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:
Dec. 25, 1990
Filed:
Mar. 07, 1989
Akira Bando, Hitachi, JP;
Osamu Nagura, Katsuta, JP;
Shigehiro Kayukawa, Hitachi, JP;
Junichi Shiozaki, Hitachi, JP;
Akira Momiyama, Hitachi, JP;
Hiroto Nakagawa, Osaka, JP;
Yasuteru Oono, Kobe, JP;
Hitachi, Ltd., Tokyo, JP;
The Kansai Electric Power Co., Inc., Osaka, JP;
Abstract
An AC-excited generator/motor apparatus comprising; an AC-excited generator/motor having an armature mounting thereon; an armature winding connected to an AC power system and a rotor mounting thereon; and an exciting winding excited by an AC current. An exciting device for supplying a controlled AC exciting current to the exciting winding comprises; a device for calculating a real slip frequency based on a difference between the phase of an armature voltage appearing on the armature winding and the rotational phase of the rotor; and a device for controlling the exciting current supplied to the exciting winding from the exciting means in response to a deviation of the real slip frequency from a predetermined allowable range of slip frequencies so as to restore the real slip frequency within the allowable range of slip frequencies.