Rewrap auto motive alternator for single phase power

[oil pan 4]

For my next possible build and this one is a doozie. I have a pretty far out set of almost impossible to meet specifications as usual that the consumer market does not meet.
I would like to build a high frequency motor driven alternator that produces much higher than normal frequency single phase power for welding aluminum.
For this build I am thinking I take an automotive alternator, butcher the stator and rewrap it in a single phase 6 pole configuration.
From what I have been reading on aluminum welding machines, as little as 90Hz can maintain an arc.
So I was thinking if I rewrapped an alternator for 6 pole single phase configuration I could get from 300 to 500Hz.
I have a pretty good idea how I might do it, but I would like to avoid getting it in 2 or 3 tries, because that would waste a lot of magnet wire and time. So kind of want to nail it on the first try.
Has anyone seen anything like this in their internet travels?

[freebeard]

Not previously; but my brain pointed Google to:

Aircraft Electrical Systems - SKYbrary Aviation Safety

All aircraft electrical systems have components with the ability to generate electricity. Depending upon the aircraft, generators or alternators are used to produce electricity. These are generally engine driven but may also be powered by an APU, a hydraulic motor or a Ram Air Turbine (RAT). Generator output is normally 115-120V/400HZ AC, 28V DC or 14V DC. Power from the generator may be used without modification or it may be routed through transformers, rectifiers or inverters to change the voltage or type of current.

Emphasis added.

[oil pan 4]

Yes I work on 400Hz air craft power generators and they are all 3-phase.
I could run single phase off a 3 phase alternator but I would be giving up a lot of power by not using all the power that can be produced by of the copper in the stator. That is bad because it takes a lot of power to weld aluminum.

[freebeard]

"All 3-phase". I didn't know that. I have to go think and do something else, but maybe there is something here:

https://www.google.com/search?q=3-phase+arc+welding

[oil pan 4]

Filtering is for turning it into DC, that is easy. Need higher frequency AC for welding aluminum at higher amp level.

[freebeard]

¯\_(ツ)_/¯

At least someone responded in your thread.

[oil pan 4]

Yeah its a pretty far out specification.
No one builds them any more, it's pretty retro obsolete.
I believe that automotive alternators are commonly wound for 4 and 6 pole.

[oil pan 4]

I just remembered there are at least 3 motor/generato and transformer rebuilding shops near by back home. I am sure one of them could do it.

[thingstodo]

Originally Posted by oil pan 4

I just remembered there are at least 3 motor/generato and transformer rebuilding shops near by back home. I am sure one of them could do it.

There is a guy that is selling his inventory about an hour away from me. Here is the Kijiji ad. It looks to me like he did alternator and generator rebuilds and is retiring? My attention span may still be too low to do this as a 'retirement job' ... but it is interesting to me.

And now to the question - would any of this help you, and if it did, what do you think it is worth?

Electric motor rewinding equipment | business, industrial | Saskatoon | Kijiji

[oil pan 4]

I think I am just going to buy used up alternators and rewrap them for 3 phase. The 250 amp AD244 and DR44G stators are $99. I am going to buy the first new stator and make notes on the number of turns, wire size and what direction the wrap goes, by butchering the old stator and measuring the wire and trying to count the turns on the new stator.
At some point I might try rewrapping one for single phase later on.
Need to learn how to rewrap the exciter, mainly need to figure out how to get the pole shoes apart with out wrecking them to rewrap with heavier wire to make more stator amps.