Re: three phase power (of the resonant kind)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>



Tesla list wrote:
> 
> Original poster: "harvey norris by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <harvich-at-yahoo-dot-com>
> making it a wye connection. Now I have scoured some
> textbooks to find references for what I am talking
> about, but have found none. The textbooks state that
> either delta or wye connections are made, but they do
> not indicate that if they are series resonant loads,
> that shorting the midpoints will then make them into 3
> tank circuits. But it is also very much common sense




This is actually discussed in power electronics textbooks and in the
"literature". It is a big issue with "off-line" switching power supplies
and various phase controlled devices like inverters and cycloconverters
that need filtering of harmonics.  Do you put the filters in delta or wye?
It kind of depends on how you want to do the filtering, and what sorts of
components you have (in terms of current and voltage ratings). Delta has
the problem of circulating currents, particularly higher harmonics, which
can't occur in Wye.  

>From a fundamentals point of view, any delta arrangement can be
algebraically transformed into an equivalent wye arrangement.  In the RF
world, this is more commonly referred to as a Pi/Tee transformation, but it
is the same, nonetheless. They're all linear circuits, and all the usual
rules apply.

  (I don't know that I would want to try and analyze a three phase circuit
with spark gaps in it, though...)