Re: alternators for 3 phase power...

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

Original poster: Harvey Norris <harvich-at-yahoo-dot-com> 


 >  > > Yes people may not realize that an alternator
 > can
 >  > overheat when no load is placed on the outputs!
 > The
 >  > stator windings are connected in wye, and
 > internal
 >  > amperage ciculation will occur depending on the
 > amount
 >  > of energized field being employed.
 >
 > Wye windings can have NO circulating current..
 > There's no loop for the
 > current to circulate in.

Yes I understand that and was a bit perplexed myself
about the phenonmenon. Just take my word for it, it
happens. I once left a running 3 phase AC circuit
running, and came back abourt 15 minutes later. The
circuit was reading 12 amps before I left it. During
this time the amperage meter connecting everything in
the WYE portion of the circuit blew a fuse, and made
the circuit open circuit. The alternator was VERY hot.
I then ran it open circuit in some other testings, and
at a certin higher voltage output from the alternator,
(35-40 volts) the action of the energized field will
cause the stator windings to get very hot.

I know this doesnt make any sense because there is
only a one wire connection in the stator wye. It IS
possible in some polar circuits for one ended
electricity to work, but it might not apply here, but
look at the problem from this standpoint; by lenz law
the stator would make a magnetic field to oppose the
field rotors changing magnetic field. At the moment in
time when one stator winding is producing its maximum
positive voltage, the other two are producing negative
voltages, so IF an opposing magnetic field is going to
happen, there must be an exchange of current between
the three stator windings.

The fact that the stator is wound in WYE, has a more
important consideration when we apply a three phase
transformer to that EMF source. You may have heard
that a WYE to WYE transformation causes balance
problems. These problems became quichkly evident when
I applied a step down transformer in DELTA to WYE in
reverse to make it a step up of voltage. This then
becomes a WYE to WYE connection on the input end,
which is a no-no. The result of this primary
connection was that the output voltages of the
secondary distributed themselves entirely unequally in
a 1-2-3 ratio. One of the three phase secondary output
voltages was three times the lowest one. Some
unexpected stuff there. So if anyone plays with
transformers hooked to AC 3 phase alternator outputs,
remember the requirement to use the DELTA attached as
a primary.

Sincerely HDN

=====
Tesla Research Group; Pioneering the Applications of Interphasal Resonances 
http://groups.yahoo-dot-com/group/teslafy/