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I have been interested in harnessing the wind power on the NSW south coast for some time and have just recently come across this site which has fired me up to get started. Please bear with me as I am completely new to this, particulary the electronics side!
I plan to build an F&P turbine based on the DIY windmill kit on this site and have so far-
- sourced a laser cutter for the mild steel plate
- sourced an F&P for a case of beer
- bought some bearings
- bought an old welder (first job will be to learn how to use the thing!)
- built a prototype prop from 100mm PVC pipe. Seemed to work well. I have a 300mm pipe lying around which I will use for my first blades, about 2.5m in diameter.
I am pretty confident about being able to bung this together using the excellent instructions and photos on this site.
My real question relates to the electronics piece. If I understand it correctly this is what I will need to do to get 240VAC from this turbine-
- get a bridge rectifier to convert the 3 phase AC from the rewired rotor to DC.
- get a controller to control the battery charging and dump the load when the battery is fully charged
- get an inverter to get 240 VAC from the DC battery
Is my understanding correct?
Ronald
KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691
Posted: 02:22am 03 Aug 2006
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I think you have the gist of it Ronald, might have paid a bit much for the F&P! Edited by KiwiJohn 2006-08-04
By the way. What is the F&P "currency" in NZ? L&P for F&P?Ronald
KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691
Posted: 07:04am 03 Aug 2006
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Hi Ronald, I guess a few L&P would do the trick in some quarters, a family member gave me a carton with half a dozen rotors and stators to match. Unfortunately I didnt know enough to get the bearings so my only project so far(a pedal generator using an exercise bike) uses a pair of the bearings that failed the roadworthy test on my trailer!
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1462
Posted: 08:02am 03 Aug 2006
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Hi Ronald,
Eh mate great to see ya getting into the RE arena. Now with the welder you bought if I may offer a couple of tips to get you going. Get some scrap steel around the same thickness of the parts you want to weld on the genny. Now say your using 10mm plate get some 3.2mm gp welding rod's( I prefer satincraft) and set the welder to about 100-110 amps. Now the secret to welding is watch the molten whirlpool as you weld. Once you get the knack you'll wonder why it took so long to get a welder.
Cheers Bryan
Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 676
Posted: 10:31am 03 Aug 2006
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G,day Ronald, You certainly have the idea worked out. I cheat a little with the electronics control in charging the battery, I use a plasmatronics solar regulator. There is a special way to wire it up, though. If you have any great hangups, you can give us a call, my business card is on the forum
Another F&P windmill builder
Good luckTrev @ drivebynature.com
brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548
Posted: 11:04pm 03 Aug 2006
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Yeah, good luck Ron, bye the way anyone that comes to the Gold Coast for a holiday or whatever, give me a call and come on up to my joint for a couple of hours , we're only 1/2 hour drive up in the mountains--lots to see.
07 55453513 0r 0427 747 748
Looks like I will have ample help along this new road I'm a travelling!
Trev, I looked at the plasmatronics product but then saw the price!
Has anyone tried the Oatley HIGH POWER SHUNT REGULATOR KIT for $26?
More electronics questions-
- where is the best place to locate the rectifier and controller? Up the tower with the turbine or with batteries? I understand there will be some power loss. Which would give the least loss?
Sorry everyone. I have just found a post of the shunt regulator which seems to answer that question - OZeTrade’s F&P VAWT Concept.Ronald
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 04:19am 04 Aug 2006
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I was initially horrified too, however I'm glad I got mine. I mainly use it with PV, but some of the benefits are being able to monitor the actual energy recovered in a day, the SOC (State Of Charge) of the battery, current in and out, battery voltage etc. It also manages the boost and equalise functions. Finally, and this will depend on your needs, but it can turn on and off loads for you. For example, I was running a video camera over 802.11 Wireless ("WiFi") LAN. The PL20 was able to turn the camera on and off at required times.
Later, when I upgraded the camera and ran it 24/7, it was easy to re-deploy the same panels, battery and PL20 to run my pump to bring water up the hill. Would start once there was enough juice to run it, could keep it running after sunset without letting the battery get completely discharged. Horses for courses, but it's great.
That's an arguable proposition.
If you run 3-phase down the mast, you will probably suffer less loss than rectifying at the head and comming down on just two conductors of similar size.
Also, if you want to brake (electrically) the thing from the ground, it's better to have access to the bare windings.
It's easier to monitor/check/replace a rectifier on the ground than up the tower.
If you wanted to "kick-start" the mill, you couldn't do it if you have the rectifiers up the top.
