48v wind gen project

[PRedATor]

I have decided to build a PM wind gen after reading and studying lots of different projects here.  Not many are 48 volts.  But from some pages there have been some guides of windings and coil sizes.

We are on a 48 volt solar with back up generator system and have lived here since february this year.

Our batteries are 535amp/hr 8 x 6v banks with a 2Kw inverter and 4Kw diesel generator, all automatic, all I have to do is check the batteries for distilled water and make sure the fuel is in the generator and have it serviced regulary.

I have started to collect all neccessary bits for construction.

Now this is what I have in mind and if any of you want to jump in and suggest alternative things by all means do so.

The magnets I have are 24 rare earth 36 x 50.8 x 12.6mm blocks to go on 2 rotor brake disks off a volvo 250 which are about 10.5" in diameter, I am thinking of having 12' diameter blades which are in lengths ready to be carved.

The magnet wire I have is 1.06mm enamelled coppar wire which in AWG is between 17 & 18 AWG.

I was going to try 140 windings of this for my stator (9 coils) wired in star configuration. What do all you guru's think of this for a start?

Thats about it for a start.

Thanks

[DanB]

I think it all sounds quite reasonable... except maybe the 12' prop part.  Your rotors are a bit small, and considering the size of the magnets and the wire my thought is perhaps 8 - 10 feet, and 10 feet would probably be pushing the limits.

[Flux]

I agree that the rotors are small for those magnets if the stated size is right.

14. " would suit them much better.
    
140. turns seems high. With the small rotors you may only be able to use that size wire.  With the 14 or 15" rotors I think you could run that wire in 2 parallel.
     
     

With small rotors I agree with Dan that no more than 10ft. I have a feeling that with the large rotors you could manage the 12ft.

Can you confirm the magnet size, it seems a bit odd.

Flux

[PRedATor]

50.8 x 36 x 12.7 is the exact measurments of the magnets from the data sheet.

I haven't put them around the rotor as of yet to see if they all fit nicely as I only just acquired them from the wreckers and dismantled it.  I may have to source some 14" ones to go on the same hub then like you two suggest. (thanks)

I would like to have the blades as big as I can have and the lengths of oregon I got cut and planed to 6' x 150" x 50".

I'll ask about the parallel wiring when I'm up to that stage. )

I can get a different size wire roll from where I got this one as its on loan and I'll only pay for what I use from it.

cheers

richard

[scoraigwind]

14 inch rotor disks would be ideal.  12 foot diameter blade rotor is no problem.

I would use about 100 turns per coil in star/series connection.  This would use about 4kg of wire.  You would have to use two of your wires in hand (from 2 reels) and connect them in parallel to fill the space.

I am assuming that the magnets are high grade neo ones.

Please note that my web pages have recently moved to http://www.scoraigwind.com

and your old bookmarks will soon be useless.

[PRedATor]

use two of your wires in hand (from 2 reels) and connect them in parallel to fill the space.

Is it that I actually use 2 strands of my wire at once to wind around for the coils? and connect them in parrallel for each phase.  To fill what space?

Excuse my misunderstanding.

Yes the mags are NdFeB

cheers

rich

[Flux]

Yes, wind two wires together and treat them as one thick one as far as number of turns are concerned.

If you use 14" discs and wind the coils with the wire you have, there will be a lot of space left between coils.  If you use a thicker wire or two thinner ones together you can use all the available space and your coils will touch.

You need to do this to keep the resistance low enough to handle the 12ft prop. It is by increasing the disc size that you gain the space to increase the wire cross sectional area to gain the extra output.

I am assuming that you aim for a stator about 15mm thick for those magnets.

Flux

[PRedATor]

Flux :  I was thinking of more like 12mm and playing with the air gap but I will have 15 as you mension.

Why don't I just goto 12, 13 or 14 gauge wire then which is 2, 1.8 or 1.6 mm, I assumed I couldn't go that thick as they are mainly for 12 - 24 v systems.

This is a good start anyway to play around with, I might have to make a couple of different stators to experiment with.

Friday night now, beer time.

cheers

[ElectricJim]

I noticed you were not to sure of the termonoligy of winding two copper strands at once, this is called bi-fillier windings, bi means winding 2 strands at the same time on a common core, there is also tri-fillier windings.

I first came across this when my 1st job as an electrical apprentist in New Guinea 35 years ago was to hold 6 copper wires in a rectangle configuration and tape them up with cotton tape, what a job that was, still remember the blisters.

Hope I was some help here, good luck with the alternator project.

[PRedATor]

The more I am reading the more I am changing my mind from one thing to the other.  Anyway I have my blades half carved (yes I know I should have not started with these but if I can't carve blades then their is no point in continuing).  My blades are now 3 metres in diameter (close to 10'), i have the front section done on all 3, just the backs left.  The timber after being planed were 145mm wide, 45mm thick so there is the drop at the root and tapers to the tip etc etc as per the instructions I followed for the measurements and carving.

I was going to go with a 3 phase 24 magnet (12 front rotor, 12 rear rotor) 9 coil project, now I'm thinking of 36 magnet (18, 18 rotor) 12 coil design.  I got 2 14" 5mm rotors cut for my hub for the magnets.

What would be better for my 10' prop?, is the rotor a good size?, stick with the 100 windings for both in parallel?

cheers

richard

[PRedATor]

I've just ordered Hugh's book.

that'l help

[PRedATor]

bump

[JW]

Bump

 you guys remember DanB's  stator when he used rectangular thick wire in the stator.

The actual thread is in the current database