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:
Jan. 12, 1982
Filed:
Apr. 17, 1980
Masahiko Akamatsu, Amagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A variable frequency power supply device supplies an AC power to a squirrel-cage motor through an AC parameter control. The control receives a command active current resulting from a command torque and a command exciting current to generate a resultant current and its phase. The command torque is produced from the actual and command motor speeds and the exciting current is caused from the actual motor speed. The control also receives a command frequency determined by the actual motor frequency and a command slip frequency also resulting from the command torque. The control controls the firing phases of thyristors in the power supply device in response to the command current, phase and frequency. The control may generate a voltage for supplying the active current and an exciting voltage to similarly control the firing phases of the thyristors. In the latter case, the exciting voltage may be added with its differential to compensate for a rapid change in active current.