4 ms·
According to Wikipedia, this is not true anymore: http://en.wikipedia.org/wiki/Hvdc http://en.wikipedia.org/wiki/Hvdc 'Depending on voltage level and construc
by onnoonno 12y ago
According to Wikipedia, this is not true anymore:
http://en.wikipedia.org/wiki/Hvdc http://en.wikipedia.org/wiki/Hvdc
'Depending on voltage level and construction details, HVDC transmission losses are quoted as about 3.5% per 1,000 km, which is less than typical losses in an AC transmission system.[16]'
- dfox 12y agoAt line-frequency skin effect is not significant for almost any practical conductor (ie. reasonably conductive and with reasonable cross-section). What gets significant for long distance transmission is that few thousand kilometer long power transmission line starts behaving like, well, transmission line even on frequencies as low as 50/60Hz. Also HVDC elegantly sidesteps problem of grid synchronization.
- davepage 12y agoOh, that is completely not true for commercial AC power transmission -- just look up at a big power pylon and see the multiple power conductors per phase. See the pretty blue picture: http://en.wikipedia.org/wiki/Skin_effect http://en.wikipedia.org/wiki/Skin_effect Skin effect in copper is about 9mm at 60Hz
- coryrc 12y agoThat's part of the reason those power lines are steel-cored with copper jackets; the other reason being strength, of course.
- votingprawn 12y agoThey're Aluminium over a steel core, not copper. A copper over steel version would be significantly heavier.
- coryrc 12y agoheadsmack yes, of course.
- dfox 12y agoI assumed that skin depth at 50/60Hz is on the order of 20mm and that 40mm diameter conductor is not entirely practical to install on pylons (or generally in longer lengths than few meters), obviously I was slightly off in that estimate.