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Forum Index : Windmills : Voltages from F&P
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| MickWh Newbie  Joined: 08/05/2010 Location: Posts: 19 |
This has possibly been covered elsewhere, but I have not been able to find it sorry. I have started putting together a windmill of my own, infact I hope to build up several as I have 6 complete machines. I have pulled out the motor and played about with bridge rectifiers off the 3 phase and turned the motor with a battery drill for simulation. My very noob question is in regards to the output voltages and how much they vary with the speed, does this get smoothed out as you split the turbine into the groups of poles? I can't imagine that my 24V battery bank is going to be too happy with an input of 150V. Or is this controlled by a turbine regulator? That would be the picaxe project I guess Other info: off grid system, 6x solar panels only on Outback MPPT, 24V battery bank. Many thanks for helping me put it all together, fantastic site! |
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Downwind Guru  Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Hi Mickwh, You need to rewire the stator so it gives more current at a lower voltage. So no, the 150 volt is not used and would fry your battery as well as you to, if care is not taken and could kill you!!!! Have a look here http://www.thebackshed.com/windmill/FPRewire.asp For rewiring of the stator as no voltage regulator will control 150 volts to the battery. What you dont understand ASK as its far better to get it right with a little help than stuff it up or worst Kill yourself. Pete. Sometimes it just works |
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KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
what stator do you have? a 60S 80S or a 100S? 24V i'd be running the hundred split in half, easy rewire and good for heaps of juice. As you have plenty, get onto Phill, save yourself a lot of trial and error spend the grand or so and get the 3.0m dual stator kit. Ours has now stood up to some beating, couple of good storms with 40m/s windspeed. Its all over at 700W into the batteries BUT makes 2-3A into 55V in 2.5-3m/s call it 150W in the slightest breeze thus power over the day tough to beat. None of us here (other than OZtules) has great wind thus a performer in low wind is a real winner. Karl Luck favours the well prepared |
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| MickWh Newbie Joined: 08/05/2010 Location: Posts: 19 |
From the pics I would guess the 60S, but will have to wait till Wednesday to get the vernier on them. Would love to go the dual, but certainly don't have the grand to spend. I do understand the rewire page, and like the idea of the staggered windings, but happy to take advise. I guess I am struggling at the moment with the theory of how rewiring the stator will limit the voltage to appropriate battery charging numbers in the high winds. IE, do all mills need a regulator, or are some of them directly wired to the battery bank. Geez it seems the answer should be obvious, sorry. Edit: since posting I have figured out that yes will need regulator. Cool, another project to build ;) |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
I would not call it a regulator as such, because its more of a dump load controller than a voltage regulator. The controller only shunts the mill power to a dumby or dump load when the batteries are charged to prevent overcharging. When the battery voltage is low, they will soak up all the mill will put out, but as the batteries charge the voltage will rise too. This will increase to above a safe level for the batteries. The controller allows us to set a switch point that we dump the windmill to a dump load to prevent over charging the batteries. The controller also has a setable cutin point to switch it back to the battery as the battery voltage falls. I guess you are aware that a mill cannot be allowed to spin free without being connected to a load of some form. Ie:- battery or dump load. Another thing for you to build .....A dump load, to go with the controller you are going to build. And the list goes on.................................... Pete. Sometimes it just works |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Of note the mill wont fry the batteries if you dont re-wire it. What will happen it it will clamp the voltage to what the bank is. This is fine and the mill will make battery charging voltage from very very low rpms. The disadvantage is the resistance of the windings means that lots of power will be dissipated as heat in those windings and of course the output will be severely limited for example a stock rewire in rough terms for 7x2C will produce 7x less voltage but 7x more current and the cutin for your nominated battery size will be 7x higher. re-wire for delta and cutin and output jump 1.7 times higher again. the 80s looks right and the 60s looks messy the 100S looks empty as far as windings go. go the rewire for 7x2c in delta and run some caps, looks like Gordon has just come up with a method to drop the CAP count. Luck favours the well prepared |
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| MickWh Newbie Joined: 08/05/2010 Location: Posts: 19 |
OK, putting it together. Turbine - rewire to suit 24v system with low to 15km/h average wind speeds. Anyone else want to offer another alternative to 7x 2C ? I was actually looking at this option with the possibility of switching to delta in higher winds, I'm sure I saw that somewhere.... maybe? Dual stator would be ideal, just need the best way of doing this on a tight budget. Wait for Gordan to post the latest cap system update. ;) Off switch (direct short?) to shut off turbine, for maintenance and such I imagine. Charge controller to divert power to 24V hot water system element. Basing this on the TL084 op amp version, as it seems to be a lot simpler. |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Looks like you are getting it sorted. I dont think the direct short is a good idea as this is not a good practice with iron core machines, its fine with AXFX machines but not iron core. A well sized resistor (dump) load is better. The TL-084 circuit that Gizmo designed is a good little control circuit. You will blow the tight budget fast enough. Pete. Sometimes it just works |
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| MickWh Newbie Joined: 08/05/2010 Location: Posts: 19 |
Progress so far, I have found 6 x 80S motors, and have started rewiring. So far I have done one as a 3 wire 7x2C Star. I figure that the 6 wire version is what I need to do to be able to switch between Delta and star. How much of an advantage is this, or not worth the effort? Am I reading things right that I need to sort out the turbine blades and therefore speed and such b4 I can figure out what capacitors to use? |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
