THREE-PHASE, DOUBLE-LAYER, FRACTIONAL-SLOT (q=3.5), 2p1/2p2=2/1 POLE-CHANGING WINDING

FIELD: electrical engineering. ^ SUBSTANCE: proposed double-layer pole-changing winding whose phase leads are connected in Y/YY or Delta/YY has Ncg = 6p2 coil groups placed in z = 6p2q slots with slot pitch ys = z/2p1, each phase being divided into two parts with odd-numbered groups in one part, even-numbered ones, in other part, and additional leads, brought out of midpoints in each phase. With 2p1/2p2 = 4/2, 8/4, 12/6, and 16/8, odd-numbered concentric four-coil groups have coil pitches ysi = 8 - 2(i - 1) at turn number (1 + x)wc, at turn number(1 - x)w of coil with i = 1, 4 and at turn number (1 + x)wc of coil with i = 2 and at turn number of coil with i = 1, 4, and at turn number (1 + x)wc, of coil with i = 2, and even-numbered three-coil groups have coil pitch ysi = 7 - 2(i - 1) at turn number (1 + x)wc of coil with i = 2 at wc turns of remaining coil groups, where z = 21 for 2p1/2p2 = 4/2, z = 42 for 2p1/2p2 = 8/4, z = 63 for 12/6, z = 84 for 2p1/2p2 = 16/8; i = 1 ... 4 is coil number in group starting from external one; 2wc is turn number per slot at x = 0.53. ^ EFFECT: equalized internal voltages and resistances among large and small coil groups of proposed winding. ^ 1 cl, 3 dwg