This paper presents two local algorithms using only currents measurements that could be
used as a back-up protection (after the loss of the voltage sensors) in directional relays for
distribution networks with distributed generation (DG), or as additional directional relay
dispatched along the feeders. These algorithms are based on the symmetrical components
(0-zero, 1-positive and 2-negative sequences) of the 3-phases currents. Due to the power
flows generated by the DG the positive sequence current argument is unforeseeable, thus it …

In this study, algorithms for directional relays using only current measurements are
presented. Developed for radial distribution networks, these algorithms will determine fault
direction based on ratios between variations of sequence currents during and before faults:
ΔI2/ΔI0 ratio for line‐to‐ground faults and the ΔI2/ΔI1 ratio for line‐to‐line faults. The ratios
are used as input of a support vector machine classifier, which was trained beforehand
thanks to simulation tools. The classifier classifies ratios into two categories, according to the …