Transmission lines are one of the most important power system
components, responsible for delivering energy from generating
plants to consumers. Those lines may present a high failure rate
since, in most cases, they cover large distances and are exposed
to different climate conditions.
The distance protection method is one of the most used techniques
for preventing damages that can be inflicted to transmission
lines. The conventional distance protection is based on
impedance measurement elements that estimate the line impedance
from the relay to the fault point using voltage and current
phasor quantities. The ANN-based algorithms have been developed
as an alternative to conventional methods, since they present very
promising results with regard to precision and operating time.
Refs. [1–7] present ANN-based algorithms that act as classifiers,
indicating whether the fault is located inside or outside the protection
zones. Refs. [8–10] present ANN-based algorithms that act as
function approximators which point out, directly or not, the fault
distance.