Experimental Analysis and Physical Mechanism Investigation of Al2O3 Effect on New and Aged Transformer Oil Properties

Document Type : Original Article


1 Department of Electrical Engineering, Gorgan Branch, Islamic Azad University, Gorgan, Iran

2 Department of Electrical Engineering, Shahrood University of Technology, Shahrood, Iran

3 Department of Electrical Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran


Al2O3 nanoparticles were used to improve the performance of the vital properties of transformer oil (TO) under normal operating conditions and when subjected to thermal aging. Different weight percentages of Al2O3 in the TO were considered to maximize the breakdown voltage (BDV). Al2O3 nanofluid (NF) increases the BDV by 116% (31.1 kV to 67.4 kV) and the heat transfer by 33.4%, and also minimizes partial discharge (PD) by 66%. The reduction of PD is also related to the ability of Al2O3 to adsorb hydrogen and acetylene, two oil-soluble gases that are effective in PD. Even Al2O3NF was more resistant to water content in TO. BDV for TO and Al2O3NF, when water content increased to more than 30 ppm, were reduced by 57% and 19%, respectively. According to Arrhenius equation, both samples were placed at 120°C for 29 days to age samples (equivalent to about 30 years). Aged Al2O3NF has continued its exceptional performance and improved BDV by 121% compared to aged TO, and also Al2O3NF showed its capacity well and improved PD compared to aged TO by 71%. All the favorable properties of Al2O3NF are conditional on the stability of Al2O3. FESEM confirms the stability of Al2O3.


