Synchronised Measurements Based Algorithm for Long Transmission Line Fault Analysis

A novel numerical algorithm for the analysis of single line to ground faults on long overhead transmission lines is presented in this paper. The algorithm is an extension of previous work by the authors and takes into consideration the shunt capacitance of the transmission line, making it applicable to long overhead transmission lines. The algorithm utilizes synchronized data sampling from both line terminals and a non-recursive parameter estimation method. The algorithm was developed using an accurate fault model including arcing phenomena and tower footing resistance, and a dynamic arc model was included in the fault model used to test the algorithm. The algorithm was derived in the time domain and simultaneously estimates the arc voltage amplitude, tower footing resistance, and the fault location. The proposed algorithm was thoroughly tested using simulated fault cases. In particular, the sensitivity of the algorithm to fault resistance, harmonics, untransposed line models, and parallel lines was investigated.