A least error squares method for locating fault on coupled double-circuit HV transmission line using one terminal data

The arcing fault has a high probability of occurence on a HV transmission line. To date, the transient resistance is always assumed as a linear constant resistance in most of the locating algorithms. On the basis of the previous achievements in arc modeling, the paper describes an ideal voltage-current transform characteristic relationship and its equivalent circuit representing for long arc, and then presents a novel short time-window method for locating arcing faults on coupled double-circuit HV transmission line using one-terminal voltage and current samples. The method proposed has the advantages as follows: (1) arcing discharge is taken into account; (2) CT saturation is considered for a short time-window, which can be chosen from the initial time of a fault, less than half period; and (3) far-terminal equivalent impedance is not required. Moreover, the requirement of high accuracy to fault location is ensured by using the least error squares method. A lot of digital simulation shows that the scheme is feasible. The method has been applied to Kunming electric network.