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Forum Index : Windmills : F&P Stator 759W output in Delta mode
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DaveP68 Senior Member  Joined: 25/11/2014 Location: New ZealandPosts: 292 |
Started doing some testing on 2 F&P Smart Drive stators today first was an 80 series and the 100 series (only tested in star mode). Started of on a 80 series (0.8 mm 42 pole) wired in Delta mode and got 759W output 950 RPM. It was un-cut with output via a 3 phase bridge rectifier was 230V @ 3.3A DC into resistor ~70 ohms. Load made from dynamic brake resistors out of Smart Drive Motor Control Modules which I do repairs on myself. Own a business specialising in repairing these smart drives so hence the interest in play with these stators. Also tried same stator wired back into its original star configuration got similar ~720W output 960 RPM into 98 ohm load @ 266 x 2.7A. The main reason for the small differences between star & delta in power is due to load miss-match. The 100 series star produced 750W @ 955RPM 136V 5.5A so results are consistent. Haven't tested a 60 series yet as need to make a suitable high power load to match it's output and plan do both 36 & 42 pole versions. The only reason they topped out at ~750W is the drill used to drive the rotor cap is limited to 1200W but de-rated below that in high gear. Yes it's possible to half cut them or even divide down to 7x2 poles per phase to lower down to a more workable voltage level with far more current output on say the 80 series. I would only cut a 100 series in half, voltage output to low beyond that. From my observation there seems to be a lot of discussion on this site relating to only using these stators in their star configuration, with delta only useful at high RPM. Yes the voltage is less for Delta but you get more current. Basically the "Power" output is the same for any given RPM as long as the load is correctly matched. I have been reading other posts on here where no more than 350W has been extracted from a single stator. One of the main reasons for this is when used to charge a battery and the working voltage is reached, then the only variable left is to increase the current output. Stator just goes into saturation mode from this point onward as the RPM increases. So connecting to a battery directly without any form of DC to DC converter using MPPT is wasting most of you upper power level potential. Don't get me wrong as some good results been achieved by those on here with stators been used on wind mills and I don't have a wind mill yet. A suitable DC to DC converter to over come these limitations would need a variable input (say 10V to 100V) with a controlled output (13.8V or 27.6V) into batteries. Basically these stators want to see a constant equivalent load. My next plan is to get a dedicated electric motor with at least 1500W output @ 1200 RPM and I expect to reach the magic 1kW output! One other thing to note with my testing is the winding's didn't event get warm. There are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :) |
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| govertical Guru  Joined: 11/12/2008 Location: United StatesPosts: 383 |
Greetings, thanks for posting. I am working on a similar DC to DC power converter project to use with a F&P for charging 12 volt deep cells. Results to date. I look forward toward results. just because your a GURU or forum administer does not mean your always correct :) |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hey Dave If you havn't see it check out the F&P section of the site http://www.thebackshed.com/windmill/Contents.asp#3 I've run a delta and a star side by side on a dual stator windmill, worked pretty good. Another forum member Bob Mann as getting over 1kW from a F&P a couple of years back using a maximizer circuit. Similar to using a intelligent DC to DC converter. The problem is the high RPM. At around 300 to 500 RPM, a F&P makes about 300 to 500 watts. And this needs a turbine around 2 to 3 meters in diameter to match. That size is a fairly easy build for most of us, and it means the F&P is a direct drive connection, so no gears/chains/etc. If we wanted to go up around 700 watts or so, we would need a bigger turbine to drive it, but a bigger turbine spins slower than a small turbine. So F&P give more power at higher RPM, but bigger turbine to match runs at lower rpm. So we need to use gears/chains/etc to gear up the rpm, and this becomes a much more difficult project to build. It would work though, there is no reason you could not get 700 watts from a F&P based wind turbine. Once you stat to go over 700 though there are losses in the F&P due to its high inductance, and power start to drop off. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292 |
Hi Glenn Thanks for the informative reply as I'm pretty new to this site and how to make power from these F&P stators. I still believe putting the output of a stator via a bridge rectifier directly into batteries best isn't the way to go. If you have to do it that way (with charge controller) well then that's the only option. Are there any other power curve charts/data tables for the output of the F&P stators on this site that I've not spotted yet? Also have you tried the newer Black rotor caps? They have a stronger magnetic field and from some other tests I've done can produce up to 40% more output for the same RPM as the arrow head white rotor caps. In my opinion the 36 pole decogged copper stator is the best on over all efficiency due to it been able to be cut into different combinations. I'm working on designing an electronic switch unit (using power MOSFETS) as that is simpler than the more complex DC to DC converters you mentioned. This involves cutting the stator in quarters but wired delta with each 3 phase 1/4 set of windings coming out to it's own bridge rectifier. From there you can electronically switch the windings in series at start up for more voltage low RPM (lease current) and all in parallel same voltage, but much higher current at higher RPM. The power curve will have less staturation hence more efficient for say going into batteries. Will keep you posted on that development. As mentioned in my first post I repair these F&P Samrt Drive Washing Machines including the repair of the motor controller boards. So have an ample supply of free electronis parts from the written off older modules that use MOSFET's etc. Very much Back Shed stuff.. Cheers David There are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :) |
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| flc1 Senior Member Joined: 20/11/2011 Location: New ZealandPosts: 242 |
Gday Dave,that sounds like the output that Im working towards with my Gridtie dual f n p wind turbine,with the help of my cousin ,I think my cousin and I will acheive somthing similar after we make a couple of changes to the stators in the turbine ,Awsom results you have there, I would be interested to see what they are if you go to a more powerful drill for your testing.Good ole f n p stators  |
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| DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292 |
Hey thanks for your feedback. Check out my latest post about one of those black rotor caps on a 36 pole stator, got 880W out with that same drill so getting close to that 1kW ouput!! Good luck with the changes you're about to make, hope get some much better results, so let me know how you get on. You could be interested in my prototype switching unit that provides a good start voltage in low wind but lots more power at the top end. The best of both worlds 
Cheers David There are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :) |
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| DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292 |
Hiya I'm also interested in build my own DC - DC converter use recovered power MOSTFET out of old F&P motor control modules as got a 100 plus of them in the workshop. Ample supply of free components. Keep me posted on your unit as watched your Youtube video which shows promising results. Cheers David There are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :) |
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| govertical Guru Joined: 11/12/2008 Location: United StatesPosts: 383 |
Hi, I am currently fabricating a manually operated hand crank F&P. Then I have to update the schematics. I will post results when available. Hopefully I will have more info in a few months. Basic drawing of test circuit showing manually controlled duty cycle. Maybe check online for info regarding DC to DC step down converter. I fabricated four 5 amp circuits and operated them in parallel. I had problems finding the parts for a higher wattage design. Hope this helps getting you started. Basic circuit just because your a GURU or forum administer does not mean your always correct :) |
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| DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292 |
Hi Thanks again for the circuit and heading me in that direction. Will do some more research into DC to DC step down converters. Cheers David There are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :) |
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