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. 22, 1976
Filed:
May. 19, 1975
Homer W Heinzman, Arlington, TX (US);
LTV Aerospace Corporation, Dallas, TX (US);
Abstract
Disclosed is an apparatus for protecting a three-phase power transmission line, having three power conductors, from intermembral electrical faults. First, second, and third sensing and rectifying means are inductively associated with respective ones of the three power conductors of the power transmission line for generating respective DC signals corresponding to the current flow through the respective, associated power conductors. A first switching means is provided for disconnecting the power transmission line from a power source upon the occurrence of a voltage imbalance between the sensing and rectifying means. Another switching means is provided for temporarily interconnecting the outputs of the sensing and rectifying means before operation of the first switching means, for preventing spurious tripping of the first switching means during sharp increases in power which do not occur as a result of a fault. In the preferred embodiment, the response time of the second switching means is shortened in the event of an increase in power involving a fault.