ASYMMETRIC FRACTIONAL-SLOT WINDING WITH 2p = 6c POLES PLACED IN z = 57c SLOTS Russian patent published in 2007 - IPC H02K3/04 H02K3/28 

FIELD: electrical and electromechanical engineering; three-phase induction and synchronous machines including slip-ring induction motors.

SUBSTANCE: novelty is that in proposed asymmetric three-phase fractional-slot lap winding with m' = m = 3-bands at 2p = 6c poles and z = 57c, with slots per pole per phase q = z/3p = 19/3 assembled of 3 pc coil groups 1G through 9G, with coil grouping 7 6 6 6 6 7 6 7 6 repeated c times, slot pitch of its concentric coils y_si = 15 - 2(i - 1) and turn number is (1 - x)w_c for coils with i' = 1.7 and turn number is (1 + x)w_c for coil with i = 4 in seven-coil groups 1G, 6G, 8G; slot pitches y'_si = 10 - 2(i' - 1) and turn number (1 + x)w_c for coil with i' = 3 in all six-coil groups; turn number equals (1 - x)w_c for coils with i' = 6 in coil groups 3G, 4G, 7G, 9G, and for coil groups 2G, 5G at slot pitch y_s = 9, turn number equals (1 - x)w_c; for coil with i' = 6 in coil group 2G and for coil with i' = 1 in coil group 5G; turn number in remaining coils of coil groups equals w_c, where c = 1, 2, 3....; i' = 1 - 7 and i' = 1 - 6 are coil numbers in coil group starting from external one; 2w_c is turn number in slots completely filled with winding.

EFFECT: reduced asymmetry and scatter ratios.

1 cl, 4 dwg