Abstract: An integrated rotary transformer and resolver and a motor including an integrated rotary transformer and resolver is provided. The integrated rotary transformer and resolver may include, but is not limited to, a stator having an outer surface and a plurality of slots disposed along the outer surface, a plurality of sensing coils, the plurality of sensing coils disposed in at least some of the plurality of slots, a rotor having a surface varying from a first predetermined thickness to a second predetermined thickness, and a controller electrically coupled to the plurality of sensing coils and configured to determine a position of the rotor based upon a voltage induced in each of the coils due to a relative thickness of the rotor opposed to the respective sensing coil.

Abstract: Controlling a synchronous electric machine includes determining a rotor field current of a wound rotor of the synchronous electric machine and determining a time-rate change in field flux linkage. A rotor field voltage is determined based upon the time-rate change in the field flux linkage, and a rotor field resistance is determined based upon the rotor field voltage and the rotor field current. A rotor temperature is determined based upon the rotor field resistance. Operation of the synchronous electric machine is controlled responsive to a torque command and the rotor temperature.

Abstract: An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator.

Abstract: Controlling a synchronous electric machine includes determining a rotor field current of a wound rotor of the synchronous electric machine and determining a time-rate change in field flux linkage. A rotor field voltage is determined based upon the time-rate change in the field flux linkage, and a rotor field resistance is determined based upon the rotor field voltage and the rotor field current. A rotor temperature is determined based upon the rotor field resistance. Operation of the synchronous electric machine is controlled responsive to a torque command and the rotor temperature.

Abstract: Automotive propulsion systems and methods of operation are provided. The automotive propulsion system includes a first voltage source, a power electronics device comprising a plurality of power switching devices coupled to the first voltage source, an electric motor having a plurality of windings coupled to the plurality of power switching devices and a neutral node interconnecting the plurality of windings, and a second voltage source coupled to the neutral node of the electric motor and the first voltage source.

Abstract: A high frequency rotary transformer for an electrical machine includes a primary transformer component having a primary transformer winding, and a secondary transformer component having a secondary transformer winding. The primary transformer winding is configured to be coupled to a DC power source via a DC to AC converter. The secondary transformer winding is configured to be coupled to a winding of the rotor. Each of the primary and secondary transformer components are mechanically coupled to either the stator or the rotor. The secondary transformer component is configured to rotate with respect to the primary transformer component to produce a magnetic flux via the primary transformer winding and the secondary transformer winding.

Abstract: Methods and systems are provided for control operation of a boost converter. The boost converter includes an input, an output, and a plurality of paths electrically connecting the input to the output. The boost converter also includes a plurality of switches disposed along the paths to control current flow between the input and the output. The system includes a controller. The controller receives a desired current to be supplied at the output. The controller determines which of the paths to utilize based at least in part on the desired current. The controller controls the switches based at least in part on the determination of which of the paths to utilize.

Abstract: An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator.

Abstract: An integrated rotary transformer and resolver and a motor including an integrated rotary transformer and resolver is provided. The integrated rotary transformer and resolver may include, but is not limited to, a stator having an outer surface and a plurality of slots disposed along the outer surface, a plurality of sensing coils, the plurality of sensing coils disposed in at least some of the plurality of slots, a rotor having a surface varying from a first predetermined thickness to a second predetermined thickness, and a controller electrically coupled to the plurality of sensing coils and configured to determine a position of the rotor based upon a voltage induced in each of the coils due to a relative thickness of the rotor opposed to the respective sensing coil.

Abstract: Systems and methods are provided for an automotive drive system using an absolute position sensor for field-oriented control of an induction motor. An automotive drive system comprises an induction motor having a rotor, and a position sensor coupled to the induction motor. The position sensor is configured to sense an absolute angular position of the rotor. A processor may be coupled to the position sensor and configured to determine a relative angular position of the rotor based on a difference between the absolute angular position and an initial angular position obtained when the induction motor is started. A controller may be coupled to the induction motor and the processor and configured to provide field-oriented control of the induction motor based on the relative angular position of the rotor.

