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:
Aug. 29, 1995
Filed:
Feb. 18, 1993
Hidefumi Shirahama, Hitachi, JP;
Yorito Jifuku, Hitachi, JP;
Akira Kobayashi, Hitachi, JP;
Keizo Shimada, Hitachi, JP;
Norikazu Tokunaga, Hitachi, JP;
Yoshimi Sakurai, Hitachiota, JP;
Ikuo Yamato, Hitachi, JP;
Tomoaki Mino, Hitachi, JP;
Satoru Inukai, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a uninterruptible power supply in which a plurality of inverters are operated in parallel, a current control loop is provided which responds to the magnitude of an output current of each inverter brought into parallel running to change a command value for a voltage waveform control circuit associated with each inverter, and the gain of the current control loop is made to be variable, whereby currents shared by the inverters can be set desirably to effectively suppress a cross current flowing between the inverters upon establishment of parallel running.