Main Subjects

  1. M. Islam, G. Lee, and S. N. Hettiwatte, "A review of condition monitoring techniques and diagnostic tests for lifetime estimation of power transformers," Electrical Engineering, Vol. 100, No. 2, (2018), 581-605, https://doi.org/10.1007/s00202-017-0532-4
  2. A. Taheri, A. Abdali, M. Taghilou, H. H. Alhelou, and K. Mazlumi, "Investigation of Mineral Oil-Based Nanofluids Effect on Oil Temperature Reduction and Loading Capacity Increment of Distribution Transformers," Energy Reports, Vol. 7, (2021) 4325-4334, DOI:10.1016/j.egyr.2021.07.018
  3. Hussain, F. A. Mir, and M. Ansari, "Nanofluid transformer oil for cooling and insulating applications: A brief review," Applied Surface Science Advances, Vol. 8, (2022), 100223, DOI: 10.1016/j.apsadv.2022.100223
  4. R. Meshkatoddini and S. Abbospour, "Aging study and lifetime estimation of transformer mineral oil," American J. of Engineering and Applied Sciences, Vol. 1, No. 4, (2008), 384-388, DOI: 10.3844/ajeassp.2008.384.388
  5. Duval, "Dissolved gas analysis: It can save your transformer," IEEE Electrical Insulation Magazine, Vol. 5, No. 6, (1989), 22-27. DOI: 10.1109/57.44605.
  6. Faiz and M. Soleimani, "Dissolved gas analysis evaluation in electric power transformers using conventional methods a review," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 24, No. 2, (2017), 1239-1248, DOI: 10.1109/TDEI.2017.005959
  7. Dai, H. Song, G. Sheng, and X. Jiang, "Dissolved gas analysis of insulating oil for power transformer fault diagnosis with deep belief network," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 24, No. 5, (2017), 2828-2835, DOI: 10.1109/TDEI.2017.005959
  8. -E. A. Mansour, "Development of a new graphical technique for dissolved gas analysis in power transformers based on the five combustible gases," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 22, No. 5, (2015), 2507-2512, DOI: 10.1109/TDEI.2015.004999
  9. Weesmaa, M. Sterner, B. Pahlavanpour, L. Bergeld, J. Nunes, and K. Sundkvist, "Study of stray gassing measurements by different methods," in Electrical Insulation and Dielectric Phenomena (CEIDP), 2013 IEEE Conference on, (2013), 184-189.DOI: 10.1109/CEIDP.2013.6748192.
  10. Xiao, W. Chen, C. Yu, and L. Jin, "Study on ZnO-based gas sensor for detection of acetylene dissolved in transformer oil," in 2018 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), (2018), 1-6, DOI: 10.1109/I2MTC.2018.8409830
  11. Rafiq, Y. Lv, and C. Li, "A review on properties, opportunities, and challenges of transformer oil-based nanofluids," Journal of Nanomaterials, Vol. 2016, (2016), Article ID 8371560, http://dx.doi.org/10.1155/2016/8371560.
  12. E. Hebner, "Measurement of electrical breakdown in liquids," in The liquid state and its electrical properties: Springer, pp. 519-537, (1988).
  13. Chiesa and S. K. Das, "Experimental investigation of the dielectric and cooling performance of colloidal suspensions in insulating media," Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 335, No. 1-3, (2009), 88-97, DOI: 10.1016/j.colsurfa.2008.10.044
  14. Asefi M., Molavi H., Shariaty-Niassar M., Babaee Darband J., Nemati N., Yavari M., Akbari M, “An investigation on stability, electrical and thermal characteristics of transformer insulting oil nanofluids”, International Journal of Engineering, Transactions A: Basics, Vol. 29, No. 10, (2016), 1332-1340, DOI: 5829/idosi.ije.2016.29.10a.02
  15. Yang, C. Li, L. Luo, R. Li, and Y. Long, "Predictive model of convective heat transfer coefficient in bone micro-grinding using nanofluid aerosol cooling," International Communications in Heat and Mass Transfer, Vol. 125, (2021), 105317, DOI: 10.1016/j.icheatmasstransfer.2021.105317
  16. V. Timofeeva, J. L. Routbort, and D. Singh, "Particle shape effects on thermophysical properties of alumina nanofluids," Journal of Applied Physics, Vol. 106, No. 1, (2009), 014304, DOI: 10.1063/1.3155999
  17. Jin, "Dielectric strength and thermal conductivity of mineral oil based nanofluids," Doctoral Thesis, (2015), https://doi.org/10.4233/uuid:10d18961-a23f-478e-b6e2-181d897d8541
  18. U. Ilyas, R. Pendyala, M. Narahari, and L. Susin, "Stability, rheology and thermal analysis of functionalized alumina-thermal oil-based nanofluids for advanced cooling systems," Energy Conversion and Management, Vol. 142, (2017), 215-229, http://dx.doi.org/10.1016/j.enconman.2017.01.079
  19. Aberoumand and A. Jafarimoghaddam, "Experimental study on synthesis, stability, thermal conductivity and viscosity of Cu–engine oil nanofluid," Journal of the Taiwan Institute of Chemical Engineers, Vol. 71, (2017), 315-322, DOI:  10.1016/j.jtice.2016.12.035
  20. M. Bhunia, K. Panigrahi, C. B. Naskar, S. Bhattacharjee, K. K. Chattopadhyay, and P. Chattopadhyay, "2D square nanosheets of Anatase TiO2: A surfactant free nanofiller for transformer oil nanofluids," Journal of Molecular Liquids, Vol. 325, (2021), 115000, DOI: 10.1016/j.molliq.2020.115000
  21. -E. A. Mansour, E. M. Shaalan, S. A. Ward, A. Z. El Dein, H. S. Karaman, and H. M. Ahmed, "Multiple nanoparticles for improvement of thermal and dielectric properties of oil nanofluids," IET Science, Measurement & Technology, Vol. 13, No. 7, (2019), 968-974, DOI: 10.1049/iet-smt.2018.5015
  22. Parvar, S. Saedodin, and S. H. Rostamian, "Experimental study on the thermal conductivity and viscosity of transformer oil-based nanofluid containing ZnO nanoparticles," Journal of Heat and Mass Transfer Research, Vol. 7, No. 1, (2020), 77-84, DOI : 10.22075/JHMTR.2020.19303.1267
  23. R. Babu and P. R. Babu, "Comparative Analysis Of Stability And Dielectric Break Down Strength of Transformer Oil Based Nanofluids."International Journal of Electrical Engineering and Technology, Vol. 11, No. 5, (2020), 113-119, DOI: 10.34218/IJEET.11.5.2020.013.
  24. Paul, M. Chopkar, I. Manna, and P. Das, "Techniques for measuring the thermal conductivity of nanofluids: a review," Renewable and Sustainable Energy Reviews, Vol. 14, No. 7, (2010), 1913-1924, DOI: 10.1016/j.rser.2010.03.017
  25. Oparanti, A. Khaleed, A. Abdelmalik, and N. Chalashkanov, "Dielectric characterization of palm kernel oil ester-based insulating nanofluid," in 2020 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), (2020),211-214. DOI:10.1109/CEIDP49254.2020.9437477
  26. Moghadassi, E. Ghomi, and F. Parvizian, "A numerical study of water based Al2O3 and Al2O3–Cu hybrid nanofluid effect on forced convective heat transfer," International Journal of Thermal Sciences, Vol. 92, (2015), 50-57, DOI:  10.1016/j.ijthermalsci.2015.01.025
  27. Rafiq, M. Shafique, A. Azam, and M. Ateeq, "Transformer oil-based nanofluid: The application of nanomaterials on thermal, electrical and physicochemical properties of liquid insulation-A review," Ain Shams Engineering Journal, Vol. 12, No. 1, (2021), 555-576, DOI: 10.1016/j.asej.2020.08.010
  28. Koutras, K.N.; Naxakis, I.A.; Pyrgioti, E.C.; Charalampakos, V.P.; Gonos, I.F.; Antonelou, A.E.; Yannopoulos, S.N. The Influence of Nanoparticles, "The Influence of Nanoparticles’ Conductivity and Charging on Dielectric Properties of Ester Oil Based Nanofluid," Energies, 13, No. 24, (2020), 6540. https://doi.org/10.3390/en13246540
  29. Wang, Z. Wang, Q. Liu, and P. Dyer, "Dissolved gas analysis of thermal faults in transformer liquids simulated using immersed heating method," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 25, No. 5, (2018), 1749-1757, DOI: 10.1109/TDEI.2018.007158
  30. Du, Y. Lv, C. Li, M. Chen, Y. Zhong, J. Zhou, X. Li, Y. Zhou, "Effect of semiconductive nanoparticles on insulating performances of transformer oil," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 19, No. 3, (2012), 770-776, DOI: 10.1109/TDEI.2012.6215079
  31. Loiselle, I. Fofana, J. Sabau, S. Magdaleno-Adame, and J. C. Olivares-Galvan, "Comparative studies of the stability of various fluids under electrical discharge and thermal stresses," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 22, No. 5, (2015), 2491-2499, DOI: 10.1109/TDEI.2015.7311022
  32. Tsuboi, J. Takami, S. Okabe, K. Inami, and K. Aono, "Aging effect on insulation reliability evaluation with weibull distribution for oil-immersed transformers," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 17, No. 6, (2010), 1869-1876. DOI: 10.1109/TDEI.2010.5658240