Patent ID: 6584417
Filing Date: 2003-06-24
Classification: G01R,H02H

Abstract:
In an electrical power system including:a transmission line for transmitting electrical power; series capacitance compensation series-coupled to the transmission line adjacent one end thereof, the series compensation including a capacitance having a value (âˆ’j XCAP); and a protective relay at the one end of the transmission line for monitoring line voltages and line currents on the transmission line; a method upon sensing a fault for determining a direction of the sensed fault, the method comprising: calculating a &Dgr;-impedance &Dgr;Z of the line based on the monitored line voltages and line currents before the sensed fault and the monitored line voltages and line currents after the sensed fault; adjusting the calculated &Dgr;-impedance &Dgr;Z according to the value of the capacitance of the series compensation (âˆ’j XCAP) to result in a modified &Dgr;-impedance &Dgr;ZMOD; and examining a phasor angle of &Dgr;ZMOD to determine the direction of the sensed fault, the fault being in a first direction if the phasor angle is between X and X+180 degrees, and being in a second direction opposite the first direction if the phasor angle is between X+180 and X+360 degrees.