THREE-PHASE DOUBLE-LAYER FRACTIONAL-SLOT (Q=15/13) LAP WINDING FOR ELECTRICAL MACHINES Russian patent published in 2004 - IPC

FIELD: electrical and electromechanical engineering; three-phase squirrel-cage induction motors and synchronous generators.

SUBSTANCE: proposed three-phase double-layer symmetrical fractional-slot winding has number of slots per pole per phase q = 15/13 of 6p = 78c coil groups; it is 2p = 26c lap winding placed in z = 90c slots. Coil groups are numbered 1G through 78G (c), coils being grouped in number series 2 1 1 1 1 1 2 1 1 1 1 1 1; slot pitch y_s = 4; even-numbered groups of each phase are differentially connected to odd-numbered ones. Groups 1G through 13G of first of similar groupings repeating 6c times have coil turn number (1 - x)w_c for double-coil groups 1G and 7G, (1 - x)w_c for groups 4G, 10G, 11G, and w_c for remaining groups with starts of phases I, II, III running from starts of groups 1G, 27G, 53G, respectively, where c = 1 and 2; w_c is turn number in completely filled up slot at optimal value of x = x_opt = 0.32.

EFFECT: improved harmonic content of mmf and reduced differential dissipation.

1 cl, 4 dwg