Author Topic: Active Pitchcontrol  (Read 331854 times)

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joestue

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Re: Active Pitchcontrol
« Reply #528 on: February 26, 2017, 02:07:09 AM »
three problems:
Slip rings.
Low efficiency of small induction motors.
Difficulty and or expense of finding someone or the tooling to wind a doubly fed induction motor.

Secondly: you need a vfd to supply the difference in frequency to the rotating or stationary coils.
The energy needed to be supplied to the machine is proportional to the torque, multiplied by the difference in frequency.

So the usual industry standard is the vfd is about one third the capacity of the generator and that covers the usual range of 40-80hz operation into (or out of) a 60hz grid.
that's a 2:1 speed control, for which constant torque is available.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

mbouwer

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Re: Active Pitchcontrol
« Reply #529 on: February 27, 2017, 03:38:19 AM »
ULR and Joestue thank you for your reply.

I see this as a search for a self build suitable radial direct drive generator.
Without the use of the controversial neodymium.

Bruce S

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Re: Active Pitchcontrol
« Reply #530 on: February 27, 2017, 10:01:21 AM »
mbouwer;
Have a search look at some of Chris O's stuff . He's built some very mills using ceramic magnets.
His posts should help you on you quest. You might also PM him, he's sure to answer. He doesn't post much while getting the farm ready for planting.

Cheers
Bruce S
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Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #531 on: February 27, 2017, 05:12:32 PM »
I see this as a search for a self build suitable radial direct drive generator.
Without the use of the controversial neodymium.

What's controversial about neo?

The toxics from mining it in China?  Weaker magnets, more copper, and copper mining in the developing world isn't all that clean either.  Copper is quite toxic (in amounts above the traces needed for good nutrition).

If you're concerned about that, consider using stacks of recycled magnets from older disk drives.  Then the toxic side-effects have already occurred, and you're actually preventing a bit more from the recycling operation.

Is there some other issue?

mbouwer

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Re: Active Pitchcontrol
« Reply #532 on: February 28, 2017, 01:30:10 AM »
ULR,

I can see what you mean.
But I read so much about it and I would like to avoid it.

electrondady1

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Re: Active Pitchcontrol
« Reply #533 on: February 28, 2017, 02:40:16 PM »
will it be a dual rotor air core radial alternator mbouwer?
  or will you involve iron?
it will be a challenge to cast and position a stator for a dual rotor  air core alternator.
 
 
 

Bruce S

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Re: Active Pitchcontrol
« Reply #534 on: February 28, 2017, 03:57:39 PM »
mbouwer;
What speeds are you looking at ? I went back a few pages , but could not find the listing.

I am curious where you are with this so far

Cheers;
Bruce
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mbouwer

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Re: Active Pitchcontrol
« Reply #535 on: February 28, 2017, 04:51:40 PM »
I see this forum as  R&D.

As a hobby I want to become part of a team designing and building small windmills and exchange ideas and parts.

No matter if the team members live in my neighbourhood or worldwide.

Cheers Rinus
 

mbouwer

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Re: Active Pitchcontrol
« Reply #536 on: March 01, 2017, 05:27:51 AM »
The ideas on the forum to make your own gearbox inspire me, and I searched in my collection.

Bruce S

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Re: Active Pitchcontrol
« Reply #537 on: March 01, 2017, 09:07:37 AM »
understood.
You might try getting in touch with gnadt1990. His posts are about gaining insight to future RE stuff, but he's aslo located in Germany and might be able to assist with finding people with the same interests.

I like your website, it pushes my German/Dutch translation to it's limits ( That's a Good thing :-D) but google translate is also my friend.

There is also a thread : http://www.fieldlines.com/index.php/topic,149203.msg1040229/topicseen.html#msg1040229 you might want to follow.

gearing can be a double edge sworn , while you can gear up easily enough there could be startup problems.

Cheers
Bruce S
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Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #538 on: March 01, 2017, 07:24:25 PM »
... I read so much about it and I would like to avoid it.

What have you read that makes you want to avoid neos?  I haven't read anything that makes ME want to avoid them.

Some of the stuff I've read makes me want to be careful with them (so I don't get "pinched by an elephant" or "hit by a flying tool" while assembling some powerful machine or otherwise handling the very strong magnets, shatter one and have flying particles, or disrupt their coating and have them rot away).  But I have yet to see anything that makes me think I should avoid them.

Gennies built with weaker permanent magnets still have very strong forces involved and must still be handled carefully to avoid accidents.
« Last Edit: March 01, 2017, 07:51:49 PM by Ungrounded Lightning Rod »

mbouwer

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Re: Active Pitchcontrol
« Reply #539 on: March 02, 2017, 08:23:38 AM »
ULR,

I see what you mean.

