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:
Feb. 20, 2018
Filed:
Apr. 07, 2013
Applicant:
Abb Schweiz Ag, Baden, CH;
Inventors:
Assignee:
ABB Schweiz AG, Baden, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02H 9/02 (2006.01); H02H 3/28 (2006.01); H02H 3/00 (2006.01); H02H 7/045 (2006.01);
U.S. Cl.
CPC ...
H02H 9/02 (2013.01); H02H 3/006 (2013.01); H02H 3/28 (2013.01); H02H 3/283 (2013.01); H02H 7/045 (2013.01);
Abstract
The present invention discloses a method for detecting a fault and a current differential protection system thereof. The method for detecting fault includes calculating fault component currents, calculating an operate current and a restraint current of all terminals, and adjusting an operate level by adapting an operate-restraint characteristic according to a fault component. The method has very small operating area for external faults, which makes the method very reliable even for the case with serious CT saturation. A very big operating area for internal faults makes the method very sensitive for internal faults even for a heavy load and high resistance fault.