Stator for rotating electric machine

A stator for a rotating electric machine, the stator comprising:

• an annular stator core having a plurality of pairs of first-phase slots, a plurality of pairs of second-phase slots and a plurality of pairs of third-phase slots that are sequentially and repeatedly provided in a circumferential direction of the stator core;
• and
• a stator coil comprised of a first-phase winding, a second-phase winding and a third-phase winding that are mounted on the stator core so as to be respectively received in the pairs of first-phase slots, the pairs of second-phase slots and the pairs of third-phase slots, the first-phase, second-phase and third-phase windings being Y-connected with each other,
• wherein
• in each of the first-phase, second-phase and third-phase slots of the stator core, there are received 2×N in-slot portions of a corresponding one of the first-phase, second-phase and third-phase windings of the stator coil in radial alignment with each other, where N is a natural number not less than 2,
• each of the first-phase, second-phase and third-phase windings of the stator coil is comprised of a pair of sub-windings that are connected parallel to each other,
• each of the sub-windings is comprised of a plurality of winding sections,
• the winding sections are classified into N winding section groups including a first winding section group and a second winding section group, each of the winding sections of the first winding section group being arranged alternately at first and second layers in the corresponding phase slots of the stator core, each of the winding sections of the second winding section group being arranged alternately at third and fourth layers in the corresponding phase slots of the stator core, and
• among the N winding section groups, each of the winding sections of (N−1) winding section groups is connected via only serial connection in the sub-winding, and each of the winding sections of the remaining one winding section group is connected via both serial connection and parallel connection in the sub-winding.