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Forum Index : Windmills : The LG Project

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Greenbelt

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Joined: 11/01/2009
Location: United States
Posts: 566
Posted: 09:38pm 18 Jul 2011
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HI Bob

Question?
If you know The Number of turns in one coil on this LG you could remove about 3% for a possible current gain at moderate wind.
Would the Cap doublers and Booster compensate for the loss at lower speed ?
-----Cheers, Roe
Time has proven that I am blind to the Obvious, some of the above may be True?
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 02:51am 19 Jul 2011
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Hi Roe

I am going the high voltage route as the windings are to light to use on low voltage with its potential output, I will keep you all posted.

All the best

Bob
Foolin Around
 
Greenbelt

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Joined: 11/01/2009
Location: United States
Posts: 566
Posted: 03:13am 19 Jul 2011
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OK Bob

Got It!
Will be waiting for the Verdict, Should do fine.
----Cheers, Roe
Time has proven that I am blind to the Obvious, some of the above may be True?
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 07:19am 19 Jul 2011
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Hi All

I did some preliminary testing today on a transformer coupled set up, still in the lathe as before and with 30 meters of 1.6 mm power flex lead.

RPM---- delta AC---delta dc - AC star ---DC star

40 ---- 1.0 ------ 1.45 ----- 1.70 ----- 2.5
52 ---- 2.2 ------ 3.20 ----- 2.80 ----- 4.0
67 ---- 3.2 ------ 4.60 ----- 4.06 ----- 5.8
88 ---- 4.5 ------ 6.50 ----- 5.70 ----- 8.3
113 --- 6.0 ------ 8.70 ----- 7.60 ----- 11.0
147 --- 7.8 ------ 11.3 ----- 9.90 ----- 14.3
190 --- 10.3 ----- 14.9 ----- 13.0 ----- 18.8
247 --- 13.4 ----- 19.4 ----- 17.0 ----- 24.6
320 --- 17.2 ----- 24.9 ----- 22.2 ----- 32.2
415 --- 22.3 ----- 32.3 ----- 28.3 ----- 41.5
540 --- 29.0 ----- 42.0 ----- 36.9 ----- 53.5
700 --- 37.0 ----- 53.5 ----- 47.0 ----- 68.0


The above figures are running without load I will hook it up to the batteries tomorrow if time allows and do some load volts and amps testing into the actual batteries.










All the best

Bob

Foolin Around
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 06:42am 20 Jul 2011
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Hi All

A bit more testing with the alternator connected to the batteries, first run was with secondary of the transformers connected in Delta.

Delta
RPM 247 amps 0 0 watts
Rpm 320 amps 2 60 watts
Rpm 415 amps 7 210 watts
RPM 540 AMPS 23 690 watts
Rpm 700 amps 45 1350 watts This is to fast to be a realistic in use measurement

Second run with secondaries connected in star.

Star
Rpm 190 amps 0 0 watts
Rpm 247 amps 5 150 watts
Rpm 320 amps 15 450 watts
Rpm 415 amps 22 660 watts
Rpm 540 amps 27 810 watts
Rpm 700 amps 32 960 watts This is to fast to be a realistic in use measurement

DC volts was 30 volts at the three phase rectifier battery voltage went to 28.5 under testing voltage drop was in the 15 meters of 6mm cable to the battery bank.

Due to the excess power available in the blades from 170 RPM with a wind speed of 4 MS I will be trying the boost modules to pick up that power before main rectifier cut in. in delta configuration this amounts to 700 odd watts available, and around 300 watts in star configuration.

Looking at this extra power situation I will try 3 boost modules one on each phase for a total of 400 watts before cut in of main rectifier. This should allow cut in at 147 rpm in delta and 113 rpm in star. this would coincide with 4 to 4.5 MS.

All the best

Bob
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BobMann

Senior Member

Joined: 30/06/2011
Location: United States
Posts: 134
Posted: 03:41am 21 Jul 2011
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Hello I turned down the Stator a little bit and reshaped it back to a hump.
The air gap on the Mann Smart Drive is .025 thousend
the brake free torqe is 14 inch LB and spin is 5 inch LB.
OMH is 31 stock stator
AC volt no load at 82 RPM is 108 volts
at 165 RPM is 215 volts
at 208 RPM IS 208 volts
at 414 RPM is 535 volts
at 703 RPM is 900 volts
Talking with Randy on magnets he said it is best to have straiet lines and after testing I must say yes. As the magnet passes the stator it snaps the flux and pushes the volts up.
Bob Mann
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 11:21am 21 Jul 2011
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Hi bob

The voltages are very interesting much higher than the LG machine, I notice you are running closer to the poles as well as the LG is .040 aprox, I will try one of the stators I have here when I get time.

