Author Topic: Active Pitchcontrol  (Read 331816 times)

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midwoud1

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Re: Active Pitchcontrol
« Reply #495 on: February 04, 2017, 02:46:54 PM »
Hi Rinus.

Do have power with motordrive on your celingfan generator?
On Youtube there are several ceilingfans converted to generators.

Rgds: Midwoud1,

mbouwer

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Re: Active Pitchcontrol
« Reply #496 on: February 05, 2017, 04:56:05 AM »
The ceilingfan motor is in its original state. I only have made a new axle in it.
I would like to find a way to use it as a generator. ( without neodymium )

hiker

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Re: Active Pitchcontrol
« Reply #497 on: February 05, 2017, 11:55:38 AM »
Cheap ceramic mags...output will be low...rewired one of mine...with some heavy wire..mounted next to a small gas engine..hit 15-20 amps output...if your going with small stuff..just use a car or truck alt...you can play around with the field coil power input to get the power output you want...treadmill motors are another way....motor conversions ........lot of options......
WILD in ALASKA

Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #498 on: February 05, 2017, 08:40:31 PM »
The point of going with permanent magnets is that the excitation field costs you a lump sum at initial construction.  With a wound field the excitation costs you an ongoing drain on your produced (or stored) energy.  This is worst when the incoming wind is low, and not just in proportion:  The slower you're spinning, the more excitation power you need to get a given output voltage.

In addition to eating much of your production (and the most when you need it the most because wind is low), wound-field excitation has the effect of raising your cutin wind speed (by eating all of your output at otherwise usable low speeds) and thus drastically reducing the fraction of the year your mill actually generates anything useful.  While wound-field generators are usable, they need a larger turbine and oversized generator, compared to a permanent magnet alternator, to deliver something useful.

Ferrite is pretty wimpy, as are most other non-rare-earth magnets, so you don't get much out of your converted fan motor's stator's already low power flux guides and windings.  Neodymium magnets were the breakthrough that took us to really practical home-brew microgeneration mills.  In a motor conversion they are strong enough to saturate the transformer iron laminates, which gets as much power out of the windings on them as it is possible to get.

If you don't want to buy some neos, see if you can find some scrapped computer disk drives and pull the neo magnets from their head actuators.

DON'T break them to fit:  Neos are plated to protect them from corrosion and will rapidly rot away if the plating is compromised.
« Last Edit: February 05, 2017, 08:44:42 PM by Ungrounded Lightning Rod »

Adriaan Kragten

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Re: Active Pitchcontrol
« Reply #499 on: February 06, 2017, 06:03:42 AM »
It is possible to get a strong magnetic field in the air gap if ferrite magnets are used but only if the magnetic flux is concentrated. Concentration is only possible for radial positioning of the magnets. To prevent a strong fluctuation of the clogging torque, the magnet grooves have to be inclined with the correct angle with respect to the generator axis. One of my first PM-generators was made this way from a 12-pole car generator and it reached an open DC voltage of 12 V at a rotational speed of 900 rpm, so at about the same rotational speed as for the original generator with an electromagnetic armature for the maximum armature current. This PM-generator is described in chapter 3 of my free public report KD-341.

mbouwer

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Re: Active Pitchcontrol
« Reply #500 on: February 07, 2017, 03:58:48 PM »
This is the ceiling-fan motor with its original stator and rotor.
Only thing I did was to make a hollow ( pitch control) shaft with heavier ball bearings in it to attach the blades.

Now if you drive it above its nominal number of revolutions per minute:
Will there be a chance then that it starts functioning as a generator?

« Last Edit: February 07, 2017, 04:07:08 PM by mbouwer »

Bruce S

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Re: Active Pitchcontrol
« Reply #501 on: February 07, 2017, 04:11:13 PM »
mbouwer;
IF that ring that I'm seeing is in fact magnets, then YES you will see voltage.
From shaky memory cells, you will actually begin to see a voltage when you begin to spin it.
The voltages will probably be high with a low current abilities.

