Distribution fault location using short-circuit fault current profile approach

Abstract

Impedance-based algorithms do not consider load current and non-uniform line impedance per unit, thus introducing errors in fault location estimates. To minimize these errors, this paper proposes a short-circuit fault current profile approach to complement impedance-based algorithms. In this approach, circuit model of the distribution feeder is used to place faults at every bus and the corresponding short-circuit fault current is plotted against reactance or distance to fault. When a fault occurs in the distribution feeder, fault current recorded by the relay is extrapolated on the current profile to get location estimates. Since the circuit model is directly used in building the current profile, this approach takes into account load and non-uniform line impedance. The approach is tested using modified IEEE 34 Node Test Feeder and validated against data provided by utilities. Location estimates are within 0.8 miles of the actual fault location when the circuit model closely represents the distribution feeder.