Single conductor 345 and 500 kV Lines
Single conductor 345 and 500 kV Lines
(OP)
Davidbeach said in thread238-225023: Minimum Corona Free conductor sizes
"Bundled 138kV? If so, that is entirely for loadability and has nothing to do with corona. Single conductor 230kV with no anti-corona provisions at the insulator strings are extremely common. The only 345kV line I'm familiar with is single conductor, but does have anti-corona hardware at each insulator. There is even a fair bit of single conductor 500kV around - that one does surprise me, but I know its there"
David, is there any way i could get some more information on those lines (ie. which lines they are so that i can try to get in touch with the owning system and confirm they have had no operating issues). I am involved in some debate at the moment where people are proposing that we calculate corona based on the surface coefficient measured for our very worst line (0.45). It would require a triple conductor bundle at 330 kV !
Any help appreciated,
John.
"Bundled 138kV? If so, that is entirely for loadability and has nothing to do with corona. Single conductor 230kV with no anti-corona provisions at the insulator strings are extremely common. The only 345kV line I'm familiar with is single conductor, but does have anti-corona hardware at each insulator. There is even a fair bit of single conductor 500kV around - that one does surprise me, but I know its there"
David, is there any way i could get some more information on those lines (ie. which lines they are so that i can try to get in touch with the owning system and confirm they have had no operating issues). I am involved in some debate at the moment where people are proposing that we calculate corona based on the surface coefficient measured for our very worst line (0.45). It would require a triple conductor bundle at 330 kV !
Any help appreciated,
John.






RE: Single conductor 345 and 500 kV Lines
RE: Single conductor 345 and 500 kV Lines
RE: Single conductor 345 and 500 kV Lines
Eo ~ r·ln(D/r)
where
r=conductor radius
D=distance between conductors
so if you can increase the spacing, you can get away with a smaller conductor radius for a given critical voltage. You'll probably see more single conductor HV stuff in rural areas and more bundled stuff where construction widths are restricted.
RE: Single conductor 345 and 500 kV Lines
All of their 345kV was a two conductor bundle per phase with a conductor bundle spacing of about 18". Conductors were typically 954 ACSR or 1,024 ACAR. Phases were spread horizontally about 20' as I recall.
Seems like I have seen 500kV with 3 and 4 conductors per phase.