A Traveling Wave-Based Fault Location Method Using Unsynchronized Current Measurements

This paper presents a traveling-wave-based fault location method for two terminal transmission lines using unsynchronized current measurements from intelligent electronic devices (IEDs) recorded at both ends. In the formulation, the method considers practical implementation issues such as IED hardware and software processing delays, and data synchronization error. In this method, two possible fault location solutions are determined using the first two traveling wave arrival time recorded at both terminals. Then, the correct fault location is identified between the two based on the faulted half-section information. Identification of faulted half-section is accomplished by comparing the rise time of the first traveling wave recorded at both terminals of the line. The proposed method does not require GPS synchronization and field experiments to calibrate the various asymmetrical delays and synchronization error. The method is tested on a 220 kV transmission line using data simulated in EMTDC/PSCAD tool with frequency-dependent phase models. The proposed method can locate faults using unsynchronized data with various asymmetrical delays, whereas classical methods work properly only for synchronized data with symmetrical delays. The performance of the proposed method is evaluated for different fault scenarios. The proposed method demonstrated high accuracy, noise immunity, robustness against fault inception angles, and high impedance faults. Test results are compared with classical two-terminal methods for a transmission line.