Devising a calculation method for modern structures of current-conducting elements in large electric machines in a three-dimensional statement

Authors

DOI:

https://doi.org/10.15587/1729-4061.2024.310049

Keywords:

hydraulic generator, rotor, pole-to-pole connection, pole-to-pole jumper, ventilation system of hydraulic generator, cooling conditions, stressed-strained state, three-dimensional calculation, strength of rotating parts

Abstract

The jumpers of rotor pole-to-pole connections are highly stressed elements in a hydraulic generator structure. These assemblies often fail due to deformation that exceeds the size of an air gap. Existing methods do not take into account the thermal component and attempts to improve the design are not based on mathematical models that make it possible to perform calculations with an accuracy of more than 50 %. The method devised in this work makes it possible to obtain boundary conditions of the third kind on the basis of three-dimensional mathematical modeling of the ventilation system of the hydraulic unit without simplifications. The method accuracy is explained by taking into account the spatial thermal component. The heat transfer coefficient determined by this method in the pole-to-pole connections area was ~250 W/(m2·K). Using FEM, mathematical modeling of the thermal stress state of pole-to-pole connections was carried out, taking into account mechanical and thermal factors. This made it possible to design the improved connection structure with additional fastening elements, which make it possible to reduce the displacement to 0.03 mm, and the stress to 53 MPa at the rotor rotation frequency of 880 rpm. This design makes it possible to enable reliable operation of the hydraulic unit under the condition of increasing the rotor rotation frequency to overspeed with disconnected combinatorial dependence, provided that the actual stresses are 0.95 % of the material yield strength. The convergence of the values obtained by the proposed method and by the HSS method exceeded 99 %. The practical result is the proposals for the hydraulic generator design modernization

Author Biographies

Oleksii Tretiak, National Aerospace University "Kharkiv Aviation Institute"

Doctor of Technical Sciences, Associate Professor

Department of Aerohydrodynamics

Serhii Smyk, Ivan Kozhedub Kharkiv National Air Force University

PhD

Department of Scientific Center Air Force

Stanislav Kravchenko, National Aerospace University "Kharkiv Aviation Institute"

PhD Student

Department of Aerohydrodynamics

Serhii Smakhtin, National Aerospace University "Kharkiv Aviation Institute"

PhD Student

Department of Aerohydrodynamics

Dmytro Brega, National Aerospace University "Kharkiv Aviation Institute"

