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:
Jun. 10, 1997
Filed:
Mar. 10, 1995
Applicant:
Inventors:
Assignees:
Hitachi, Ltd., , JP;
Primary Examiner:
Int. Cl.
CPC ...
H02M / ;
U.S. Cl.
CPC ...
363132 ; 363137 ; 363 56 ;
Abstract
The invention is directed to a neutral point clamped electric power conversion apparatus having four semiconductor switching elements connected in series. The capacity of outer free wheel diodes connected in reverse parallel with outer semiconductor switching elements are increased compared to that of inner free wheel diodes, thereby minimizing, an imbalance in losses between the inner and the outer free wheel diodes.