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:
May. 27, 2014
Filed:
Mar. 14, 2013
Fanuc Corporation, Yamanashi, JP;
Masakazu Niwa, Yamanashi, JP;
Koujirou Sakai, Yamanashi, JP;
FANUC Corporation, Minamitsuru-gun, Yamanashi, JP;
Abstract
A motor drive device () of the present invention includes a converter unit () and an inverter unit (). The converter unit () includes: power supply voltage monitoring unit () for detecting a power failure; DC link voltage detecting means (); capacitor total capacity calculating means () which calculates total capacity of DC link smoothing capacitors () and calculates a DC link low-voltage alarm detection level for an instantaneous power failure; DC link low-voltage alarm detection level setting means () which varies the DC link low-voltage alarm detection level for an instantaneous power failure as necessary; and alarm generating means () which monitors the DC link voltage and generates an alarm to protect the converter unit. In the case where a power failure is detected, the DC link low-voltage alarm detection level is increased in accordance with the total capacity of the DC link smoothing capacitors ().