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. 07, 1995
Filed:
Mar. 11, 1994
Hitachi, Ltd., Tokyo, JP;
Abstract
A power conversion system for converting between a.c. and d.c. power has a pair of line commutated converters connected in series, and each is connected to a corresponding transformer, one of which transformers is YY connected and the other of which is Y.DELTA. connected. A pair of minimum voltage detectors generate minimum voltage signals, a first one of the minimum voltage signals being YY related and a second one of the minimum voltage signals being Y.DELTA. related. The power conversion system has a control circuit which generate two phase control signals for controlling the pair of line commutated converters respectively. When a fault occurs in a.c. or d.c. apparatus connected to the power conversion system, the control circuit generates the phase control signals on the basis of the first and second minimum voltage signals respectively. In this way, each of the line commutated converters are controlled by an independent signal, so that the power conversion of each is optimized.