THREE-PHASE POLE-CHANGING WINDING Russian patent published in 2004 - IPC

FIELD: electrical engineering; variable-speed motors. SUBSTANCE: proposed 20/4 pole-changing winding has 24 coil groups with equal number of coils per group, winding pitch y = z/2p₂. Coil groups are numbered in phases according to number series of 8i - 7, 8i - 5, 8i - 4, 8i - 2, 81 + 5, 8i + 7, 8i + 8, 8i + 10; coil groups bearing numbers 8i - 2, 8i - 4, 8i + 8, 8i + 10 have twice as small number of turns than those numbered 8i - 5, 8i - 7, 8i + 5, 8i + 7. In order to obtain 20-pole arrangement voltage should be applied to starting leads of coil groups 8i - 7. When voltage is applied to finishing leads of coil groups 8i + 8 with starting leads of coil groups 8i - 7 being integrated, four-pole winding is obtained. EFFECT: enhanced reliability of speed control at uniform coil distribution among slots; enhanced utilization of active materials at all speeds. 1 cl, 5 dwg