Best would be to start spinning the motor with known speeds and a volt-meter to find beginning of voltages and highest out.
Once there, you can go further if you wish.
OF course; your current limits are going to be a function of the wire sizes.

Cheers;
Bruce S
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Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #502 on: February 07, 2017, 09:32:04 PM »
This is the ceiling-fan motor with its original stator and rotor.
Only thing I did was to make a hollow ( pitch control) shaft with heavier ball bearings in it to attach the blades.

Now if you drive it above its nominal number of revolutions per minute:
Will there be a chance then that it starts functioning as a generator?

It has a two-phase winding.

The ring looks like a "squirrel cage" - a conductive component dragged around by the magnetic field from the coil/laminate assembly and the magnetiztion from the eddy currents that field generates within it.

If you connect a capacator across ONE of the phases to make a resonant circuit (leaving it otherwise unconnected), leave the other unloaded at low voltages (for instance, by hooking it to a rectifier and battery, which won't pull appreciable current until the voltage gets to the battery voltage plus two diode drops), and the rotor has a bit of residual magnetiztion to get things started, when you spin it up to where it's going a tad faster than the RPM corresponding to the resonance, you should start pumping energy into the "ringing" of the tuned circuit - up to the point where the core is saturating.  It will start "fighting back" to try to keep itself from spinning appreciably above that RPM.

At that point the magnetic lines that are "nearly pinned" by the eddy currents in the rotor will also be dragging through the other phase's winding, generating a voltage and transforming shaft HP into electrical energy you can harvest.

There are substantial downsides to this approach - among them that (like a wound field) you have copper losses, both in the resonant winding and the rotor, and that it only works at a narrow range of RPM.  Nevertheless, it can give you nontrivial generation without further conversion of the rotating electrical machine to add either magnets or a field coil to the rotor.
« Last Edit: February 07, 2017, 09:38:01 PM by Ungrounded Lightning Rod »

mbouwer

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Re: Active Pitchcontrol
« Reply #503 on: February 08, 2017, 05:43:14 AM »
It is a FRAMEWAY AC~ CEILING FAN MODEL: FW 48 230 V~ 50 HZ 60 W 310 rpm

Can you tell me how to start to get those 60 Watts out of it?

hiker

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Re: Active Pitchcontrol
« Reply #504 on: February 08, 2017, 01:04:35 PM »
Made a few ceiling fan gens...toss the ring...super glue mags on the inner side of a case cover..use spacers if you have to ..to get a close air gap ...on your motor it looks like ..the mags would have to overhang a bit..sence your case is split down the middle of the motor ?  Should still work..just glue down well...I like to use epoxy stick..to fill in the gap between the mags..drys rock hard..then just resemble the motor...tah dah....your done...just give a spin...and light up some l.e.d.s....yours is a high voltage motor...not sure what it would do...ide rewire for 12v use if that's what want...easy to do on these little motors....have fun...
WILD in ALASKA

hiker

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Re: Active Pitchcontrol
« Reply #505 on: February 08, 2017, 01:20:34 PM »
Ps..the amount of mags are determined by the number of coils you have..on the outer ends of the lams..looks like ..14-16.?..  That's the number of mags you need..glue the mags down..north south north south..all the way around..just hold a mag in your hand.. Put near a case mounted mag..it should pull your hand down..next case mounted mag should push your hand away..then next mag will of course pull your hand down...and around you go....simple...
WILD in ALASKA

hiker

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Re: Active Pitchcontrol
« Reply #506 on: February 08, 2017, 01:23:25 PM »
Now if you want to rewire for 3 phase....its a whole different  story..
WILD in ALASKA

mbouwer

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Re: Active Pitchcontrol
« Reply #507 on: February 08, 2017, 04:55:06 PM »
My goal is: -- not to use neodymium ( or ceramic magnets )
                 -- participate in a team to design and make a real nice direct drive generator.

