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. 11, 2014
Filed:
Feb. 11, 2011
Shinichi Horikoshi, Yamanashi, JP;
Takashi Harada, Yamanashi, JP;
Masatomo Shirouzu, Yamanashi, JP;
Yasusuke Iwashita, Yamanashi, JP;
Shinichi Horikoshi, Yamanashi, JP;
Takashi Harada, Yamanashi, JP;
Masatomo Shirouzu, Yamanashi, JP;
Yasusuke Iwashita, Yamanashi, JP;
Fanuc Corporation, Yamanashi, JP;
Abstract
A motor driving apparatus capable of detecting during operation a ground fault and a phase-to-phase short circuit by distinguishing one from the other is provided while minimizing an increase in cost. The sum of three-phase AC currents supplied from a three-phase AC power supply to an AC/DC converter is detected by a current sensor. When overcurrent is detected by an overcurrent detector, if the sum of the currents detected by the current sensor is zero, it is determined that the fault is a phase-to-phase short circuit, but if the sum is not zero, it is determined that the fault is a ground fault.