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. 17, 1983
Filed:
Jun. 17, 1980
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R / ; H02H / ; H02H / ;
U.S. Cl.
CPC ...
324 51 ; 340650 ; 361 86 ; 363 58 ;
Abstract
Shortcircuit in an arm including a series connection of GTO's and reactors of an inverter is detected by sensing a voltage across the reactor. In one method, the shortcircuit in the arm is detected when voltages are coincidently applied to a P-line arm reactor and an N-line arm reactor for a predetermined time period. In another method, it is detected when an integrated value of a voltage across at least one of the reactors exceeds a predetermined level.