Underground VS Overhead Transmission lines
Underground VS Overhead Transmission lines
(OP)
Differences in protection systems and practices of the protection on overhead vs undergroud transmission lines.
any thought anyone.
any thought anyone.






RE: Underground VS Overhead Transmission lines
RE: Underground VS Overhead Transmission lines
Underground switchgear is very different in design from the type that is mounted on a pole. In my experience the underground devices did not auto reclose. I'm not sure if they ever communicated with sectionalizers or not.
RE: Underground VS Overhead Transmission lines
RE: Underground VS Overhead Transmission lines
Reclosers & sectionalisers are typically used on distribution lines were as a delayed auto reclose DAR 15-30second is used on transmission lines. Speed of protection operation on both ug & o/h systems is fast providing the fault is in zone, this minimises system disturbance
RE: Underground VS Overhead Transmission lines
RE: Underground VS Overhead Transmission lines
On the other end, faults on cables are more rare.
HV cables are generally much shorter than OH lines, this means that often people use differential relays to protect them, instead of distance protection.
But statistics are statistics... everything should be analyzed for itself.