Author Topic: Active Pitchcontrol  (Read 159352 times)

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mbouwer

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Re: Active Pitchcontrol
« Reply #459 on: August 25, 2015, 07:59:12 AM »
Almost all the professionals use it.
Diy turbines with active pitchcontrol are hard to find.
How come?

Smithson

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Re: Active Pitchcontrol
« Reply #460 on: August 30, 2015, 07:55:01 PM »
Hi:  I have a few questions.  I must say this is a very clever idea.  Thank you for sharing.

1.  Why do you limit the rpm from 180 to 350?  I was thinking Scoraig Wind (Hugh) in one of his textbooks said that the maximum rpm for an axial is 3 times the cut in rpm.  So that could be give or take 600 rpm.  It could make a lot more power but maybe not as reliable.

2.  I've only read about six pages of the thread so maybe someone has mentioned this but does the Sun Gear need to have a tooth count diviisonable by 3?

    My understanding ( only a personal opinion) is that the the reason side facing is used on the axial flux is because they need speed.  The machine you have probably only has 12lbs of copper whereas the Jacobs had maybe 30lbs so it could turn at a maximum of 300rpm and make full power.   Thank you.     Arch.      Ps.  I couldn't do the electronics (progaming) anyway but I might try the rpm counting

mbouwer

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Re: Active Pitchcontrol
« Reply #461 on: August 31, 2015, 06:27:14 AM »
Smitson,

The electronics for the steering of Midwouds turbine is also on this topic.
And real good functioning for years now.

Greetings Rinus

midwoud1

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Re: Active Pitchcontrol
« Reply #462 on: August 31, 2015, 11:52:26 AM »
 Hi Arch.

Between 180 - 350 Rpm it's running safe. No high centrifugal forces. 600 Rpm is dangerous.
The amount of sunwheel teeth here  is 37 to keep the hub compact. Disc diam. is 280 mm.
More or less teeth gives the same result to move the blades synchronous.
The generator here has 5 kg copper  9 coils  and 2x 12 magnets  to make 800 watt  ( Hugh Piggott  3 meter windmill )
With a microcontroller you can switch easy to change the behavior with software, of rpm and charge power.
But it is not a must . The Rpm counter has a variable voltage output ,use that as a switch command trigger between the desired Rpms.
Tension level active.
The actuator makes steps of 0,5 seconds.

Rgds. Frans.

midwoud1

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Re: Active Pitchcontrol
« Reply #463 on: December 20, 2015, 01:23:41 PM »
To all Fieldliners   Merry Christmas and a happy NewYear

                                Frans.


kitestrings

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Re: Active Pitchcontrol
« Reply #464 on: December 21, 2015, 01:17:13 PM »
Merry Christmas Frans.  ~ks

mbouwer

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Re: Active Pitchcontrol
« Reply #465 on: December 22, 2015, 01:25:37 PM »
Frans,

We heard that some guys want to go further on the basis of your prototype.
That's good news.

Regards Rinus

mbouwer

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Re: Active Pitchcontrol
« Reply #466 on: April 09, 2016, 01:49:04 PM »
Blade suspension for the new mock up.



mbouwer

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Re: Active Pitchcontrol
« Reply #467 on: April 19, 2016, 05:04:09 AM »
Blade suspencion completed.

mbouwer

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Re: Active Pitchcontrol
« Reply #468 on: September 18, 2016, 03:03:01 AM »
In 2011 this Midwoud topic began and sometimes there were enthusiastic reactions.
I wonder if other windmill builders have gone further with this concept of active pitch.

midwoud1

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Re: Active Pitchcontrol
« Reply #469 on: September 18, 2016, 04:34:45 AM »
There was some criticism on the actuator control system.
Imagine if something fails in wiring or powersupply , Does the blade-angle follow a sudden windgust ?
It all worked perfect as a prototype.
I think its time for a bigger windmill.

mbouwer

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Re: Active Pitchcontrol
« Reply #470 on: September 19, 2016, 12:56:00 PM »
Exchange of ideas could improve the design.

mbouwer

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Re: Active Pitchcontrol
« Reply #471 on: October 22, 2016, 02:40:09 PM »
Now I am trying to make a radial direct-drive generator. Starting with this package
with outside diameter 364 mm

hiker

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Re: Active Pitchcontrol
« Reply #472 on: October 22, 2016, 05:24:01 PM »
14 inch rotor..neos or ceramic mags ? looks like a good start..made one useing a exersize bike flywheel..glued down some cheap ceramic mags to that--made a stator  from a couple pieces of plywood-with a metal curved flatbar for the coils--metal insert in each coil hole...20-15  3phase   55winds two in hand  #17 wire..maxed out close to 400 watts with currant gearing...
whats your layout ?
WILD in ALASKA