On their website Enercon writes:

... excited annular generator, there is no need for the use of permanent magnets that are manufactured from highly controversial neodymium (rare earths).

How you interpret that?

Bruce S

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Re: Active Pitchcontrol
« Reply #540 on: March 02, 2017, 09:38:28 AM »
mbouwer
Personally I see that statement as an opinion; unless they quantify the "highly controversial " portion.

I can saw with all due respect, if you assemble a brake hub with ceramic mags such as Chris O did (mine were only 1/2 the size) you will quickly see how those forces can be just as dangerous.

I stayed away from Noes due to the cost involved when I started learning & my ceramics came to me free. The ones salvaged from HDD are crazy strong and I now regularly use them behind the ceramics. I cannot build full sized 'mills due to urban living and safety laws. But the coffee can mills are great little backups to solar lawn light panels.

Hope this helps too

Bruce S
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mbouwer

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Re: Active Pitchcontrol
« Reply #541 on: March 03, 2017, 05:37:09 AM »
It would be nice to meet someone on the forum who is building the 2- or 3F from Hugh.
 

midwoud1

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Re: Active Pitchcontrol
« Reply #542 on: March 03, 2017, 07:04:27 AM »
Like the recipe book the 2F is valueable as well.
I learned alot with Hugh's construction books and info at internet.
It is the base of my succesful active pitchcontrol windturbine run for many years.
Using ferites which are good embedded in epoxy or polyester will hold at higher rpms .

Rgds  Fbm.

Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #543 on: March 03, 2017, 02:27:33 PM »
On their website Enercon writes:

... excited annular generator, there is no need for the use of permanent magnets that are manufactured from highly controversial neodymium (rare earths).

How you interpret that?

"Controversial" doesn't mean "bad".  "Controversial" means "some people are talking about it and have differing opinions".

Usually it's uninformed newsies regurgitating the handouts of somebody with a competing product that is impacted by whatever they're slamming.  (The newsies do this because they need something to print to get their next paycheck.  Edit:  My wife points out that "They also do that because six major corporations own just about all of the media in the US and some of them have very diversified holdings - possibly including a competing product.")

Any windmills at all are "controversial".  "Oh NO!  They KILL THE POOR BIRDIES!"  Note that this meme started showing up right after a plan was announced to build offshore windmills that would have been visible from the Kennedy compound on Martha's Vinyard.  All of a sudden windmills went from earth-saving carbon-replacing green tech to sky-mowers cutting down migrating flocks and hunting raptors.

(Hint:  Birds die where they live.  The area around a wind farm is a prime hunting ground for raptors, so guess where their corpses end up.  As for migrating birds, wind farms are a drop in the bucket compared to glass skyscrapers and moving vehicles.  {Have YOU ever seen a goose corpse in one of those open grassy fields?}  Hunting license numbers are adjusted to keep the flocks at a healthy population, so even if giant windfarms DID kill a significant number, rather than maybe an occasional bird, the relevant states' fish-and-game departments would cut the number of licenses and at least the gamebirds would be unaffected.)

If all you are worried about is "controversial" you're worried about nothing but where a particular news fad went.  Look for the truth, if any, behind the controversy.  But don't expect to find any substance:  If they had anything real, they'd have used it instead of trolling with "controversial".

But if you still think "controversial" means "significantly bad", why are you making a windmill at all?

Avoiding controversy means becoming a conformist, being herded, and having your life (and death) controlled, by the people who run the media or are skilled at applying social pressure.
« Last Edit: March 03, 2017, 07:41:20 PM by Ungrounded Lightning Rod »

mbouwer

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Re: Active Pitchcontrol
« Reply #544 on: March 03, 2017, 04:54:54 PM »
ULR,

What you are writing is quite clear to me.

My point is that I find the making of a safe reliable windmill rather complicated.

And I think it would become easier in cooperation with other disciplines.
Just like in a company.

 So the intention is to make contact with windmillfriends and exchange ideas and parts.

Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #545 on: March 03, 2017, 07:56:46 PM »
ULR,

What you are writing is quite clear to me.

My point is that I find the making of a safe reliable windmill rather complicated.

And I think it would become easier in cooperation with other disciplines.
Just like in a company.

 So the intention is to make contact with windmillfriends and exchange ideas and parts.

