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Tim L
New Member
United Kingdom
70 Posts |
 Posted - 28/02/2008 : 17:23:53
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OK, I've just bashed together a wind turbine and Del has got me to join, how do I stick in a Powerpoint pres showing roughly what I've perpetrated?
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speo
Junior Member
Canada
120 Posts |
Posted - 28/02/2008 : 17:57:57
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Hi Tim,
You can't upload files here. You can upload it somewhere else and post the URL.
Speo
www.windpulse.com |
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gotwind
Forum Admin
United Kingdom
1067 Posts |
Posted - 28/02/2008 : 17:58:12
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Hi Tim.
You can link to a Powerpoint presentation, limited access though (to Mac users e.t.c)
Just host it somewhere on the net and post the link in this thread.
Cheers. |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 28/02/2008 : 18:17:05
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host? Not sure how to do that. Got a few pix and would like to place them here if I can.
Basic details:
9ft 3 blade prop driving 1KW stepper motor, planning restrictions force it to be only 3 m or so above the ground at the moment and because it's close to the house and in turbulent air I have fixed it to point in 1 direction. However, it works - getting about 14A at 12V (designed to run at 24V but 3m prop desn't run too fast so have reconfigured). |
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gotwind
Forum Admin
United Kingdom
1067 Posts |
Posted - 28/02/2008 : 18:29:05
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Sounds interesting.
Hosting, simply means a place on the net where you can upload a file to, be it an image or whatever, http://photobucket.com/ is one of the free ones.
Heres how to post images on this forum.
The Futures Green - Getwind of it. |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 28/02/2008 : 18:35:06
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quote:
Originally posted by gotwind
Sounds interesting.
Heres how to post images on this forum.
The Futures Green - Getwind of it.
Still don't know how to get pix on here. However, here's the latest conversation with Del - I hope he doesn't mind me cutting&pasting:
Hi Del, yes the champagne had a heck of a hammering after that!
Answers to your questions are in blue below.
Tim
....................................................................................................................
Nice one Tim,
I recognise the genny as from renewablecomponents from ebay. £180ish? They did sell a few on their previous evolution models that had a lot of cogging effect but sold them very cheap. A few of the guys from www.gotwind.org bought them but weren't able to modify them well enough to use.
Yep, you've got it, that's one of the cheap old ones there, I grabbed it for £47. It does indeed take quite a bit to start up, at the moment I'm running it on a 9ft dia 3 blade wooden prop. Though I'm seriously considering going for one of RenewableComponents' own 6-bladed 6ft props instead (not on eBay but available direct from their own website), after watching a Danish wind turbine on UTube. It overspeeded and actually exploded. I'm not too comfortable with my own wooden effort after seeing that, the blades would make fine javelins at a few hundred RPM. Even though each one is secured to that 5mm aluminium disk by 5 x M10 high tensile steel bolts, the wood itself could fracture. I'm hoping that the torque would be similar or higher from a professional 6 blader as opposed to my badly-carved and unaerodynamic 3 blader, and that the smaller dia would also let it turn a bit faster than my present prop.
It's currently working quite well for something only a few feet up in the air (planning restrictions) and close to the house in a lot of turbulence. The turbulence is why I currently have it pointed in a fixed direction, when I move house (sometime in the next couple of years, probably), one of the considerations will be somewhere with smoother air and with higher than my current location's average 4.5 m/s, and then I'll stick a swivel mount and a tail on it.
Are you running it at 12v? I thought they were either 24v or 48v units?
Yes, only 12V at the moment, the dia of the prop needed to get it going means that it doesn't spin fast enough to hit 24V very often so I came down to 12 for starters. Seems to work, but I'd much rather work with high voltage/low current than the other way around. You know the old saying: "Volts Jolt, But Amps Cramp." I really, really don't like high currents. Perhaps I will reconfigure the head unit to include voltage doubling.
How come your own flux axiel design never worked sufficiently? Seems a shame after all the work you put in.
To be honest I got hacked off with it, the redesign to pull the magnetic flux through the stator coils from the single magnet rotor introduced a horrific amount of cogging, so it's sitting in the loft at the moment. But if when I move, the new place has a stream that I can waterwheel, I'll have torque to spare.....
Do you need shotty diodes when you're rectifying the output. I thought the bridge rectifier would take care of that?
True. At the moment the turbine head unit does the rectifying with 3 x 35A bridge rectifiers. I'm half expecting them to blow up and will probably replace when they do with one of RS Components' nifty 3-phase 86A bridges (RS 193-133). The 3 Schottkys in the picture are the barrier to stop the juice coming back out again, each is only 30A so I have stuffed 3 in parallel to run at 90A or thereabouts. Luckily their forward drops are fairly well matched to each other.
