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Forum Index : Windmills : F&P@PE
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| brucedownunder2 Guru  Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hey Dutchy ,,come on back to the irc--I miss you Bruce Bushboy |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Here's the link to that post. http://www.thebackshed.com/windmill/forum1/forum_posts.asp?T ID=762&KW=double+output&TPN=4 Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Dinges Senior Member  Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Thanks for the link Glenn. Herbnz, excellent job indeed, just the kind of relevant data one would love to see. And pretty good efficiency results for the F&P as well, in the 70-80% range below 200W output power. Guess that gets Bryan off the hook... unless he really wants to test a F&P to destruction, that is... <evil grin> Peter. |
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herbnz Senior Member Joined: 18/02/2007 Location: New ZealandPosts: 258 |
Hi Would have spend more time back then but not much interest so went on to other projects. There is I know one member here all set up and ready to test, but will let him come on in his own good time. Dr Chalko's results are puzzling in the least I lost faith when I read He seemed to believe the current limiting was due to saturation. Also on looking his publised papers this was only practical paper rest from memory to do with abstract subjects. Herb |
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oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Kiwijohn, I think it was Dinges who did some decent tests on the motor conversion, and it's inherent mechanical losses (all losses not directly connected with making power) I hope he will chime in and castigate or agree with me (strike out whichever is not applicable). From memory, the losses went up with the rpm in a tidy fashion. It was surprising how much power it took just to turn the thing over quickly... before hooking up the batteries. I found the same thing with the iron loss in the Seeley when I increased the flux with bigger magnets. The power doubled, but I think the iron loss was at least doubled as well.... fortunately the power is squared, and the iron loss linear. I did not torque measure it so I was/am unable to say if it just appeared linear, or not, but I think Dinges researched this well. (as he always does .... unlike me  )
..........oztules edit: Hang on, I have actually found the offending article... (searching fieldlines is not always fruitful) I would use the quote button, but I still can't seem to find it  .....
Anyway, here it is ......shamelessly stolen from Dinges scribblings hidden in the fieldlines vault........... Start quote: "I've temporarily installed a small wheel (diameter 22 mm; radius 11 mm) on the axle. With a black sharpie I put a marker on the white nylon wheel. I took a piece of string, about 1 m long, and wound it around the wheel. Then weight was added to the wheel. The trick here is to add so much weight that it unwinds slowly, evenly. Shouldn't accelerate or decelerate. I used various Neo magnets as weights, they're easy to clamp onto the string. In this case, 2 20x20x10mm neos were needed, that's 70 gram of weight. The assumption is made that all power is needed for overcoming stator losses. Any other losses (in the bearings, air resistance...) are assumed to be neglegable. The calculations: 1) P = F * v P [W] (power) F [N] (force) v [m/s](velocity) 2) v = omega * r omega [rad/s] (angular velocity) r [m] (radius of the wheel; here 11 mm = 0.011m) Combining 1) and 2) gives 3. P = F * omega * r 4. F= m * g m [kg] (mass of the weights, here 70 gram = 0.07kg) g = 9.81 m/s^2 So, F = 0.7N r = 0.011m Entering this in equation 3) gives: P = 0.7 * omega * 0.011 P = 0.077 * omega So, we now have a function of Power as a function of omega, the angular velocity. we need another equation: 5) omega = 2 * pi * f where f [Hz] is the rotational frequency, in rev/s. To convert from RPM, we need 6) n = f * 60 (or: f = n/60) n [RPM] f [Hz] For various RPMs, we can now calculate omega and then power. n = 100 ; omega = 10.5 rad/s; P = 0.08W n = 200 ; omega = 21 rad/s ; P = 0.16W n = 500 ; omega = 53 rad/s ; P = 0.41W n = 1000 ; omega = 106 rad/s ; P = 0.81W n = 1500 ; omega = 159 rad/s ; P = 1.22W n = 2000 ; omega = 212 rad/s ; P = 1.63W Above we see that, at 100RPM, the loss in the stator is .08W; at 500RPM it's 0.41W, etc. For all other RPMs we can interpolate, since the relation between RPM and stator losses is linear." End Stolen material. Well, it looks fiendishly complicated.... so it must be good 
