Light Weight Wind Turbine Project - as I build it.

[Steadfast]

I am now building my first wind turbine to power my shed which I use one day a week.
I am sharing my project on line as I build it.
So, check up on my progress as I go... And, If you spot me making any mistakes LET ME KNOW!

This is a Light Weight Wind Turbine Project for out here in (level 1 wind) Raleigh NC where we average 10 - 20 mph winds.  Thus, I am building a wind sensitive, light weight turbine that will generate electricity at 3 mph.

I bought the book "HomeBrew Wind Power" and I have been in touch via email with Dan its author about my project. He likes to build massive 100 mph wind turbines, but he is also interested in my ideas and says it can be done.

Book link:
http://www.amazon.com/Homebrew-Wind-Power-Dan-Bartmann/dp/0981920101

I will post pictures of my progress live as I progress in this project!

Starting from the bottom up!
This is my Anchor and Hinge for the wind turbine tower.
(This way, if a big storm comes in, I can pull one of my bolts and lower the tower and turbine safely to the ground)


Hour Glass shaped 180 pound concrete base with 10 inch 5/8 anchor bolts setting. (check out that Plumb Bob)
the pipe is 1.5 inches wide.

[Steadfast]

My tower will be 30 feet tall.
I intend on using my shed as an anchor so that I don't have to use cables.
more on that structure to come.


My Ametek 40VDC Motor Measures: 4" in diameter, 4 7/8" long…
I am making a container that will fit the motor, plus allow a little room for 2 steel hose clamp straps to slide inside the container to strap the motor in place inside the container. (I'll cut the 2 hose clamp strap holes)
Standard Steel Container should measure: 4.25' inside, 5” long, with a 17mm hole in one end, split in half and hinged.


My Blades are Aluminum Falcon Blades...

Here is a link to the video:
http://youtu.be/PglkMtHGN74

[DamonHD]

I am no expert at all, but attaching your mast to the shed is IMHO likely to induce nasty (and possibly noisy) vibrations in the shed and do it no good at all, never mind the risk of the thing being blown onto the shed.

Anyway, ignore me, I do solar mainly!

Rgds

Damon

[JW]

I've also heard of this type of noise. When the tower is attached to a structure, noise will resonate inside the structure.

[Steadfast]

That makes sense... Its a good thing I don't live in my shed...

[tecker]

 Your going to need some wind to get Charging done . Those are fairly high speed blades . Don't get frutrated just plan on integrating a 2 or three amp solar panel in series to the dc motor . The Ametek will add amperage in moderate winds and the commutator will pulse the solar into you battery bank with a small amount of current . I don't have any idea what the normal wind is in your area but motors of that type are best used in pairs .

[Steadfast]

Right you are,
I own a 140 watt portible solar panel and controller I can always suppliment with in a pinch.

[Steadfast]

Sooooo, Ya Gotta have a PLAN...  Here are some of mine...

The furling tail assembly (which should furl under 20 mph winds):
My Falcon blades are each 2.5 ft long.
So. I get a 5 foot sweep.

Also, Dan told me that his (20 MPH) furling tail assembly (for a 10 foot sweep) weighs 15 pounds and is as long as one of his blades. not counting the birch wood tail vain.

So mine must be 2.5 feet long and 7 pounds.

Here are my plan schematics for the tail:

Yup your seeing it right! That's a industrial door hinge for the furling pivot... ha ha!

I am cutting the tail beam out of 1/4 inch aluminum.


Here are my plans for the Generator System:

[tanner0441]

Hi

Optimistic comes to mind.... 12V system, DC high rev motor for charging, 2500W inverter with grid connection..... Have you done your sums on the load the inverter will put on the battery? Over 200Amps. The amtek motor will never keep pace with it.

You say you only want to run you shed for one day a week, what load will the shed require? If it is only a couple of lights then 12V lighting would be the way to go. If it is already grid connected and has flourescents fitted then yes go for an inverter.  I have 330 AH of batteries at 12V my inverter is 650W pure sine wave, (flourescents buzz like hell on MSW) and in real terms I only run for 4 to 6 hour of lighting around 130 W with one fluorescent and a mix of CFLs. It then take days for the 80W of solar and 200W of wind to charge them back up. Because in the real world the wind or sunshine is rarely at optimum for long enough.

