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:
May. 04, 2010
Filed:
Jun. 29, 2007
Zoran Gajic, Västerås, SE;
Torbjörn Einarsson, Sala, SE;
Sethuraman Ganesan, Bangalaore, IN;
ABB Technology Ltd., Zürich, CH;
Abstract
A protective relay for an electrical power distribution system and a method. The protective relay includes first and second current transformers arranged to sense a respective current flowing into a power line, and a voltage sensing device arranged to sense the voltage of the power line. The protective relay further includes a first and a second device for determining the direction of a fault within the system based on a current signal from the first and second current transformers and a voltage signal from the voltage sensing means. The protective relay further includes a third device for determining the fault direction based on a sum of the current signals from the first and second current transformers and a voltage signal from said voltage sensing means. A controller determines whether a fault is internal or external based on the fault directions determined by the first, second and third devices.