Hi Jerry - its hard to say, I wish I had a chaulk board here so we could really discuss it all in detail. Ive not done testing with it all - so I cannot really say from 'experience'.
I'd just say this...
in a 3 phase machine, wired in Star, there is always some current flowing through all the conductors all the time, in the alternator. If we rectify each phase, there will be times when there is no current flowing.
Ill try to get into this more later, when I have more time to ramble ;-)
I think in Delta - and perhaps with your 2 phase garbo-gens and the F & P - things might be different, because you are trying to adapt existing windings to a specific application. In that case, rectifyiong each phase, or coil individually might be the way to go. In the case of a normal 3 phase alternator - Im fairly sure it makes sense to allow current to flow through all the conductors all the time.
In a 3 phase machine, wired in Star - our 'output Voltage' is generated basicly by 2 phases, which are 120 deg apart. So we get the voltage of the first phase, and .73 X the voltage of the 2nd phase. So it might seem like were not making the best use of our windings, but... pick any time while this thing is under a load, and there will be current flowing because one, or the other of those phases will be in a 'good' place. If we rectify them all seperately and wind our coils so that just 1 phase gets us our max. Voltage, then we can either wire in Delta - or we can rectify each phase seperately as you suggest. If we wire each phase seperately - then all the current from that phase is forced to run through those coils, and when were at t0 Volts in our sine wave, no current is flowing. During that time - its dead conductor.
I think in low power tests you would not notice a difference between Delta, or rectifying each phase seperately. You might improve things rectifying each phase seperately if there are misplaced, or unidentical coils in there - which would cause currents to run 'round inside the stator. But if the stator is perfect, then in low power tests youd probably see little difference. In higher power tests, I think youd find Delta to be more efficient and act as though resistance is lower.
Its hard for me to explain - I need to think about a better way, perhaps I should do some testing. It makes sense to me though - there is no way Id build a 3 phase stator and rectify each phase seperately. You dont see this done in car alternators,a nd other 3 phase machines - they usually go with Star. I can see in tests with a F & P, or with a garbogen, which is basicly a 2 phase machine -why you might do this. In a machine thats specifically designed for the purpose though - I don't think it makes sense to include rectifying each phase seperately into the design. I think its not necessary, and I believe it would make the machine less efficient.
