Technology

The Korean Institute of Electrical Engineers (대한전기학회)
권호 표지
DOI QR코드

DOI QR Code

Renewable Low-viscosity Dielectrics Based on Vegetable Oil Methyl Esters

  • Yu, Hui (College of Chemistry and Molecular Science, Wuhan University) ;
  • Yu, Ping (College of Chemistry and Molecular Science, Wuhan University) ;
  • Luo, Yunbai (College of Chemistry and Molecular Science, Wuhan University)
  • Received : 2016.08.02
  • Accepted : 2016.12.22
  • Published : 2017.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

Vegetable oil dielectrics have been used in transformers as green alternatives to mineral insulating oils for about twenty years, because of their advantages of non-toxic, biodegradability, and renewability. However, the viscosity of vegetable oils is more than 3 times of mineral oils, which means a poor heat dissipation capacity. To get low-viscosity dielectrics, transesterification and purification were performed to prepare vegetable oil methyl esters in this study. Electrical and physical properties were determined to investigate their potential as dielectrics. The results showed that the methyl ester products had good dielectric strengths, high water saturation and enough fire resistance. The viscosities (at $40^{\circ}C$) were 0.2 times less than FR3 fluid, and 0.7 times less than mineral oil, which indicated superior cooling capacity as we expected. With the assistance of 0.5 wt% pour point depressants, canola oil methyl ester exhibited the lowest pour point ($-26^{\circ}C$) among the products which was lower than FR3 fluid ($-21^{\circ}C$) and 25# mineral oil ($-23^{\circ}C$). Thus, canola oil methyl ester was the best candidate as a low-viscosity vegetable oil-based dielectric. The low-viscosity fluid could extend the service life of transformers by its better cooling capacity compared with nature ester dielectrics.

