رحمن دشتی

Restoration of electrical energy after each distribution feeder's outage can improve the reliability indices and its efficiency. Accurate fault locating can cause the Power distribution (PD) systems to restore rapidly. PD networks include many branches, laterals, sub-laterals and load taps. Thus, accurate fault locating is very complicated and important. In the present paper, a new combined method is proposed for locating the single-phase fault to earth in PD networks. An impedance-based fault-location algorithm is also used to find the possible fault locations. Then, the new method is proposed for determining the faulty section using voltage sag matching algorithm. In this method, after single-phase fault to ground, the possible locations of fault are determined by using the impedance-based fault-location algorithm. The same fault is simulated in possible locations, separately. The voltage, then, at the beginning of feeder is saved and amplitude and angle of the voltage differences are determined and online databank is generated. This databank is compared with the obtained and recorded amplitude and angle of the voltage differences for actual fault. The real location of fault is specified by the matching value of each possible fault location