Direct algorithm for fault location in transmission lines with unknown electrical parameters and desynchronized signal registers.
Fault Location, Synchonization of Measurements, Transmission Lines.
As energy systems grow in size and complexity, transmission lines are increasingly susceptible to the occurrence of a disturbance, highlighting the short circuit as the most worrying event for the electric power system. In such cases, the defective line must be disconnected from the electric power system quickly and precisely, to remove the emergency situation of the whole system. For the system to have high reliability, electric utilities need to identify the location of the defect as soon as possible. In this way, it has become a common practice of the electric utilities the use of fault locators algorithms. Most of these algorithms, in the literature, depend on tools to synchronize measurements of voltage and current, between the terminals of the line, as well as equivalent circuit parameters. Therefore, efforts have been made to develop strategies that improve the accuracy of these locators. In this work, angle synchronization method and fault location method were proposed, based on the fundamentalfrequency phasor approach, independent of the electrical parameters of the transmission line and of iterative processes. The synchronization algorithm proposed is independent of the transient characteristics of the fault signals since it depends only on pre-fault voltage and current phasors. In addition, it identifies angles in any quadrant and is insensitive to operation conditions of the system. The tool developed for fault location requires pre and post-fault current and voltage phasors, work for all types of faults (symmetrical and asymmetrical), and for transposed and untransposed transmission lines. The evaluation of these algorithms is performed through fault simulations by the ATPDraw software. The obtained results prove the efficiency of the methods in finding the synchronization angle between two terminals of a transmission line, and to find fault location with good precision.