I think the aligned magnets also reduce cross poling as well.

All the best

Bob
Foolin Around
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 11:21am 22 Jul 2011
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Hi All

I have wired up the controller for testing using three boost modules one on each phase to squeeze the watts out of the lower end of the mill, this gives a potential of 320 watts below normal cut in speed,

Module parameters

Module Properties: Non-isolated step-up module (BOOST)

Input voltage :10-32V

Output voltage:

(1) continuously adjustable (12-35V)


Output Current: 10A (MAX)

Input Current: 16A (MAX) (more than 10A, please enhance heat sink)

Output power: natural cooling 100W (MAX), to enhance heat sink 150W (MAX) real power

Easy to drive 65W 90W dual-core notebook includes

With a 12V battery with a common 19V 3.42A notebook computer module temperature is about 45 degrees

Conversion efficiency: 94% (input 16V output 19V 2.5A when measured) (for reference only)

Output Ripple: 2% (MAX) 20M-bandwidth

Operating temperature: Industrial grade (-40 ℃ to 85 ℃) (ambient temperature exceeds 40 degrees,

lower power use, or to enhance heat dissipation)
Full load temperature rise: 45 ℃

No load current: 25mA typical

Load regulation: ± 0.5%

Voltage regulation: ± 0.5%

Dynamic response speed: 5% 200uS

Short Circuit Protection: None (Please enter the installation of fuses or protection circuits)

Input reverse polarity protection: No, please comply with our plate or

in the input reverse polarity protection diode in series.
Connection mode: free solder, terminals

I have used these ones as they better heat sinks but will fit a cooling fan as well if they are inclined to run to hot,

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=110711 024540&ssPageName=STRK:MEWNX:IT#ht_2258wt_916

I will put up some more pictures tomorrow to show the general arrangement.

All the best

Bob
Foolin Around
 
VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 07:41am 23 Jul 2011
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Hi All

Finished wiring the controller today, bit slow aren't I, but had a fly in here with 50 odd plane come visiting, so that slowed me down to a crawl, decided to use one common rectifier for the boost modules as I didn't have room for three on the heat sink, should be OK but test tomorrow will tell.

A preliminary check has the power coming in slowly at 2.5 MS up to 7 MS when the main rectifier cuts in by 8.5 MS the main rectifier equalizes the boost modules so they drop out, this depends on battery charge levels, that is for float at 27.5 volts. If the batteries are lower the boost modules will stay on with the main rectifier until float is achieved.

I checked the down lead today and am getting 9 volts drop over 30 Meters this is at 200 volts so is around 4% loss in the lead so a 2,5 mm lead is the order of the day when installed, this is with a load of over 1000 watts so around 40 watts.

With the loss in the 24 volt side of nearly 2 volts that is another 50 or so watts, shows why we need big wire for low voltage dc systems. In the grand scheme of things though it only looses power like that at high loading's, at low loading I couldn't measure the voltage drop, so at up to 300 watts you could say near enough to zero losses. No need to panic too much.

Back to the ongoing saga tomorrow.

All the best

Bob
Foolin Around
 
VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 07:04am 24 Jul 2011
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THE WIZARD THE FOOL AND THE MAGIC SMOKE

Well it had to happen sooner or later The fool was trapped by the Chinese wizard and made magic smoke.

I went to test the controller today and the result was the escape of lots of magic smoke, I has set up the modules and tested them for voltage out, all was well but when I fired up the lathe I was greeted by an acrid smell, you know the magic smoke smell.

After jumping up and down and saying a soliloquies of self appraisal I decide to see where I stuffed up, traced the circuit checked another module with more smoke in it, and what I found was the diodes where marked wrong, the copy wizard of the north strikes again, as I had the remainder of the packet of bridge rectifiers I checked them and the diodes where all marked with transposed terminals, not happy Jan.