Adriaan Kragten

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Re: Active Pitchcontrol
« Reply #473 on: October 23, 2016, 02:53:36 AM »
In my report KD 437 of 2010 I describe a pitch control system for the 2-bladed rotor of VIRYA-15 wind turbine. I have made certain choises resulting in a design for which the mechanism is shown in figure 7 of KD 437. Other starting conditions will result in a different design. In chapter 6 of KD 437 I give some arguments for certain choises and these arguments may be of help if someone wants to design his own system. KD 437 can be copied for free from my website: www.kdwindturbines.nl at the menu KD-reports.

mbouwer

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Re: Active Pitchcontrol
« Reply #474 on: October 23, 2016, 12:11:52 PM »
To start I would like to make a small low-speed synchronius generator with separate exitation.
The laminations are now modified and have 96 poles.

SparWeb

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Re: Active Pitchcontrol
« Reply #475 on: October 23, 2016, 09:28:16 PM »
Why did you cut off the outer edge of the ring???  :(
The available flux path is now cut by 1/4.
You will increase saturation, and self-heating, and have less steel to absorb the heat through.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

mbouwer

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Re: Active Pitchcontrol
« Reply #476 on: October 24, 2016, 04:30:46 AM »
The intention is to make a small scale Enercon generator. (http://www.enercon.de)

Later on I want to grind  the lamination core to the inner diameter of 295 mm

Now I have made a fixed axle pin.

SparWeb

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Re: Active Pitchcontrol
« Reply #477 on: October 24, 2016, 12:33:56 PM »
I don't see how cutting down the teeth ID will help.  You have choked the MMF to 1/3 or 1/4 of its original capability, by increasing the magnetic path resistance.
The power curve will flatten out very early.  The medium range power will suffer from low efficiency and the high end will run hot.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

hiker

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Re: Active Pitchcontrol
« Reply #478 on: October 24, 2016, 12:49:20 PM »
So your going for field coils on the rotor not mags ?  Once it's started should power it self like a car alt.
WILD in ALASKA

Adriaan Kragten

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Re: Active Pitchcontrol
« Reply #479 on: October 25, 2016, 04:44:46 AM »
I have had contact on a Dutch forum with Mr. Brouwer about his generator. The original stator stamping has 48 grooves and is ment for an 8-pole asynchronous motor. Mr. Brouwer has not reduced the outer diameter but removed the original 48 grooves completely and replaced them by 96 much smaller grooves. So he has increased the inner diameter. He will make a 32-pole armature with 32 separate electro magnets. For a 32-pole armature, the pole pitch is 11.25 degrees. For an optimal coil, there are three stator spokes within each coil. Half of the magnetic flux flowing through these three spokes bends to the left and half bends to the right when the flux arrives at the bridges in between the bottom of a groove and the outside diameter. The width of a bridge must be at least a factor 1.5 times the width of a stator spoke to prevent that the steel at the bridge is saturated earlier than the steel at the spokes. In the photo it seems to me that the bridge is wide enough.

If the original stamping with 48 grooves would have been used for a 16-pole generator, it would be allowed to reduce the outer diameter such that the bridge has half the original width. Then you get the same strength of the magnetic flux in the bridge as for the original stamping and an 8-pole generator. 

mbouwer

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Re: Active Pitchcontrol
« Reply #480 on: October 25, 2016, 07:45:57 AM »
Now after this mock-up,
how to make a better start trying to make a real nice small Enercon-like generator?

SparWeb

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Re: Active Pitchcontrol
« Reply #481 on: October 25, 2016, 12:55:02 PM »
Thank you for the explanation Adriaan!  I did not realize that he had done that. 
Yes I see now that there is adequate flux path when the pole count is increased to 32.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

mbouwer

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Re: Active Pitchcontrol
« Reply #482 on: October 26, 2016, 03:33:56 AM »
On the Dutch Ecologieforum   http://www.ecologieforum.eu/viewtopic.php?f=40&t=2566&start=1095
there are more photos.

Also many Enercon turbines around here.


hiker

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Re: Active Pitchcontrol
« Reply #483 on: October 26, 2016, 09:17:02 AM »
What kind of draw will all those field coil have ? 
WILD in ALASKA

mbouwer

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Re: Active Pitchcontrol
« Reply #484 on: October 26, 2016, 11:04:25 AM »
Hiker,

I would like to ask people with expertise: please respond to this question.
« Last Edit: October 26, 2016, 11:12:33 AM by mbouwer »

mbouwer

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Re: Active Pitchcontrol
« Reply #485 on: December 04, 2016, 01:23:30 PM »
To find the knowledge for a design and to make a small direct-drive synchronius generator with separate exitation is going to take some time.

In the meantime I modificated a ceiling fan to a small generator.
« Last Edit: December 04, 2016, 01:45:01 PM by mbouwer »