Improving the Thermal and Electrical Properties of Transformer Oil Using ‎Hybrid Nanofluid

Document Type : Research paper


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

2 Department of Electrical Engineering, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran

3 Department of Mechanical Engineering, Faculty of Engineering and Technology, University of Mazandaran, ‎Babolsar, Iran


Improving the insulating and thermal properties of transformer oil is one of the factors in the use of nanoparticles (NPs) in oil. However, the use of NPs may only have a positive effect on some properties of the oil or even have a negative effect on the other properties of the oil. For this reason, hybrids nanofluid(HNF) were used to improve the properties of the transformer oil. By performing the Breakdown Voltage (BDV) test on different weight percentages (wt%) of TiO2 and CNT, it was proved that the best wt% for TiO2 is 0.0075 and for CNT is 0.001 to maximize the BDV. In this case, the HNF was able to improve the BDV and heat transfer by 9% and 8%, respectively. Another surprise that the HNF has been able to reduce the amount of C2H4 and C2H6 dissolved in oil by more than 70%. This reduction in the number of gases has another very desirable result and has reduced the PD by 63%. HNF proved that by using the right combination of different nanomaterials in transformer oil, more properties of the transformer oil can be improved.


[1]   Q. Zhang et al., “Recent advances of SnO2-based sensors for detecting fault characteristic gases extracted from power transformer oil”, Frontiers Chem., vol. 6, pp. 364, 2018.
[2]   V. Behjat, A. Shams, and V. Tamjidi, “Characterization of power transformer electromagnetic forces affected by winding faults”, J. Oper. Autom. Power Eng, vol. 6, pp. 40-49, 2018.
[3]   Z. Moravej and S. Bagheri, “Condition monitoring techniques of power transformers: A review”, J. Oper. Autom. Power Eng., vol. 3, pp. 71-82, 2015.
[4]   M. Duval, “A review of faults detectable by gas-in-oil analysis in transformers”, IEEE Electr. Insulation Mag., vol. 18, pp. 8-17, 2002.
[5]   Q. Zhou et al., “Hydrothermal synthesis of hierarchical ultrathin NiO nanoflakes for high-performance CH4 sensing”, Frontiers  Chem., vol. 6, p. 194, 2018.
[6]   M. Duval and J. Dukarm, “Improving the reliability of transformer gas-in-oil diagnosis”, IEEE Electr. Insulation Mag., vol. 21, pp. 21-7, 2005.
[7]   S. Besner, J. Jalbert, and B. Noirhomme, “Unusual ethylene production of in-service transformer oil at low temperature”, IEEE Trans. Dielectrics Electr. Insulation, vol. 19, pp. 1901-7, 2012.
[8]   Z. Gong et al., “Photoacoustic spectroscopy based multi-gas detection using high-sensitivity fiber-optic low-frequency acoustic sensor”, Sensors Actuators B: Chem., vol. 260, pp. 357-63, 2018.
[9]   J. Faiz and M. Soleimani, “Dissolved gas analysis evaluation in electric power transformers using conventional methods a review”, IEEE Trans. Dielectrics Electr. Insulation, vol. 24, pp. 1239-48, 2017.
[10]   F. Wan et al., “Using a sensitive optical system to analyze gases dissolved in samples extracted from transformer oil”, IEEE Electr. Insulation Mag., vol. 30, pp. 15-22, 2014.
[11]   W. Chen et al., “Diode laser‐based photoacoustic spectroscopy detection of acetylene gas and its quantitative analysis”, Europ. Trans. Electr. Power, vol. 22, pp. 226-34, 2012.
[12]   K. Nagapriya et al., “Laser calorimetry spectroscopy for ppm-level dissolved gas detection and analysis”, Scien. Rep., vol. 7, pp. 1-10, 2017.
[13]   G. Ma et al., “Tracing acetylene dissolved in transformer oil by tunable diode laser absorption spectrum”, Scien. Rep., vol. 7, pp. 1-8, 2017.
[14]   G. Yan et al., “Fiber-optic acetylene gas sensor based on microstructured optical fiber Bragg gratings”, IEEE Photonics Tech. Letters, vol. 23, pp. 1588-90, 2011.
[15]   A. Ghaffarkhah et al., “On evaluation of thermophysical properties of transformer oil-based nanofluids: a comprehensive modeling and experimental study”, J. Molecular Liquids, vol. 300, p. 112249, 2020.
[16]   A. Mashhadzadeh et al., “Experiment and theory for acetylene adsorption in transformer oil”, J. Molecular Structure, vol. 1230, p. 129860, 2021.
[17]   N. Sabiha, S. Ghoneim, and M. Hessien, “Breakdown performance of transformer oil in the presence of single-phase nanocrystalline ZnO and nano-partial substitution”, IET Sci. Measure. Tech., vol. 13, pp. 737-45, 2019.
[18]   M. Rafiq, Y. Lv, and C. Li, “A review on properties, opportunities, and challenges of transformer oil-based nanofluids”, J. Nanomaterials, vol. 2016, 2016.
[19]   M. Akbari et al., “An investigation on stability, electrical and thermal characteristics of transformer insulting oil nanofluids”, Int. J. Eng., vol. 29, pp. 1332-40, 2016.
[20]   L. Rajkonwar et al., Studies on epoxy based TiO 2 nano-filler for high voltage application”, 2018 Int. Conf. Power Energy, Control Transm. Syst., 2018.
[21]   S. Qing et al., “Thermal conductivity and electrical properties of hybrid SiO2-graphene naphthenic mineral oil nanofluid as potential transformer oil”, Materials Res. Express, vol. 4, p. 015504, 2017.
[22]   M. Sulemani et al., “Effect of nanoparticles on breakdown, aging and other properties of vegetable oil”, 1st Int. Conf. Power, Energy Smart Grid, 2018.
[23]   M. Rafiq et al., “Transformer oil-based nanofluid: The application of nanomaterials on thermal, electrical and physicochemical properties of liquid insulation-A review”, Ain Shams Eng. J., 2020.
[24] X. Wang et al., “Dissolved gas analysis of thermal faults in transformer liquids simulated using immersed heating method”, IEEE Trans. Dielectrics Electr. Insulation, vol. 25, pp. 1749-57, 2018.