? "Michael A. Terrell" ?????? ??? ??????
m...

Tzortzakakis Dimitrios wrote:

The regulation, at least in Europe, is done at 150/15 kV substations and
at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x
25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500
A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).


So they have developed 100% efficient transformers?

.net/ISP.htm
Of course not:-) These are approximate figures (like the 21 kV 10 kA
alternator, which in fact is 9823 A 21200 volts or whatever). But the
efficiency of large transformers or transmission lines, when they operate at
optimum is 99%.




--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr