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:
Aug. 02, 2005
Filed:
Dec. 14, 2001
Murari Saha, Väster{dot over (a)}s, SE;
Eugeniusz Rosolowski, Wroclaw, PL;
Jan Izykowski, Wroclaw, PL;
Murari Saha, Väster{dot over (a)}s, SE;
Eugeniusz Rosolowski, Wroclaw, PL;
Jan Izykowski, Wroclaw, PL;
ABB AB, Västerås, SE;
Abstract
The present invention relates to a method for calculating the distance to fault in a section of a power transmission network, which section is arranged with line terminals at both ends, each terminal including impedance relays (AA, BB), including the steps of, at the occurence of a fault; measuring the apparent impedances by each relay, measuring the relaying currents, determining the type of fault, checking whether the fault involves a fault resistance or not, and, if so, solving a quadratic equation for complex numbers, resolving the quadratic equation for the real and imaginary components, obtaining two quadratic equations for a fault distance in which the coefficients are real numbers, combining the two equations and obtaining a distance to fault, or, if not so, solving a quadratic equation for real numbers, obtaining two solutions for the distance to fault d, dand comparing the solutions as 0<(dor d)<1 pu, where pu is the length of transmission lines between the line terminals.