In some very strong wind gusts, i'd say around 35mph the paralled configuration it did not make any differece, but as more gusts came, being series together i saw more amperage. I watched for about 30 min both ways just to make sure.
You have a lot of resistance and also the windings are 90 deg out of phase so you are seeing the vector of the individual voltages.
Rectifying separately and feeding 12v should give you more amps, but don't forget you need twice as many amps for the same power at 12v so you may be as well off as you are.
If your trial with windings rectified separately feeding the battery was at 24v, try it again at 12v and see if you can get more WATTS. If not you are not going to improve things by rewinding.
If the parallel connected thing does produce more watts then you can wind with more turns to get the same thing at 24v.
Don't forget you change other factors when you connect in parallel. You are never going to stall as it is at 24v but you may do so with it parallel connected at 12v.
Ultimately you may do slightly better by rewinding it for 3 phase but generally there is very little difference between the 2 phase case ( which you have in parallel) and 3 phase. You will likely be able to find a compromise that gives nearly double the power at 25mph if you are prepared to trade the performance at 10 mph. No details of your prop so I can't offer much other help.
Flux[ Parent ]
If I were to go to 12v, I would have to go to a larger prop because it hits 12v at pretty low rpms. My main concern with the 12v aspect was wether or not the windings could handle the current. Since there would be more amps running at 12v than at 24v.
Thankyou again [ Parent ]
I assumed that you used the series connection to get reasonable cut in at 24v but it may be more a case of the fairly ineffective nature of the series winding bringing you out of stall easier.
If it cuts in at 10 mph with single winding on 24v you are slow enough. You could try adding series line resistance to the paralleled windings at 24v or even temporarily try it at 36v.
I am inclined to agree with you about 12v if it is that slow. I think I would try it at 36v to see what happens, that way you can see where you are going.
Hope this helps.[ Parent ]
As you had identical resistance on the start and run windings I assumed that most likely this was what you had. It seems just chance that your resistances are equal in this case and you have a start winding with few turns and wound with very thin wire, possibly capacitor start but just as likely resistance split phase start.
In reality the start winding is virtually useless to you and will contribute very little, the thing is never going to even approximate to a 2 phase machine. Single phase things don't do very well anyway but even so I think you are stalling with the main winding. By adding the start winding in series you are doing little more than adding 5 ohms as a form of line resistance and it is bringing you a bit more out of stall.
Without rewinding to a true 2 phase or 3 phase you will not get any great improvement but I still think it will go better at 36v.
This brings the cut in speed down to about 190 rpms. At 370 rpm now I get 60vac, instead of 42vac. I'm sure this will limit my amperage a little, but it truly seems like I made this better.
By the way the coils were poorly sodered, so I re-sodered them, which i'm sure will help more amps to come through. I think I read somewhere that some cheaper induction motors the splices from the leads to the coils is sometimes not that great.
I'm going to make a set of 8 foot blades, according to hugh's plans and see how it does. I'll definately try to let you guys know. I think his plans for 8 foot rotor is around 7 or 8, which they should do just fine
I dont think i'm gonna use the start winding at all, it doesn't really seem to do well by itself. Like you said.
Thankyou for your time MMinspired [ Parent ]
This is incredibly slow for a 5ft prop. I am not sure why you are getting best results with such a low cut in speed unless your prop is much lower tsr than you think. Certainly you are more in the speed range of the 8ft prop and whatever happens the large prop will have far more power. I am not sure that such a tiny alternator is going to hold down an 8ft prop so you will need to make every attempt to make it furl as early as possible. In low winds you will be way ahead but you will need to watch it in high winds.
