Analysis of the ground effect in the single phase fault location for power distribution systems

This paper presents a comparison of two different alternatives for locating single phase faults, considering the influence of the soil resistivity and the fault resistance. The compared methods are the proposed by a commercial software developer and one of the classic impedance based fault location methods. Tests were performed using three different soil resistivity models, based on the measurements taken directly from field. According to the results in a 34kV power distribution system, the performance of the simple impedance based fault locator is better than the obtained using the commercial software, especially in such cases of high resistance faults. Additionally, the soil resistivity models which best represents the real systems are those which give better results in the fault location, showing the influence of this variable.