A Traveling Wave-Based Fault Locator for Two-and Three-Terminal Networks

The high frequency components in fault waveforms present undesirable effects to most fault location algorithms and as a consequence filtering of postfault signals, to remove the high frequency transients, is essential for accurate fault location. A fault location algorithm that derives from travelling wave principles can cope with high frequency transients since these basically depend on travelling wave phenomena. The development of such an algorithm is the objective of this paper. Using the telegraph equations as a line model, voltage and current samples taken at one end of a line within the first 5 ms of fault inception are used to generate instantaneous voltage and current profiles for the rest of the transmission line. The voltage and current estimation is based on the solution of the equations of the line model by the method of characteristics. Criteria functions involving any of the square of the voltage, the square of the current, or the product of the two are applied for determination of the fault position. Fault position is given by the peak variation in tangent to the above basic functions. The algorithm finds application in fault location on two and three-terminal networks at both transmission and distribution levels.