Patent ID: 8395871
Filing Date: 2013-03-12
Classification: G01R,H02H

Abstract:
1. A protective relay for providing protective control to a power system carrying three-phase power, the protective relay comprising: a processor; at least one computer readable medium; program instructions stored on the at least one computer readable medium and executable by the processor to perform a faulted phase detection method comprising: receiving signal values representative of electrical properties of the power carried by the power system; processing the signal values to produce processed signals, respectively, the processed signals having components of the signal values removed that are the same frequency as the nominal operating frequency of the power system; adding the processed signals to produce a sum; dividing the sum by a predetermined number to yield a quotient; determining whether the quotient falls within one of a plurality of predetermined ranges; and using the determination of whether the quotient falls within one of the predetermined ranges to determine whether the power system has a single-phase fault, a two-phase fault, or a three-phase fault.