A C ELECTRIC MACHINE Russian patent published in 1997 - IPC

FIELD: electric machine engineering. SUBSTANCE: invention refers to A. C. electric motors which can be used in various branches of industry both as motors of controlled drives and generators. Invention is aimed at solving of problem of design of electric machine with electromagnetic reduction with small equivalent leakage inductance of stator in variants of synchronous machine with all types of excitation, asynchronous machine and machine with double feed which will lead to improved mass-and-size and energy parameters of both machines proper and electric drives and power installations with their usage. A. C. electric machine has two three-phase windings on stator each being connected to corresponding group of external terminals. Like phase windings of mentioned three-phase windings are space shifted with reference to each other through 1/6 pole pitch of stator. Specified like phase windings, for instance 3 and 6, are connected in opposition to like external terminals A and A of each of groups A, B, C and A, B, C of external terminals. Pole pitches of rotor and stator are different, that is not equal. Specified make corresponds to time shift between currents of like phase winding through 5/12 period of currents of stator. Resulting magnetic field created by windings of stator has only fifth and seventh spatial harmonics and does not include fundamental harmonic. Description presents examples of manufacture of stator and rotor of machines of various types. EFFECT: improved mass-and-size and energy parameters of A.C. electric machine. 8 cl, 14 dwg ЫЫЫ1