Then you've come to the right place.  B-)

By the way:  If I sounded annoyed, it's because I am.  But not with you.  I'm annoyed by people who use social pressure judo like the "controversial" trick, and that they'd use it on one of our newer people, with the possible result of misguiding him into making a less effective mill.  (I've had far too much of this stuff lately, thanks to the recent political season going into overtime.  B-b )

clockmanFRA

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Re: Active Pitchcontrol
« Reply #546 on: March 04, 2017, 02:38:37 AM »
Hi mbouwer,

As I have said, your are welcome to pop down the road, (but you might have to come through Belguim!), for a couple of days and examine and talk about my 3.7m, 12 footers, Hugh Piggott design Wind Turbine farm.

How many do you need to be a farm, three ?.

Hughs design is Simple, and Robust. Yes there are areas for improvement, but considering one of mine is getting on for nearly 10 years of flying, with just one tail jumping, the modifications are pretty minimal.

And where one of mine has failed its normally due to my new fiberglass blades being twice the weight of Cedar blades. Yes I stick to Cedar now, because I have a local source.
  Note to 'Damon' with 'Bruce' hiding behind, (what a sight that would be hehe).  .... No 2 shed a blade when one delaminated the two halves at the root, a weak point for fiberglass blades. And throws it about 200 meters across the road.

midwoulds pitchcontrol is fascinating and I enjoy reading his posts.

Just about to re-balance my No3 after its modifications and re-launch. James a RE guy from the UK is here helping me around the place for a couple of weeks on a Cultural Exchange, WORKAWAY arrangement. As he was part of a team that built a HP at V3 near Nottingham UK. Its real nice to talk to folk who love there Wind Turbines.

Dead Birds.. In Nearly 10 years, I have only seen one starling at the foot of my No 1, but considering it was being eaten by one of the local cats when I found it, that might not be a fair conclusion of a Turbine strike.

I find Fish at the base of my No 3, In a half eaten state...... I think one of my cats Mr 'Puosoin Rouge' likes the new non moss covered concrete base as eating surface. Very odd staring at the depths of a 100,000 litre pond to see a black and white cat swimming up towards you with a Gold fish in its mouth. !

Sorry rambled of topic.



 
Everything is possible, just give me time.

OzInverter man. Normandy France.
http://www.bryanhorology.com/renewable-energy-creation.php

3 Hugh P's 3.7m Wind T's (12 years) .. 5kW PV on 3 Trackers, (8 yrs) .. 9kW PV AC coupled to OzInverter MINI Grid, back charging AC Coupling to 48v 1300ah battery

DamonHD

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Re: Active Pitchcontrol
« Reply #547 on: March 04, 2017, 04:10:05 AM »
How many do you need to be a farm, three ?.

1 in the limiting case, or 0 if you are still in 'research' phase.

3 is luxury!

Rgds

Damon
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mbouwer

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Re: Active Pitchcontrol
« Reply #548 on: March 04, 2017, 05:31:48 AM »
Nowadays with internet and sending parcels all over the world,
for me I think it's much more fun to contribute to mills of friends,
than work on my own all the time in my backshed.

Think of all the possibilities of new materials, electronics, new windmill techniques.
It's only a question of disciplines finding each other.

mbouwer

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Re: Active Pitchcontrol
« Reply #549 on: March 04, 2017, 03:18:44 PM »
And just like Kitestrings and Clockman show us:

All that matters is a good team.

mbouwer

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Re: Active Pitchcontrol
« Reply #550 on: March 12, 2017, 06:00:59 AM »
In:    http://www.windstuffnow.com/main/poured_stator.htm
I read about a poured stator.

Is someone on this forum doing so?
And where to find the right kind of iron powder?
« Last Edit: March 12, 2017, 06:05:12 AM by mbouwer »

hiker

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Re: Active Pitchcontrol
« Reply #551 on: March 12, 2017, 09:57:59 AM »
Machine shop....should be able to get some cut offs or grinding waste their....home or lowes depot sell a product called epoxy stick...one brand has steel in it..would cost a pretty penny for enough for a full size stator..coffee can size..?
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Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #552 on: March 14, 2017, 06:58:26 PM »
Machine shop....should be able to get some cut offs or grinding waste their....home or lowes depot sell a product called epoxy stick...one brand has steel in it..would cost a pretty penny for enough for a full size stator..coffee can size..?

Ordinary steel will eat a lot of power and turn it into heat, due to hysteresis.  You need powdered transformer iron or (better yet) the powder that they use to cast "ferrite" transformer toroid and cup inductor "cores" for circuit boards.  (NOT the kind they use for ferrite beads, which in some cases may also be deliberately "lossy".)

mbouwer

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Re: Active Pitchcontrol
« Reply #553 on: March 15, 2017, 05:51:18 AM »
Perhaps if I could find the powered transformer iron at a reasonable price I could make a stator mould.

