Effect of ferromagnetic paste on insulating properties of transformer oil

THE PURPOSE. Consider the problem of using a special ferromagnetic paste, which fills the air gaps in the magnetic circuit of an oil power transformer, in order to reduce its losses, by reducing eddy currents in the magnetic circuit. Conduct experiments to determine the dynamics of change of high-voltage breakdown of transformer oil, after adding ferromagnetic paste to it.
METHODS. To solve this problem, several samples of ferromagnetic paste have been developed, differing from each other using different binding material for ferromagnetic powder. The samples were placed in containers for several days filled with transformer oil. With the help of electrical installation AIM-90, measurements of high-voltage breakdown of transformer oil of each sample were carried out. Thanks to this method, it was possible to determine how the ferromagnetic paste affects the insulating properties of the transformer oil.
RESULTS. For clarity, the results of all samples were plotted. Based on the graph, it became clear that in some samples of transformer oil a significant amount of mechanical impurities formed from ferromagnetic paste appeared, which extremely negatively affected the insulating properties of the oil. There were also samples in which the properties of the oil practically did not change.
CONCLUSION. As conclusions, there was a certain vision of which ferromagnetic paste can be used in the design of an oil power transformer, it was also possible to understand which samples of ferromagnetic pastes extremely negatively affect the insulating properties of the transformer oil.

1. Bogoroditsky NP, Pasynkov VV., Tareev BM. Electromechanical materials. 6th ed., reprint. L.: Energiya, 1977. 322 p.

2. Dolgopol TL, Chernichenko AV, Galinov DS. Analysis of ways to reduce idling losses of power transformers. Power engineering and energy saving: theory and practice: Collection of materials of the IV All-Russian Scientific and Practical Conference: electronic collection, Kemerovo, December 19-21, 2018 / Edited by V.G. Kashirskikh, I.A. Lobur. – Kemerovo: Kuzbass State Technical University named after T.F. Gorbachev, 2018.

3. Biryulin V.I., Chernyshev A.S., Zub O.S. Forecasting of electricity losses at substations. Electrica. 2013;5;02-03.

4. Vaganov M.A. Transformers: textbook. stipend. St. Petersburg: Publishing house of SPbSETU «LETI», 2014. 112 p

5. Bogoroditsky NP, Pasynkov VV, Tareev BM. Electromechanical materials. 6th ed., reprint. L.: Energy, 1977. 322 p.

6. . Yu. Bragin, Panteleeva LA, Pokoev PN, Bragin IYu. Influence of ferromagnetic paste on transformer characteristics. Technological trends of sustainable functioning and development of agroindustrial complex: Materials of the International scientific and practical conference dedicated to the Year of Science and technology in Russia. February 24-26, 2021, Izhevsk. Izhevsk: Izhevsk State Agricultural Academy, 2021. pp. 90-94.

7. Zakharov MA, Bragin IYu, Pokoev PN, et al. Testing of magnetic properties of ferromagnetic paste at different temperatures. Innovative potential of agricultural science of the XXI century: contribution of young scientists and researchers: materials of the All-Russian Scientific and Practical Conference. October 24-27, 2017, Izhevsk. Izhevsk: Izhevsk State Agricultural Academy, 2017. pp. 198-200.

8. Pokoev PN. Testing the resistivity of ferromagnetic paste. Innovative technologies for the implementation of the program of scientific and technical development of agriculture: materials of the International scientific and practical Conference. February 13-16, 2018, Izhevsk. In 3 Vols. Izhevsk: Izhevsk State Agricultural Academy, 2018;3:85-88.

9. Bragin IYu, Lekomtsev PL, Panteleeva LA, et al. Development and research of ferromagnetic paste of increased viscosity. Nizhny Novgorod State University of Engineering and Economics Bulletin of NGIEI. 2020;6 (109):36-48.

10. Alekseev BA. Condition control (diagnostics) of large power transformers. M.: NC ENAS, 2002. 216 p.

11. Noskov VA. Utility model patent No. 143671 RU IPC H01F 27/245 / Magnetic circuit assembled from plates of electrical steel, the joints of which are covered with a material with high magnetic permeability / application no. 2013130526. Registered on 26.06.2014. Published on 27.07.2014 Byul. No. 21.

12. Valiullina D.M., Zagustina I.D., Kozlov V.K. Determination of the qualitative composition of impurities in spent transformer oil. Kazan: Bulletin of the KSPEU. 2018;10:4 (40). :25-32.

13. Vagapov T.R., Volkova T.R. Transformer oil as a diagnostic medium of power transformers. Electrotechnical complexes and systems: mater. international Scientific and Practical conference 2016 pp. 39-42.

14. Types of transformer oil tests [Electronic resource]. Access mode: https://leg.co.ua/info/transformatory / (accessed: 20.11.2021).

15. Karthik R., Sree Renga Raja T. Investigations of transformer oil characteristics. IEEJ Trans Elec Electron Eng. 2012;7:369-374.

16. Okabe S., Ueta G., Tsuboi T. Investigation of aging degradation status of insulating elements in oil-immersed transformer and its diagnostic method based on field measurement data. IEEE Transactions on Dielectrics and Electrical Insulation. 2013;20(1):346-355.

17. Bragin, I.Yu. Comparison of ferromagnetic properties of various materials / I.Yu. Bragin, L.A. Panteleeva, [et al.]. Bulletin of the Izhevsk State Agricultural Academy. 2021;2 (66):37-42.

18. Bystritsky G.F., Kudrin B.I. Selection and operation of power transformers. Moscow: Publishing Center «Academy», 2003.

19. Voldek, A.I. Electric machines: textbook for students of higher educational institutions. 2nd ed. Pererab. and additional. L.: Energiya, 1974. 840 p.

20. Vezir Rexhepi. An Analysis of Power Transformer Outages and Reliability Monitoring. Energy Procedia. 141. December 2017;141:418-422. https://doi.org/10.1016/j.egypro.2017.11.053.

21. Mangara BT. On some methods of reliability improvement of engineering systems. Bloemfontein, Free State, South Africa: University of the Free State; 2015 p. 155.

22. Kopylov I.P. Electric machines: textbook for universities. 3rd ed., ispr. M.: Higher School, 2002. 607 p.

23. Leshchinskaya, T.B., Naumov, I.V. Power supply of agriculture. M.: KolosS, 2008. 665 p.

24. Tikhomirov, P.M. Calculation of transformers: textbook. Manual for universities. 5th ed., reprint. and additional. M.: Energoatomizdat, 1986. 528 p.