High Accuracy Location of Faults on Electrical Lines Using Digital Signal Processing

A signal processing algorithm is developed to estimate the location of a discontinuity, e.g., a fault, on an electrical line. It is applied to sampled time-domain reflectometry (TDR) data and performs “pecstral” analysis of the transmitted and reflected pulse signals. The “Pecstrum” algorithm is based on a transform similar to the one used in the well-known “Cepstrum” technique; i.e., the “time domain” versus “quefrency domain” transformation. However, in this paper it is demonstrated that the performance of the “pecstrum” estimator is significantly better then the methods proposed so far. The proof of this statement is given on a theoretical as well as on a practical basis; the proposed solution has been tested out firmly, is operational in industrial digital reflectometers, and has been shown to be robust and successful in practice.