Electric drive system with static pulsed power transfer

A method of pulsed power transfer in an electric drive system in a vehicle, the electric drive system having a controller with a processor and tangible, non-transitory memory, and an electric machine with a stator assembly and a rotor assembly, the method comprising:

• incorporating a plurality of multi-phase stator windings in the stator assembly, including a first stator winding and a second stator winding, the rotor assembly including rotor windings having a single phase;
• adapting a first inverter to feed the first stator winding;
• adapting a second inverter to feed the second stator winding;
• commanding selectively excitation of the rotor windings with a pulsed field current, via the controller, such that a direct-axis (d-axis) stator flux linkage is generated, a d-axis stator voltage being induced in the first stator winding and the second stator winding by the d-axis stator flux linkage;
• and
• enabling pulsed power transfer through interaction of the d-axis stator voltage and respective d-axis winding currents in the first stator winding and the second stator winding.

A vehicle comprising:

• an electric machine having a stator assembly and a rotor assembly, the stator assembly having a plurality of multi-phase stator windings, including a first stator winding and a second stator winding, the rotor assembly including rotor windings having a single phase;
• a first inverter adapted to feed the first stator winding;
• a second inverter adapted to feed the second stator winding;
• a controller in communication with the electric machine, the controller having a processor and tangible, non-transitory memory on which instructions are recorded for a method of pulsed power transfer;
• wherein the controller is configured to selectively command excitation of the rotor windings with a pulsed field current such that a direct-axis (d-axis) stator flux linkage is generated, a d-axis stator voltage being induced in the first stator winding and the second stator winding by the d-axis stator flux linkage;
• wherein the controller is configured to selectively command excitation of the first stator winding and the second stator winding with alternating d-axis currents at a same frequency as the pulsed field current, to generate the respective d-axis winding currents;
• wherein the d-axis stator flux linkage is in phase with the pulsed field current, and the d-axis stator voltage is 90 degrees ahead of the d-axis stator flux linkage;
• and
• wherein the pulsed power transfer is enabled through interaction of the d-axis stator voltage and respective d-axis winding currents in the first stator winding and the second stator winding.