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:
Apr. 14, 1998
Filed:
Feb. 05, 1996
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
An induction motor control system for electric vehicles having a DC power supply, an inverter, and an induction motor, includes a current control mechanism having a flux controller. The flux controller reduces the stator flux to improve the torque output of a motor at the limit of the voltage supply from the inverter. The reduction in flux is adjustable as the actual limit of voltage available to power the motor varies. A flux reference .lambda..sub.so generated according to efficiency control requirements can be adjusted by a flux weakening quantity generated by the controller in the constant power range of operation. The DC bus voltage, the rotor speed and stator flux reference values are input to the flux controller so that the motor can be operated to achieve improved torque output approaching the theoretical maximum torque output or to maximize efficiency as needed. In addition, the flux control influences generation of a stator current that improves the torque output throughout the entire range of motor speed.