The paper presents a study of dynamic thermal processes in ultra-high-speed microgenerators power of 55 W with the rotational speed of 800,000 rpm for UAV. A large-scale study of current works devoted to this topic were done where the main shortcomings were identified. A mathematical description of heat exchange processes in microelectromechanical energy converters with a flight time of no more than 10 minutes was developed in a non-stationary formulation. A study of the thermal state of the microgenerator operating in a short-term mode without a special cooling system is conducted. An experimental study of the heating dynamics of its active parts is carried out using the method of physical analogies. On the basis of experimental studies, the FEMM model is verified. Afterwards, combined electromagnetic and thermal calculations of microgenerator are conducted.
2. Zwyssig, C., J. W. Kolar, and S. D. Round, "Mega-speed drive systems: Pushing beyond 1 million RPM," IEEE/ASME Transactions on Mechatronics, Vol. 14, No. 5, 564-574, 2009.
3. Zwyssig, C., S. D. Round, and J.W. Kolar, "An ultrahigh-speed, low power electrical drive system," IEEE Transactions on Industrial Electronics, Vol. 55, No. 2, 577-585, 2008.
4. Zwyssig, C., J. W. Kolar, W. Thaler, and M. Vohrer, "Design of a 100 W, 500000 rpm permanentmagnet generator for mesoscale gas turbines," Proceedings of IEEE Industry Applications Conference 2005, Conference Record of the 40th IAS Annual Meeting, Vol. 1, 253-260, Hong Kong, Oct. 2–6, 2005.
5. Zwyssig, C., S. D. Round, and J. W. Kolar, "Power electronics interface for a 100W, 500000 rpm gas turbine portable power unit," Proceedings of Applied Power Electronics Conference, 283-289, Dallas, Texas, USA, Mar. 19–23, 2006.
6. Tuysuz, A., M. Steichen, C. Zwyssig, and J. W. Kolar, "Advanced cooling concepts for ultra-highspeed machines," 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia), 2194-2202, 2015.
7. Isomura, K., M. Murayama, S. Teramoto, K. Hikichi, Y. Endo, S. Togo, and S. Tanaka, "Experimental verification of the feasibility of a 100W class micro-scale gas turbine at impeller diameter 10mm," Proceedings of the Fifth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applicati, 254-261, Tokyo, Japan, Nov. 28–30, 2005.
8. Park, C. H., S. K. Choi, and S. Y. Ham, "Design and experiment of 400,000 rpm high speed rotor and bearings for 500W class micro gas turbine generator," International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (Power MEMS), 1-4, Daejeon, 2011.
9. Beyaz, M. I., B. M. Hanrahan, J. Feldman, and R. Ghodssi, "An integrated permanent-magnet microturbogenerator supported on microball bearings," Journal of Microelectromechanical Systems, Vol. 22, No. 3, 2013.
10. Saban, D. M., C. Bailey, D. Gonzalez-Lopez, and L. Luca, "Experimental evaluation of a high-speed permanent-magnet machine," Petroleum and Chemical Industry Technical Conference, 2008.
11. Uzhegov, N., E. Kurvinen, J. Nerg, J. T. Sopanen, and S. Shirinskii, "Multidisciplinary design process of a 6-slot 2-pole high-speed permanent-magnet synchronous machine," IEEE Transactions on Industrial Electronics, Vol. 63, No. 2, 174-178, 2016.
12. Huynh, C., L. Zheng, and D. Acharya, "Losses in high speed permanent magnet machines used in microturbine applications," J. of Engineering for Gas Turbines and Power, Vol. 131, No. 2, 1-6, 2009.
13. Dorrell, D., "Combined thermal and electromagnetic analysis of permanent-magnet and induction machines to aid calculation," IEEE Transactions on Industrial Electronics, Vol. 55, No. 10, 3566-3574, 2008.
14. Vong, P. and D. Rodger, "Coupled electromagnetic-thermal modeling of electrical machines," IEEE Trans. on Magn., Vol. 39, No. 3, 1614-1617, 2003.
15. Ismagilov, F., V. Vavilov, I. Hairullin, and D. Gusakov, "High efficiency ultra-high speed microgenerator," Proceedings of IECON 2016 — 42nd Annual Conference of the IEEE Industrial Electronics Society, 1670-1674, 2016.
16. Ismagilov, F., V. Vavilov, V. Aiguzina, and V. Bekuzin, "Minimization of energy losses in ultrahigh- speed electrical rotating machines," ElektrotehnisKi Vestnik, Vol. 84, No. 1-2, 56-60, 2017.
17. JSC, "Scientific and production association “INTROTEST” electronic source,", Link: http://www.-introtest.com/ (date of the application 16.08.2017).
18., , Electronic source, Available: http://www.introtest.com/usr/06/MK4E/MK4E magnitoprovod.pdf (date of application 24.09.17).
19. PJSC, "Asha metallurgical plant,", Electronic source, Link: http://www.amet.ru/ (date of the application 16.08.2017).