Re: Why no corona?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 9/9/02 5:11:47 PM Pacific Daylight Time, tesla-at-pupman-dot-com
writes: 
>
> Hi list,
> Was wondering.
> Power transmission lines, before a substation, can carry from 100Kv to more
> the
> 600Kv. So why no corona? Seems we battle corona quite a bit at much lower
> voltages. <shrugs>
>
> Rick W.
> Salt Lake




Hi Rick,

I'm sure some of the utility power guys could answer this better
than myself, but I believe all of the very high voltage transmission
lines (> 300 kV) use methods that keep the radius of curvature
relatively large. Things like 3 or 4 seperate calbes for each phase
greatly increases the effective circumferance of the conductor(s).
Where the end of a conductor terminates in open air, they are
capped with a with spherical end caps or corona rings to suppress 
corona formation. Corona represents relatively little energy loss, but 
if it goes unchecked for the entire length of the transmission line,
then the losses would really add up.

Coiling in Memphis,
David Rieben