Improving the Efficiency of Аlternating-Current Machine Windings
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The properties of a magnetic field that the current of a three-phase winding of the starter of an induction motor generates greatly depend on winding type. The smaller the quantity of higher (parasitic) harmonics with respect to the fundamental (working) harmonic in the curve of magnetomotive force, the greater the winding efficiency. Three-phase six-band windings have become widespread. Increasing the number of phases promotes a decrease in the quantity of higher harmonics, but a special six-phase supply source is needed for this. A three-phase combined 12-band winding is considered, the electromagnetic properties of which are close to the properties of a six-phase winding. Such a winding is compared to a standard six-band winding with respect to the differential scattering coefficient that characterizes the magnetic field on the basis of the content in it of higher harmonics. Two variants of windings were compared: with continuous and noncontinuous phase bands. The calculation results of differential scattering coefficients of windings for 24, 36, and 48 slots falling per pair of poles are presented. Calculation of the least theoretically possible differential scattering coefficient was performed for a combined winding with continuous phase bands. A high efficiency of combined winding with continuous phase bands as compared with standard winding and combined winding with noncontinuous phase bands was demonstrated.
Keywordsac machine induction motors higher harmonics combined winding differential scattering coefficient Gerges’ diagram
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- 1.Popov, V.I., Novye skhemy trekhfaznykh obmotok elektricheskikh mashin s uluchshennymi elektromagnitnymi svoistvami (New Schemes of Three-Phase Windings of Electric Machines with Improved Electromagnetic Properties), Nizhny Novgorod: Vozhsk. Gos. Inzh.-Pedagog. Univ., 1998.Google Scholar
- 2.Heller, B. and Hamata, V., Harmonic Field Effects in Induction Machines, Amsterdam: Elsevier, 1977.Google Scholar
- 3.Vol’dek, A.I., Elektricheskie mashiny (Electric Machines), Leningrad: Energiya, 1978.Google Scholar
- 4.Kasten, H., Wirkungsgradsteigerung von Asynchronmaschinendurch den Einsatz einer Wicklung mit Stern-Dreieck-Mischschaltung, in Jahresbericht 2010, Dresden: Elektrotech. Inst., 2010.Google Scholar
- 5.Gwozdziewicz, M. and Gawron, S., Application of stardelta mixed stator winding in synchronous machine, with permanent magnets on the rotor surface, Pr. Nauk. Inst. Masz., Napkdowi Pomiarow Elektr., 2011, vol. 65.Google Scholar
- 6.Kučera, J. and Hapl, J., Vinutí Elektrických Strojů Točivých, Praha: Nakl. Česk. Akad. Věd, 1959.Google Scholar