Like the look of your charge controller. What have you got insidfe the box that will handle 1KW and what dump load are you using?
<embarrassed grin> er....it's a standard Beewind 50A unit. Yes, I know, I know. In due course and when I can be assed (probably when it's blown up!) I'll whip up a simple little pulse width modulator controller, probably using an LM324 chip, and drive a few power MOSFETs (like RS 193-464) to do the actual power switching. In the meantime I've arc-suppressed the relay contacts with a 100R resistor and a 0.47UF X2-type capacitor in series across them. Driving the sensor from just one of the batteries means that it will still work on an overall 24V system (if I reconfigure to 24V).
Dumps are interim and utterly simple. They're just a few cheap 3KW convector radiators from B&Q in parallel, about £14 each. At 24V each one should eat about 300W. OK, the resistivity might not be linear with voltage, but it should be more or less close enough. In my new place (dreaming again) I'll probably stick a couple of 24V 600W immersion elements into a secondary hot water cylinder. If I get an indirect type cylinder I'll be able to supplement the wind with some thermosyphoning solar panels I could knock up out of old black-painted radiators thrown in insulated glass-fronted boxes.
What's your thinking of having separate boxes for incoming power and charge control? Surely the voltmeter will just default to the battery voltage level when all connected up but as you say it's showing high and 16v?
I'm using the LCD meter in the charge controller box (meter from DPMeters) as a battery monitor rather than measuring the raw input to the system as a whole. The analogue meters in the incoming box do that, and I always think that while you can't beat digital for accuracy, there's just something more gutsy about bouncing needles. It's showing high because the measurement point comes before all the electronics voltage drops further down the line - I think. Or I calibrated it wrong!
I've recently bought a Futurenergy PMG. I managed to strike a deal with the supplier that meant we could get them for £105 + VAT plus P&P if we bought 5 and so I managed to get a few guys from the gotwind forum to buy some with me. Not sure it it'll ever get used where I live (too big really) but i will hopefully be emigrating to France later this year so I will be used there big time.
Best wishes for France. I understand they're a lot more progressive about domestic wind generation planning regs than this bloody country!
Do you fancy joining the Gotwind forum now and showing all your very neat work?
I might just do that. Nothing ventured, nothing gained, and having lurked on various sites it might be time to put something back.
PS: Neat???? You haven't seen inside the boxes...........
Cheers
Del. |
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Sundowner
New Member
Ireland
58 Posts |
Posted - 28/02/2008 : 22:15:48
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Hi Tim L,
Congrats on getting one off the ground, I'm an ex lurker too.
Any more information you can give on the actual motor you're using would be appreciated.
I'd love to see your pictures too 'cos pictures to me makes things a lot clearer.
Regards,
Sundowner.
Sundowner....huh.........thats what they call us.......Sundowners |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 29/02/2008 : 16:34:46
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Tried to join Photobucket but couldn't - seems it doesn't believe that anyone in this day and age can do without a mobile phone. Huh.
Instead I've created a blog (first go at that, too), which I hope will be available with words and pictures here:
http://mostlydiywindturbine.blogspot.com/2008/02/mostly-diy-wind-turbine.html
Sundowner - good luck with your own project! |
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Sundowner
New Member
Ireland
58 Posts |
Posted - 29/02/2008 : 19:17:38
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The link works ....great pictures..seeing it makes it easier to understand.
Sundowner....huh.........thats what they call us.......Sundowners |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 29/02/2008 : 20:06:53
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YEEAAARGGHHHHHHH
Blowing a hoolie here, alternator doing its nut, voltage peaking at 18V DESPITE being supposedly clamped to 12 by the 2 car batteries in parallel. Brief periods between gusts show battery voltage sinking back from 18 to 13.1, which is where the controller shuts off the dump.
Anyone know what to do, or do I boil my batteries? Maybe I add more dumps in parallel - have run out of B&Q radiators but still have a socket left, so it would have to be four 60W table lamps on a 4 way extension lead.......will try that
Edited to add: Kicking myself. Putting the two 12V batteries in parallel halved my dump capacity as well. Merde, merde, merde. Saturday shopping will include a 24V 1KW inverter.
