Patent ID: 8749090

Claim:
An automotive propulsion system comprising: a first voltage source; a power electronics device comprising a plurality of power switching devices coupled to the first voltage source; an electric motor comprising a plurality of windings and a neutral node, the plurality of windings being coupled to the plurality of power switching devices and the neutral node interconnecting the plurality of windings, the electric motor including a plurality of current sensors that measure the flow of current through a respective one of the plurality of windings; a second voltage source coupled to the neutral node of the electric motor and the first voltage source; and a processing system in operable communication with the first and second voltage sources, the power electronics device, and the electric motor, the processing system being configured to: generate sensed synchronous frame currents based only on the flow of current measured by the plurality of current sensors, an angular position of the motor and an angular speed of the motor; determine a desired power flow for the second voltage source; generate commanded synchronous frame currents based on the desired power flow, an available voltage of the first voltage source and the second voltage source, the angular speed of the motor and a received torque command; generate commanded stationary voltages for the electric motor based on the generated commanded synchronous frame currents and the sensed synchronous frame currents; convert the commanded stationary voltages into duty cycles; and operate the plurality of power switching devices based on the duty cycles such that an alternating current (AC) waveform with a direct current (DC) component is generated based on the desired power flow, and the plurality of power switching devices generate a positive direct DC component when power flows to the second voltage source and generate a negative direct DC component when power flows from the second voltage source.