hiker

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Re: Active Pitchcontrol
« Reply #508 on: February 08, 2017, 09:50:40 PM »
Try a cap. Across the lead out wires..hit it with a few volts while its spinning..Should only take a secound..then disconnect power..if that worked..you should have power output on the lead out wires..check with a voltage meter...then try a small load....won't get much with that motor...if you get no power out....then you will have to make some small field coils for each output coil..not sure if that would work on such a low output motor.gen...of course you will have to hit it with a few volts to get things started..done this with car alts..once going the alt powers the field coil......
WILD in ALASKA

mbouwer

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Re: Active Pitchcontrol
« Reply #509 on: February 09, 2017, 04:35:16 PM »
I understand that this is a wrong way trying to make a generator. It wo'nt work.

Hiker,
You mentioned rewiring for 3 phase. Is that an option?
The outer ring is 14 coils. The inner ring 7 coils.
« Last Edit: February 09, 2017, 04:56:16 PM by mbouwer »

mbouwer

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Re: Active Pitchcontrol
« Reply #510 on: February 14, 2017, 02:40:28 PM »
Not so many wind turbine builders here in the Netherlands. But I always want to come in contact with them.


Bruce S

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Re: Active Pitchcontrol
« Reply #511 on: February 14, 2017, 03:57:05 PM »
I like the blades!
You do know that once you put up a 'mill there's normally 3 days of no wind  ;).

Cheers;
Bruce
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mbouwer

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Re: Active Pitchcontrol
« Reply #512 on: February 14, 2017, 04:17:46 PM »
The turbine is from the Danish Technical University

Cheers Rinus

Bruce S

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Re: Active Pitchcontrol
« Reply #513 on: February 14, 2017, 04:32:08 PM »
IF you don't mind me asking> Where are you located?
There used to be a good dozen of the home built units on the way to Amsterdam from Brussels.

Not every large tho, only around 2 meters tip to tip. 3-bladed units that were right along side the beautiful 4-bladed grinding mills. This was back in 2007 - 2009

Cheers 
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Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #514 on: February 15, 2017, 03:50:52 AM »
...
You do know that once you put up a 'mill there's normally 3 days of no wind  ;).

That's not just Murphy's law.

In the poleward part of the temperate zones the weather systems tend to come by roughly periodically, several days apart.  It has to do with downwind propagation of waves in the boundary between the (ant)arctic and temperate zone regions.  Three-ish calm days, or a bit more, is typical.

When you're installing a mill you wait for calm and dry weather, so you're not working in the rain or wrestling with big airfoils in strong or gusty winds.

So you put it up at the beginning of a calm period.  Then, when you've got it up, and are waiting with bated breath for some wind to make it spin, you get to wait out the remaining days of the calm period before you get to see whether your new mill actually works.  B-)

Or at least that's the case if you don't have something that gives you a daily "lake effect" cycle.  (Like northern San Jose CA, where the "lake" is S.F. Bay and the "island" is the valleys to the south.  Or Altamont Pass in CA, where the "lake" is the Pacific Ocean, the "island" is the Central Valley, and the pass is the notch in a wall of mountains between them.  Or my ranch, where the "lake" is Tahoe and the ice caps on the Sierra Nevada mountains, the "island" is the desert portion of Nevada, and Monitor Pass forms the funnel throat.)

In lake effect situations a windmill is the power takeoff on a solar heat engine the size of an appreciable fraction of a continent.  B-)
« Last Edit: February 15, 2017, 04:20:51 AM by Ungrounded Lightning Rod »

mbouwer

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Re: Active Pitchcontrol
« Reply #515 on: February 15, 2017, 05:14:55 AM »
Bruce,

It is in the South, not so far from the coast where I live.
And I would like to form a team with others who want to use windenergy.

