ABSTRACT
Distance relays provide good dependability for bolted faults but they can face problems detecting resistive faults, specially in short lines. The fault resistance can also affect the security of the relay.
This paper explains the concept of the apparent resistance. The influence of the remote infeed with load flow and non-homogeneity of the system on both Quadrilateral and Mho characteristics is described. The effect of the ground resistance on the phase to earth loops during a phase-phase-ground fault is also reviewed.