AirX rewire

[DualFuel]

Hi,
I have for AirX wind turbines. They were all given to me, because none work.
I am thinking about how to bring the wild AC out of the turbine. Apparently, I only have two isolated slip rings to work with. This suggests, to me, using a three phase rectifier in the nacelle, and sending in regulated DC down the tower. From there, any number of schemes could be used to regulate the output.
Seeing as the output is pitiful to begin with, I would like to fool around with a boost converter. That is down the road, right now.
The simplest three phase rectifier appears to be one from a 10SI GM alternator. The rectifier has terminal studs that match the stator leads. Mounting is wonky because of the way GM mounted the rectifier in the alternator housing.
Who, on this forum, has been here before? I would like to here from you about this.
Thanks,
DualFuel

[DualFuel]

A pic of some of the parts.

[MagnetJuice]

I found this video:

https://www.youtube.com/watch?v=adb6jc3xfXU

Is that the same as you have? And did you meant to say that you have four of them?

Ed

[SparWeb]

It will probably work, but you can do better.
The parts in the GM alt are sized for high amperage, hence the heat sink, but limited in other ways.  Your AirX will never crank out that many amps.

I assume you will cut the wires from the board to the brushes, but leave the board in place to support the brushes?

[DualFuel]

Yes Ed the Primus is almost identical to the video. I do have four of them....all bad. I also have a bad Chinese one too.
Spar, the brush holder appears to demount from the board, allowing the brushwires to be bolted to the three phase rectifier.
I am really bummed that I can't get the wild AC down out of the nacelle.
I have parts for two good towers...a Rohn and another comercially built one. Both are going up this summer. Both will have tilt. I have some nice gin poles and hand winches to make raising and lowering the turbines, a one man job.
I would like to get some kind of repair groove going with these AirX turbines so I can put the other two up on guyed poles.
Years back we had the AirX up on a 55 foot tower, and it charged well over the winter....until it didn't, and when it quit the snow was too deep to bring the pole truck over to lower the tower. So this iteration, I am concentrating on making the towers more workable.
I read in the forums about adding a tail....seems about right. The Chinese turbine is up on the test tower right now and it keeps getting pushed to the side. Seems like when ever it starts making power, it gets pushed aside. It's not doing the screeching halt thing,  that the AirXes do when they have a fault.
Anyhow, thank you for responding and I will get busy and see what can be done to get them spinning.
DF

[SparWeb]

I watched the video again.
Does it sort-of look like it has 3 slip rings?  Or are there really just 2?

[DualFuel]

Hi,
It has three slip rings. The top is attached to the black wire, the middle is attached to the red wire. The bottom is attached to the green wire. The green brush is built into the nacelle.
Last night I was able to separate the board from the brush holder. I discovered that the brush holder also contains a half wave three phase rectifier. The other half wave is sent through some sort of mosfets and control structure on the board. It had a huge cap, and huge inductor. I will try and reverse engineer the board later....if the three phase full wave rectifier plan fails.
I was able, with very little trouble, to install a $2 rectifier in the nacelle, and bolt on a replacement set of turbine blades from Raptor.
I am still looking for a tail extension solution.
These mounting plates, I bought from Missouri wind and solar, have provision for mounting only two blades. Hmmmm, I am thinking of testing a AirX with only two blades. Swept area and all that.

[Adriaan Kragten]

I have looked at the video and saw that the construction of the head bearings and the slip rings is rather complicated. Most of my VIRYA wind turbines have no slip rings at all and have a flexible cable in the tower which twists if the head rotates. The cable can make about 50 revolutions for a 12 m tower and a 14 m cable with a loop at the bottom. There is a connector at the bottom of the loop which can be disconnected if the cable twist has become too much. But I have also developed a simple slip ring construction for places where nobody can correct a too large cable twist. This works as follows.

The 3-phase current is rectified by a 3-phase rectifier which is mounted in the terminal box of the generator. So only two DC phases are left. For the head bearings, I use bronze INA Permaglide plain bearings with an inside coating of teflon and lead. I use a flanged bearing at the top which takes the weight of the head and a normal bearing at the bottom. These bearings have a very low electrical resistance so they can guide an electric current. So one of the two DC phases is guided through the head bearings. This means that now I need only one slip ring for the other DC phase.

The slip ring was made axial in stead of radial as used for normal slip rings. As it is axial, it is positioned in the heart of the head pin and therefore it takes only very little space and it can be mounted in a tower pipe with a small inside diameter. The head pin was made out of stainless steel as this works nice in combination with the Permaglide bearings even without lubrication or sealing against water. The swivel housing was also made of stainless steel. The contact was made of bronze and spring loaded. Because of the spring load, you need a certain minimum torque which has to be supplied by the cable which goes down in the tower. This means that the contact isn't moving for small oscillations of the head but only if the angle of rotation is that much that the moment in the cable becomes larger than the friction moment. This strongly limits the wear of the contact. The cable which goes downwards has a massive copper wire size 2.5 mm^2. This system has worked for some years without problems on the VIRYA-1.25 windmill.

I have made a copy of the assembly drawing of the VIRYA-1.25 head and swivel to give a better insight in this construction and this copy is added as attachment. Anyone can use this construction.

[DualFuel]

Adriaan,
Thank you for your reply and sharing your insights.
I searched "VIRYA" to try and understand the relationship between the drawing you provided, and the rest of the turbine. I am still not clear on how the entire machine is constructed.
I have heard about not using slip rings at all. I will try this with one of the AirXes. I am sure if I removed the AirX from turbulence by placing it's tower in a wind way, I wouldn't see very much turning. The wind comes off a long Western reach from Lake Superior. I have long wished to place a tower on my ridge facing that reach. One of the engineering constraints is the distance from the tower to the battery bank. This distance could be overcome by wild AC.
I have found some stainless steel sheet metal to make bigger tails with.
Our fall weather has begun here...so I have burn a bunch of diesel to get these tower bases, and gin poles bases buried. Yikes!
DF

[Adriaan Kragten]

Adriaan,
Thank you for your reply and sharing your insights.
I searched "VIRYA" to try and understand the relationship between the drawing you provided, and the rest of the turbine. I am still not clear on how the entire machine is constructed.

If you go to my website: www.kdwindturbines.nl and then to the menu VIRYA-folders, you find two folders and one extended specification in which ten free VIRYA designs are described. In the folder it is described where you can find detailed drawings of each design. The VIRYA-1.25 isn't a free design but the VIRYA-1.36 looks very much the same except that it has a different generator. The assembly drawing of this windmill will give you a good insight in the construction of the entire machine.

If you have to bridge a large distance in between the windmill and the battery, it is cheaper to transport a DC current than an AC current if the generator winding is made for a certain battery voltage. If you use copper wire of a certain size, for instance 2.5 mm^2, it can be proven that you have the same losses in three cables for an AC current than in two cables for a DC current. This is because an AC current is flowing only during 2/3 of the time (for star rectification).

[DualFuel]

I have had the Chinese turbine, and one airX up since September. They are incredible failures.
Open circuit voltage 22vdc
Amperage under load .24amp
These measurements are made with a cordless drill.
On the tower, I get a bunch of turbulence. I measure most of the output below the battery bank resting voltage. The only load that I have been able to place on the turbines is a bunch of LEDs on a bread board.
As a very lame and expensive attempt to harvest some of the spinning going on out there, I hooked up a 150watt boost converter and am charging little UPC batteries.
I have one thought, I recently found an original airX blade. It is considerably shorter then the raptor blades. I wonder if the longer blades simply turn slower?
DF