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Edited by - Tim L on 29/02/2008 20:53:09 |
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donniedingle
Junior Member
United Kingdom
102 Posts |
Posted - 01/03/2008 : 14:42:37
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hi tim.
thats a great set of figures, you need a bigger battery bank, 2x12v batteries is a waste of time and effort, i use no charge controller on my setup, i just keep adding batteries to soak up the power thats being harvested, you say you have all this stuff attached, thats just proof your batteries are no where near enough up to the capacity you are getting from your turbine.
i very often see my battery bank sat at 17v and they take no harm, once the wind dies the batteries settle down to 13+ volts.
regards donnie.
just keep her spinning.. |
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speo
Junior Member
Canada
120 Posts |
Posted - 01/03/2008 : 15:21:00
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"i very often see my battery bank sat at 17v and they take no harm"
How is it possible to bring the bank to 17V, don't you have a controller?
How do you know that they take no harm? I think they get hurt every time you charge them beyond the charging parameters. They don't die on you right away, but do get harmed, and will die sooner than normal. Am I wrong?
Speo
www.windpulse.com |
Edited by - speo on 01/03/2008 15:23:06 |
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donniedingle
Junior Member
United Kingdom
102 Posts |
Posted - 01/03/2008 : 15:33:23
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hi speo.
no i don't have a controller, just 1000A capacity battery bank, when i say its at 17v i don't mean for days on end.
when i was an apprentice engineer ** yrs ago i always remember at college being taught vehicle electrics, before alternators ...lol. and i always remember the tutor telling us about battry boost chargers, it was not the extra amps you put in to the battery when on boost, rather the machine raised the voltage to nearly 20volts and so through out life i have stood by my learning ...lol. (just hope my minds ok lol)
Donnie.
just keep her spinning.. |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 01/03/2008 : 16:05:10
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Hi Donnie
At the moment I don't have anything running off the batts, they're just to clamp the volts (OK, and to give me a little bit of power if I need to), so I hope I'm not wrong when I suggest that perhaps capacity shouldn't have been an issue if I'd had a divert load that could eat all the power being produced?. Anyway, this morning I ordered a 1KW 24V inverter. I'll plug one of those electric radiators into it and we'll see how the system likes that. Inverter should be useful anyway in a power cut and if I'm wrong about the batteries and need to add some more I can still do it.
Have now put the 2 batts back in series and they're reading a no-load 26.1V. Turbine regularly hitting 18V again, though more often wandering around between 10 and 16V, but the big difference now is that instead of chewing my lip while watching the ammeter hit 25A and waiting for the 12V batteries to boil, it's sitting there most of the time looking dumb, running less than 26V and should continue to do that while I sort out a better dump. Though I just nipped down to peek at the meters and right then it gusted to 30V and about 10A and the dump flicked on for a few seconds. That's good, yesterday it was on all the time.
Once the dump is fixed, I'll see about getting real proper blades to drive the thing faster than the 200 to 300 RPM I think I'm getting from the 9ft wooden prop.
I never expected it to be so ruddy difficult to buy bladesets, though. I got all the way through the purchasing process on 2 different American websites (one of them being Magnets4less) before finding that they wouldn't or couldn't ship to the UK, and RenewableComponents hasn't answered my email. Following up on Sundowner's Navitron tip, it looks like their blades may well not be a good buy, someone was saying that they were huge and noisy for the power they produce and had fractured around the boltholes. Not something one wants to hear when they could be doing 600RPM. <Sigh>. |
Edited by - Tim L on 01/03/2008 16:44:51 |
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donniedingle
Junior Member
United Kingdom
102 Posts |
Posted - 01/03/2008 : 16:39:50
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hi tim
the magnet for less guy on ebay, i have actually spoken to him on the phone, and i did get prices from both firms to the uk, though not very cheap, it was the guy that i spoke to who told me the navitron blades are the same ones from china, small world eh . he also suggested that you sandwich the blade root between 2 steel plates to prevent the cracking issue, but on one site i noticed a write up and they claimed they were miles out of balance, but the navitron one work out much cheaper than the usa ones, and dam its typical your parcel gets checked for customs and then you have 17.5% vat to pay, i got stung for parts from bluewind, just how they are random drawn by custom men..lol.
but to get any decent power output you need the big blades, wether they are noisy or not, but here is gordons number at renewable components, 018907-50099, ask for gordon, but he has just got the tooling in for his 3mtr blades, they have been tested and will be in production any day now, just mention my name. and that fresh off him only this week tim.
Donnie.
just keep her spinning.. |
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Tim L
New Member
United Kingdom
70 Posts |
Posted - 01/03/2008 : 16:55:14
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Donnie
ye Gods it is a small world indeed! I too remember reading about a bladeset sold as "balanced", but one blade was found to be several ounces heavier than the other 2. Could be the same article.
Thanks for Gordon's phone number, I'll call him probably next week. Properly shaped 3m blades ought to do a lot better, and be a lot safer, than my wooden efforts. |
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Newbie ex-lurker
