Tom Bruhns snipped-for-privacy@msn.com posted to sci.electronics.design:
From the few handfuls of times that i have made the calculation, it seems to be about 370 ohms. That can't be a coincidence can it?
DC Power Transmission
Aug 28, 2007
24 Replies
Jamie jamie_ka1lpa_not_valid_after_ka1lpa snipped-for-privacy@charter.net posted to sci.electronics.design:
You should read up before you post, see:
formatting link
Sure it can. The serious high-power ones around here are certainly higher than 370 ohms, which would have a spacing/wire-diameter ratio of only 11:1 -- that's for a two-wire line in free-space but should be quite close for differential mode of two wires of a three-wire line, well above ground. What I see around here is a spacing/diameter ratio more like 100:1.
If I'm not mistaken, another advantage of a high-voltage DC line is much less corona loss than an AC line. -- Yes, since I was unsure about this, I did a little search and uncovered a paper from ABB at
formatting link
that has a lot of info comparing high-end (multi-gigawatt) AC and DC power transmission lines. Looks like typically corona loss from DC lines and AC lines is similar in clear weather, but much less for the DC lines in rain or ice conditions. See page 5 of the reference. Anyway, looks like a pretty good paper that will answer much of what has come up in this thread, a lot more authoritatively and quantitatively than the postings here. ;-)
Cheers, Tom
formatting link
(also called Path
65) 3100 megawatts capacity
formatting link
(also called Intermountain) 1927 megawatts capacity
Tom Bruhns snipped-for-privacy@msn.com posted to sci.electronics.design:
formatting link
Nice link.
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required