Bruce S

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Re: Active Pitchcontrol
« Reply #516 on: February 15, 2017, 08:53:53 AM »
ULR;
During my short stay in the south eastern region of MI there was the lake effect of Lake MI too, the bad part, it was most noticeable during the winter (AND still is according to kin that still lives in that area).

mbouwer ;
You should have NO problems finding fellow 'mill DIYers . Once they see your mill I'm certain they will be stopping by.

Best of Luck
Bruce S
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mbouwer

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Re: Active Pitchcontrol
« Reply #517 on: February 15, 2017, 12:19:48 PM »
On the photo above is a working model that we made in 1990 of the Stork Newecs 45
We had a club here then: the Gewiekste.
The mill and also the club do'nt exist anymore. Always seeking new windmillfriends.
« Last Edit: February 16, 2017, 07:39:54 AM by mbouwer »

Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #518 on: February 19, 2017, 12:27:08 AM »
ULR;
During my short stay in the south eastern region of MI there was the lake effect of Lake MI too, the bad part, it was most noticeable during the winter (AND still is according to kin that still lives in that area).

Where were you there?  (I was born in Grand Rapids and raised in Ann Arbor and Milan before eventually moving west.)

Ann Arbor and Milan were far enough from the great lakes that the daily cycle lake effect winds were absent, or at least not particularly noticeable compared to the prevailing and weather-system winds.  (We left G.R. before I was old enough to remember much, but I understand they also have a related phenomenon of the same name there - where the humid wind off the lake onto the cold land dumps LOTS of snow and silverthaw ice in the winter onto the first tenish miles inland from the western coast.  B-b )

mbouwer

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Re: Active Pitchcontrol
« Reply #519 on: February 22, 2017, 04:57:50 AM »
We also made this water turbine. With pitchable blades.

midwoud1

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Re: Active Pitchcontrol
« Reply #520 on: February 22, 2017, 08:02:16 AM »
Living in Northwest Holland . Average wind 5m/sec .40 Miles north of Amsterdam.
Classic waterpumping windmills fixed pitch .
Those mills were used to create new land from sea and lakes.


Bruce S

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Re: Active Pitchcontrol
« Reply #521 on: February 22, 2017, 09:00:02 AM »
ULR;
During my short stay in the south eastern region of MI there was the lake effect of Lake MI too, the bad part, it was most noticeable during the winter (AND still is according to kin that still lives in that area).

Where were you there?  (I was born in Grand Rapids and raised in Ann Arbor and Milan before eventually moving west.)

Ann Arbor and Milan were far enough from the great lakes that the daily cycle lake effect winds were absent, or at least not particularly noticeable compared to the prevailing and weather-system winds.  (We left G.R. before I was old enough to remember much, but I understand they also have a related phenomenon of the same name there - where the humid wind off the lake onto the cold land dumps LOTS of snow and silverthaw ice in the winter onto the first tenish miles inland from the western coast.  B-b )
ULR, sorry for the late response. Work got in the way for several days ;-(.

There is a small town on the south east area of the lake "Baroda " The high school I went to name is LakeShore high. Great time. At the time they had no such thing as snow days, even while the snow was being measured in feet not inches. Everyone was expected to won a snowmobile or tractor. Moved up there for family reasons; worked a 7 acres of Welsh's grape farm in early 70s moved back to Missouri so I could graduate both high-school and Automotive school.  The refuse collector hired me for winter work, he and I found enough cast-off stuff to build two stills. He was slightly amassed a teenage could "teach" him something.
I learned that I knew more about farming that I learned while still a kid, than I realized.
 It's pretty cool to figure out, all the while we were playing out in the hay bales, milking cows, gutting chickens, turkeys and rabbits as kids; we were also learning.
 
Most people here in MO have no clue about driving in REAL snow. In 73 it was so #$@!% COLD! my coffee got stone cold before I could clean the snow off the windows.

