THREE-PHASE FRACTIONAL-SLOT (Q=1/7) ELECTRICAL MACHINE WINDING Russian patent published in 1997 - IPC

FIELD: multipolar AC machines. SUBSTANCE: double-layer winding with number of poles 2P=14 in Z=72 slots of evenly displaced coils with spacing in slots Y_s, combined in 6p=42 coil groups numbered from 1G to 42G, with coils grouped in them in row 2221221 repeated six times, contains in the first phase series-connected groups with numbers 1G+(3K)G at an opposite connection of the even groups relative to the odd ones, and for the other two phases their numbers alternate at intervals of 2p=14 and 4p=28 groups, the first and second coils in the two-coil groups have numbers of turns (1-X)W_coil and (1+X)W_coil for groups 1G+(7C)G and 5G+(7C)G and (1+X)W_coil for groups 2G+(7c)G, (1+X)W_coil and groups 4G+(7c)G and 7G(7c)G have number of turns (1+x)W_coil, where Y_s=6, K=0,1,2..., (p-2); 2W_coil - number of turns of each slot, and the value of parameter "X" is selected within 0,20≥x≥0,35. EFFECT: reduced differential dissipation. 4 dwg