All that said, it's possible that it'd be easier to cool the rectifiers if they were up in all the clear air. (But then, you'd have to stop the birds, wasps etc messing with it, or blocking the cooling vents)
Thanks for your thoughts Ross. You have covered two topics which I have not read up on - electric breaking and kick-starting.
How do you achieve the two? I can quess on the kick starting that you release the load so the blades begin to spin freely but this is just a guess.Ronald
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1462
Posted: 09:06am 04 Aug 2006
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Hiya Ronald,
Eh mate I have one of those oatley shunt regulators monitioring my bank of nife batteries. I had to change a few resistors but for nearly 12 months it's been working perfect. I only have a 80 watt solar panel charging them and just about everytime I go up to the shed thru the day the shunt regulator is dumping excess power into the dumpload which is some heating wire also from oatleys. For the price of the kit you can't go wrong and if your dumpload needs to bigger than 250 watts you can mount the mosfets on a seperate board with heavier tracks.
Cheers Bryan
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 10:49pm 04 Aug 2006
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I'm making some assumptions here, hope they fit your application!
1. Assuming you have a polyphase alternator (2 or more phases, 3-phase is more common), you can provide some electrical braking to the mill by simply short-circuiting all three connections (regardless if it's star or delta wound). In most cases, if you short the windings while the prop is stationary, unless you get an almighty gale, there just isn't enough torque to get the prop turning. (Try it - get any permanant-magnet alternator and spin it by hand. Now try it with the output shorted!).
Note, braking a mill that's running at full speed is almost guaranteed to do serious damage to *something*.
(A double-pole, single-throw switch is enough for a 3-phase machine, connect one winding to the 'A' side of each switch, and the other two windings to 'B' sides. When "off", no windings are connected. When "on", all 3 are shorted)
2. Kick-starting is one of those experimental things that may or may not help. How often have you had a breeze that would be strong enough to do something, if only you could get the prop turning! Whacking current INTO the alternator can make it act like a motor. (You need some more complicated tricks to actually make it turn, but just dumping current into one winding alone may be enough to get the thing moving).
Of course, starting it un-loaded is pretty much required, but in most peoples configurations this happens automatically. In a simple setup with a bridge rectifier across the machine output, then to a battery, the alternator won't actually deliver any current until the voltage is higher than the battery terminal voltage plus twice the voltage drop across the diodes.
In my case, the machine has to get up to about 53 volts before any non-trivial current flows, at which point the mill is moving pretty quick. (I've seen it putting 25 amps into my batteries at 56 volts in a good wind).
Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 676
Posted: 11:34am 05 Aug 2006
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Thanks Ross, for the explanation of the Plasmatronics, you are very knowlegable about electrics. Being a reseller of wind & solar gear I have often come across the fear of cost. Often, initially cheap stuff is exactly that, cheap, but then in the whole picture, its not!!! The frustration & system failure rate is high. Some solar regulators cut out the charge too soon, batteries don't fill properly, leads to sulphation buildup at a rapid rate, & batteries die, apart from all the lost energy that you could have had. There are good batteries (AGM with a Megapulse, life expectancy is 8 yrs)and cheap ones. Cheap inverters that just can't take the pace & burn out, or doing damage to sensitive equipment, & thus repair costs.
I just read a report on the cheap Chinese wind turbines. There are some problems.
1 Blades need to be balanced
2 Ripples on one blade
3 No slip rings.
4 Sharp edges need to to be filed off
5 Wires need to be cable tied to avoid chaffing
6 The spplied tower is unsafe for use.
7 Electrical components are poor quality, and a better regulation system is recommended
Enough raving, ........Milkwood, think about want you really want, source all available info you can. Wise choices, is where you will save a dollarTrev @ drivebynature.com
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 10:13pm 05 Aug 2006
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Absolutely!
I had 48 x 2V/300AH AGM connected as two banks of 24. Should have been fantastic, but the (#^*%^#* contractors completely destroyed them on me while I was out of town. Managed to completely, totally discharge them and said nothing. There were 3 lots of contractors on-site at the time, each denies being the guilty party so not much I can do. :(
Until I can afford to replace them, I'm having to "make do" with a bank of 220AH/6V Trojan wet cells and a 48V megapulse.
I've seen more than a few of them too! I ended up buying a proper RAPS5 unit from Selectronics in Melbourne. 5KW continuous, 10KW surge. Has a million tricks including full genset control, synchronises to the genset then drops the load/inverter/generator in parallel. Cost close to $10K but has been running 24/7 for 18 months, runs all the computers, $30K worth of C-Bus gear etc, plus all the appliances (fridge, microwave, dishwasher etc).
