Quasi-bilateral method for determining the distance to the ground fault of unilateral power lines

Abstract

In this paper the method to determine fault location in case of ground fault at power line with isolated neutral has been proposed. Estimation of fault's distance is carried out based on line's operating mode parameters (namely phase currents and voltages to ground) at the start of the line. Fault's distance calculation is implemented using vectors of line's operating mode parameters from both sides of the line. Verification of the method has been conducted experimentally as well as via math modelling. Method's errors were caused mostly by small currents' value alteration in case of fault, existence of resistance at fault's location and power line's load resistance change. Research about impact on method's accuracy due to distance to the fault as well as resistance value at the fault location has been carried out.