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:
Oct. 14, 1997
Filed:
Aug. 25, 1995
Tokunosuke Tanamachi, Hitachinaka, JP;
Kiyoshi Nakamura, Hitachinaka, JP;
Masanori Kobayashi, Nishiibaraki-gun, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A control apparatus for controlling an electric vehicle, electric car, rolling stock and electric locomotives, which ensures that an inverter output frequency command for its inverter will not depend on the rotor frequency of the induction motor, but controls the inverter output current using a constant current control system, thus preventing an overcurrent, and is capable of accelerating or decelerating the vehicle at a torque precisely corresponding to a current command. The inverter output frequency command is incremented or decremented in accordance with a frequency-to-time rate-of-change command which has been updated by the current control system. Since the inverter output frequency command is adapted basically not to depend on the rotor frequency of the induction motor, and since the output current of the inverter is controlled by the constant current control system, there are such advantages according to the invention that an overcurrent is not likely to occur, and the vehicle can be accelerated or decelerated at a torque precisely corresponding to the current command.