Automated model-based transmission line fault location method using reduced equivalent circuit

Transmission lines are a vital part of power systems and are prone to a variety of short-circuit faults. Transmission line faults must be accurately identified and cleared so as to restore the faulted line back to normal operation in the shortest amount of time possible. Common fault locating practices used by utilities involve multiple manual data analysis stages which could cause time delays. This thesis presents an automated model-based transmission line fault location approach to improving the existing manual process. A fault location process comprises of data preprocessing of the fault record and estimating the fault location using impedance-based techniques. This thesis first elucidates the data preprocessing steps, proposes and validates an algorithm for determining the fault current and voltage. It then proposes an automated fault location method by simulating relevant fault scenarios on a reduced equivalent circuit to determine the fault location. The proposed fault location method is implemented using MATLAB and OpenDSS. The need and process of forming reduced equivalent circuits for automating the fault location process are presented. A test circuit was used to illustrate the method and to evaluate the technical capabilities of the algorithm. The technical performance of the proposed fault location method was analyzed on a variety of aspects such as line and generator outage, the presence of mutual coupling, the presence of fault resistance, and multiple combinations of the above. The algorithm is robust and capable of handling the above mentioned issues which affect the fault location estimate.