[email protected]> wrote:
> Ah yes, that rings a bell. I remember articles about compasses on
> ships not working and concerns about migratory birds getting lost when
> they first brought it online.
>
>
> On Fri, Jan 28, 2011 at 3:21 PM, Cor van de Water <
[email protected]>
> wrote:
> > That is also a nice one and certainly not the last,
> > if you look though the list of HVDC projects then
> > you see that only the last few years they are
> > ramping up quickly:
> > http://en.wikipedia.org/wiki/List_of_HVDC_projects
> >
> > What I was recollecting (from memory) was the
> > Baltic Cable which is a true monopole without
> > return wire (the Baltic sea is the return)
> > http://en.wikipedia.org/wiki/Baltic-Cable
> >
> >
> > Cor van de Water
> > Director HW & Systems Architecture Group
> > Proxim Wireless Corporation http://www.proxim.com
> > Email:
[email protected] Private: http://www.cvandewater.com
> > Skype: cor_van_de_water IM:
[email protected]
> > Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
> > Tel: +91 (040)23117400 x203 XoIP: +31877841130
> >
> > -----Original Message-----
> > From:
[email protected] [mailto:
[email protected]] On
> > Behalf Of Peter Gabrielsson
> > Sent: Saturday, January 29, 2011 3:07 AM
> > To: Electric Vehicle Discussion List
> > Subject: Re: [EVDL] Edison Vindicated
> >
> > It was done very recently, 2000 in fact.They do however use return
> > cables, just non insulated return cables, to avoid the issues you
> > listed. The SwePol link runs at 450kV and uses 792 thyristors arranged
> > in three 16 metres (52 ft) high thyristor towers at each station, Asea,
> > now known as ABB, has been doing this since the 1930's
> >
> >
> >
> > On Fri, Jan 28, 2011 at 12:37 PM, Lee Hart <
[email protected]>
> > wrote:
> >> On 1/28/2011 1:54 AM, Cor van de Water wrote:
> >>> BTW, AC may be fine for long distance *overhead* transport but more
> >>> than 10 years ago I read about a new cable that was layed between
> >>> mainland Europe and Scandinavia through the sea. Since a cable has so
> >
> >>> high capacitance, a large part of the power would disappear if they
> >>> would attempt to send AC over that seacable, so instead they used DC
> >>> and they reduced the cost of the cable by just running ONE conductor
> >>> with insulation and protection; the sea was used as return....
> >>> Of course this was very high voltage to reduce the current.
> >>> They also fenced off the area around the return electrode to avoid
> >>> anybody would be electrocuted while swimming there.
> >>
> >> This must have been done a long time ago. DC power lines can be more
> >> efficient, but they have also caused environmental problems if not
> >> done right. The magnetic field messes up compasses and migratory
> > birds.
> >> Running DC through a ground return causes serious corrosion and
> >> gassing problems. in seawater for example, you'd be dissociating the
> >> salt into chlorine gas and sodium hydroxide (making the seawater
> > caustic).
> >>
> >> Truly strange things can happen with long AC powerlines as well. The
> >> capacitance and inductance makes them behave like RF transmission
> >> lines, and you start having to worry about impedances, reflections,
> >> and radiation. A famous example from back in the 1930's was a 300 mile
> >
> >> run that just happened to resonate at 60 Hz. All the power they put
> >> into it was *radiated* just like a radio antenna!
> >> --
> >> Lee A. Hart | Ring the bells that still can ring
> >> 814 8th Ave N | Forget the perfect offering
> >> Sartell MN 56377 | There is a crack in everything
> >> leeahart earthlink.net | That's how the light gets in -- Leonard
> >> Cohen
> >>
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> >
> >
> >
> > --
> > www.electric-lemon.com
> >
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>
> --
> www.electric-lemon.com
>
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