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, 1996
Filed:
Sep. 23, 1994
Leif Eriksson, Sala, SE;
Murari M Saha, Vasteras, SE;
ASEA Brown Boveri AB, Vasteras, SE;
Abstract
A method and a device, after a fault has occurred in a power network, for measuring and recreating the phase currents I.sub.B prior to the occurrence of the fault by determining continuously, starting from sampled measured values of the phase currents up to the time of the fault for each phase, the amplitude I and the phase angle .phi. of the phase currents based on two consecutive sampled measured values, whereupon a comparison is made between the last determined value I.sub.k obtained and the rated current I.sub.n of the power network. If I.sub.k is greater than I.sub.n, it is considered that a fault has occurred and the phase currents prior to the fault are indicated as I.sub.B =I.sub.k-1 .multidot.sin (.phi..sub.k-1 +.omega.(t-t.sub.k-1)).