Русская версия English version
Home / 2019 issue 1 / Analytical method for the evaluation of electromagnetic vibrations in the seven-phase ac motor

Analytical method for the evaluation of electromagnetic vibrations in the seven-phase ac motor

V.M. Tereshkin

Vestnik IGEU, 2019 issue 1, pp. 61—69

Download PDF

Abstract in English: 

Background. It has been established that with an increase in the number of motor phases, the magnitude of the phase current and the level of vibrations of electromagnetic origin decrease. There are works that provide an analysis of the spectrum of the space-time harmonics of the resulting current of a four-phase winding, as well as five-phase and three-phase windings. However, the problem of studying the effect of time harmonics of phase currents of the symmetric seven-phase winding on the formation of space-time harmonics has not been studied yet. The aim of the work is to identify the unique properties of the seven-phase winding, in which the space-time spectrum of the resulting current contains only the first harmonic.

Materials and method. We used an analytical method for calculating the space-time harmonics of the resulting current of a seven-phase winding for given time phase harmonics. The analytical approach used is original and represents a development of the theory of electric machines. The study assumes that the air gap is uniform. Considering this question with this assumption makes it possible to reveal the main features of the field in the air gap formed by the seven-phase winding as compared with the windings having a different number of phases.

Results. The seven-phase winding of the electric machine is considered, namely, its ability to form a resultant (space-time) sinusoidal current, despite the presence of time harmonics of phase currents. It has been established that the odd time harmonics of the phase currents of the symmetrical seven-phase winding do flow in phases but do not form space-time harmonics of the forward and reverse sequence, which completely excludes one of the factors of vibrations of electromagnetic origin. The phase currents of the seventh time harmonic of the symmetric seven-phase winding do not have a relative time shift, which excludes the very fact that they can flow.

Conclusions. It has been established that there are no higher harmonics in the spectrum of the resulting space-time current of the seven-phase winding that forms the magnetizing force and the flow in the gap. This circumstance may have a favourable effect on the decrease in the level of vibrations of electromagnetic origin. The properties of the seven-phase winding may be of particular interest in the implementation of the electric drive with vector control.

 

References in English: 

1. Chan, C.C. The State of the Art of Electric, Hybrid and Fuel Cell Vehicles. Proc IEEE, 2007, vol. 95, no. 4, pp. 704–718.

2. Chan, C.C., Bouscayrol, A., Chen, K. Electric, Hybrid and Fuel-Cell Vehicles: Architectures and Modeling. IEEE Transact Vehicular Technol, 2010, vol. 59, no. 2, pp. 589–598.

3. Global EV Outlook: Understanding the Electric Vehicle Landscape to 2020, Apr. 2013. Available at: http://www.iea.org/publications/globalevoutlook_2013.pdf.

4. Levi, E., Bojoi, R., Profumo, F., Toliyat, H.A., Williamson, S. Multiphase Induction Motor Drives – A Technology Status Review. IET Electric Power Applic, 2007, vol. 1, no. 4, pp. 489–516.

5. Dwari, S., Parsa, L. Fault–Tolerant Control of Five–Phase Permanent–Magnet Motors With Trapezoidal Back EMF. IEEE Transact Indust Electron, 2011, vol. 58, no. 2, pp. 476–485.

6. Williamson, S., Smith, S. Pulsating Torque and Losses in Multiphase Induction Machines. IEEE Transact Indust Applic, 2003, vol. 39, no. 4, pp. 986–993.

7. Duran, Mario J., Barrero, F.J., Toral, S.L. Multi-Phase Space Vector Pulse Width Modulation: Applications and Strategies». Int. Conf. on Renewable Energies and Power Quality (RE&PQJ), 2007, Journal № 5.

8. Duran, Mario J., Barrero, F.J., Toral, S.L., Levi, E. Multi-dimensional space vector pulse width modulation scheme for five-phase series-connected two-motor drives. IEEE Int. Elec. Machines and Drives Conf. (IEMDC), Antalya, 2007.

9. Levi, E. Multiphase electric machines for variable-speed applications. IEEE Trans. Industrial Electronics, May 2008, vol. 55(5), pp. 1893–1909.

10. Dwari, S., Parsa, L. Fault–Tolerant Control of Five–Phase Permanent–Magnet Motors With Trapezoidal Back EMF. IEEE Transact Indust Electron, 2011, vol. 58, no. 2, pp. 476–485.

11. Williamson, S., Smith, S. Pulsating Torque and Losses in Multiphase Induction Machines. IEEE Transact Indust Applic, 2003, vol. 39, no. 4, pp. 986–993.

12.Vieri Xue. Center-Aligned SVPWM Realization for 3- Phase 3- Level Inverter, Application Report SPRABS6. October, 2012.

13. Golubev, A.N., Ignatenko, C.B. Elektrotekhnika, 2000, no. 6, pp. 28–31.

14. Golubev, A.N., Ignatenko, C.B. Elektrotekhnika, 2001, no. 10, pp. 17–22.

15. Babaev, M.B., Golubev, A.N., Ignatenko, C.B. Vliyanie chisla faz na pul'satsii momenta i vibroshumovye kharakteristiki AD [The effect of the phase number on the torque pulsation and vibration and noise parameters of induction motors].  Tezisy dokladov II Mezhdunarodnoy konferentsii po elektromekhanike i elektrotekhnologiyam v 2 ch., ch. 2 [Abstracts of the II International conference on electromechanics and electric technologies, in 2 parts, part 2]. Krym, 1996, рр. 150–152.

16. Kozyaruk, A.E., Rudakov, V.V. Sistemy upravleniya elektroprivodov. Pryamoe upravlenie momentom v elektroprivode peremennogo toka [Electric drive control systems. Direct torque control in the AC electric drive]. Saint-Petersburg:  SPGGI(NIU), 2007. 75 р.

17. Kozyaruk, A.E. Pryamoe upravlenie momentom v elektroprivode peremennogo toka mashin i mekhanizmov gornogo proizvodstva [Direct torque control in the AC electric drive of machines and mechanisms of mining industry]. Saint-Petersburg: SPGGI(NIU), 2008. 99 р.

18. Usol'tsev, A.A. Sovremennyy asinkhronnyy elektroprivod optiko-mekhanicheskikh kompleksov [Modern induction electric drives of optical-mechanical complexes]. Saint-Petersburg: SPb NIU ITMO, 2011. 164 р.

19. Vol'dek, A.I. Elektricheskie mashiny [Electric machines]. Leningrad: Energiya, 1974.

20. Tereshkin, V.M. Vestnik Moskovskogo aviatsionnogo instituta, 2018, vol. 25, no. 3, pp. 212–219.

21. Tereshkin, V.M. Vestnik Moskovskogo aviatsionnogo instituta, 2018, vol. 25, no. 4, pp. 229–239.

 

Key words in Russian: 
семифазная обмотка двигателя, результирующий вектор тока, временные гармоники фазных токов, вибрации электромагнитного происхождения
Key words in English: 
seven-phase motor winding, resultant current vector, time harmonics of phase currents, vibration of electromagnetic origin
The DOI index: 
10.17588/2072-2672.2019.1.061-069
Downloads count: 
24