So $36 of modules are reduced to a carbon tax and I am stupid for not checking the diodes with the meter before installing.

That will delay the controller for a week or two as I only have two modules left so ordered some more today.

Ain't this fun

All the best

Bob

Sick Bird Fool



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Don B

Senior Member

Joined: 27/09/2008
Location: Australia
Posts: 190
Posted: 07:26am 27 Jul 2011
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Hi Bob,

I am coming in late on this thread, but I have a few comments that might be helpful.

On the matter of cogging, it can be a benefit as well as a problem. Where you have iron in the magnetic circuit, the strength of the cogging is also an indicator of the goodness of the magnetic circuit, and hence its output capability. The problem is that the cogging means that the blades need even more torque to start, and, when running, there is more chance of the cogging noise transferring down your tower and upsetting the neighbourhood, or the wife.

When the blades are stationary, they are at an extremely high angle of attack to the wind, and are deeply stalled. Consequently, they need a wind speed above their minimum generating speed in order to generate enough torque to start. If the wind never gets quite that fast, then you have lost useful generation. The higher cogging force obviously makes starting even harder.

But there is a way of overcoming this problem which I am sure that you could set up if you wish. It is a technique that I have used with the wind generators on the boat, and I called it kick starting. On my set up, I was measuring the wind speed and, when the wind got up to the required starting speed, I sent a series of DC pulses to the windings to start the blades turning.

If you use star connection this is easy, and could be done with three relays that send a short DC pulse to each phase in turn. If you sequence the pulses correctly, the blades begin turning in the correct direction. You only need a few pulses in the train to get the blades moving.

In my case, the generators were delta connected internally, so the pulsing was more complicated, as you had to switch all three phases at once (one positive and two negative), and the blades sometimes began turning in the wrong direction. Surprisingly though, even though they turned in the wrong direction initially, this broke them out of the deep stall, and they soon reversed themselves and began turning in the correct direction. All that they needed was the initial kick to get them moving.

For the delta connection, I used electronic switching, but it could still be done with relays with a bit more complication. You certainly don't need high speed pulses. In your case, as you can access all 6 winding connections, I would stick with a star kick starting arrangement.

On the matter of your blades, I would point out that there is a difference between blades designed to work as a propellor, and blades designed for a wind turbine. The lift side of a propellor is on the front, while that of a turbine is on the back, and the angles are different.

When you have enough wind speed, even cricket bats will work as blades, but, if you want to squeeze the last poofteenth of power out of low wind speeds, then you need turbine blades designed for the purpose.

I hope that you have some luck putting the magic smoke back into your diodes.

Regards
Don B
 
Rastus

Guru

Joined: 29/10/2010
Location: Australia
Posts: 301
Posted: 02:01pm 27 Jul 2011
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Hi Bob,
Parts incorrectly marked isn't something I would have suspected,so you've done me a favor even though it cost you.I'll have in mind to double check everything,which isn't a habit that comes naturally.
Hi Don B,
I've heard the cricket bat theory before,but not convinced.Cheers Rastus
see Rastus graduate advise generously
 
VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 02:19pm 27 Jul 2011
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Hi Don

Thanks for the suggestion on relieving the cogging by a kick start. I hope I will not have to much of a problem as the blades are oversize for the generator 4 meter dia. Trying to get some low down power recovery, that is what caused the smoke in the boost modules.

It is a bit of a Heath Robinson machine as I am using delta from the alternator at high voltage down the pole, I tried star but the windings got to hot. It comes down to three transformers also wired in delta with a boost module on each leg, the problem with the diodes was they where letting AC into the boost modules and hence the smoke. As they where 10 amp modules they loaded up the machine heavily at low rpm.

With the delta delta setup it is doing 600 watts at 350 rpm, I have now fitted a cap doubler while waiting for new modules and it is cutting in at 150rpm so all interesting to play around with, the cogging will rear its ugly head maybe when its up, I have experimented with a relay pulsed with a cap feeding one phase and an inductor feeding the other with the relay on the third. similar to what you say.

All the best

Bob
Foolin Around
 
brucedownunder2
Guru

Joined: 14/09/2005
Location: Australia
Posts: 1548
Posted: 09:10pm 27 Jul 2011
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Hi Don and Crew,

Don, interesting post ,,, I've done exactly that in the past with my F&P neo conversion ,because it was cogging a lot.

