"Dimitrios Tzortzakakis" wrote in message
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Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr
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"TimPerry" schreef in bericht
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"AllTel - Jim Hubbard" wrote in message
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I am curious about what would happen to an electrical current in 2
situations.....
Assume that you have 2 wires that, when joined, complete a closed
electrical
DC circuit with electrons flowing thusly.....
------------ ============
eeeeeeeeee eeeeeeeeeeeeeee
------------ ============
If you flattened out the end of each wire where they connect , would
the
resulting electron paths be more like figure A or Figure B?
neither ... research "skin effect"
Most of the times this just aplies to AC (high frequency) circuits
Or of line-to-line voltage equal or above 220 kV.Therefore transmission
lines of 400 kV are always designed with a double conductor, thus to
reduce
the corona discharge due to skin effect.
Oh boy, you have a 'couple of crossed wires' there.
"Skin effect" is the phenomenon where electric current flow is forced out
from the center of a conductor due to the self-inductance in the conductor
when carrying AC current. The higher the frequency, the more pronounced the
current shift to the exterior. It's mostly a problem with high current
situations, even if the voltages are so low that corona discharge is not a
problem.
"Corona discharge" is *NOT* caused by AC or skin effect. Corona discharge
is caused by a high voltage gradient in the space around a conductor. This
is a combination of the voltage applied to the conductor and the effective
radius of the conductor. A high voltage, or very small effective radius can
increase the gradient to the point where the air is ionized. Simple proof
is that corona discharge is a problem with high DC voltage systems as well
as AC.
Sometimes hollow tubes are used for high frequency power conductors. This
reduces the weight and cost by eliminating the central part of the
conductor, where 'skin effect' has rendered the impedence high anyway. So
little admittance is lost for a great savings in material/weight.
And for high voltage systems, multiple parallel conductors are used to give
a larger 'effective radius', thereby reducing the corona losses.
But the two phenomenon are not related, and the two techniques used are not
really related.
daestrom
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