
472 Power System Transients
Thechoice between sheath cross-bonding or core cross-bonding varies by
country and/or utility company.
In a cross-bonded cable, both ends of three-phase sheaths are short-cir-
cuited and are always grounded at every major section, because the cross-
bonding becomes a transition point of traveling waves during a transient,
and a high overvoltage appears on the sheath. For the grounding of the
sheaths, long grounding rods and/or a small grounding mesh are adopted.
However, it is not easy to get a low-enough impedance, especially in a moun-
tainous area. The sending and/or receiving ends are grounded to a substa-
tion grou ...