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Forum Index : Windmills : Chinese windmill
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Shelly Newbie Joined: 22/12/2009 Location: SpainPosts: 25 |
I bought sometime ago a small (400 watt) downwind generator. Its design looked interesting and has a furling system because the generator is off set from the pivot point. After spending time building a controller (see other posts in electronics) I was looking forward to producing some power. Nothing, absolutely nothing. I have mounted it in my pillar drill at 480 rpm. Testing the voltage between the phases shows 40 volts but no amperage. The voltage measured across a rectifier is 15.6v but this was measured when it was mounted on its mast. There is connectivity between the phases as tested with a multi meter set to resistance. Does anyone have any idea what is wrong and how I can resolve the problem? |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi Shelly, the offset you mention would likely be just that needed to allow the downwind mill to track a changing wind direction. The Skystream has a similar offset. There is an additional offset between the mill axis shaft rotation and the Yaw pivot. This may provide a furling moment. The windmill will not produce any amps without a loading. If you can explain how and where the measurements were taken, and if AC, or DC was measured. Can the metering measure AC & DC, volts and amps. A picture may help as well. Gordon. PS is the windmill an Aladdin 400 like this? Aladdin 400 site become more energy aware |
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Shelly Newbie Joined: 22/12/2009 Location: SpainPosts: 25 |
Hi Gordon, Yes this is the generator. The gen was originally connected to a large battery bank through the supplied controller. I ditched the controller and put in its place the controller that has graced the electronics forum. There was no difference. There is an ammeter in the wind gen circuit that even in a strong wind has never shown a charge of more than 1 amp. The only voltage, apart from the battery voltage, was taken across the the rectifier (one phase to -) and read 15.6 volts. This was DC. The 40 volts taken across the phases the other day was AC. The gen is now in pieces and there is no sign of damage to the windings and the stator doesn't appear to touch the windings. There is a lot of cogging and if the phases are shorted the gen stops or is difficult to turn. From this I presume there is not a lot wrong with the gen, but it doesn't explain why there is no amperage. The gen has been installed for several months on a 10 metre mast. I don't live in a high wind area but occasionally we have strong winds. I live off grid using solar panels as the prime charger. The wing gen was to have been used as a backup on overcast days. I'll take a couple of photos tomorrow of the gen in pieces. Thanks for replying Shelly aka Brian |
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Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Shelly; -A couple of thoughts come to mind, #1 are you certain your diodes are not damaged? they could be shorted internally rather than open. As Gordon has noted, if there is no load the ammeter will show nothing. #2 Is the ammeter connected in series with your Load? Here is a modified old post of mine showing my thoughts on a proper hookup. Time has proven that I am blind to the Obvious, some of the above may be True? |
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MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Shelly According to Alton's Calculator, a turbine of 1.3 meters diameter must be spinning under load in about 26 miles per hour of wind in order to make 400 watts. That also corresponds to a shaft speed of around 1200 rpm!! Could it be that it just hasn't spun fast enough to achieve it's "cut-in" speed? Just a guess. . . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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Shelly Newbie Joined: 22/12/2009 Location: SpainPosts: 25 |
Thanks folks for the replies. The gen was wired up as per your diagram. I am now going to dismantle the wiring to make up a test rig to try and sort this problem out. As far as the rotational speed is concerned at 480 rpm in the pillar drill should have produced around 25 watts. The amp meter read 0.1 amps. I have used 2 amp meters and both showed the same. Over the next few days I'll try and do some tests and let you know how I get on. Brian |
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wallablack Senior Member Joined: 10/08/2011 Location: AustraliaPosts: 164 |
The windmill will not produce any amps without a loading. If a mill is directly connected, after a bridge rectifier, to the grid tie inverter is this considered a "load" Foolproof systems do not take into account the ingenuity of fools. |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Wallablack It would be a load if the inverter is loaded onto the grid but from my experience the time the GTI takes time to sync with the grid (30 seconds or so) and this delay allows the mill to accelerate and generate higher volts than the Gti can take, so it drops out on overvoltage and the mill runs on unloaded. All the best Bob Foolin Around |
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Shelly Newbie Joined: 22/12/2009 Location: SpainPosts: 25 |
Sorry I haven't replied earlier but I only had notification of posts today. An update. The gen at the moment is out of commission. I messed around with it for a while and got nothing from it. I bought some other blades, 7 of them, from Missouri Wind and Solar. Very helpful and speedy delivery. I had the boss modified but it wasn't modified enough and in a strong wind the boss came loose smashing the blades against the mast. The boss is repairable, the blades not. I have not done anymore with it because in this part of the world, Spain, to buy from out of Europe import taxes are payable. That isn't a problem, the problem is that I am forced to use a third party to import which costs (20€) but when the goods are only worth about the same, to me it's not worth it so for now until I can come up with another idea I shall find something else to do! Thanks for all your help. |
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