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#Post#: 3147--------------------------------------------------
accessories you need for wind turbine , how to control high spe
ed stall
By: happygolucky Date: June 4, 2014, 7:12 pm
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i have been reading some interesting studies on why a vawt
stalls... at high speed ....very interested in this subject... @
ness you made a comment i see there is some circuitry work that
you make a boost circuit design to help with low speed
charging... dose a MPPT controller for wind help an maximize
power an prevent stalling..
what other equipment do you need other than a items below
how do you control high speed stall ..an short the wind
turbine.. surely thy must be a way..to eliminate stall on a
vawt ?
@ness:said
The larger the wire the better in my opinion, only concern is in
(high winds will tsr drop due to the power of the alt making it
stall ?) (a sort of mismatch between alt and blade power).
lynx: said
A couple things,
You don't want to draw more power than there is at a given wind
speed or the turbine will stall. I wouldn't want to draw any
power until tsr approaches 1 Better to extract power when rpms
are higher. The VAWTs that I design will act as drag machines
but there is far more power above tsr 1. HP = speed x torque,
HP equates to watts
In a perfect world you would design the alt to output along a
power curve that allows the turbine to run between 1.2-2.5 tsr.
In a 6 mph wind the 175 will need to turn at 60 rpm for a tsr of
1.2 Nessproject's boost circuit pretty much meters low wattage
at the slow speeds.
A stronger alt with big magnets and low resistance will act more
like a direct short and stop a turbine faster and harder. The
175 is just about impossible to turn by hand at 1/2 rpm when
shorted.
list of accessories needed with a wind turbine setup..
1 you need a dump load what kind
2 rectifier
3 charge controller
4 dc watt an volt meter
5 wire for turbine
6 dead short system
7 battery bank
8 pole mount
9 POLE MOUNT ANEMOMETER
10 ground rod an amp breaker..
anything else.. you need
HGL
#Post#: 3150--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: lynx wind Date: June 5, 2014, 6:54 am
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Hmm.... don't believe everything you read.
I haven't seen high speed stall. I have seen losses in the
alternator at high speed to where the alternator is down to
12-15% efficient. That is something we are working on and is
more a matter of cost. The 175 alt is the best compromise I can
come up with between performance and cost.
What you need:
1. Bridge rectifier with boost circuit about $15
2. 1-4 deep cycle 12 volt batteries
3. a stop switch SPDT center off 10 amp
4. Some use for the power, daily lighting, occasional heavy use
of an inverter....
Unless you are in a high wind zone you will rarely see enough
power to warrant needing a dump load. That could be something
to add later if you see a need. Definitely do not use fuses or
breakers. Use run wiring that is heavier than the wire in the
stator. An anemometer will tell you very little unless you use
a data logger.
But, if it is hobby and for fun, then by all means dive in and
get everything.
#Post#: 3152--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: happygolucky Date: June 5, 2014, 10:19 am
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lynx,
that's what i thought! the data did not match.. lynx some of the
stuff, i do read is from the early pioneer day's , basic
foundation knowledge, it was an issue then, an still may with
some erroneous bogus design claims. but they where building
monster vawts experimenting..an comparing to the hawts ....i
read one guy had to use a rope to start his vawt hahah :D...
that one did not put out very much it was a beast of nothing..
a axial flux alternator stacked dual stator to heavy . a lot
of bashing too i suspect.. i did not believe it just questioned
it ... then an now story.
as the song goes...We've Come a Long Way Baby ..in
technological advancements material, designs etc. ..an yes you
do have to weed out the malarkey..
i have seen the current charts studying betz law, lenzs, TSR
etc.. where dose that 12-15% go what happens ...i get straight
line winds a lot more so in the winter .... i suspect some over
speed. i'm no expert just trying to make sense of it all in a
year..impossible to cram it all together in a short period of
time... compared to your knowledge an experience nowhere close
, but i'm gaining some ground mechanical is a breeze... it's
all the little things that spoil the fox...... .. you have made
it faster,lighter more efficient, none cog,.. an materials have
been changing rapidly.... do you loose power with just 3
airfoils! not with your mechanical design ..a gyro vawt ? my
wheels turning..
