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. 30, 1989
Filed:
Apr. 05, 1988
Applicant:
Inventors:
Hung J Li, Coral Springs, FL (US);
James P Garrity, Coral Springs, FL (US);
Assignee:
Westinghouse Electric Corp., Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 68 ; 361 79 ;
Abstract
Loss-of-potential supervision for a distance relay controlling a circuit breaker in a poly-phase electric power transmission system is provided by blocking circuit breaker trip signals in the presence of a low voltage condition and the absence of an increase in current of more than a predetermined amount. Overblocking is prevented for weak feed conditions, a circuit breaker closing on a fault, transients induced by replacement of a fuse, and sequencing caused by tripping of a remote breaker.