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. 03, 2003
Filed:
May. 02, 2000
Jeffrey B. Roberts, Viola, ID (US);
Daqing Hou, Pullman, WA (US);
Hector Altuve-Ferrer, Nuevo Leon, MX;
Schweitzer Engineering Laboratories, Inc., , WA (US);
Abstract
A system for detecting ground faults in a compensated electric power distribution network includes the determination of zero sequence voltage (V ) and zero sequence current (I ) on a power line and calculating the zero sequence conductance (G ) therefrom. The operation of the conductance calculation circuit occurs only under selected power line conditions involving minimum values of zero sequence voltage, zero sequence current and positive sequence voltage, to ensure the accuracy of a fault direction determination. The conductance values are processed on an adaptive basis in which the difference between the most recent conductance value and a conductance value from a selected previous point in time is determined and then compared against threshold values to make forward and reverse fault declarations.