NINE-PHASE FRACTIONAL-SLOT WINDING FOR ALTERNATING-CURRENT MACHINES Russian patent published in 2004 - IPC

FIELD: electrical and electromechanical engineering; nine-phase squirrel-cage induction motors for variable-speed ac drives.

SUBSTANCE: proposed winding designed for use in variable-speed ac drives supplied with power from semiconductor frequency changers is double-layer winding with pole pair number 2p = 10 and number of slots per pole per phase q = 3/5, whose winding coils are grouped and disposed in row 1 1 0 1 0 in z = 54 slots accommodating 54 coils K numbered from 1K to 54K with slot pitch y_s. With phase number m = 9, belt number m' = 2m = 18 coils 1K + 3(k) and 2K + 3(k), each having (I - x)w_k turns, and each coil 3K + 3(k) has (I + x)w_k turns. Series-connected in first phase are coils 1K, 12K, 23K, -28K, -39K, -50K with starting lead of phase from start of 1K and its finishing lead from start of 50K; coils of each next phase are alternating at interval of 12 numbers within K = 54 coils relative to coils of first phase, where y_s = 6.2w_k is turn number of filled up slot; x = 0.09, and value of k in coil numbers varies between 0 and 2m = 17, minus sign at coil number indicating its differential connection in phase.

EFFECT: eliminating mmf of most pronounced fractional harmonic to reduce differential dissipation in five-phase winding.

1 cl, 3 dwg