As for vibration with a DC motor it will not be as bad as an AC turbine but the potential for damage to the building is real. Also your drawing does not show any isolating diodes to stop the motor behaving like a motor from your battery.

You contruction looks reasonable but your planning needs going over a bit more.

Brian.

[tanner0441]

Hi

On second look I see you have a charge controler but no dump load shown.

Brian

[Steadfast]

I have no flourescent tube lights, I am just wired for a few bulbs.
I also use my shed on the weekends. and plan to use it to run standard hand tools and such.
The batteries are huge and hopefully will act as big buckets for my energy to flow into.
I bought a charge meter and with regular observation and the slow charge time I am hoping I will not need a dump load.  but if it does I guess I can always buy a dump load controller and hook it up to a small cube fridge with some cokes in it...

what do you see that I can do to improve my planning needs?
what do you think needs going over a bit more?

I am not into the "cutting and welding materials" stage yet...

 

[Steadfast]

Yikes!   
What sort of diodes do I need to keep the flow going one way?

update
Thanks to Dan Fink's excellent and patient advice, I ordered this from Jameco. 

35924 DIODE,SIL REC,1N1188,35Amp, 1 4.2500 4.25


696626 HEAT SINK,TO-220,1 HOLE,BLACK, 1 2.2500 2.25

[Steadfast]

Revised Wind Turbine Generator Layout

[klsmurf]

Shouldn't that 20A fuse between the turbine and battery be left out?  Fuse blows, turbine goes o.c. and possibly run away.

Just asking, I've never put one there.

[tanner0441]

Hi

What is the AmpHour rating of your batteries? A fridge as a dump load is not a good idea, you want a good set of power resistors that can sink the worst case output of the generator, and the 20A fuse has been mentioned.

Brian

[JW]

I would use a 50amp breaker (self-reset) for the DC lines... I have also found you can use a 300amp SCR as a rectifier in a bridge configuration (6/w 3phase) for cheaper than the rectifier diode listed, and the thread dia is about a 1/2in to the heatsink, and the trick is to leave the gate termial isolated, in other words you can get a SCR with higher ampere rating for less the cost of a large package rectifier diode...



http://www.allaboutcircuits.com/vol_3/chpt_7/5.html
Image's from link

[bvan1941]

jw,
great observation and recommendation on the SCR's !!!
It's usually not thought of that way. Glad to see you point that out
Bill

[dinges]

I have also found you can use a 300amp SCR as a rectifier in a bridge configuration (6/w 3phase) for cheaper than the rectifier diode listed, and the thread dia is about a 1/2in to the heatsink, and the trick is to leave the gate termial isolated, in other words you can get a SCR with higher ampere rating for less the cost of a large package rectifier diode...

Are you sure about using SCRs as rectifiers? Don't think it works like that. Just grabbed a few large SCRs out of the box and none behave as a diode, with the gate left unconnected.

The link (allaboutcircuits) shows that when the gate is left disconnected it behaves as a Shockley diode (which is a 4-layer diode). Note that this is not a Schottky diode! (which is a 2-layer diode).

If I'm wrong, please correct me.

[JW]

Are you sure about using SCRs as rectifiers? Don't think it works like that. Just grabbed a few large SCRs out of the box and none behave as a diode, with the gate left unconnected.

Well this one does, as you can see from the picture I have my Fluke 88 connected in "diode test mode" with the gate isolated and its passing the diode check...



Are you sure to have polarity correct? Im getting a reading of less than one ohm.

[dinges]

Are you sure to have polarity correct? Im getting a reading of less than one ohm.

Yes, I see. It appears the SCR is defect. Have you tried measuring it with other polarity? (reversing the meter leads)

Notice that in the allaboutcircuits article that in the schematic, they talk of controlled rectification; they've left out the electronics to drive the gates of the SCRs, but that's definitely needed to use SCRs as rectifiers (as e.g. in synchronous rectifiers).

Tested a few more known-good SCRs, and all measure fine on the semi-conductor analyzer (with ability to measure the most important parameters of SCRs), but none show any diode action between K and A; which is to be expected, because in that case the Gate would be useless....

