Measured impedance at relaying point considering transmission line capacitance

This paper investigates the measured impedance by a distance relay considering the transmission line capacitance by utilizing a pi model for the line. The distance relay ideal tripping characteristic is presented. The measured impedance and the tripping characteristic are compared with those of in the case of neglecting the line capacitance. In the case of zero fault resistance, especial attention is paid to the deviation of the measured impedance from its actual value caused by the line capacitance.