New approach to directional fault location for overhead power distribution feeders

The results of investigations into a new approach to fault localisation in overhead distribution systems are presented. The method proposed does not use the fundamental power frequency currents but is based on detecting fault-induced high frequency components on distribution lines. This should enable the detection of discharges from the low-level breakdown of insulators, which cannot be detected by conventional methods. The fault direction is determined by filtering the output voltage from stack tuners and comparing the resulting signal levels on each side of a tuned trap circuit unit. Simulation results are used to illustrate the basic features of the performance of the new scheme on a simple radial 11 kV feeder system