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. 24, 1992
Filed:
Mar. 20, 1990
Akira Bando, Hitachi, JP;
Chikara Tanaka, Hitachi, JP;
Keiji Saito, Hitachi, JP;
Tadao Kawai, Katsuta, JP;
Eizo Kita, Kyoto, JP;
Keiichi Mitsuhashi, Hikone, JP;
Yasuteru Ohno, Kobe, JP;
Hiroto Nakagawa, Mishima, JP;
Hitachi, Ltd., Chiyoda, JP;
The Kansai Electric Power Co., Inc., Osaka, JP;
Abstract
An improved electric power conversion system comprising a multi-phase bridge circuit composed of semiconductors such as thyristors and an associated firing circuit. It is so constructed that: if the AC input current Iac flowing in the bridge circuit is equal to or larger in value that the DC output current Idc flowing out of the bridge circuit, it will be decided than an inner defect or fault is caused, and possible expansion of inner defect will be prevented by disabling the firing circuit to extinguish the thyristors in the bridge circuit, and if the AC input current Iac is smaller than the DC output current Idc in value, the bridge is permitted to continue the operation of power conversion, thus eliminating unnecessary interruption which otherwise would be caused by exterior disturbances. Also, an improved electric power conversion system may be equipped with a device to prevent an adverse effect from being caused by abnormal rise of thyristors' temperature.