Hmm. I got one of those "cheap" turbines - the 1KW/1.5KW 3m dia jobs with 8m tower. (The first lot that came in aparantly). Yes, the blades were out of balance, but worse, they were out of line. Even with near-perfect static balance, the thing shook badly until I set to and shimmed each blade manually to get them all within 2mm at the tips (one was nearly 40mm out!).
What do you mean by "ripples" on one blade?
Mine has slip-rings, perhaps it's the smaller ones without?
Not too many sharp edges on mine, fortunately.
The wiring was indeed pretty ordinary though.
The electronic "regulator" it was supplied with is complete junk. Not worth using at all. In the first 2 weeks, I never, ever, saw it putting any current into the batteries. According to the importer, it dumped load until the frequency was stable. *WHAT THE??!* So I pulled the damn thing out and replaced it with 3 decent 35A bridge rectifier packs and an ammeter. It's been great ever since. We haven't had enough wind yet to put me in an overcharge situation, but I'll use the PL20 as a shunt reg if it comes to that.
The mast however well,... it seems adequate - just.
Supplied as 4 lengths of thickwall steel pipe with bell
ends, the mast is quite strong (but only 8.5m), but it was supplied with wire rope that was (a) too short and (b) too thin for my liking (4mm gal rope). They also only supplied enough "Crosby Clips" (wire clamps) for *ONE* at each end of each guy, and NO thimbles at all. I added a heap of clips and thimbles for each end, and sourced 6 or 8mm gal rope locally. I also got a length (6.5m) of 4" gal pipe to use as a gin pole to raise and lower it:
Oh, and the "steps" up the side are just 40x40 RHS held on with large U-bolts. It starts as far up as my ladder will reach (about 3m) - to stop the locals climbing up!
Here it is flying:
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1462
Posted: 10:30pm 05 Aug 2006
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Hiya Ross,
Eh mate you've done a great job at explaining things . Just one thing though, when I bring this page up a password box pops up for Albury.house and on closing this box results in your pictures not displaying. I've tried closing explorer and re-opening this thread only to find the same thing. It's a shame we can'y see those pic's mate
Cheers Bryan
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 10:43pm 05 Aug 2006
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Ahh, crap. My bad. Try that now.
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1462
Posted: 10:54pm 05 Aug 2006
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Cool Ross that fixed it mate Thanks
dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574
Posted: 11:28pm 05 Aug 2006
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hi Ross
just earlier this morning l did had same problem as Bryan1 anyway now is fix up thank Ross l do fine is very interesting to show the photo on windmill tower and l wonder if you done the fabication by building windmill poles ? and i have some enquiring about useing steet or highway lamp pole some ago as do not need Wires to be cable down and still working out which is cheaper to buy or build it my self and l do know some of street pole are manfacture in Philippines .
Dwyer the bushman
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 11:45pm 05 Aug 2006
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I didn't fabricate the mast - it was supplied in the "kit" from China. If I were to do it again though, I would use 4" thickwall gal pipe from a local source.
My old mast (comms mast, I'm an amateur radio operator, and use microwave radio comms in my day-to-day work) is a 47 foot self-supporting tower. I was always nervous in high winds, although it never moved.
I know guys are ugly, and can get in the way, but I like the confidence. I can walk around it and *FEEL* tension. I KNOW that if the guys are firm (but not at tight as a guitar string!) then things are good. I KNOW how hard I can pull on it before the guy snaps or the footing moves, and given basic trig, how much force that can "hold" at the top of the tower. In this regard, guys appeal to me.
We have a mob down here who make the concrete light/power poles up to about 30 metres I think. The smaller ones, about 10m are quite expensive - I think about $4K each, plus transport/installation.
The thing that scares me is if you have a decent size prop on the top, in a decent breeze, that is a significant (horizontal) force. Problem with that is that the turning moment at the base where it's mounted is vastly higher (think "leverage" - with a 10 metre lever!)
You probably won't know how close it is to keeling over until its too late! (I'm not just talking about the pole buckling, it's also the footings and/or attaching bolts)
If you just "dig a hole" a metre deep in the dirt, what happens after a week of rain and the dirt gets all soft and squishy?
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Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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. Just one thing though, when I bring this page up a password box pops up for Albury.house and on closing this box results in your pictures not displaying. I've tried closing explorer and re-opening this thread only to find the same thing. It's a shame we can'y see those pic's mate
