Minimum Corona Free conductor sizes
Minimum Corona Free conductor sizes
(OP)
Does anyone have a list/chart/reference standard for minimum corona free conductor sizes?
I will appreciate any information I can get.
Thanks
I will appreciate any information I can get.
Thanks






RE: Minimum Corona Free conductor sizes
RE: Minimum Corona Free conductor sizes
I know the EPRI Red Book has some info on it. I'll see if I can find it and post some additional info. If you're not an EPRI member, it will cost you a kajilion dollars! : )
RE: Minimum Corona Free conductor sizes
Sorry, I don't have any charts or information.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Minimum Corona Free conductor sizes
RE: Minimum Corona Free conductor sizes
See if the attachment comes through OK. This is Peek's equation or formula from 1929.
RE: Minimum Corona Free conductor sizes
Actually I think that the effective radius (in terms of corona onset/avoidance) of a four-plex bundle is much greater than the actual radius of the conductors comprising the bundle. Hence my use of the term "effective radius".
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Minimum Corona Free conductor sizes
Keith Cress
kcress - http://www.flaminsystems.com
RE: Minimum Corona Free conductor sizes
However I am not aware of any recent standards or references that may have this information to validate that data.
Thanks magoo for the equation. I will try it on a couple of conductors
A chart or table would be very handy or if you know of a standard name and number which may have this info.
RE: Minimum Corona Free conductor sizes
say zazmat,
What voltages are you dealing with
and
Are they single conductor lines or multi-conductor bundles?
RE: Minimum Corona Free conductor sizes
Eo = go·delta^(2/3)·r·m·ln(D/r)
where
Eo=critical disruptive voltage in kV to neutral
go=critical gradient in kV per cm (21.1 kV/cm, but Section 10 gives more accurate numbers and includes bundled conductors)
delta = air density = 17.9·b/(459+°/f)
b=barometric pressure in inches of Hg
r=conductor radius in cm
D=distance in cm between conductors for 1Ø or equivalent Ø spacing for 3Ø
m=surface factor (0.82 for stranded, 0.92 for segmental)
It also has corona loss curves for different conductor types.
RE: Minimum Corona Free conductor sizes
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Minimum Corona Free conductor sizes
Thanks jghrist. This would even work on bundled conductors.
Magoo2 most of the lines I work with are 345, 138 and 69kV.
And 138kV and 345kV lines do require multi-conductor bundles.
Mostly
2-795kcmil, 2-1590kcmil ACSR and 2-2500kcmil AAC
Thanks all for your valuable input.
RE: Minimum Corona Free conductor sizes
RE: Minimum Corona Free conductor sizes
delta = air density = 17.9·b/(459+°F)