I actually just pulsed dc current up the 3 phase lines and it does work ,Not every time , but ,I think ,maybe if I remember , 1out of 3 times and yes, the blades did turn. I was thinking at the time if someone smart enough could come up with a gadget that sequenced this pulsing in the correct and timely order then we 're on a winner . Any Takers to design such a beast??..

Bob , watching intently, u are doing a good job ,keep going ..

still constructing my tracker,, she's a big strong beast. I've seen up to 120Kph winds comne up this valley .

Bruce
Bushboy
 
VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 01:00am 28 Jul 2011
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Hi Bruce

Just playing with several ideas at the moment, as in reality my location is as much good as a hip pocket in a singlet as far as wind energy is concerned.

The solar is the way to go and the tracker makes it even better, but the cost is hard to justify on the pension. I too have to build several trackers but a health problem a few weeks ago has taken the wind from the sails, so playing windmills at the moment as it is easier.

Bob
Foolin Around
 
brucedownunder2
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Joined: 14/09/2005
Location: Australia
Posts: 1548
Posted: 01:35am 28 Jul 2011
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Hi Bob , Chin up Ol mate,, hope you are feeling better in a day or so ..

The tracker I'm building is from old gal steel left over from a truck load I got from the local tv tower re-build ,,A 3 case of beer deal with the riggers...

She's 3x3x1/4 angle so it ain't goin anywhere real fast,lol.

Ilda comes home Saturday , cleaning the house today .. takes her 4 days to travel.
Middle of Brasil up in the amazon area.

Take care , mate

Bruce.
Bushboy
 
VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 06:39am 28 Jul 2011
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Hi Bruce

Looks like a very solid job mate, the only thing that worries me is the single pole mount as with the winds you mention there will be a lot of force on the panels, might need some extra side bracing.

Slowly feeling a bit better and doing a bit now but not up to speed yet.

All the best

Bob
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VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539
Posted: 07:04am 28 Jul 2011
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Hi All

One of our members asked me about driving a GFI direct off the generator, so I tried it today, a 14 to 28 volt unit not a success as the open load voltage of the generator exceeded the input voltage of the Inverter before the Inverter could lock onto the mains frequency as that took over five seconds. It shut down on over voltage so I then tried it with batteries to clamp the voltage and it worked OK.

I tried it with a higher voltage unit 24 to 48 volts, it did lock on but when it loaded up it dropped the voltage to a point of being useless.

I think it would need a high voltage MPPT Inverter that could follow the speed / voltage changes to be a success, running it direct it would require a voltage range of 150 to 350 volts MPPT with some big caps to even out the loading to some degree.

I have gone back to Delta Delta setup as the Star Delta was heating the windings to much as beyond 750 watts I believe it is putting out more power than the windings can safely take.

The only other thing I may try later is a star delta switching at the transformers, this would get the minimum power point to just under 200 rpm.

I have changed the boost module to a single unit 10 amp one and that gives me useful power from 220 rpm 8 amps over the boost module and the cap doubler or 230 watts.
That would be approx 5 MS on 3.6 meter blades.

Next step is the mounting and furling and slip ring assembly.

All the best

Bob
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Rastus

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Joined: 29/10/2010
Location: Australia
Posts: 301
Posted: 06:54pm 29 Jul 2011
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Hi Bruce,
I'm wondering if the position the rotor comes to rest is the reason for the 1/3 DC start up success.If the rotor rest position could be controlled/set for the same position every time,the DC start up pulse could be more consistent and reduce the more complex timing issues?Do you think the idea could have merrit?Any comments welcome as long as Bob doesn't mind and I'm not of track.Cheers Rastus
see Rastus graduate advise generously
 
brucedownunder2
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Joined: 14/09/2005
Location: Australia
Posts: 1548
Posted: 09:03pm 29 Jul 2011
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Hi Rastus,, I must say that this pulsing was not my idea ,,I got it from members of this forum long time back ,,. I'm not smart enough to think of those bright ideas, but I'm not bad with a hammer and welder ...

I think, way back , I used to be smart, then I met this girl ,since then it's been all down hill,lol.

Crazy bushboy
Bushboy
 
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