Keywords

References

  1. D. Cao, Chromatographic analysis and fault diagnosis for transformer oil, China Electric Power Press, 2010.
  2. M. Heathcote, J & P transformer book, Newnes, 2011.
  3. T.O. Rouse, "Mineral insulating oil in transformers," IEEE Electrical Insulation Magazine, vol. 14, no. 3, pp. 6-16, 1998. https://doi.org/10.1109/57.675572
  4. Y. Bertrand, and L. Hoang, "Vegetable oils as substitute for mineral insulating oils in medium-voltage equipments," CIGRE Reports, D1-202, 2004.
  5. S.Z. Erhan, and S. Asadauskas, "Lubricant basestocks from vegetable oils," Industrial crops and products, vol. 11, no. 2, pp. 277-282, 2000. https://doi.org/10.1016/S0926-6690(99)00061-8
  6. S. Boyde, "Green lubricants. Environmental benefits and impacts of lubrication," Green Chemistry, vol. 4, no. 4, pp. 293-307, 2002. https://doi.org/10.1039/b202272a
  7. M. Shinke, K. Miyazato, T. Tada, Y. Takeuchi, Y. Nakagami, R. Shimizu, M. Kosaka, and M. Wada, "Fundamental studies on development of environment friendly vegetable oil filled transformer," IEEJ Transactions on Power and Energy, vol. 123, pp. 187-193, 2003. https://doi.org/10.1541/ieejpes.123.187
  8. M.A.G. Martins, "Vegetable oils, an alternative to mineral oil for power transformers-experimental study of paper aging in vegetable oil versus mineral oil," IEEE Electrical Insulation Magazine, vol. 6, no. 26, pp. 7-13, 2010.
  9. N. Azis, J. Jasni, M.Z.A. Ab Kadir, and M.N. Mohtar, "Suitability of palm based oil as dielectric insulating fluid in transformers," Journal of Electrical Engineering & Technology, vol. 9, no. 2, pp. 662-669, 2014. https://doi.org/10.5370/JEET.2014.9.2.662
  10. C. Watkins, "Transforming the transformer industry," Inform, vol. 19, no. 8, pp. 524-526, 2008.
  11. C. P. McShane, "Vegetable-oil-based dielectric coolants," IEEE Industry Applications Magazine, vol. 8, no. 3, pp. 34-41, 2002. https://doi.org/10.1109/2943.999611
  12. T. Oommen, "Vegetable oils for liquid-filled transformers," IEEE Electrical Insulation Magazine, vol. 18, no. 1, pp. 6-11, 2002. https://doi.org/10.1109/57.981322
  13. S. Tenbohlen, and M. Koch, "Aging performance and moisture solubility of vegetable oils for power transformers," IEEE Transactions on Power Delivery, vol. 25, no. 2, pp. 825-830, 2010. https://doi.org/10.1109/TPWRD.2009.2034747
  14. F.M.T. Luna, B.S. Rocha, E.M. Rola, M.C. Albuquerque, D.C. Azevedo, and C.L. Cavalcante, "Assessment of biodegradability and oxidation stability of mineral, vegetable and synthetic oil samples," Industrial Crops and Products, vol. 33, no. 3, pp. 579-583, 2011. https://doi.org/10.1016/j.indcrop.2010.12.012
  15. S.Z. Erhan, B.K. Sharma, and J.M. Perez, "Oxidation and low temperature stability of vegetable oil-based lubricants," Industrial Crops and Products, vol. 24, no. 3, pp. 292-299, 2006. https://doi.org/10.1016/j.indcrop.2006.06.008
  16. M. Rafiq, Y. Lv, Y. Zhou, K. Ma, W. Wang, C. Li, and Q. Wang, "Use of vegetable oils as transformer oils-a review," Renewable and Sustainable Energy Reviews, vol. 52, pp. 308-324, 2015. https://doi.org/10.1016/j.rser.2015.07.032
  17. C.P. McShane, "Relative properties of the new combustion-resist vegetable-oil-based dielectric coolants for distribution and power transformers," IEEE Transactions on industry applications, vol. 37, no. 4, pp. 1132-1139, 2001. https://doi.org/10.1109/28.936406
  18. D. Martin, J. Wijaya, N. Lelekakis, D. Susa, and N. Heyward, "Thermal analysis of two transformers filled with different oils," IEEE Electrical Insulation Magazine, vol. 1, no. 30, pp. 39-45, 2014.
  19. C.P. McShane, K.J. Rapp, J.L. Corkran, G.A. Gauger, and J. Luksich, "Aging of paper insulation in natural ester dielectric fluid," in Transmission and Distribution Conference and Exposition, 2001 IEEE/PES, 2001.
  20. S. Liang, R. Liao, L. Yang, J. Li, C. Sun, and H. Sun, "Thermal aging characteristics of natural ester impregnated Kraft paper and thermally upgraded paper insulation," in High Voltage Engineering and Application, 2008. ICHVE 2008. International Conference on, 2008.
  21. M. Amanullah, S.M. Islam, S. Chami, and G. Ienco, "Analyses of physical characteristics of vegetable oils as an alternative source to mineral oil-based dielectric fluid," in IEEE International Conference on Dielectric Liquids, 2005. ICDL 2005.
  22. M. Amanullah, S.M. Islam, S. Chami, and G. Ienco, "Low viscosity vegetable oil-based dielectric fluids," Google Patents, 2007.
  23. D. Y. Leung, X. Wu, and M. Leung, "A review on biodiesel production using catalyzed transesterification," Applied energy, vol. 87, no. 4, pp. 1083-1095, 2010. https://doi.org/10.1016/j.apenergy.2009.10.006
  24. T. Kanoh, H. Iwabuchi, Y. Hoshida, J. Yamada, T. Hikosaka, A. Yamazaki, Y. Hatta, and H. Koide, "Analyses of electro-chemical characteristics of palm fatty acid esters as insulating oil," in 2008 IEEE International Conference on Dielectric Liquids, 2008.
