A NEW FAULT LOCATION TECHNIQUE FOR 2-TERMINAL AND 3-TERMINAL LINES

This paper presents a new method for the computation of fault location in two- and three-terminal high voltage lines. The method is based on digital computation of the three-phase current and voltage 60/50 Hz phasors at the line terminals. The method is independent of fault type and insensitive to source impedance variation or fault resistance. Furthermore, it considers the synchronization errors in sampling the current and voltage waveforms at the different line terminals. The method can be used on-line following the operation of digital relays or off-line using data transferred to a central processor from digital transient recording apparatus. The paper starts with a two-terminal line to explain the principles and then presents the technique for a three-terminal line. The proposed technique was first tested using data obtained from a steady state fault analysis program to evaluate the convergence, observability and uniqueness of the solution. The technique was then tested using EMTP-generated transient data. The test results show the high accuracy of the proposed technique.