Hope that clears it up Kiwijohn. ...........oztules Village idiot...or... just another hack out of his depth |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Well guys, Give it so time and get that 1.5Kw 3 phase motor mounted on my 4' lathe and with using the vfd and with the flat belt drive I'll have enough grunt for doing the test. Dinges I'll once agian disagree with you over doing bench tests over using real world conditions to test a generator. Jusr by putting the caps in serial worked a treat and untill Gordon came up and saw them I reckon everyone thought I was crackers to publish those kind of figures for a standard 100S in delta. Now with the 'jerry rigging' exercise if I see an extra 3-5 amps I'll be wrapped and send a decent royality over to Jerry in time for xmas 
Cheers Bryan |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Bryan, There is Jerry rigging and Jerry rigging. Jerry's original idea was to rectify every individual coil with it's own bridge rectifier, and add up all the outputs. In the case of your F@P thats 42 (I think) coils, and so 42 rectifiers. He would wind each coil for the expected output voltage using thin wire to gets the required turns. Later, people referred to rectifying each phase group individually as jerry rig, as no-one else I know off actually wanted to rewind their coils to Jerry's specs, and wanted to be able to switch from star to jerryrig... which is not possible in it's original guise. It is the 9 coils and nine rectifiers on his small axial that generated the high output figures, and a similar one that survived 1.6kw for 10 or so hours with no furling and a 4 foot prop from memory...... and I think 22 gauge wire. (250 turns)...(spider web stuff)....that was at 60 mph winds, later survived 80 mph winds.... no output figures for that though. Which scheme are you going with.... rewire to true jerryrig (42 little rectifiers) or the individually rectified "Delta" (three bridges). If you want to test "radical" then try the true jerry-rig....42 coil/rectifier one. Just curious........... .......oztules Village idiot...or... just another hack out of his depth |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Thanks oztules, apparently my subjective evaluations require a little honeing! 
Now then, I respecfully suggest this may be a contender for inclusion in the collective wisdom of all 'Back Sheders'. "If you find the F&P or similar configured alternator too big for your application you can always reduce it's 'size' by removing stator fingers and coils" For example, ..a human powered system ..you can only have a small turbine ..you only have very light winds ..you want to run at high RPM from a low torque drive ..you want to experiment and have something less than a 5KW lathe! |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi oztules, The principle of jerry rig is to primarily reduce circulating current losses between windings. If the coils are in series and not connected to other phases or parallel same phase coils there are no circulating currents. Any imbalance in coil emf appears as a reduced average emf, with resulting reduced power to the load. Bryan, I would only go the 14 series coils to caps then to rectifier. Gordon. become more energy aware |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Oztules, your memory and searching skills are scary; I had forgotten all about that experiment. Yes, indeed, I did once measure the stator losses of one of those tiny induction conversions. http://www.fieldlines.com/story/2006/8/12/213549/997 http://www.otherpower.com/images/scimages/3538/report_conver sion.pdf Had forgotten all about it .
That setup (with a wheel, bit of string and a weight) was done before I knew about De Prony brakes, but is in essence pretty similar. Of course, with De Prony brakes one can test at many different RPMs, so that renders this previous test more or less obsolete: it gives only *one* datapoint for efficiency (at near-zero RPM), whereas with a De Prony brake setup one can determine the efficiency curve over the entire operational range of the motor. Yes, that's what I wrote at the time and it's correct, but remember, in that test I was *only* measuring iron losses, not copper loss; I was talking there of 'stator losses' when I really should have been talking of 'iron losses'. The De Prony brake tests (of e.g. the 500W conversion) take the copper losses into account as well and are therefore much more valuable/useful. Just another reason why I wouldn't conduct the experiment like that anymore, but use De Prony brake measurements. Agreed, Oztules, and that's one of the reasons I dislike the term 'Jerry rigging': it means different things to different people and is meaningless to anyone who doesn't read Fieldlines. Over the past years I've seen the term used for both individual-parallel rectification ('delta-ish') and series connection with capacitors. Apparently, there's a 3rd way too, I understand from your words... The term 'individual rectification, parallel DC outputs' (or something similar) seems much more descriptive to me and anyone outside the field. And no ambiguity about the exact variant of Jerry rigging we're talking about. Doesn't sound as catchy as 'Jerry rig' though.