  25. A. Rottig, L. Wenning, D. Broker, and A. Steinbuchel, "Fatty acid alkyl esters: perspectives for production of alternative biofuels," Applied microbiology and biotechnology, vol. 85, no. 6, pp. 1713-1733, 2010. https://doi.org/10.1007/s00253-009-2383-z
  26. L. Meher, D.V. Sagar, and S. Naik, "Technical aspects of biodiesel production by transesterification - a review," Renewable and sustainable energy reviews, vol. 10, no. 3, pp. 248-268, 2006. https://doi.org/10.1016/j.rser.2004.09.002
  27. U. Schuchardt, R. Sercheli, and R.M. Vargas, "Transesterification of vegetable oils: a review," Journal of the Brazilian Chemical Society, vol. 9, no. 3, pp. 199-210, 1998. https://doi.org/10.1590/S0103-50531998000300002
  28. Y. Kasahara, M. Kato, S. Watanabe, M. Iwahashi, R. Wakamatsu, T. Suzuki, A. Kanetani, T. Kano, and T. Tamura, "Consideration on the relationship between dielectric breakdown voltage and water content in fatty acid esters," Journal of the American Oil Chemists' Society, vol. 89, no. 7, pp. 1223-1229, 2012.
  29. S. C. Cermak, G. Biresaw, T. A. Isbell, R. L. Evangelista, S.F. Vaughn, and R. Murray, "New crop oils - Properties as potential lubricants," Industrial Crops and Products, vol. 44, pp. 232-239, 2013. https://doi.org/10.1016/j.indcrop.2012.10.035
  30. M.J. Ramos, C.M. Fernandez, A. Casas, L. Rodriguez, and A Perez, "Influence of fatty acid composition of raw materials on biodiesel properties," Bioresource technology, vol. 100, no. 1, pp. 261-268, 2009. https://doi.org/10.1016/j.biortech.2008.06.039
  31. A. Kamal-Eldin, and R. Andersson, "A multivariate study of the correlation between tocopherol content and fatty acid composition in vegetable oils," Journal of the American Oil Chemists' Society, vol. 74, no. 4, pp. 375-380, 1997. https://doi.org/10.1007/s11746-997-0093-1
  32. W. Neff, T. Mounts, W. Rinsch, H. Konishi, and M. El-Agaimy, "Oxidative stability of purified canola oil triacylglycerols with altered fatty acid compositions as affected by triacylglycerol composition and structure," Journal of the American Oil Chemists' Society, vol. 71, no. 10, pp. 1101-1109, 1994. https://doi.org/10.1007/BF02675903
  33. D. Martin, and Z. Wang, "A comparative study of the impact of moisture on the dielectric capability of esters for large power transformers," in 2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena, 2006.
  34. Y. Du, A.V. Mamishev, B.C. Lesieutre, M. Zahn, and S.-H. Kang, "Moisture solubility for differently conditioned transformer oils," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 8, no. 5, pp. 805-811, 2001. https://doi.org/10.1109/94.959706
  35. D. Martin, N. Lelekakis, W. Guo, and Y. Odarenko, "Further studies of a vegetable-oil-filled power transformer," IEEE Electrical Insulation Magazine, vol. 27, no. 5, pp. 6-13, 2011. https://doi.org/10.1109/MEI.2011.6059976
  36. H. Borsi, and E. Gockenbach, "Properties of ester liquid Midel 7131 as an alternative liquid to mineral oil for transformers," in IEEE International Conference on Dielectric Liquids, 2005. ICDL 2005., 2005.
  37. D. Martin, I. Khan, J. Dai, and Z. Wang, "An overview of the suitability of vegetable oil dielectrics for use in large power transformers," in TJ/H2b Euro TechCon Conf., Chester, UK, 2006.
  38. R. Liao, J. Hao, G. Chen, Z. Ma, and L. Yang, "A comparative study of physicochemical, dielectric and thermal properties of pressboard insulation impregnated with natural ester and mineral oil," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 18, no. 5, pp. 1626-1637, 2011. https://doi.org/10.1109/TDEI.2011.6032833
  39. D. Martin, and Z. Wang, "Statistical analysis of the AC breakdown voltages of ester based transformer oils," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 15, no. 4, pp. 1044-1050, 2008. https://doi.org/10.1109/TDEI.2008.4591226
  40. X. Wang, and Z. Wang, "Particle effect on breakdown voltage of mineral and ester based transformer oils," in 2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, 2008.
  41. A. Tekin, and E.G. Hammond, "Factors affecting the electrical resistivity of soybean oil methyl ester," Journal of the American Oil Chemists' Society, vol. 77, no. 3, pp. 281-283, 2000. https://doi.org/10.1007/s11746-000-0046-0
  42. R. Dunn, and M. Bagby, "Low-temperature properties of triglyceride-based diesel fuels: transesterified methyl esters and petroleum middle distillate/ester blends," Journal of the American Oil Chemists' Society, vol. 72, no. 8, pp. 895-904, 1995. https://doi.org/10.1007/BF02542067
  43. A. Srivastava, and R. Prasad, "Triglycerides-based diesel fuels," Renewable and sustainable energy reviews, vol. 4, no. 2, pp. 111-133, 2000. https://doi.org/10.1016/S1364-0321(99)00013-1
  44. A. S. Ramadhas, S. Jayaraj, and C. Muraleedharan, "Biodiesel production from high FFA rubber seed oil," Fuel, vol. 84, no. 4, pp. 335-340, 2005. https://doi.org/10.1016/j.fuel.2004.09.016
  45. T. Oommen, C. Claiborne, E. Walsh, and J. Baker, "A new vegetable oil based transformer fluid: development and verification," in Electrical Insulation and Dielectric Phenomena, 2000 Annual Report Conference on, 2000.