Re: Why no corona?

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Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

> Was wondering.
> Power transmission lines, before a substation, can carry

> from 100Kv to more the 600Kv. So why no corona?

	1) There is.  Not a lot as its designed out, to
	save energy and emi noise and .... :

	2) Corona is a function of voltage AND (i say AND)
	smallest radius of curvature.  By designing with
	large radius of curvature, onset of corona is
	stalled off.

	(hence: presence of Large Radius shapes on TC top loads
	and VdG top terminals...)

	Such lines typically use 'bundled' conductors, that is
	groups of conductors, per phase, spaced 12" or so and
	braced.  This 'fakes' the e field into 'thinking' its
	on a 12" dia conductor.  cf any EE text.

> Seems we battle corona quite a bit at much lower voltages.

	From smaller diameter things...
	There is a parameter, which i am not looking up,
	roughly voltage divded by radius of smallest radius
	piece of electrode.  Small radius concentrates the
	field, forces local gas breakdown.  What's called
	'corona'.

	One can experiment with either VdG or Tesla coil,
	with varius radius electrodes added on.

	best
	dwp

...the net of a million lies...
	Vernor Vinge
There are Many Web Sites which Say Many Things.
	-me