Article

Received 17.06.2025

Revised 19.11.2025

Accepted 29.12.2025

Retrieved from Vol. 28, No. 2, 2025

Pages 179 -189

Shostak, Ya., & Reshetnikov, Yu. (2025). Improvement of the impregnationtechnology of traction motor windings in order to improve the parameters of rotor imbalance. The National Transport University Bulletin: A Scientific and Technical Journal, 28(2), 179-189. https://doi.org/10.32703/2617-9040-2025-46-13

Improvement of the impregnationtechnology of traction motor windings in order to improve the parameters of rotor imbalance

Yaroslav Shostak Yuriy Reshetnikov

The work is devoted to improving the quality indicators of balancing rotors of electric machines by technological methods on the example of overhaul of traction electric motors of electric trains of series EP2,  EP9,  EPL2,  EPL9,  ED9  at  PrJSC  "Kyiv  Electric Wagon  Repair  Plant".The  features  of  the technological process of eliminating mechanical imbalance of rotors during the manufacture and repair of electric motors are analyzed. The causes of mechanical imbalance of rotors are clarified. The degree of influence  on  the  imbalance  of  rotors  of  uneven  distribution  of  impregnation  compound  over  the volume  of  electrical  windings  is  experimentally  investigated.  The  hypothesis  put  forward  about  the possibility of partial compensation of static imbalance of rotors by controlling the distribution of the compound during application of electrical insulation (impregnation) of windings is confirmed. A method of  controlling  the  distribution  of the  compound  during  impregnation  is  proposed.  The  essence of the method is to fix the rotor in the drying chamber in a position corresponding to the phase angle of the “heavy spot”, namely by placing it with the “heavy spot” up. Controlling the distribution of the compound over the rotor volume can be considered as a technologicalmethod for improving balancing performance. The method makes it possible to improve the quality of balancing by reducing the mass of balancing loads during the final balancing of rotors by up to 70%

railway transport; wagons; electric train; rotor balancing; traction electric motors; electrical insulation of windings; impregnation of windings
  1. Danylevskyi, V. & Zaika, D. (2018). Extension of electric locomotive operation with use of new newest materials in capital repair. Transport Systems and Technologies, 1(32), 14–25. https://doi.org/10.32703/2617-9040-2018-32-1-14-25. 
  2. Hildinger, T., Weidner, J. (2017). Progress in development of a nanocomposite stator winding insulation system for improved generator    performance.          2017       IEEE       Electrical               Insulation          Conference.            (EIC).      139–142. https://doi.org/10.1109/EIC.2017.8004655. 
  3. Wrobel, R., Williamson, S. J., Booker, J. D., & Mellor, P. H. (2016). Characterizing the in situ thermal behavior of selected electrical machine insulation and impregnation materials. IEEE transactions on industry applications, 52(6), 4678–4687. https://doi.org/10.1109/TIA.2016.2589219. 
  4. Verba, І. & Danilenko, О. (2018). Balancing rotating tool systems: many questions and some answers. Promising technologies and devices, (12), 30–38. http://www.irbis-nbuv.gov.ua/cgibin/irbis_nbuv/cgiirbis_64.exe?C21COM=2&I21DBN=UJRN&P21DBN=UJRN&IMAGE_FILE_DOWNLOAD=1&Im age_file_name=PDF/ptp_2018_12_6.pdf. [in Ukraine].
  5. Tiwari, R. (2017). Rotor systems: analysis and identification. CRC press. 1092.     https://doi.org/10.1201/9781315230962.
  6. Ágoston, K. (2015). Fault detection of the electrical motors based on vibration analysis. Procedia technology, 19. 547–553. https://doi.org/10.1016/j.protcy.2015.02.078. 
  7. Ibraheem, A. A., Ghazaly, N. M., & Abd el-Jaber, G. (2019). Review of rotor balancing techniques. American Journal of Industrial Engineering, 6(1), 19–25. https://doi.org/10.12691/ajie-6-1-3. 
  8. Khudonogov, A., Dulskiy, E., Ivanov, P. (2018). Basis for Local Methods of Insulation Hardening of Traction Rolling Stock Electrical Machines. International Scientific Conference Energy Management of Municipal Transportation Facilities and Transport EMMFT 2017. EMMFT 2017. 692. 109–119. https://doi.org/10.1007/978-3-319-70987-1_12  
  9. Liu, M., Li, Y., Ding, H., & Sarlioglu, B. (2017). Thermal management and cooling of windings in electrical machines for electric vehicle and traction application. 2017 IEEE Transportation Electrification Conference and Expo (ITEC). 668–673. https://doi.org/10.1109/ITEC.2017.7993349. 
  10. Safiyev, E., Rahimli, I., & Mammadov, N. (2024). Method of qualitative impregnation of electric motor windings. Przegląd Elektrotechniczny, 8, 238. https://doi.org/10.15199/48.2024.08.48. 
  11. Wrobel, R., Williamson, S. J., Booker, J. D., & Mellor, P. H. (2016). Characterizing the in situ thermal behavior of selected electrical machine insulation and impregnation materials. IEEE Transactions on Industry Applications, 52(6), 4678–4687. https://doi.org/10.1109/TIA.2016.2589219.
  12. Liu, H., Ayat, S., Wrobel, R., & Zhang, C. (2019). Comparative study of thermal properties of electrical windings impregnated with alternative varnish materials. The Journal of Engineering, 2019(17), 3736-3741. https://doi.org/10.1049/joe.2018.8198. 
  13. Morais, T. S., Der Hagopian, J., Steffen Jr, V., & Mahfoud, J. (2014). Optimization of unbalance distribution in rotating machinery with localized non linearity. Mechanism and Machine Theory, 72, 60–70. https://doi.org/10.1016/j.mechmachtheory.2013.09.012.
  14. Shostak, Y., Holovashchenko, O., Reshetnikov, Y., Tkachenko, V. (2024). Improvement of the technological process balancing electric machine rotors on a balancing machine. Eastern-European Journal of Enterprise Technologies, 4(7(130)), 60–69. https://journals.uran.ua/eejet/article/view/309867.
  15. Jiang, L., Shi, C., Li, X., Ma, H., & Cao, Y. (2025). Dynamic balance optimization method for aero-engine rotor without trial weight. Advances in Mechanical Engineering, 17(6). https://doi.org/10.1177/16878132251343928. 
  16. Mamontov, О. (2025). Vibration method for measuring static unbalance of rigid rotors. Ukrainian Metrological Journal, (1), 34–40. http://umj.metrology.kharkov.ua/article/view/325890. [in Ukraine].
  17. Babenko, O., Lavrenko, Ya., & Kurenkov, М. (2014). The influence of static and dynamic imbalance on the oscillations of the centrifuge shaft, taking into account gyroscopic effects. Journal of Mechanical Engineering NTUU" Kyiv Polytechnic Institute", (70), 36–42. https://doi.org/10.20535/2305-9001.2014.70.35249.  [in Ukraine].

https://doi.org/10.32703/2617-9040-2025-46-13