New impedance-based fault location method for unbalanced power distribution systems

Summary This paper presents a novel formulation of impedance-based fault location method for overhead unbalanced distribution systems. The proposed method uses a general fault location equation that is applicable to all possible single and compound shunt fault types. This is in contrast with existing impedance-based methods which use an equation for each fault type and do not cover all types. The proposed method also overcomes the limitation of the conventional method, which requires the identification of fault type. Only the fundamental values of voltages and current measured at the substation terminal are required for the proposed method. The single-phase and three-phase laterals and the capacitive effect of distribution line are considered in this paper. The proposed method was evaluated and tested on a modified IEEE 34-bus distribution system using PSCAD/EMTDC software. Test results verify the accuracy and robustness of the proposed method.