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:
Apr. 28, 2015
Filed:
Aug. 21, 2013
Henrik Johansson, Vasteras, SE;
Joseph Menezes, Vasteras, SE;
Stefan Roxenborg, Vasteras, SE;
Tord Bengtsson, Vasteras, SE;
Henrik Johansson, Vasteras, SE;
Joseph Menezes, Vasteras, SE;
Stefan Roxenborg, Vasteras, SE;
Tord Bengtsson, Vasteras, SE;
ABB Research Ltd., , CH;
Abstract
A method for enhancing the reliability of generator ground fault detection based on a signal injection scheme, wherein the generator includes a winding. The method includes injecting a test signal at a predefined frequency to the winding, measuring an electrical quantity of a response signal in the winding resulted from the injected test signal, and detecting a ground fault based on the measured value of the electrical quantity. The method further includes continuously determining the frequency of the response signal, and discarding the present measured value corresponding to the determined frequency when the determined frequency deviates from the predefined frequency with a first threshold value.