Re: this was probably really stupid

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

Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

At 11:34 AM 5/26/2004 -0600, you wrote:
>Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
>
>Ed:
>
>I have always wondered how these long distance EHV lines avoid producing
>excessive corona.
>
>The cables do not appear to be very large in diameter --- perhaps an inch or
>two at best.  With that small radius and diameter, why don't they emit
>tremendous corona?
>
>With corona inception potential around 67 kV per inch (30 kV/cm) they should
>be glowing a lot with their small diameters.  Especially in rainy weather.
>
>Dr. Resonance

As Ed mentioned, it's all in the bundling.  Bundling also reduces 
inductance (which is a BIG deal for long distance high power transmission 
lines.. it makes the system hard to stabilize), and reduces skin effect 
losses.  All in all, bundling is a "good thing".  Around here (southern 
CA), you see a lot of two conductor bundles (probably on the 138 or 345kV 
lines), but occasionally 3 or 4 conductor bundles.  Looking at some photos 
of the "Path 15 improvement" project, it looks like they are 3 wire bundles 
(Path 15 is a 500kV line)
http://www.wapa.gov/media/cct/2004/may14/26no102a.htm

I found a picture of a DWP line claimed to be 750kV DC that looks like a 
dual bundle.  However, I always thought that line ran at 500kV (maybe it's 
a voltage to ground vs voltage between conductors issue)