An improved GPS current traveling-wave fault locator in EHV transmission networks using few recordings

This paper presents an improved method for estimating the fault location in electric power systems based on transient signals obtained from traveling wave recorders (TWS). These recorders are installed at few substations where traveling waves are utilized to locate faults in the transmission system using current signals only. The recorded signals are compared to a reference signal and the time delay of the first wave fronts is receded at each TWS. The minimum path for the traveling wave has been calculated using Dijkstra algorithm to select the closest TWS recorder. The fault location is determined by accurately time-tagging the arrival of the traveling wave at monitored ends of the transmission lines and comparing the time difference to the total propagation time of the lines. The time signal is obtained via satellite from the global positioning system (GPS). Fault distance calculation is done using double end method and the appropriate two current traveling wave signals. Validation of fault location is carried out by the alternative transient program (ATP/EMTP) simulations for a typical 400 kV power system