MULTIPHASE FRACTIONAL-SLOT WINDING OF AC MACHINE Russian patent published in 2004 - IPC

FIELD: electrical and electromechanical engineering; twelve-phase squirrel-cage induction motors. SUBSTANCE: proposed winding used for induction motors supplied with power from semiconductor frequency converter incorporated in variable-speed ac drive is m = 12-phase, m' = 12-section double-layer fractional-slot winding with pole per phase number q = 6/5 and p = 5 placed in z = 12 pq = 72 slots with most conspicuous fractional harmonic component removed from its magnetomotive force. It has ten pole pairs and is assembled of 12p = 60 coil groups numbered from 1G to 60C and slot pitch y_s of coils grouped in line 2 1 1 1 1. Each double-coil group 1G + 5(c) has (1-x)w_c turns per coil and (1-x)w_c turns for groups 3G + 5(c) and 4G + 5()c). Connected in series opposition in first phase are groups 1G, 13G, 25G, 37G, 49G with starting phase lead tapped from starting lead of 1G and its finishing lead, from finishing lead of 49G; groups of each next of m = 12 phases are alternating at intervals of 25 numbers within 60 groups relative to first-phase group, where y_s = 9; 2w_c is turn number in each slot; x = 0.13; c in coil group numbers varies between 0 and m' - 1 = 11 at number of phase sections m' = m = 12. EFFECT: reduced differential dissipation. 1 cl, 3 dwg