Great Times ;-D
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CraigM

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Re: Active Pitchcontrol
« Reply #522 on: February 22, 2017, 11:38:30 AM »
Living in Northwest Holland . Average wind 5m/sec .40 Miles north of Amsterdam.
Classic waterpumping windmills fixed pitch .
Those mills were used to create new land from sea and lakes.

Last fall I spent a week in the Netherlands on business with GE Wind Turbine division. Great place for wind and enjoyed the history of how the windmills were used to perform many different mechanical work loads. My great grandparents are from the region, we're all very tall, 6 foot [1.83 meters] or more so I felt right at home with all of the "giant" people.

Can't wait to return, it's a great piece of the world.

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

mbouwer

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Re: Active Pitchcontrol
« Reply #523 on: February 22, 2017, 01:04:30 PM »
CraigM,

Can you tell us something about GE Wind Turbine Division and their turbines?

Regards Rinus

CraigM

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Re: Active Pitchcontrol
« Reply #524 on: February 23, 2017, 12:37:57 PM »
Rinus,

Sorry, not much I can share that isn't already out on the internet. Our company is contracted by GE to manage their inventory requirement for small fabrications, small electrical and fasteners. As a contractor we are required to sign non-disclosure and proprietary information documents. We are also not allowed to carry phones or camera devises inside their manufacturing facility.

What I can tell you, and further information is available on the internet, is their primary platform for on-shore wind is call the DFIG (Dual Fed Induction Generator) in 1.6MW to 2.85MW. The last PMG model was made around 2012 and I believe it was 3.2MW.

Hope this helped a little.
CM
Brain engaged in Absorption Charge Mode... please wait, this may take awhile.

mbouwer

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Re: Active Pitchcontrol
« Reply #525 on: February 24, 2017, 04:40:46 AM »
Thank you for your reply.
It must be very enjoyable to be dealing with modern wind technology.

mbouwer

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Re: Active Pitchcontrol
« Reply #526 on: February 25, 2017, 03:29:11 PM »
What is the problem for self builders to use this DFIG-system in a small generator?‎

Ungrounded Lightning Rod

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Re: Active Pitchcontrol
« Reply #527 on: February 25, 2017, 11:43:34 PM »
What is the problem for self builders to use this DFIG-system in a small generator?‎

Complicated electronics (amounting to a three-phase inverter / speed control - somewhat more complicated than an inverter and necessary for the machine to deliver power).  It has to match the electrical machine, too.

The generator has three-phase windings on both the stator and on the rotor, the latter with a set of slip rings.  It's more complicated to build - and far harder than a motor conversion to build right.  And it's a specialized piece of equipment that you won't find lying about.  Doing a motor conversion would get you a stator, but then you'd have to build the wound rotor (with silicon-steel laminated flux path) and slip ring assembly (which would require an expanded bell housing on one end. You MIGHT find such a device lying around.  But they're orders of magnitude more rare than induction motors.

PMAs are drastically simpler.  They're also far more forgiving on tolerances, making them ideal for home-brew.

= = = =

For a giant commercial mill they make a lot of sense.  They match the line frequency despite the arbitrary RPM of the shaft.  The electronics doing the frequency conversion does it for only one of the two sets of windings, so it's smaller than one to convert wild-frequency AC carrying ALL the energy of the mill to the line.  It also does the excitation, so you don't need a second "field coil" controller.  Power is pulled out on BOTH sets of windings, so the mill has a similar advantage over a wound-field generator to that of a PMA:  You don't pay a lot of energy for excitation.  Splitting the output between the two sets of windings means the currents in each are lower.  Since the resistive losses go with the SQUARE of the current density the double-wound electrical machine is more efficient than a single-wound.

But there's enough equipment and engineering involved that it only makes sense in a wind farm full of big machines.  For a small home-brew operation KISS is the word.  (Or buy one designed by a big operation with a farm of engineers.)
« Last Edit: February 26, 2017, 12:01:33 AM by Ungrounded Lightning Rod »