A Fault Location Scheme for Active Untransposed Distribution Systems Using a Limited Number of Synchronized Measurements

This paper presents a fault location scheme for unbalanced and untransposed distribution systems which contain different types of distributed generation (DG). A general formula has been derived for any fault type using a limited number of synchronized measurement points. To avoid having to synchronize all the measurement points, the voltage and current measured locally at the DGs are processed locally to calculate the equivalent impedance of the DG at the non-fundamental frequencies. This is then used in the fault location process. The IEEE 34-bus feeder is simulated using the distributed parameter model for the lines and is used to validate the proposed scheme. Uncertainties associated with fault type, fault location, fault resistance, inception angle, noise in measurements and load profile are considered in the evaluation. The simulation studies demonstrate that the scheme can have a high accuracy and is robust