Signal processing and discriminating techniques incorporated in a protective scheme based on travelling waves

The incorporation of correlation techniques in a protective scheme based on travelling waves is described and it is shown that important features of signals arriving at the relaying point can be extracted, even from complex waveforms, using correlation techniques. The influence of window length on detection accuracy is also investigated. The results are used in a protective algorithm, previously described by the authors, to obtain reliable relaying information. A method for dealing with close-up faults is also presented together with a range of results showing the discriminating ability of the algorithm.