FIELD: electrical and electromechanical engineering; twelve-phase squirrel-cage induction motors. SUBSTANCE: proposed winding used for induction motors supplied with power from semiconductor voltage converters in variable-speed ac drives is double-layer m = 12-phase, m' = 12-section fractional-slot lap winding with number of slots per pole per phase q = 6/7, p = 7, 2p = 14 poles, placed in z = 12 pq = 72 slots with most conspicuous fractional harmonic component removed from its magnetomotive force. It has C = 72 coil groups numbered from 1C through 72C at slot pitch ys grouped in row 1 1 1 1 1 1 0. Each coil 1C + 6(c) and 6C + 6(c) has (1+x)wc turns; each coil 2C + 6(c) and 5C + 6(c), wc turns, and each coil 3C + 4(c) and 4C + 4(c), (1+x)wc turns. Connected in series opposition in first phase are coils 1C, 12C, 22C, 32C, 53C, 63C with starting phase lead tapped from starting lead of 1C and its finishing lead, from finishing lead of 63K; coils of each next phase are alternating at interval of 42 numbers within C = 72 relative to first-phase coils, where ys = 2; 2wc is turn number in each slot; x = 0.17; c varies in coil numbers between 0 and 11. EFFECT: reduced differential dissipation. 1 cl, 3 dwg
