Abstract: A method and system for determining a torque current in an electric machine coupled to a polyphase bus. The method comprises: detecting a rotational position of the electric machine with a position encoder; controlling an inverter comprising a plurality of switching devices, the inverter having an input coupled to a direct current bus, and an output coupled to the polyphase bus. Where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method also includes measuring a current from the direct current bus; and capturing the current at a predefined interval of time.

Abstract: Disclosed herein is a method for determining a torque current in an electric machine coupled to a polyphase bus. The method comprises: detecting a rotational position of the electric machine with a position encoder; controlling an inverter comprising a plurality of switching devices, the inverter having an input coupled to a direct current bus, and an output coupled to the polyphase bus. Where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method also includes measuring a current from the direct current bus; and capturing the current at a predefined interval of time. Also disclosed is a system for determining a current in an electric machine coupled to a polyphase bus, the system comprising: a position encoder coupled to the electric machine to detect rotational position; an inverter having an input coupled to a direct current bus, and an output coupled to the polyphase bus.

Abstract: A method of minimizing the torque ripple produced by unbalanced phase currents in a sinusoidally excited motor is disclosed. The method comprises measuring the position of the motor; sampling the phase currents of the motor generating thereby at least one phase current; synchronizing the at least one phase current of the motor with the position of the motor; determining the imbalance in the magnitudes of the at least one phase current of the motor; generating a set of modulation index terms for reducing the imbalance in the magnitudes of the at least one phase current to ensure acceptable torque ripple characteristics over the operating velocity of the motor; and generating a set of minimized line-to-ground voltage commands.

Abstract: A method and system for stabilizing a vehicle employing an electric power steering system is disclosed. The method includes receiving as inputs, a desired torque command representative of a steering wheel torque and a vehicle speed signal. The method also includes acquiring an acceleration signal representative of vehicle acceleration. The method further comprises generating an assist torque command, which is a combination of the desired torque command and a compensating torque command where the compensating torque command is responsive to the vehicle speed signal and the acceleration signal.

Abstract: A windshield wiper system having variable frequency induction motor control for reducing wipe speed at reversal points includes an induction motor, a wiper and blade assembly operatively connected to the motor, a sensing means for detecting when the position of the wiper and blade assembly is within a preselected range of one of the reversal points, and a motor control responsive to the control signal generated by the sensing means for causing the motor to reduce wipe speed during the preselected range prior to the reversal point to reduce pattern growth, noise, and water expulsion. The sensing means takes the form of a cam or plate operated switch driven by the induction motor. The control signal derived from the cam operated switch is provided as an input to a voltage controlled oscillator, whose variable frequency output is used to vary the frequency of the excitation voltage applied to the windings of the three phase induction motor.