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:
Dec. 13, 1977
Filed:
May. 27, 1976
Otto Lanz, Niederrohrdorf, CH;
BBC Brown Boveri & Company Limited, Baden, CH;
Abstract
An apparatus for localization of a line fault wherein at a measuring location on the line there is provided a voltage- and current-measurement circuit, the outputs of which carry a number of voltage-current signal pairs independent of one another with respect to the line inductances and line capacitances. A summation circuit having at least two outputs is connected with the measurement circuit through the agency of at least one voltage- and one current signal channel. In the summation circuit there are additively and subtractively superimposed at least one pair of mutually independent voltage- and current signals, if necessary after multiplication of at least one of these signals by a constant factor, into traveling wave signals associated with oppositely moving traveling waves, these traveling wave signals appearing at corresponding outputs of the summation circuit. An integration circuit forms time integrals of the traveling wave signals and an evaluation circuit links or processes at least two traveling wave-time integrals into an evaluation function characterizing the fault direction and/or the fault distance from the measuring location or at least a predetermined reference location on the line. The voltage signal channel encompasses two parallel branches, one of which comprises an oscillating circuit having a natural frequency contained in the fault-free line voltage.