Combined Impedance and Branch Current State Estimation Method for Fault Location in Electric Power Distribution Systems

Precise fault location is a strong concern of modern distribution systems that aims to increase system availability. This function has been part of FLIRS (Fault Location, Isolation, and Restoration) module of Distribution System Management systems. Since the corrective actions and service restoration depend on it, the precise location capability avoids major delays in maintenance and minimize safety issues. The literature on this topic for transmission systems is abundant; however, for distribution systems due to its topology and parameter characteristics associated with new functions and devices, advances are demanded. In this context, the fault location method based on branch-current state estimation in combination with the impedance-based fault location algorithm is proposed. With the proposed method, difficulties faced by the impedance only based methods, such as the multiple fault location possibilities, are minimized with the use of few meters. Simulation results confirmed high accuracy with low computational effort, resulting in an interesting method for FLIRS application in the context of modern distribution systems.