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:
Apr. 05, 1994
Filed:
Feb. 20, 1992
Tsunehiro Endo, Hitachiota, JP;
Shizuo Takahashi, Funabashi, JP;
Masaya Taniguchi, Shimizu, JP;
Hiroshi Maruyama, Shimizu, JP;
Seiji Ishida, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Inverter control method and apparatus which are immune to the influence of load disturbance and detection noise and permit stable minimization control of motor current, in order to attain high efficiency of an AC motor and of an inverter adapted to drive the same. A memory group is provided having a plurality of sets of memories for storage of data pieces representative of exciting current commands standing for manipulated variables and data pieces representative of motor currents standing for controlled variables. An upper limit value (IDUP) and a lower limit value (IDLW) defining a fluctuation region of the exciting current command are determined so that an exciting current command data piece corresponding to a motor current data piece which is the smallest of all the current data pieces in the memory group falls within the fluctuation region. The fluctuation region is determined so as to minimize the motor current, the exciting current command being fluctuated within the fluctuation region.