DELTA is a must 1.7x the output but similarly not much chop without the caps to make it work down low too. caps are cheap ebay ebay ebay. Delta is a fair bit more complex to rewire. As for the two stators, call Phill OZAX engineering and send him a hub or make a jig so you can just loctite it to the shaft. I'd recommend sending and paying method, i stuffed a few trying to get the hole perfectly centered not easy without some tools! this will vastly simplify your mill too, use the bearing block out of the tub. Luck favours the well prepared |
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| MickWh Newbie Joined: 08/05/2010 Location: Posts: 19 |
Doh! fair point, alright, I think I will change the unit to a 6 wire star/delta, that way when it is up and running I can add the caps and easily rewire to delta. This all makes so much more sense once you actually start doing it, I just hope that the furling part works like that when I get to it. |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
oncw the re-wire is done, load it back up on the shaft and give it a spin. if it doesnt spin very well, pick out the internal seals on the bearings and pluck out the main water seal from the plastic bearing. should spin well then when shorted not spin well. If it makes no difference shorted or not......you got it wrong 
the best of us has done it and can be messy to fix... Luck favours the well prepared |
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| MickWh Newbie Joined: 08/05/2010 Location: Posts: 19 |
Well I seem to have got it right, shorted out makes it very hard to turn. I am in a rather fortunate situation in that I am doing this as TAFE in the middle of the course I am doing. I will post up some photo's on the finished product as I imagine you guys will think it rather hilarious. |
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terryb45 Newbie Joined: 30/05/2010 Location: AustraliaPosts: 4 |
hey guy's greetings form oz my question's is which way to wire a smart drive for direct injection into the grid via a latronic's 2.5 kw inverter ????? what iam thinking of doing is to put about 6 f/p motors on 1 shaft and connect it to a small electric motor (i have no electrical background only learning & trying to get it wright hopefully through what you guy's put up on here )so i hope to put out more power than i use (eg motor current draw) . i have 8x 170watt solar pannels and a 2.5kw inverter so i only make at best on a good day 8kw. what i am trying to do is use my inverter to the max 24hrs a day because i live in the city i cannot put up a windmill as council restriction dont let me . to put up more pannels is a cost problem so hence the idear !!!!i would need to run it through a windmill controler into the inverter as i have been told the power need's in strings equal to 4 x 170 watt's (eg 680watts) ???? so the power i would get out of the smart drives i think need's to go into windmill controler 1st then into the inverter correct ???? your help would be greatly welcome |
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GWatPE Senior Member  Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
In this arrangement just stick to solar. You are talking free energy, and using a motor to drive an alternator, and hoping to produce more power is not going to happen. The power utility won't mind, as they can sell you the power to make it run. Check out other responses to free energy questions on this and other forums. Gordon. become more energy aware |
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| terryb45 Newbie Joined: 30/05/2010 Location: AustraliaPosts: 4 |
thank's gordon yes i have read some of the other forum's but none have given me any rewiring options that are best suited for f/p motors in direct injection to the grid via my inverter .!!!! i understand what you are saying about using power to create power but the point i was trying to get at is if you have a small motor using let's say 1kw to spin only the magnite's decoged there i hope be a light load on the motor and if so i thought why not try to capitalize on that by putting more than one motor on the same shaft then hopefully make more power to supass the 1kw you are using if i could do that the power company here only charges 0.17c on useage but pays 0.47c on what you return to the grid get the drift ???? |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5124 |
What Gordon is saying is true, you cant get out more than you put in, the laws of physics wont let you, no matter how hard you try. As an example, a F&P might make 500 watts, so you if combine a 4 F&P's onto one shaft, and expect to get 2kw out, then your little motor is going to need to put at least 2.5 or more kw in. So you'll need 2.5kw to make 2kw. It just doesn't work, you can never get out more than you put in. If you want to drive a F&P with a wind turbine, then that will work, cause you are putting power in from an external source. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| terryb45 Newbie Joined: 30/05/2010 Location: AustraliaPosts: 4 |
thank's glenn i understand what you & gordon are saying but it would be nice if it could be done!!!! hey?? no one has yet told me the best way to wire the f/p motors for grid use so any help would be nice . can some one please help me with this as most of you only put up info on battery conection then grid or just to battery has anyone done a grid through inverter connection ?????? thank's terry  |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Due to the fact that its "Wild AC" out of the F&P and the frequency is very high i would think it is not practical to use with GTI, this is why you are getting no advice on wiring a stator for direct grid connection. The solution is to rectifire the wild ac to dc and charge a battery, then you have a useable voltage source that can be feed to a inverter. Many before you have asked this question and have thought of the idea you have, Its nothing new, but the simple fact is, it dont work as you want it to. If it did we would all have been doing it for years. There was a thread some time back about using electric motors to run a second electric motor to generate 3 phase power, and this might be closer to what you need as the frequency will be closer matched, but the fact remains for every 10cents you put in you get 2cents out. Thats my 20 cents worth. Pete. Sometimes it just works |
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aussepom Newbie Joined: 03/03/2010 Location: AustraliaPosts: 7 |
Hi, It seems that you all are trying to mimic a standard alternator, with poles etc, that is all very well but you forget that the winding in the standard alternators and motors are done in this way for a fix speed, a four pole is 1450rpm for 50hz, if it falls below or goes above this is causes losses, these affect the performance. You have to forget this line of thinking, I have already proven it and I run a test unit to do all these test, wind generators, for the DIY must be able to work over a wide range of speeds. The thinking of the so called ‘flux lines’ is also wrong and was proven some time ago by Howard Johnson, I have even done some test on circular mags, that he did not cover and there are some totally different results to that of square and rectangular mags. But until I can find away to posts pic I can not show you. My mag motor does not have any 'coging'it. aussepom |
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