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:
Feb. 03, 2015
Filed:
Aug. 19, 2011
Hiroyuki Yamai, Hitachinaka, JP;
Yasuo Noto, Hitachinaka, JP;
Yoshio Akaishi, Hitachinaka, JP;
Kohei Myoen, Hitachinaka, JP;
Hiroyuki Yamai, Hitachinaka, JP;
Yasuo Noto, Hitachinaka, JP;
Yoshio Akaishi, Hitachinaka, JP;
Kohei Myoen, Hitachinaka, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Abstract
According to the present invention, an overcurrent fault detection device includes: an inverter converting DC current to three-phase AC currents for driving a motor; a DC voltage detector; phase current detectors; a rotational position detector that detects a rotational angle of the motor; a control circuit that controls a gate drive circuit, which controls the inverter at every predetermined cycle, based upon the phase current values, a motor rotational angle detection value, and a speed command or a torque command from a higher-order control device; and a first decision-making circuit that detects an overcurrent based upon the phase current values at every predetermined cycle, wherein: the first decision-making circuit determines whether or not the phase current values exceed a predetermined amplitude threshold value by frequency detection for any of the phase current values exceeding the predetermined amplitude threshold value, and determines that an overcurrent has occurred upon detecting the frequency.