Electric rotating machine drivable with a single three-phase inverter

An electric rotating machine comprising:

• a stator including a hollow cylindrical stator core and a stator coil, the stator core having a plurality of stator core teeth that are formed at a predetermined pitch in a circumferential direction of the stator core, the stator coil having three terminals via which three-phase AC current is input to or output from the stator coil;
• and
• a rotor disposed radially inside of the stator core, the rotor having a plurality of magnetic poles the polarities of which alternate between north and south in the circumferential direction of the stator core,
• wherein
• the number of the stator core teeth is equal to 12×n, and the number of the magnetic poles of the rotor is equal to 10×n or 14×n, where n is a natural number,
• the stator coil is comprised of first and second winding groups, the first winding group including 2×n X-phase windings, 2×n Y-phase windings, and 2×n Z-phase windings, the second winding group including 2×n U-phase windings, 2×n V-phase windings, and 2×n W-phase windings,
• the stator coil is wound around the stator core in a concentrated winding manner so that each of the windings of the first and second winding groups is wound around a corresponding one of the stator core teeth,
• the windings of the first and second winding groups are connected to form 2×n Δ-Y connections that are arranged one after another in the circumferential direction of the stator core,
• each of the Δ-Y connections is formed of six different-phase windings including one X-phase winding, one Y-phase winding, and one Z-phase winding of the first winding group and one U-phase winding, one V-phase winding, and one W-phase winding of the second winding group, the six different-phase windings being adjacent to one another and arranged in a phase sequence of U, X, V, Y, W, and Z in the circumferential direction of the stator core,
• for each of the Δ-Y connections, the U-phase and X-phase windings are wound in opposite directions, the V-phase and Y-phase windings are wound in opposite directions, and the W-phase and Z-phase windings are wound in opposite directions, and
• each of the Δ-Y connections is a combination of a Δ connection and a Y connection, the Δ connection being formed by Δ-connecting the three different-phase windings of one of the first and second winding groups, nodes between the Δ-connected windings being respectively connected to the three terminals of the stator coil, the Y connection being formed by Y-connecting the three different-phase windings of the other winding group to define a neutral point therebetween, the Δ and Y connections being combined by connecting ends of the Y-connected windings opposite to the neutral point respectively to the nodes between the Δ-connected windings.