Mary B

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joestue

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Re: Active Pitchcontrol
« Reply #555 on: March 15, 2017, 07:55:02 PM »
the whole point of using a core is so that you don't have to shove magnetic flux through air, which costs you nothing if its from a magnet, except for the one time expense of a bigger magnet. due to the resistance of copper, it is not practically possible to make an electromagnet air core motor. btw, the core has an additional benefit: the flux lines don't go through the conductors, they go through the core, as such the coils don't have near as much eddy current losses, but in an axial flux machine that's probably not a problem unless you exceed 60 to 300 hz at 1T flux densities, and its practical to use fine wire. but if you want to get 100,000 rpm on an 8 pole machine, you will probably have to use 30 gauge wire or finer (yes, somewhere i have a document on this, experimental flywheel energy storage iirc).

But the air gap flux densities that you're dealing with in an axial flux neodymium machine exceed practical flux limits of cheap powdered iron cores. you could have a powdered core made that could handle 1T flux densities, but it's cost would exceed the wire or sink EDM cost of cutting slots into a toroidal transformer core. -water jet cutting them would be better. but finding a place that can cut 2 inch thick steel may be difficult. also the coil would probably have to be unwound, then re-wound with epoxy between the layers to make sure the metal doesn't shift during the process. the coil would have to be set up on a rotary table with some kind of deflector i would imagine to due to the topology.

practical flux densities for ferrite is .4T, and they compress the powder to tens of thousands of psi to get the density required. you can't just mix it up with epoxy. look at the cost of those ferrite cores. at the low frequencies involved here ferrite bead material will work just fine though, and you could probably buy bricks of it and then cut and fit them together to make a core. this would be practical for a ferrite magnet motor, but with neodymium it would be of no practical assistance.


radial flux machines are more efficient than axial flux anyways, why not just make a motor conversion? once you add a core to an axial flux machine its not much lighter than a radial machine
« Last Edit: March 15, 2017, 08:00:14 PM by joestue »
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CraigM

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Re: Active Pitchcontrol
« Reply #556 on: March 15, 2017, 08:41:39 PM »
Ran across this site a while back that is promoting sinter and powdered metallurgy for motor design. I've have never seen a motor core done in this way.

http://www.gkngroup.com/sintermetals/products/mechatronics/radial-flux-motor-and-generator-components/Pages/default.aspx

Brain engaged in Absorption Charge Mode... please wait, this may take awhile.

mbouwer

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Re: Active Pitchcontrol
« Reply #557 on: March 16, 2017, 05:58:55 AM »
Joestue,

You say:"The powdered iron has to be compressed. You can't just mix it with epoxy".
But suppose I organize the coils in a mould and pour the flued in. In a short time the stator is ready.
Do you think less efficiency will be a big problem then?

joestue

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Re: Active Pitchcontrol
« Reply #558 on: March 16, 2017, 11:47:31 AM »
If you do use iron powder, then it can help.

Ferrite powder has a maximum flux density of .4T, as such it will be no help in a neodymium system.

To get reasonable permeabilities with iron powder, then yes it has to be compressed. by reasonable i mean more than like, 10.
But with an air core system any improvement is better than nothing since your magnets are already sized for no core at all.
The frequency is fairly low, the hysteresis losses may not be significant, I believe the bulk of any efficiency loss would be eddy currents. you may want to bake the iron powder to get a uniform coating of oxide on the surface.
« Last Edit: March 16, 2017, 11:55:06 AM by joestue »
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hiker

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Re: Active Pitchcontrol
« Reply #559 on: March 16, 2017, 06:56:35 PM »
posted this awhile back;;bike alt......coils mounted to a flat steel band...coils have stacked steel inserts in the coil holes....steel inserts made out of steel cutoffs from a length of flat steel..these were super glued together ..then glued down to the steel band...coils  mounted over them....mags are ceramic with neos glued on top for some extra kick...mags are glued down to the flywheel...with epoxy stick  around each mag....thought their might be a lot of cogging..but it spins over with my finger...some drag thou..because the wheel has a slight drag to it....so far its worked out great as a exersize bike...max 60v with currant gearing...lights up a 400w-28v.  aircraft landing light.....to 25v..best i could do at the time...fun stuff
WILD in ALASKA

hiker

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Re: Active Pitchcontrol
« Reply #560 on: March 16, 2017, 07:12:26 PM »
not sure why two picts..loaded..    heres a  vid. link...if it works ?    https://www.youtube.com/watch?v=yl2OGvOoTj0         https://www.youtube.com/watch?v=kSqNOVECurc
« Last Edit: March 16, 2017, 07:31:36 PM by hiker »
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