Improved Impedance Based Parameter Free Fault Location Estimation Algorithm for Two Terminal Transmission Line Using Phasor Components

This paper presents a new impedance based fault location identification method on two terminal transmission lines without using transmission line parameters. The voltage and current phasors from both the terminals of the transmission line are used for calculating fault distance on the transmission line. The value of the zero sequence compensation factor is also calculated using the during fault values of voltages and currents without using the known values. The impedances calculated from the pre-fault and during-fault values of the voltages and current phasors are compared for fault location identification. Further, the fault point voltage, thereby fault resistance is also obtained accurately. The proposed method is independent of transmission line parameters accuracy and the efficiency is tested for different fault types and fault distance on the transmission line. A 10 bus system is considered for simulation studies which is modelled in PSCAD software and the algorithm is implemented in MATLAB.