NINE-PHASE FRACTIONAL (q=4/5) WINDING OF A C ELECTRIC MACHINE Russian patent published in 2004 - IPC

FIELD: electrical engineering, electric machine making. SUBSTANCE: invention refers to nine-phase asynchronous motors with squirrel-cage rotors supplied from semiconductor frequency converters in frequency-controlled A C drive. Invention is aimed at achievement of technical result consisting in manufacture of double-layer m=9-phase, m'=18-zone fractional winding with q= 4/5 and p=5 in 2=18pq=72 slots with elimination of most strongly expressed harmonic of fractional order from its magnetomotive force to reduce differential dissipation. Main feature of invention lies in manufacture of double-layer winding with 2p=10 poles with number of slots per pole and phase q= 4/5 and row grouping 1 1 1 1 0 in z=72 slots of K=72 coils with numbers from 1K to 72K and slot pitch y_s.. With number of phases m=9, phase zones m'=2m= 18 coils 1K+4(k) and 4K+4(k) have number of turns (1+1)w_k and coils 2K+4(k) and 3K+4(k) have (1-x)w_c turns. In first phase coils 1K, 16 K,-23K, 30K,-37K, - 52K, 59K,-66K are connected in series with start of phase from start of 1K and its finish from start of 66K and coils of each next phase alternate with interval of 16 numbers within limits of 72 coils with reference to coils of first phase, where y_s = 6,, 2w_c are numbers of turns in each slot, x=10 and value k in numbers of coils changes within limits from 0 to 2m-1=17 and sign (-) by number of coil indicates its connection in opposition in phase. EFFECT: manufacture of windings with reduced differential dissipation. 3 dwg