A simplified algorithm for digital distance protection based on Fourier techniques

Algorithms for digital distance protection based on Fourier series techniques are examined. An approach based on a variable-frequency sampling technique is proposed. The algorithm is examined from a theoretical point of view, and its behavior is simulated under fault conditions typical of the Italian electrical network. The algorithm is shown to behave in the same way as other Fourier series-based algorithms and to have the advantage of reducing the computational burden.<>