This topic contains several Images of High Voltage DC Transmission circuits, plus some descriptive text.

Thanks to ECN Member Bjarney for contributing these Images and information!!!

If you have Q's or comments, feel free to post 'em!

Scott S.E.T.

Now, to the pics!!!
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Pacific DC Intertie from Northern Oregon to Southern California
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Image #1: High Voltage DC Transmission lines
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Image #2: High Voltage DC Transmission lines
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Image #3: HVDC lines - note the 3 Phase High Voltage AC lines behind the HVDC lines
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Image #4: HVDC lines - note the 3 Phase AC lines again
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Below I have attached some "Snipped Text" about these Images and types of systems
(Text also from Bjarney):

<snip>

Pacific DC Intertie from Northern Oregon to Southern California

Three-phase AC power is fairly universal all over this planet, but occasionally there are deviants.
A few pictures of DC-power lines, rated at ±500kV 3100 amperes.
At its ends there are converters to 230kV 3ø for "local" use.


Pacific DC Intertie from Northern Oregon to Southern California
Converter stations: Celilo / Sylmar

One western-US circuit is ±500kV. Line rated at 3100 amperes and {ha!} 3100MW.

Under a pole-outage condition, by treaty-the nodes can be run with a ~1600-ampere earth return for up to 20 minutes-primarily in deference to telecommunications interference.
Transfer capacity is significantly constrained in this mode, but is operable.

Earth return seemingly creates very interesting problems. Return-current polarity changes based on which pole has failed. Ground electrodes of cast iron are located in marsh at the north, sea at the south.

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end.


[This message has been edited by Scott35 (edited 10-06-2002).]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!