THREE-PHASE FRACTIONAL-SLOT (Q=15/7) DOUBLE-LAYER 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 symmetrical fractional-slot lap winding is 2pc-pole winding placed in z = 90c slots; number of slots per pole per phase q = 15/7; it has 6p = 42c coil groups numbered 1G through 42G(c), coil grouping being in number series 3 2 2 2 2 2 2; even-numbered groups in each phase are differentially connected relative to odd-numbered ones. With concentric coils having slot pitch y_ni = 9, 7, 5 for three-coil groups and y'_ni = 8, 6 for two-coil groups, groups 1G through 7G out of first similar groupings repeated 6c times have coil number (1 - x)W_c for coils with y_ni = 9 and 5 in group 1G, (1 + x)W_c for coils with y'_ni = 8 in groups 4G, 5G, and W_c for remaining coil groups; starts of phases I, II, III run from starts of groups 1G, 15G, 29G, respectively, where c = 1, 2; 2W_c is turn number per slot at optimal values of x = 0.29.

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

1 cl, 4 dwg