My suspicion is that your SCR is defect and is a dead short. By reversing the DMM leads you should be able to verify for sure.

Either that, or my knowledge about SCRs is seriously lacking....

[JW]

My suspicion is that your SCR is defect and is a dead short. By reversing the DMM leads you should be able to verify for sure.

I just did that, and you are correct its a dead short. interesting.

Just as an aside I abandoned any attempts to use SCR's with the switching arrays im running now, Mosfets when syncronised can give those low impeadance (switching) readings using DC. The problem with SCR's is that they are subject to 0volts threshold, so SCR's work great as diodes when used in the bridge configuration. The schematic's are pretty clear as to DC output. So for the same reason an SCR is no-good for a DC switching application (mosfets n/p channel) it is usable as a rectifier when the gate is not energized.

they talk of controlled rectification; they've left out the electronics to drive the gates of the SCRs, but that's definitely needed to use SCRs as rectifiers (as e.g. in synchronous rectifiers).

Im going to look for where it says the gates need to be rectified to convert AC to DC.

[JW]

aH Ha now I see what you mean

[JW]

Im just wondering, is it possible to cast a trigger coil in the stator, if anyone wanted to take the leap too-

but that's definitely needed to use SCRs as rectifiers (as e.g. in synchronous rectifiers).

they've left out the electronics to drive the gates of the SCRs,

"synchronous rectification" SCR's are way cheaper than rectifier diodes for current capacity, so if you could make a cheaper rectifier with a simple trigger circuit (cast into the stator) wouldnt that be worth the effort.

Doesnt seem that hard with the 3/4 9/12 coil-magnet-ratio

[Steadfast]

Ummm.. you guys are hurting my electicity ignorant brain.... I am an expert and even savant in many medias and art forms, but I am a dolphin at a mountian climbers convention when you guys start to talk electric tech like this... please speak to me about electricity and circuits as if I am much more mentally challenged... 
See, look under my name...  it says "newbie" for a reason...
thanks...

[tecker]

Ty the gate to the anode with a signal diode for half wave Rectifier

[tanner0441]

Hi

The reason for the diode in his circuit is as a blocking diode to stop the batteries back feeding into the motor when the motor output voltage falls below the battery voltage.  It only needs to be a single diode of adequate rating the right way round, the motor is already putting out DC so it does not need rectifying.

We still don't know the capacity of the batteries. If the batteries are big enough to run power tools then that size motor will struggle to keep them charged.

Brian

[Steadfast]

Cool... gotcha! 
my batteries are 2 new golf cart 6v deep cycle batts wired in series for 12v.

[DamonHD]

That still does not tell us the *capacity* of the batteries, in Ah (amp.hours).

Rgds

Damon

[fabricator]

You never, ever, put fuses in the lines from the turbine to the batteries, you risk a runaway and there is no reason for it.

[Steadfast]

Hmmm... ok....I can remove that fuse... you are sure... right?

[fabricator]

Hmmm... ok....I can remove that fuse... you are sure... right?

Yes, if that fuse blows the alternator doesn't have anything to control it, so it will just run as fast as the wind will move it, at some point the smoke will get out of your alternator, meaning you burned the insulation out of your stator.

[birdhouse]

stead fast-
i second the fuse removal.  fuses are designed to protect the wiring.  IE: not let it get too hot.  my solution for this, is to not use a fuse, and use wiring that is large enough to never get too hot based on my mills maximum output. 

you mentioned #10 coming down the tower to the batteries.  #10 carries 30amps fairly well.  at 12v thats ~360 watts.  i have a hard time thinking that little ametek is going to push 360 watts unless it's gale force winds, and then if your using PVC blades, they would probably break at some point right around there. 

i'm not trying to be a debbie downer, but rather realistic.  the costs of grid tying an ametek in a legitamite manner for an ametek motor is kinda absurd.  even if you were driving that motor with a gasoline engine and the gas was free, the payback on the grid tie would take a very long time.  also, two 6v golf cart batteries really don't have a lot of capacity.  you may be better off using them via an inverter to just try to keep your shop lighting running. 

anyways, hope the mill turns out great!

adam

[fabricator]

I agree, the grid tie is completely unrealistic, you'll be pretty lucky to get enough power to keep your lights on let alone actually putting power back into the grid.