Abstract: Systems and methods are provided for discharging a voltage bus. An electrical system comprises a first switch coupled to a first voltage rail, a second switch coupled between the first switch and a second voltage rail, and a control system coupled to the first switch and the second switch. The control system is configured to alternately activate the first switch and the second switch such that an energy potential between the first voltage rail and the second voltage rail is dissipated through the first switch and the second switch.

Abstract: A rotor assembly is assembled by providing an elongated rectangular strip of material having a first edge and a second edge defining a width, cutting the elongated rectangular strip to form a first patterned strip having a first side corresponding to the first edge, winding the first patterned strip portion around the perimeter of the rotor core such that the first edge is adjacent to the perimeter and the patterned strip portion forms a continuous laminated ring structure. Two laminated ring structures can be cut from a single strip, thereby reducing waste material and forming a strong structure.

Abstract: A high frequency rotary transformer for an electrical machine includes a primary transformer component having a primary transformer winding, and a secondary transformer component having a secondary transformer winding. The primary transformer winding is configured to be coupled to a DC power source via a DC to AC converter. The secondary transformer winding is configured to be coupled to a winding of the rotor. Each of the primary and secondary transformer components are mechanically coupled to either the stator or the rotor. The secondary transformer component is configured to rotate with respect to the primary transformer component to produce a magnetic flux via the primary transformer winding and the secondary transformer winding.

Abstract: A busbar assembly for an inverter module has a power module, a capacitor module with at least one capacitor, and a battery all interconnected by a busbar. The busbar includes a base busbar portion that is electrically coupled to the battery and a branch busbar portion that extends from the base busbar to the power module and that electrically connects to the capacitor module at points located between the base node and the power module.

Abstract: Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and introducing predetermined error on the estimated reference axis. The method further includes the steps of determining if a speed of the permanent magnet motor is greater than a predetermined threshold speed and setting the control reference axis to 180° added to the estimated reference axis if the speed of the permanent magnet motor is greater than the predetermined threshold speed or setting the control reference axis to the estimated reference axis if the speed of the permanent magnet motor is less than or equal to the predetermined threshold speed.

Abstract: Automotive propulsion systems and methods of operation are provided. The automotive propulsion system includes a first voltage source, a power electronics device comprising a plurality of power switching devices coupled to the first voltage source, an electric motor having a plurality of windings coupled to the plurality of power switching devices and a neutral node interconnecting the plurality of windings, and a second voltage source coupled to the neutral node of the electric motor and the first voltage source.

Abstract: Methods and apparatus are provided for sensing currents on a plurality of phases and determining current information therefrom. The multi-phase boost converter includes a single sensor coupled to all of the plurality of phases and a controller coupled to the sensor for determining the current information in response to currents on each of the plurality of phases sensed by the sensor. The sensing method utilizes the gate drive signals and the DC current sensor output to calculate the currents on each of the plurality of phases sensed by the sensor.

Abstract: Systems and methods are provided for discharging a voltage bus. An electrical system comprises a first switch coupled to a first voltage rail, a second switch coupled between the first switch and a second voltage rail, and a control system coupled to the first switch and the second switch. The control system is configured to alternately activate the first switch and the second switch such that an energy potential between the first voltage rail and the second voltage rail is dissipated through the first switch and the second switch.

Abstract: Methods and apparatus are provided for improved discharge of a DC bus which provides power to an inverter. An electric motor system provided with the improved discharge method for discharge of the DC bus includes an electric motor, the inverter which provides electric control for the permanent magnet electric motor, the direct current (DC) bus which provides power to the inverter, and a processor. The processor generates operational control signals and provides such operational control signals to the inverter. In response to detecting a predetermined discharge signal, the processor generates operational control signals for generating a ripple current in motor windings of the electric motor to dissipate energy from the DC bus through a passive load, the passive load including the motor windings of the electric motor.

Abstract: Methods and apparatus are provided for discharging a direct current (DC) bus providing power to a motor control circuit in an electric motor system. The method includes the steps of detecting a predetermined discharge signal and generating operational control signals comprising phase currents for dissipating energy from the DC bus through a passive load in response to detecting the predetermined discharge signal, wherein the passive load includes motor windings of an electric motor of the electric motor system. The method also includes the step of providing the operational control signals to the motor control circuit for discharging the DC bus through the motor control circuit and the motor windings of the electric motor.