Optimal Fault-location Estimation in Distribution Systems with Distributed Generations

To enhance the accuracy and reliability of fault-location estimates, an optimal fault-location estimator for power distribution systems with distributed generations is proposed in this article. Voltage and current measurements recorded at certain location/locations, such as power generation sites, are employed to estimate the fault location. The proposed method is able to make the most of available measurements, which may be from one location or multiple locations. Based on optimal estimation theory, the method is able to estimate the fault location, fault resistances, and true value of measurements. A chi-squared test is adopted to detect and identify possible bad measurements for improved estimation results. Evaluation studies based on a sample power distribution system have been carried out. Evaluation studies have demonstrated that the proposed method is effective for obtaining accurate fault-location estimates, as well as detecting and identifying possible bad measurements.