Distance estimation technique for single line-to-ground faults in a radial distribution system

A simple yet powerful algorithm to estimate the distance to a single line-to-ground fault on a distribution feeder is proposed. The algorithm is implemented in a power monitor instrument and the estimation of distance is made within the instrument itself. The algorithm is designed to work where the only available data to the instrument are a single point measurement taken at the substation and the positive and zero-sequence impedance of the primary feeder. The single point measurement consists of three-phase voltage and current waveforms. Network topology data are not available to the algorithm. The new technique accommodates computational power and data constraints while maintaining adequate accuracy of the measurements