HTML http://video.mit.edu/watch/physics-demo-lenzs-law-with-copper-pipe-10268/
my hobby has an always was a passion now.. coming true.. i'm
hungry..for more!
thx for clarifying..
good to know all the things required to set up for wind..i kinda
take after my dad a gadget man.. :)
#Post#: 3153--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: lynx wind Date: June 5, 2014, 10:38 am
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Where does the power go?
For rough example let's say for the swept area there is the
following amount of watts available in a certain windspeed (you
can look this number up if you know diameter and height)
10 watts x 45% turbine efficiency x 95% alternator efficiency =
4.25 to load, + .25 watts wasted as heat in the stator
100 watts X 45% turbine efficiency X 65% alternator efficiency =
29.25 watts + 15.75 watts wasted as heat in stator
1000 watts X 45% turbine efficiency X 30% alternator efficiency
= 135 watts to load + 315 watts wasted as heat in stator
10,000 watts X 45% turbine efficiency X 10% alternator
efficiency = 450 watts to load + 4050 watts wasted as heat in
the stator (catching on fire probably before this point!) By
the way this is 6hp required to give about .6hp in watts
What is resistance? Imagine trying to pump 4.5 gallons of water
/hr through a 1" hose - no big deal
Now try to pump 450 gallons of water/hr through the same hose -
it takes a lot more power and pressure
The diameter of wire we use is a lot like that hose.
Unfortunately the useable area in proximity to the magnetic
field is only so big.
#Post#: 3156--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: happygolucky Date: June 5, 2014, 11:42 am
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got it physics! can't get around it..must change some variable's
larger gauge wire to could lower resistance ?length an space
of wire ,circuitry to help reduce resistance rpm etc. it is a
science. heat sound like the biggest problem..
#Post#: 3157--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: lynx wind Date: June 5, 2014, 12:41 pm
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An easy way to dump power that is a benefit. I forgot to
mention this and it is so easy.
The PowerJack 300 GTI is set to pull power at 14 volts DC,
nothing under. So what you do is hook up your 12 volt battery
bank to the GTI, nothing happens except an indicator light comes
on showing that you are hooked up. Plug the power jack into a
110v wall outlet.
Hook up the turbine through the boost rectifier circuit. In
light to moderate winds the batteries will charge and approach
fully charged at 14 volts with no harm. When winds kick up and
voltage exceeds 14 volts it dumps through the GTI back to the
grid. It takes a 15 mph wind to do this.
I have two Power Jacks still in box (I would sell these for $100
each). I haver used one for four years continuously for my
solar panels with no problems.
#Post#: 3159--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: happygolucky Date: June 5, 2014, 4:34 pm
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thanks lynx..
that fine lynx ... i will take them chargers..i been moving
real slow getting it done right ..that adhesive take 5 days or
more to completely set dry... talked to company about it... know
all about it,, cleans up nice will work fine just slow... going
to be a bit longer... so i have time.. i just laid the last bit
of adhesive down a 1/8 seam slow to dry.. probably did not have
to but @sut mentioned something, i think .....you will see no
seam.. see pic's
epoxied fiberglass spars today you have to do it quick an in 2
batches..it real close to being done.. i would rather take the
time an go slow a few more days an it will be a center piece in
my yard.. a state rep want's to see it when its finished.. your
dream may become a reality i said Michigan needs a alternative
tax credit an alternative resources.... i have to re -mount my
solar mad .. got off phone with vendor it will only support 2
panel so i need a new solar rack or pole or another design no
big deal been giving wind vawt priority.. .. what is you idea
on a flag pole from menard it has a 2" ID i know you have it
all figure out what ever is best.. have to do some math when i
go to set threaded rod in..
its almost done..
HGL
#Post#: 3163--------------------------------------------------
Re: accessories you need for wind turbine , how to control high
speed stall
By: lynx wind Date: June 6, 2014, 7:34 am
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I am not sure what the term "stall" means in this topic. There
is some thinking that at a certain rpm a wind turbine appears
almost like a solid and wont spin faster. I haven't seen it
yet.
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