Fault Location Approach to Distribution Networks Based on Custom State Estimator

This paper presents a properly designed branch current based state estimator (BCBSE) used as the main core of an accurate fault location approach (FLA) devoted to distribution networks. Contrary to the approaches available in the literature, it uses only a limited set of conventional measurements obtained from smart meters to accurately locate faults at buses or branches without requiring measurements provided by phasor measurement units (PMUs). This is possible due to the methods used to model the angular reference and the faulted bus, in addition to the proper choice of the weights in the state estimator (SE). The proposed approach is based on a searching procedure composed of up to three stages: ① the identification of the faulted zones; ② the identification of the bus closest to the fault; and ③ the location of the fault itself, searching on branches connected to the bus closest to the fault. Furthermore, this paper presents a comprehensive assessment of the proposed approach, even considering the presence of distributed generation, and a sensitivity study on the proper weights required by the SE for fault location purposes, which can not be found in the literature. Results show that the proposed BCBSE-based FLA is robust, accurate, and aligned with the requirements of the traditional and active distribution networks.