Re: this was probably really stupid

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


Do these cables have any insulation on them or are they bare like the lower
HV lines?

Dr. Resonance

 > >
 > >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)
 >
 >
 >
 >
 >