The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 27, 1994
Filed:
May. 13, 1993
Robert S Wedeen, Manhattan Beach, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A torque oscillation compensation system and circuit that senses battery current to compensate for electrical motor torque pulsations. An input source provides a torque/current command input signal that drives the motor, and a summing device has one input coupled to receive the torque/current command input signal. A controller is coupled to the summing device and to power switching circuitry that is coupled between the battery and the electric motor. An oscillation compensation circuit is coupled between the battery and the summing device that generates a compensation signal that is combined with the torque/current command input signal and compensates for output shaft oscillators. The oscillation compensation circuit comprises an AC coupling capacitor, an amplifier having a predetermined transfer function that is designed to provide for the proper amount of compensation. The present invention compensates for the torque fluctuations caused by induction motors and permits stable operation thereof. The novelty of the present invention is that compensation is achieved by sensing the AC ripple component of the battery or DC power supply input to power switching circuitry used to drive the motor. This signal is an indication of torque fluctuation and is used to to modulate the motor current and/or motor slip and/or commutating angle and/or the motor field current to eliminate the torque fluctuations of the motor output shaft.