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:
Mar. 10, 2009
Filed:
Dec. 04, 2006
Hirokazu Tajima, Mie, JP;
Yasuaki Hachisu, Mie, JP;
Hirokazu Tajima, Mie, JP;
Yasuaki Hachisu, Mie, JP;
Fuji Electric FA Components & Systems Co., Ltd., Tokyo, JP;
Abstract
An inverter that supplies a desired primary voltage (v) to an induction motor, a current detector that detects a primary current (i) from the inverter to the induction motor, a voltage designation value calculating unit that generates a voltage designation value (v*) for generating the voltage v, an idling-time speed estimating unit that calculates an estimate value (ω) of the rotation speed when the induction motor is idling, and a sequence circuit that commands the operations of these units are provided. The idling-time speed estimating unit switches a method for deriving the estimate value on the basis of a current value in the case where a short circuit is generated between windings when the induction motor is idling.