Hybrid excited rotary machine

An electric machine, comprising:

• a stator;
• a rotor core surrounded by the stator and rotatable about an axis, the rotor core having axially opposite ends and a plurality of slots, each slot extending through the rotor core between the axially opposite ends and containing at least one respective conductive bar and at least one respective permanent magnet, wherein the conductive bars are radially inboard relative to the permanent magnets and extend beyond the axially opposite ends of the rotor core, and wherein the at least one respective conductive bar and at the least one respective permanent magnet contained within each slot are separated by a respective space;
• and
• an annular end ring assembly at one end of the rotor core containing a first terminal conductor galvanically coupled to a first subset of the conductive bars and a second terminal conductor galvanically coupled to a second subset of the conductive bars,
• wherein the at least one respective permanent magnet contained within each slot comprises a respective first magnet and a respective second magnet, wherein the first magnets are intermediate the second magnets and the conductive bars,
• wherein the respective first magnet and the respective second magnet have at least one of a temperature rating and a coercivity that are different from one another, and
• wherein the annular end ring assembly further contains a secondary coil of a rotary transformer.

An electrified powertrain for a vehicle, comprising:

• a battery pack;
• a traction power inverter module (“TPIM”) connected to the battery pack, and configured to change a direct current (“DC”) voltage from the battery pack to an alternating current (“AC”) voltage;
• and
• a rotary electric machine, comprising:
• a stator energized by the AC voltage from the TPIM;
• a rotor core surrounded by the stator and rotatable about an axis, the rotor core having axially opposite ends and a plurality of slots, each slot extending through the rotor core between the axially opposite ends and containing at least one respective conductive bar and at least one respective permanent magnet, wherein the conductive bars are radially inboard relative to the permanent magnets and extend beyond the axially opposite ends of the rotor core, and wherein the at least one respective conductive bar and at the least one respective permanent magnet contained within each slot are separated by a respective space;
• and
• an annular end ring assembly at one end of the rotor core containing a first terminal conductor galvanically coupled to a first subset of the conductive bars and a second terminal conductor galvanically coupled to a second subset of the conductive bars, the annular end ring assembly further containing a secondary coil of a rotary transformer for energizing the conductive bars;
• a rotor shaft connected to the rotor, and configured to rotate about an axis of rotation in conjunction with the rotor when the stator is energized;
• and
• a transmission coupled to the rotor shaft and powered by the electric machine.