Simply try typing '(quote=Oztules) abcdefgh (/quote)', with the round brackets replaced by square ones. Can't get simpler than that... if even a windows loser like I can, then surely a Linux whiz like you can...  BTW, I did notice that clicking on a user's profile now also shows all the files a user uploaded. Nice! Thanks Glenn.
Peter. (pst, Oztules, I s'pose it shows your modification requests rank lower on Glenn's priority list than mine! )
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Dinges: "then surely a Linux whiz like you can.."..... You haven't seen me trying to compile a program without the right dependencies have you
Yes thanks to Glen we can see all the upload files now,..... stories and comments to follow?? Copper losses only occur once we start to generate into a load (skin losses are insignificant, and I only take notice of them at 20khz and upwards for pwm transformer winding), same with eddy currents in the copper, although your string method would have incorporated the copper eddy currents too. I thought it was a good novel way to measure these losses.... so well done anyway. Life is tough at the bottom of the request rank, think I'll have to go fishing and think about it a bit.... the beach is only 900 meters away...... life has it's good bits too.
.........oztules Village idiot...or... just another hack out of his depth |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi oztules, The quote button is at the top right corner of the normal window we would view posts on. Is it possible that the screen resolution has pushed the button out of view. This happens on my laptop when posts that include large images appear. Gordon. PS the embedded command dinges mentioned has the same result as the macro button, without the need to delete unwanted text etc. become more energy aware |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Hehehe, now I have it!!!..... suffer Dinges, I have been let loose with the quote button......... and I ain't afraid to use it 
Thanks Gordon... ......oztules Village idiot...or... just another hack out of his depth |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
[QuOTE=dinges][QuOTE=dinges] |
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feix62k Newbie  Joined: 30/07/2008 Location: AustraliaPosts: 36 |
hi are there any premade slipring assemblys available or could somone email me a few clues thanks Shane Ive got 2 7 phase moters ready just got to make the mounts 1 42 unit and 1 36 I think does it realy help using slip rings dont the days seem lank and long when nothing gos right and everthing gos wrong |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
The need for sliprings is really a function of local wind conditions. If you have wind predominantly from one direction, then sliprings would be optional. If you opt for no sliprings, then provision for removing cable twisting will be needed. BTW, both my mills have sliprings. Gordon. become more energy aware |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
The maintenance of the 24V battery has been an issue in my system. I had been using a voltage limiting diversion load. I decided that a commercial unit with settable equalize, boost, absorb and float voltages and times was needed. I had looked at a BS2 and a picaxe, but I achieved only limited success. I wanted to PWM regulate to the set voltages and direct the excess power to the grid. ON/OFF control was not desirable with the grid connection. I ended up interfacing a PL20 unit with my PWM boost 24-48V converter. The PL20 has 120Hz PWM output. This was not compatible with the 20kHz switching on my converter. I opto coupled the PL20 PWM output and integrated this signal onto the reference signal of the modulator. This changable voltage was compared with the feedback battery voltage and allowed one system to track the other. The PL20 modulated around the SOC setting and this was regulated by the booster with the surplus power going back to the grid through a PVE1200. The regulation holds the battery at the set voltage when there is excess power. One more aspect is now automated. If the grid is OFF, then the normal windmill braking may function to protect the battery. I am not supporting any brand in particular. I happen to have used a PL20 and PVE1200, but any battery maintenace controller with a PWM output could be used. I had used an SMA grid inverter as well with good results. The PVE1200 is supposed to consume 0W from the grid when it shuts down. Mine consumes 7-9W all the time and 19-20W when connected to the grid. I have added a SSR that disconnects the PVE1200 from the mains when the battery voltage has fallen to <27.6V for 10 minutes. If the voltage rises to >27.6V, then the grid is connected again. This has reduced unnecessary power consumption when surplus power is not available in the battery. I had hoped to eliminate the battery, but I will probably need a few hundred thousand uF to provide an effective battery substitute. Gordon. become more energy aware |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi