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. 20, 2007
Filed:
Jul. 06, 2005
Yasushi Matsumoto, Tokyo, JP;
Hidetoshi Umida, Tokyo, JP;
Yasushi Matsumoto, Tokyo, JP;
Hidetoshi Umida, Tokyo, JP;
Fuji Electric Systems Co., Ltd., Tokyo, JP;
Abstract
The driving apparatus according to the invention includes an inverter that drives multiple induction motors connected in parallel, and a secondary current calculating circuit that calculates the components iand iof a total secondary current value, which is the sum of the secondary currents of all the motors. The apparatus further includes a current deviation quantity calculating circuit that calculates a deviation quantity, for which the total secondary current value deviates from a reference trace. A torque regulating circuit regulates the motor torque based on the calculated deviation quantity. The driving apparatus for driving multiple induction motors according to the invention facilitates quickly detecting the widening caused in the rotating speed differences and preventing the rotating speed differences from widening.