Characterization of the effect of the insulating material of covered cables on the impulse breakdown behavior of single- and three-phase compact distribution lines

Abstract This paper aims to characterize the influence of the insulating material of covered cables on the impulse breakdown behavior of typical single- and three-phase compact distribution line configurations. Based on high voltage tests with standard lightning impulse voltages, three main features are investigated: (i) minimal values of breakdown voltage, (ii) time for disruption, and (iii) pinhole location. The results indicate larger withstand levels for the single- and three-phase structures when high-density polyethylene (HDPE) is used instead of crosslinked polyethylene (XLPE) in the insulating layer of the cables. Differences up to 60% are reported. Also, HDPE-covered cable presents a shorter time for disruption. Typically, voltage breakdown was observed in the wavefront for HDPE-covered cables and in the wavetail for XLPE-covered cables. Finally, tests with punctured samples showed that the value of the disruptive voltage is influenced by the pinhole location along the cable cover.