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:
May. 10, 1988
Filed:
Apr. 29, 1987
Junichi Shiozaki, Hitachi, JP;
Takao Kuwabara, Hitachi, JP;
Akira Bando, Hitachi, JP;
Kenichi Ono, Kodaira, JP;
Akihiro Sakayori, Hitachi, JP;
Ichiro Hitomi, Katsuta, JP;
Masahiro Minato, Takamatsu, JP;
Shigeaki Hayashi, Suita, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed in a variable speed pumping-up electrical power system comprising a variable speed generator/motor, a frequency converter connected between the generator/motor and an a.c. power system, a controller controlling an effective power input to the generator/motor by controlling the frequency converter on the basis of the difference between an actual effective power input from the a.c. power system and an externally-applied effective power command, and a correction circuit correcting the effective power command on the basis of the difference between the frequency of the a.c. power system and a frequency setting.