mill hookup

[outback]

hi everyone,thanks for the help with the wire sizing,i think i new the answer just figured some one might have a different way that might be cheaper.i did a little picture here will this hookup work? my future plan or goal would be to have mutiple units on my hill.will a configuration of mills hook up like this not causing a problem with the phase since i would have blocking diodes on each phase? hope this makes since.thanks outback

[johnlm]

I doubt it will work.  It looks like you are trying to half wave rectify each phase (through the blocking diodes) with no common return back to the neutral point of your 3 phase alternators.

John

[outback]

in other words it wont alternate?

[ghurd]

You have places for the electrons to leave, but not return.

They need to go 'around', not just 'out'.

Like- you have 6 positives and 0 negatives.

G-

[Ungrounded Lightning Rod]

Yep.  Open circuit.

[outback]

ok how do i do that with out rectifing every thing before the junction box?

[richhagen]

To combine the power into one lead back over the 700 feet to your dwelling, you will likely have to use 6 diodes per mill (or two or three bridge rectifiers) and rectify it to DC, then you can combine it and send it down two conductors (positive and negative) as DC back to your dwelling.  The AC will be out of phase and of different frequency from one mill to the other.  Of course, the more current in your lines, the larger the losses in those lines, although this mainly would affect you during windy periods with high energy generation.  Rich

[kitno455]

you have to rectify before you add the output together, cause you have no mechanical governor keeping the two gens exactly in phase with each other. trying to add AC waves that are not syncronized is A Bad Thing (tm)

allan

[ghurd]

Put the rectifiers where you show the blocking diodes.

[outback]

well boys and girls,in the last couple of days with all this talk on wire size losses and such in my situation the power house at mills and converting to ac before i start that 700' trek to the house looks like the best way for my personal setup.i really dont mind the losses that bad.didn't have anything before i had a mill.thanks for the help outback

[jimjjnn]

Ghurd is correct. With the diodes blocking where you have them,you are getting 1/2 wave rectification thus losing the other 1/2 wave. you lose 1/2 of your  power the way you show in the picture. The bridge rectifier diodes will give you full wave rectification and full power less the drop across the diodes in the bridge. A lot more efficient .

[Norm]

  Gee 700 foot....You could almost have two battery packs have a little rail car....charge

one pack at the mill while you are using the other pack at the house.

              I'm half serious....

                ( :>) Norm.

[zap]

Norm I like the cable car idea.  After a few weeks of operation you should be able to figure out how much "standby" power you'd need while the battery banks are in transit.  Cable cars are pretty efficent since the one going down is basically pulling the one that's going up.

Of course you'd need about 1500 feet or so of rail and wire rope, also, double battery banks are going to wear out quicker than 700 feet of heavy power cable.  The power cable should last a life time, the battery banks won't.  A little figuring of the economics would be in order.  

But just getting to ride the battery banks up and down the hill would be a kick... at least the first few months!  : )

Or you could always try and reinvent Tesla's wireless power transmission.

[John II]

Others would need to verify or disqualify my thinking on this, but I don't see why the 3 phases off of each mill could not be combined If....

(1) The Mills were totally identical in blade and generator size.

(2) On identical towers in nearly identical wind sites fairly close to each other.

It looks like to me that one wind generator would always want to ( motor ) the other generator if they were to get un-even wind. With that being said... they would tend to pretty well keep locked to the same rpm and in phase with each other regardless of the load applied to them.

If things were identical and the match was close enough, I don't see why you couldn't parallel them up and forgo the diodes altogether. If they are not identical, then this definitely will not work.

John II

[Flux]

The basic idea is ok but the wind is not steady enough to make this work.

Paralleling alternators is not that easy with engines with good governors and and alternators designed for the job.

If you put an array of anemometers in front of a windmill you will find that the wind is not usually constant across the rotor. With 2 rotors spaced by a finite distance there is no chance of the power being anywhere near similar enough to maintain syncronism.

In theory you may be able get it to work with one synchronus and one induction generator but I am not going to try it.

The cable requirements are nearly the same on the ac and dc sides with low reactance generators so it seems sensible to use 2 rectifiers and carry the dc to the load, but in terns of cost there would not be much difference between heavier dc cables and 2 runs of lighter 3 phase with the rectifiers at the battery end.

Flux

[finnsawyer]

If you rectify at the mills, you can get a higher dc voltage, up to 40 volts from each mill depending on the diode drops and current draw.  Higher voltage means you can tolerate more loss in your 700' line.  You don't specify current, so I guess I'd say do some experimenting with rectifying at the mills.  See if you can make it work for what you want to get out.  I'm assuming your 24 volts is the rms value or nearly so.

[tannoyman]

Would it be possible to build a three rotor machine, and sandwich two stators between three rotors? Magnets on both sides of the middle rotor.

You get two generators syncrnised, on one tower with one set of blades

Saving 2/3rds of the build costs

If this is dumb, escuse me I'm new to this

Erik

[nothing to lose]

That sounds ok, but you have 1/1 of the wind to drive 2/1 of gennie

Silly me:)

Seriousliy there are some problems with that, one being one balde of the same size will not give 2 windmills worth of power, so you don't acompliased the goal trying to put two mills together. Unless perhaps you made larger blades or a different type etc..

Still problems, more blades or larger blades might provide more torque but not more speed. Most likely I think they would run slower meanung you need more wind for the same speed, speed is what makes the power. Adding 2 mills together you will need both speed (same as 1 mill) and more torque because you are now driving 2 gennies instead of one. You still don't get double the power though. Maybe more power than one gennie, but not double, unless maybe you build a front dual rotor gennie, and a second dual rotor back further as 2 totally seperate units on one shaft.

I have given that some thought. Use like a double bearing jack shaft. Mount 3 blade prop and dual rotor at the front, a second daul rotor genie on the other end lined up exactly the same, then the 2 second 3 bladed prop would be turned so the line up in the center of the front blades. This would sort of give you both a 6 bladed prop and 2 3 bladed props at the same time in a way. If the blades are far enough apart it might not be too bad. Furling out of high winds would be a problem though since you basically have an up wind and downwind gennie on one shaft.