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:
Aug. 26, 1997
Filed:
Nov. 07, 1995
Sanshiro Obara, Tokai, JP;
Shigeyuki Yoshihara, Hitachinaka, JP;
Hiroyuki Yamada, Hitachinaka, JP;
Nobunori Matsudaira, Hitachi, JP;
Hitachi, Ltd., , JP;
Abstract
The present invention provides a protection apparatus in a control system for an electric vehicle which is capable of performing back-up driving by using a back-up control method, without using output from sensors even if the sensor in the control system for ordinary driving is failed. When at least one of the current sensor, the speed sensor and the accelerator sensor is detected to be abnormal, a back-up control voltage v1 is output as an abnormal signal from a running back-up control circuit. As a result, the running back-up control circuit sets the limiter of the output of the current control circuit to zero and switches the control signal to the inverter from vector control to V/f voltage control.