all, A bit of an update. My windmill setup has produced over 4kWhr on 2 successive days now. I still have a problem with loading. The windmills electric brakes keep turning on, shutting the mills down. The power produced now exceeds the battery inverter loading during moderately windy sessions. I keep adding appliances to the battery inverter, but this is probably not the best solution. This is not sustainable during periods of light winds. I am trying to keep non metered battery power usage to less than 1kWhr per day, to minimise battery cycling. I will need to look at increasing the current limiting on the boost converter for the grid inverter. We can make better use of my surplus RElectrickery on the AC side. We still produce less power from the windmills than the base load of the house, so no wind energy is exported. This will be the limit of the windmill systems. Gordon. BTW the PVE1200 disconnection system is working well. When the battery is being used, the inverter is OFF, AC&DC disconnected and is not enabled until it is needed again. The automation of the battery charging and maintenance appears to have added lost capacity back to usable. I hope to be able to tidy the eagles nest of interlock wiring and sensing, once the systems are all fully tested. You can never have too many sealed enclosures to hide a mess of wiring. become more energy aware |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi all, I have finally lowered my AxFx mill. There is a bit of a lull in the wind. This has given me the opportunity to do a photo shoot and repack the bearings and give the housing and blades a makeup session. The machine has withstood the sea air quite well. Here are some photos. Gizmo may be able to strip some of my photos and place with the personal articles. 6476 This photo is of the alternator still attached to the yaw box with the extraction screws in place 
this photo is the extraction screws fully inserted, ready for rotor halves to be separated 
this photo is of the two rotor halves separated 
this photo is of both rotor halves laid flat after the stator has been removed from the yaw box 
this photo is of a close up of the wiring connection to the stator. The 4phase wiring is soldered to moulded in brass inserts in the stator. 
This photo is of all of the alternator components, including the 2 rotor halves, the stator and bearing hub, the 4phase bridge rectifier and the blade attachment adapter. 
I made the alternator as a motor in 1994. The alternator is basically a 4phase, dual rotor axial flux unit. The dual rotor fully contains the stator, with the electrical output wiring exiting the alternator through the hollow shaft. The assembled unit forms an environmentally sealed unit, with the only rotating point protected by a labrynth seal being at the rear. This contains a water flinger and 2 step dust seal, to protect the bearings from foreign matter, with minimal friction. You will notice that there are many bolts in the construction. The rotors consist of many layers of aluminium and iron plate that is internally bolted together. The two iron magnetic return paths are bolted to the inside surface of the outside aluminium plates with 22 countersunk cap screws on each plate. Each of the rotor halves is keyed on the outer rings to provide accurate magnet rotor, stator and bearing alignment. The stator is aligned centrally between the magnet surfaces with 0.5mm tollerances. The twin magnet rotors consist of 22 radially aligned 1"x1"x0.5" N34 Neodymium Iron Boron magnet blocks. The copper coils are arranged in 11 series coils and 4phases. The coils were moulded in resin. The bearing housing is one piece of aluminium stock that was machined, bored and milled. The stator is insulated and thermally bonded to this hub with a specially fitted aluminium adapter. Each phase only has to pass a maximum of 4amps, and each phase has a 1ohm resistance. The stator has to only dissipate 64W at maximum power output. The milled recesses in the stator adapter plate were designed for the solid state commutator, that is not needed as an alternator. This alternator did take a long time to make. I used no engineering diagrams and no laser cutting. I have to admit that I made some mistakes, I broke a 1/8" tap in one of the rings that forms the outer spacers, that was unable to be removed and the choice of an 11 factor did make some difficulties with holes and magnet placements. The aluminium moulding for the stator I milled with assistance of a rotary table, but no CNC stuff. Enough for now. I hope I have not put too many people off, who may wish to go and build their own machine from scratch. Gordon. become more energy aware |
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| feix62k Newbie Joined: 30/07/2008 Location: AustraliaPosts: 36 |
where did you get the plans to build such a beast. and what blades do you run 3,4,6 dont the days seem lank and long when nothing gos right and everthing gos wrong |
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