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:
Jul. 01, 1996
Shigeyuki Yoshihara, Hitachinaka, JP;
Hiroshi Katada, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Car Engineering Co., Ltd., Ibaraki, JP;
Abstract
A control apparatus for an electric vehicle has an inverter for feeding currents to a three-phase AC motor corresponding to applied PWM signals, three current sensors, each of the sensors detecting a current of a respective phase in the three-phase AC motor, a revolution speed detector for detecting the speed of the three-phase AC motor, a motor control unit for controlling the three-phase AC motor which includes a current demand generating unit, a current control unit for performing feedback control based on the current demands and currents detected by the current sensors, and a PWM signal generating unit. To detect anomalies in the current sensors or the motor control circuit, there is also provided an anomaly detection unit for detecting an anomaly in the detected currents by checking whether monitoring index obtained by processing three values of the detected currents exceeds a preset threshold level and for outputting a current anomaly indicating signal, and an anomaly specifying unit for inputting diagnostic currents to the three-phase AC motor by judging the current anomaly indicating signal and identifying an anomalous current sensor among the three current sensors based on detection results of the diagnostic currents detected by the three current sensors. The control apparatus executes a motor control corresponding to one of a presence and a non-presence of an anomaly in the three current sensors.