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DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292
Posted: 10:57am 09 Jan 2017
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Hi all
Have completed a new test on a F&P 36 pole copper stator wired 6x2C Delta Black rotor cap this time using a Capacitor Multiplier in parallel with main rectifier.
Readings were 59 VDC, 11.86 A @ 520 RPM, so that is a 700 W output from a single stator.
The best I got from a 42 pole 100s stator wired Delta using Capacitor Multiplier into same load was 59.5 VDC, 8.07 A @ 600 RPM output 480 W.
Haven't recorded the power output vs RPM from 60 up to 450 RPM yet to graph as this takes a bit of time. This was only done at around 500 RPM to verify what the maximum power output was. Using MPPT will get slightly more power, say another 25W.
I'm no longer going to do any testing on 42 pole stators unless someone requests me to do so for a specific setup.
These 36 pole stators if used to charge batteries will provide best results on a 48 VDC systems. To be useful at 12 or 24 VDC may need a rewire to say 0.9-1 mm conductor size. They can be used on 24 VDC setup, but wired Delta 12x1C. A but tricky to rewire, but is possible. So their use is a bit more restricted without rewiring using a thicker gauge or the use of a MPPT inverter/charge controller.
Using Dual 36 pole copper stators with black rotor caps direct drive at around 550 RPM, it may be possible to get close to 1400 W (1.4 kW) "Peak Power output" into a 48 VDC battery system.
DavidEdited by DaveP68 2017-01-15There 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 :)
carl1 Regular Member Joined: 16/04/2007 Location: AustraliaPosts: 79
Posted: 07:16pm 14 Jan 2017
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Hi Dave
just reading thru all your posts, great info.
Do you have a figure (Nm) for the cogging resistence of the black rotor smart drive?
I have a set of blades 2.2m , ex Lakota mill, which don't overcome cogging so easy.
At the moment I use an LG motor , decogged with " Black 600 blades " 2.0 m , poor output ( 12v system) : 20knts - 20 amps with MPPT.
I want to try a black rotor with an old 1mm stator on 7-phase.
Harald
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 12:04am 15 Jan 2017
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That's a big wind generator for a yacht
The furling is ingenious,it looks like an electric ram from a medical plinth was used. I use a similar ram for remote steering (from the bow) on my yacht.Klaus
DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292
Posted: 12:41am 15 Jan 2017
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Hi Harald
At this stage have no figure (Nm) for the Black rotor cap.
Did put a 12 VDC drill on one and measured the power required to turn it at about 6 to 8 W, so not much to answer your question another way. These F&P 36 pole stators are "Factory Decogged" like the LG stators.
Best thing to do, is try using the F&P 36 pole copper stator wired Delta 12x1C with a black rotor cap. Cut in RPM will be around 210 RPM with a max of 30 - 35 Amps output @ 12 VDC. With a "Cap Multiplier" will up your output power buy about 35% if designed correctly.
A 12 VDC system is very limiting for power output, as current is just too high and restricts your set up options.
Cheers
David
Edited by DaveP68 2017-01-16There 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 :)
carl1 Regular Member Joined: 16/04/2007 Location: AustraliaPosts: 79
Posted: 02:23am 15 Jan 2017
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Hi Dave thanks. As much I know cogging has nothing to do which way the motor is wired.
My LG motor , even decogged , rounded ends and twisted, has to much magnetic holding force for the " Lakota" blades to start, unless a gust of 15kts comes thru.. From data I did 10 years ago ( see my old entries) at that time the new " 60DS" had a cogging of around 80 to 100gramms , I can't remember if this was at the rotor measured or at 1m radius. With the new black rotor it might be more?
I can't go bigger in blades dia, they won't fit thru the entrance of the boat. The windmill is only up at anchor.
re: 12V ; I use a Midnight classis MPPT. so max. open voltage is 150VDC.
from your published data: F&P Stator power O/P MPPT vs battery: the 3x4c should be the pefect setup with your programming data of the MTTP - thanks!! If cogging permits it.
Measuering the holding torque of the rotor should be simple: tape a stick even across the front of the rotor and measure the weight you need to put on one end when it starts overcoming the magnetic holding force.
cheers
Harald
Btw: a week ago in a gust at Inskip , 35kts, 35amps , 1.6m 3-blade , the whole mill crashed down on deck when the pivoting pin sheared off. Lost my best blades (old frg) from a German " Black 300 ", extended to 1.6m.
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 02:42am 15 Jan 2017
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Dave, im unsure if you are suggesting a high voltage system or direct 12v charge.
If direct 12v charge then 200 rpm cutin is a very high speed and has too much loss when a target cutin of 100+/- rpm would be a better range.
Why have a mill spinning and making no power in low winds (@-200 rpm), that is where the cap voltage doubler was designed for, to pick up on small power where the rpm was not quite enough to reach cutin.( not to compensate for a bad design of too high of cutin)
Much below 80 rpm cutin the mill wont break out of stall, but anything above around 100 rpm cutin for a direct charge system is a huge waste of wind energy with no return.
Yes the blades might sound to be crap and hence why you suggest a very high cutin. but why design a mill limited to crap blades dont make good advice when one considers all the work involved to produce a working mill.
Sometimes it just works
DaveP68 Senior Member Joined: 25/11/2014 Location: New ZealandPosts: 292
Posted: 10:56am 15 Jan 2017
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Hi Harald
You never gave me the specifications of your MPPT setup, as that creates so many unknowns. Without that I just will advise on direct connection to the battery only. Which why I put 12x1C above. Having worked in the Aviation sector I'm very exact and only give advise on what little information I'm given.
Seems you have worked out what you need off my tables anyway, good on you.
As for the holding torque, haven't got any scales to do the weight measurement so that is why I haven't published it. No data no advice it's that simple. When I get access to some scales one day, it will be published.
Thanks for the feedback re tables.
DavidThere 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 :)
flc1 Senior Member Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 02:20pm 15 Jan 2017
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Hi Carl1, I would start by changing your blades,to a design similar to mine or phillm's blades, and maybe larger diameter,to overcome whatever cogging there may be.. just a thought? FredEdited by flc1 2017-01-17
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