PhD, Associate Professor

Department of Aerohydrodynamics

Anton Zhukov, "Kharkiv Electric Machine-Building Plant" LLC

PhD Student

Serhii Serhiienko, "Kharkiv Electric Machine-Building Plant" LLC

PhD Student

Yevhen Don, Kharkiv National Automobile and Highway University

PhD

Department of Cars named after A.B. Gredeskula

References

  1. Liu, X., Luo, Y., Wang, Z. (2016). A review on fatigue damage mechanism in hydro turbines. Renewable and Sustainable Energy Reviews, 54, 1–14. https://doi.org/10.1016/j.rser.2015.09.025
  2. Selak, L., Butala, P., Sluga, A. (2014). Condition monitoring and fault diagnostics for hydropower plants. Computers in Industry, 65 (6), 924–936. https://doi.org/10.1016/j.compind.2014.02.006
  3. Kobzar, K. O., Gakal, P. G., Ovsyannykova, O. O. (2015). The Review of the Methods Used for the Analysis of the Thermal State of the Turbo-Generator Rotor with the Intermediate Hydrogen Cooling. NTU “KhPI” Bulletin: Power and Heat Engineering Processes and Equipment, 15, 112–117. https://doi.org/10.20998/2078-774x.2015.15.14
  4. DeCamillo, S. M., Dadouche, A., Fillon, M. (2013). Thrust Bearings in Power Generation. Encyclopedia of Tribology, 3682–3690. https://doi.org/10.1007/978-0-387-92897-5_57
  5. Zhou, C., Bian, X., Liang, Y., Zong, R. (2018). Numerical calculation and analysis of temperature field for stator transposition bar in hydro-generator. International Journal of Thermal Sciences, 125, 350–357. https://doi.org/10.1016/j.ijthermalsci.2017.12.004
  6. El-Zohri, E. H., Shafey, H. M., Kahoul, A. (2019). Performance evaluation of generator air coolers for the hydro-power plant of Aswan High Dam at Egypt. Energy, 179, 960–974. https://doi.org/10.1016/j.energy.2019.05.006
  7. Li, D., Li, W., Li, J., Liu, X. (2020). Analyzing regularity of interpolar air motion and heat dissipation coefficient distribution of a salient pole synchronous generator considering rotary airflow. International Communications in Heat and Mass Transfer, 119, 104828. https://doi.org/10.1016/j.icheatmasstransfer.2020.104828
  8. Verma, S., Chelliah, T. R. (2024). Restoration of extra-high voltage power grids through synchronous and asynchronous hydro units during blackout – A comprehensive review and case study. Electric Power Systems Research, 228, 110054. https://doi.org/10.1016/j.epsr.2023.110054
  9. Dang, D.-D., Pham, X.-T., Labbe, P., Torriano, F., Morissette, J.-F., Hudon, C. (2018). CFD analysis of turbulent convective heat transfer in a hydro-generator rotor-stator system. Applied Thermal Engineering, 130, 17–28. https://doi.org/10.1016/j.applthermaleng.2017.11.034
  10. Bucur, D. M., Cosoiu, C. I., Iovanel, R. G., Nicolae, A. A., Georgescu, S.-C. (2017). Assessing the Operation of the Cooling Water System of a Hydro-Power Plant Using EPANET. Energy Procedia, 112, 51–57. https://doi.org/10.1016/j.egypro.2017.03.1058
  11. Goričanec, D., Pozeb, V., Tomšič, L., Trop, P. (2014). Exploitation of the waste-heat from hydro power plants. Energy, 77, 220–225. https://doi.org/10.1016/j.energy.2014.06.106
  12. Olkkonen, V., Haaskjold, K., Klyve, Ø. S., Skartlien, R. (2023). Techno-economic feasibility of hybrid hydro-FPV systems in Sub-Saharan Africa under different market conditions. Renewable Energy, 215, 118981. https://doi.org/10.1016/j.renene.2023.118981
  13. Stancel, E., Cadis, M., Schiau, C., Ghiran, O., Stoian, I. (2007). Temperature Monitoring – Improved Diagnosis Support for Hydro Power Generators. IFAC Proceedings Volumes, 40 (8), 177–181. https://doi.org/10.3182/20070709-3-ro-4910.00029
  14. Bomben, S. G., LeBlanc, J.-B. (2009). Experience with field coil interconnection failures on large hydro generators Part I. 2009 IEEE Electrical Insulation Conference. https://doi.org/10.1109/eic.2009.5166391
  15. Chaulagain, R. K., Poudel, L., Maharjan, S. (2024). Design and experimental analysis of a new vertical ultra-low-head hydro turbine with the variation of outlet flow level on the head drop section of an open canal. Results in Engineering, 22, 102240. https://doi.org/10.1016/j.rineng.2024.102240
  16. Zito, R., Ardebili, H. (2019). Energy Storage: A New Approach. John Wiley & Sons. https://doi.org/10.1002/9781119083979
  17. Keyhani, A. (2019). Design of Smart Power Grid Renewable Energy Systems. John Wiley & Sons. https://doi.org/10.1002/9781119573265
  18. Rotor Inspection (2020). Handbook of Large Hydro Generators, 417–463. https://doi.org/10.1002/9781119524205.ch9
  19. Rausand, M., Barros, A., Hoyland, A. (2020). System Reliability Theory. Wiley Series in Probability and Statistics. John Wiley & Sons, Inc. https://doi.org/10.1002/9781119373940
  20. EN IEC 60034-33:2022. Rotating electrical machines - Part 33: Synchronous hydrogenerators including motor-generators - Specific requirements. Available at: https://standards.iteh.ai/catalog/standards/clc/f12936e0-2cf5-4b1d-990f-b3ee4f12ca57/en-iec-60034-33-2022
  21. Wang, H. (2023). Similarity and Dimensional Analysis. A Guide to Fluid Mechanics. Cambridge: Cambridge University Press, 230–245. https://doi.org/10.1017/9781108671149.009
  22. Tretiak, O., Kritskiy, D., Kobzar, I., Arefieva, M., Nazarenko, V. (2022). The Methods of Three-Dimensional Modeling of the Hydrogenerator Thrust Bearing. Computation, 10 (9), 152. https://doi.org/10.3390/computation10090152
  23. Tretiak, O., Kritskiy, D., Kobzar, I., Sokolova, V., Arefieva, M., Tretiak, I. et al. (2022). Modeling of the Stress–Strain of the Suspensions of the Stators of High-Power Turbogenerators. Computation, 10 (11), 191. https://doi.org/10.3390/computation10110191
  24. Tretiak, O., Kritskiy, D., Kobzar, I., Arefieva, M., Selevko, V., Brega, D. et al. (2023). Stress-Strained State of the Thrust Bearing Disc of Hydrogenerator-Motor. Computation, 11 (3), 60. https://doi.org/10.3390/computation11030060
  25. Anderson, D. A., Tannehill, J. C., Pletcher, R. H., Ramakanth, M., Shankar, V. (2020). Computational Fluid Mechanics and Heat Transfer. CRC Press. https://doi.org/10.1201/9781351124027
  26. Putignano, C., Afferrante, L., Carbone, G., Demelio, G. (2012). A new efficient numerical method for contact mechanics of rough surfaces. International Journal of Solids and Structures, 49 (2), 338–343. https://doi.org/10.1016/j.ijsolstr.2011.10.009
  27. Gerling, D. (2014). DC-Machines. Electrical Machines. Springer, 37–88. https://doi.org/10.1007/978-3-642-17584-8_2
  28. Li, W., Liu, Y.-P., Peng, X.-F. (2012). The generalized HSS method for solving singular linear systems. Journal of Computational and Applied Mathematics, 236 (9), 2338–2353. https://doi.org/10.1016/j.cam.2011.11.020
Devising a calculation method for modern structures of current-conducting elements in large electric machines in a three-dimensional statement

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Published

2024-08-21

How to Cite

Tretiak, O., Smyk, S., Kravchenko, S., Smakhtin, S., Brega, D., Zhukov, A., Serhiienko, S., & Don, Y. (2024). Devising a calculation method for modern structures of current-conducting elements in large electric machines in a three-dimensional statement. Eastern-European Journal of Enterprise Technologies, 4(1 (130), 87–96. https://doi.org/10.15587/1729-4061.2024.310049

Issue

Vol. 4 No. 1 (130) (2024): Engineering technological systems

Section

Engineering technological systems

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Copyright (c) 2024 Oleksii Tretiak, Serhii Smyk, Stanislav Kravchenko, Serhii Smakhtin, Dmytro Brega, Anton Zhukov, Serhii Serhiienko, Yevhen Don

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