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Discussion Starter · #1 ·
Home lighting (24VDC) and Data Centers (380VDC) are moving to
Direct Current power distribution for efficiency reasons:
http://spectrum.ieee.org/energy/the-smarter-grid/directcurrent-networks-
gain-ground

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

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Discussion Starter · #2 ·
DC has always been a fine high efficiency power for electronic equipment and
some motors. Long distance power distribution is the only situation where AC
excels because of the simple iron core and copper wire wound Transformer can
shift the ratio of Voltage and Current for the same power (Watts) level and
because the losses in longer distances than about a mile are best managed by
using high voltages and low currents where most losses are resistive the
loss is current squared times resistance the lower the current the greater
the transmission efficiency. Oh Gosh that feels like a classroom lecture...
Imagine the consternation when I introduced three phase alternators and
motors to a class of fifty who barely understood how a flashlight worked!
Oh but it was fun for me too and there are about 6,000 more technicians in
Florida because of my efforts for 20 years.
Regards,
*Dennis Lee Miles* (Director) *E.V.T.I. inc*.
*www.E-V-T-I-Inc.COM <http://www.e-v-t-i-inc.com/> *(Adviser)*
EVTI-EVAEducation Chapter
*
++++++++++++++++++++++++++++++++
The "Stone Age" didn't end because they ran out of Stones;
It ended because they started using their Brains !
+++++++++++++++++++++++++++++++++++++++++++++

Cor van de Water <[email protected]> wrote:

> Home lighting (24VDC) and Data Centers (380VDC) are moving to
> Direct Current power distribution for efficiency reasons:
> http://spectrum.ieee.org/energy/the-smarter-grid/directcurrent-networks-
> gain-ground<http://spectrum.ieee.org/energy/the-smarter-grid/directcurrent-networks-%0Again-ground>
>
> 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
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



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Discussion Starter · #3 ·
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.

Regards,

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 Dennis Miles
Sent: Friday, January 28, 2011 1:10 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Edison Vindicated

DC has always been a fine high efficiency power for electronic equipment
and some motors. Long distance power distribution is the only situation
where AC excels because of the simple iron core and copper wire wound
Transformer can shift the ratio of Voltage and Current for the same
power (Watts) level and because the losses in longer distances than
about a mile are best managed by using high voltages and low currents
where most losses are resistive the loss is current squared times
resistance the lower the current the greater the transmission
efficiency. Oh Gosh that feels like a classroom lecture...
Imagine the consternation when I introduced three phase alternators and
motors to a class of fifty who barely understood how a flashlight
worked!
Oh but it was fun for me too and there are about 6,000 more technicians
in Florida because of my efforts for 20 years.
Regards,
*Dennis Lee Miles* (Director) *E.V.T.I. inc*.
*www.E-V-T-I-Inc.COM <http://www.e-v-t-i-inc.com/> *(Adviser)*
EVTI-EVAEducation Chapter
*
++++++++++++++++++++++++++++++++
The "Stone Age" didn't end because they ran out of Stones;
It ended because they started using their Brains !
+++++++++++++++++++++++++++++++++++++++++++++

On Fri, Jan 28, 2011 at 2:09 AM, Cor van de Water <[email protected]>
wrote:

> Home lighting (24VDC) and Data Centers (380VDC) are moving to Direct
> Current power distribution for efficiency reasons:
> http://spectrum.ieee.org/energy/the-smarter-grid/directcurrent-network
> s-
> gain-ground<http://spectrum.ieee.org/energy/the-smarter-grid/directcur
> rent-networks-%0Again-ground>
>
> 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
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



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Discussion Starter · #4 ·
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



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
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



--
www.electric-lemon.com

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Discussion Starter · #5 ·
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
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



--
www.electric-lemon.com

_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
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_______________________________________________
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Discussion Starter · #6 ·
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.


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
>>
>> _______________________________________________
>> | REPLYING: address your message to [email protected] only.
>> | Multiple-address or CCed messages may be rejected.
>> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>> | OTHER HELP: http://evdl.org/help/
>> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
>
> --
> www.electric-lemon.com
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
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> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
>



-- =

www.electric-lemon.com

_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
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Registered
Joined
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70 Posts
Discussion Starter · #7 ·
I thought those resonant 300 mile long arrays were for the government ELF
testing comms to submarines ;-)

On Fri, Jan 28, 2011 at 2:36 PM, Peter Gabrielsson <
[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
> >>
> >> _______________________________________________
> >> | REPLYING: address your message to [email protected] only.
> >> | Multiple-address or CCed messages may be rejected.
> >> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >> | OTHER HELP: http://evdl.org/help/
> >> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> >>
> >
> >
> >
> > --
> > www.electric-lemon.com
> >
> > _______________________________________________
> > | REPLYING: address your message to [email protected] only.
> > | Multiple-address or CCed messages may be rejected.
> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > | OTHER HELP: http://evdl.org/help/
> > | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> >
> > _______________________________________________
> > | REPLYING: address your message to [email protected] only.
> > | Multiple-address or CCed messages may be rejected.
> > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > | OTHER HELP: http://evdl.org/help/
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> >
>
>
>
> --
> www.electric-lemon.com
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
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>
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Discussion Starter · #8 ·
Dennis Miles wrote:
> DC has always been a fine high efficiency power for electronic equipment and
> some motors. Long distance power distribution is the only situation where AC
> excels
> <snip>

HVDC transmission has many benefits. Not the least of which is isolation
of electricity grids:

http://www05.abb.com/global/scot/scot271.nsf/veritydisplay/8d8fb19f8cde3db3c125707b004b2e6e/$File/42-46%203M550_ENG72dpi.pdf

Which, for example, protected Quebec from going down during the 2003
Northeast Blackout. They are also more efficient.

Cory

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Discussion Starter · #9 ·
Gentlemen technology has made the difference, compared to today, in the
1930's when Edison was selling communities DC power systems, there was no
easy way to change the voltage, as it traveled down the wires, the I x R
drop reduced the voltage every foot and a mile or so from the generator is
about as far as it worked. so every 3 or 4 miles they built another
generating plant with steam turbine, generator and steam boiler. Vacuum
tubes are low current devices so there was no way to invert the voltage to a
high value for transmission and reduce it for use in a totally DC system.
That is why the Edison system used many small generating plants. it was not
a network. Thank George Westinghouse for the modern network's beginning.
Thank Nicoli Tesla and not Tomas Alva Edison.

Regards,
*Dennis Lee Miles* (Director) *E.V.T.I. inc*.
*www.E-V-T-I-Inc.COM <http://www.e-v-t-i-inc.com/> *(Adviser)*
EVTI-EVAEducation Chapter
*
++++++++++++++++++++++++++++++++
The "Stone Age" didn't end because they ran out of Stones;
It ended because they started using their Brains !
+++++++++++++++++++++++++++++++++++++++++++++

Cory Cross <[email protected]> wrote:

> Dennis Miles wrote:
> > DC has always been a fine high efficiency power for electronic equipment
> and
> > some motors. Long distance power distribution is the only situation where
> AC
> > excels
> > <snip>
>
> HVDC transmission has many benefits. Not the least of which is isolation
> of electricity grids:
>
>
> http://www05.abb.com/global/scot/scot271.nsf/veritydisplay/8d8fb19f8cde3db3c125707b004b2e6e/$File/42-46%203M550_ENG72dpi.pdf
>
> Which, for example, protected Quebec from going down during the 2003
> Northeast Blackout. They are also more efficient.
>
> Cory
>
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