Patent ID: 6601001
Filing Date: 2003-07-29
Classification: G01R,H02H

Abstract:
Relay equipment for an electrical power line, comprising:a fault-detection apparatus including a) a signal-deriving means for deriving first and second signals representative of a voltage and current, respectively, at a first end of said line; b) a calculating means for calculating, from said first and second signals and from defined values of series and shunt parameters of said line, a value of voltage and current associated with a point along said line intermediate said first end and a second end of said line, said calculating means being operative for calculating said voltage and current values at said intermediate point in a calculation using a value of a derivative of said second signal with respect to time on the basis of the matrix relationship: [v1i1]=[1-(R0+L0&it;&dd;&dd;t)-C0&it;&dd;&dd;t1]&it;â€ƒ[v0i0]â€ƒwhere v1, i1 are said voltage and current at said intermediate point, v0, i0 are said voltage and current at said first end of the line, R0 and L0 are said series parameters of the line and C0 is a shunt parameter of the line; and c) a fault-location determining means for determining from said calculated voltage and current values where a fault lies relative to said intermediate point.