Abstract: A high impedance AC coupling arrangement that processes a transducer feedback signal derived from an output shaft of an electric vehicle motor to compensate for electrical motor pulsations. The high impedance AC coupling arrangement is coupled between the transducer and a summing device and generates a feedback compensation signal that is combined with an input signal to compensate for output shaft oscillations. The high impedance AC coupling arrangement includes a loop amplifier having a predetermined transfer function that is coupled to the transducer, and AC coupling circuitry, typically including a plurality of coupling capacitors, that is coupled between the loop amplifier and the summing device. A limiter circuit having first and second oppositely coupled diodes is coupled between a voltage source and a point between the AC coupling capacitors. A cascode amplifier is coupled to the AC coupling circuitry.

Abstract: A torque oscillation compensation system and torque estimator that uses torque emulator/observer feedback derived from an electric vehicle motor drive train. The present torque oscillation compensation system is adapted for use with an electric vehicle comprising a source of torque command signals and an electric motor that is controlled by a power switching circuit. The power switching circuit is responsive to the torque command signals and provides pulse width modulated signals for driving the motor. The system comprises a torque estimator that is coupled to received pulse width modulated signals provided by the power switching circuit, and motor currents and speed, for providing estimated torque feedback signals derived therefrom.

Abstract: A torque oscillation compensation system and circuit that uses torque transducer feedback derived from an output shaft of an electric vehicle motor to compensate for electrical motor pulsations such as are experienced in an electric vehicle. A torque input source provides a torque input signal, that is coupled to a summing circuit. A controller is coupled to the summing circuit, and power switching circuitry is coupled between the controller and the electric motor. A torque transducer is coupled to the output shaft of the motor to sense torque pulsations. An oscillation compensation circuit is coupled between the torque transducer and the summing circuit that generates a feedback compensation signal that is combined with the torque input signal to compensate for output shaft oscillators.