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. 17, 1985
Filed:
Aug. 31, 1983
Murari M Saha, Vaster.ang.s, SE;
ASEA Aktiebolag, Vaster.ang.s, SE;
Abstract
A fault point in a line section of a three-phase power transmission line, is determined by measuring currents and voltages at a measuring point arranged adjacent the near end of the section. The type of fault (single-phase/multi-phase ground fault/phase-to-phase fault) is determined and the parameters in a quadratic equation are determined using the relative distance (n) from the measuring point to the fault point as a variable. The equation is derived in advance from the electrical relationships between the complex values of the line impedance, the source impedances of the networks located ahead of and behind the fault, and measured currents and voltages following elimination of the fault resistance and possible zero sequence components. The parameters in the equation are determined by the type of the fault, by the measured voltages and currents and by said impedances. The equation is solved directly by means of a numerical square root method. When calculating the parameters, the fundamental frequency components of the measured values are used, which components are obtained by digital filtering of the measured values.