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. 13, 1984
Filed:
Nov. 15, 1982
Nobuyoshi Muto, Hitachi, JP;
Hiroshi Nagase, Hitachi, JP;
Keijiro Sakai, Hitachi, JP;
Yasuo Matsuda, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a method and apparatus for operating an induction motor by an inverter of the pulse-width modulation (PWM) type, wherein the slip frequency is calculated from the speed command and the actual motor speed so as to produce the phase compensation signal, and the frequency command for the inverter is produced by adding the phase compensation signal, the slip frequency signal and the motor speed signal. The primary current command is calculated from the slip frequency, the amplitude ratio of pulse-width modulation is calculated basing on the primary current command and the actual primary current, and the inverter is controlled in accordance with the amplitude ratio so as to control the primary current of the induction motor.