Along with the increasing complexity of electric power systems,
there is an increment on the quality standards of the electric
energy supplied. The power quality refers also to the continuity
of the service, which is greatly affected by failures that
produce outages of transmission and distribution lines. Failures
in distribution networks significantly affect the cost and quality
of power supplied [1], and there is a continuous search for actions
to reduce the possibility of failures.
One method to improve the reliability of power distribution
systems is by replacing overhead bare conductors with covered
conductors (CC) in primary feeders [2]. The use of covered conductors
in distribution systems in not new; in some countries
these conductors have been used for more than 20 years. However,
its use has become more attractive in several parts of the
world due to the impact that CC has on the reliability of medium-
voltage feeders. The CC can consist of up to three XLPE extruded
layers: the first layer is a semi-conducting strand shield,
the second layer is the insulation layer, and the third layer is a
track-resistant covering layer. The construction of a three layer
cable is presented in Figure 1. CC is used in two common ways
on medium line voltage systems (5–69 kV) [3]