Author Topic: My 17' Turbine so far  (Read 42585 times)

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nekit

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Re: My 17' Turbine so far
« Reply #54 on: July 24, 2011, 07:53:46 AM »
Eight resistors, on an AC 3-phase configuration...  Are the phases of the dump load balanced equally?

Oh maybe it doesn't matter at all.  One phase will have a bit more current than the others...  by 50% maybe?  Have you measured the current in the dump load phases?

Yeah when buying from e-bay it's hard to find the right quantity of things - some times too many sometimes not enough.


I've been worried about this too.  I think I'm going to change this to equalize things out.  When I purchased the resistors it was a group of eight.  At first I thought the unequal legs wouldn't matter that much, but it's bothering me.

I can remove 2 resistors for 2 in each leg, 6 total and 27.2 ohms.  This is a little more resistance than I wanted, but not sure and close to the limit of the wattage of the resistors.

I could buy 1 more resistor for 3 in each leg, total 9 for 40.8 ohms.  Not sure if this will be too soft (not enough resistance) in high winds to keep the gen under control.

Any thoughts everyone?

kitestrings

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Re: My 17' Turbine so far
« Reply #55 on: July 26, 2011, 02:10:21 PM »
nekit,

We've have the same Omron (24V) sensing relay, and plan to use it as Rob Becker has described for high voltage fail-safe protection of our controllers.  Like you, I'd prefer to load to a resistor bank rather than shorting the windings (though we may incorporate for other conditions), so I'm interested in your results.

Others may be able to help more, but you might fiind this site useful for size and configuration of your load bank:

http://www.watlow.com/reference/tools/3phase.cfm

example - if you had six of the resistors wired in wye (pairs in series), at 250V I believe you'd dissipate about 4 kW, and the balanced load would be roughly 70% of the rated capacity of the individual resistors.  Other combinations may fit your design closer, but I think this is where I'd start.

Good luck,

~kitestrings

nekit

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Re: My 17' Turbine so far
« Reply #56 on: July 30, 2011, 08:10:03 AM »
Here's my curent configuration on my dump load.  Seems to be a nice load on the turbine and should hold up.

I puchased another resistor.  I have 3 resistors  on each leg of the of the 3 phase for a total of 9 resistors.  2 resistors are in parallel and 1 is in series on each leg.  Has 27.2ohms across each leg, which seems about right.  We'll see.

nekit

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Re: My 17' Turbine so far
« Reply #57 on: July 30, 2011, 11:24:59 AM »
I posted a video of tower going up, if interested.  I got it down to about 5 min up or down with one person.

Here's the link;
http://www.youtube.com/watch?v=9ET9iJ8vJO0

bj

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Re: My 17' Turbine so far
« Reply #58 on: July 30, 2011, 02:19:39 PM »
   5 minutes is impressive.   All the attention you paid to the details is paying off.
"Even a blind squirrel will find an acorn once in a while"
bj
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SparWeb

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Re: My 17' Turbine so far
« Reply #59 on: July 31, 2011, 02:04:59 PM »
So what's your tower like when it gets near vertical, and the balance passes over center?  In the video it seems only a bit of handling is required to bring it gently down by hand.

(Always interested in tower stuff, you know that).

As for the resistors, symmetry is pretty, but overall if the resistance is low enough to effectively limit speed, doesn't overload other components, and the resistors themselves can take the heat, then you've got it, whethe it's symmetrical or not.   Long term reliability and ability to troubleshoot problems in the future do benefit from having balanced phases, so it's not all theoretical.
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

nekit

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Re: My 17' Turbine so far
« Reply #60 on: August 01, 2011, 07:21:35 PM »
So what's your tower like when it gets near vertical, and the balance passes over center?  In the video it seems only a bit of handling is required to bring it gently down by hand.

(Always interested in tower stuff, you know that).

As for the resistors, symmetry is pretty, but overall if the resistance is low enough to effectively limit speed, doesn't overload other components, and the resistors themselves can take the heat, then you've got it, whethe it's symmetrical or not.   Long term reliability and ability to troubleshoot problems in the future do benefit from having balanced phases, so it's not all theoretical.

SparWeb
The first couple times I went up and down with the tower I had a tractor with a bucket to control the last bit of travel going up and at the beginning going down.  After a few times I noticed that it didn't have much force behind it in this  last part and just tried it by hand.  I sure this won't work on some tower, but the balance on mine seems to work out.

To start it down I just put some slack in the winch cable and pick up on the gin plow to about 6', then it goes on it's own.  Going down I just have to slow by hand the last 6' and then clamp it down.

frackers

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Re: My 17' Turbine so far
« Reply #61 on: August 01, 2011, 08:39:13 PM »
I've got a spare bit of HT cable wrapped round a 40kg paving slab that I hang from the trailing guy wire (I've got a turnbuckle in just the right place!!) - that provides enough bias both up and down to prevent any bumps  ;)

Robin Down Under (Or Are You Up Over)

SparWeb

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Re: My 17' Turbine so far
« Reply #62 on: August 02, 2011, 07:57:26 PM »
To start it down I just put some slack in the winch cable and pick up on the gin plow to about 6', then it goes on it's own.  Going down I just have to slow by hand the last 6' and then clamp it down.

Yup, that's what I thought.  Nice feeling isn't it?  800 pounds of steel pivoting under your finger...    8)
One of the addictions that TomW keeps mentioning. 
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

nekit

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Re: My 17' Turbine so far
« Reply #63 on: August 07, 2011, 08:04:17 PM »
Here's my curent configuration on my dump load.  Seems to be a nice load on the turbine and should hold up.

I puchased another resistor.  I have 3 resistors  on each leg of the of the 3 phase for a total of 9 resistors.  2 resistors are in parallel and 1 is in series on each leg.  Has 27.2ohms across each leg, which seems about right.  We'll see.

Correction this has 20.4 ohms between legs.  I forgot the resistors in parallel 1/2 the resistance of them.

nekit

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Re: My 17' Turbine so far
« Reply #64 on: October 17, 2011, 07:53:47 AM »
Thought I'd give an update on my turbine.  Seems to be working good so far.  Still fine tuning, but has been up and running for almost 4 months now.  Has survived 40+ mph gusts.

One update I've been meaning to post is a design change.  In my pictures you may notice I had a hand cable winch that was running up the tower and designed to pull in the tail if needed.  Well it didn't work.  I didn't have enough leverage and was pulling on the tail too close to the pivot.  The winch and cable didn't have enough strength and the cable had too many bends to pull in the tail.  Over the past several months I have shut down the turbine in some fairly high winds(40mph) with just the shorting brake and it seems to work fine.  At this point I don't see a need to redesign the tail winch system.  Just an FYI.  I din't want anyone to copy my bad design.

nekit

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Re: My 17' Turbine so far
« Reply #65 on: October 29, 2011, 08:37:45 PM »
Here are some figures I posted on another thread on my turbine production a few weeks ago.  Last week I had my best day yet.  Averaged 12 mph wind for the day and produced 21 kwh for the day.

"  I have a 17' grid tied with an Aurora inverter that collects data.  Over the past several months I've seen a average daily production of 6kwh in mostly low wind days.  The past few days I've been getting an average daily wind in the 9-10mph range and have been getting 14kwh per day.  This is an average wind for 24hrs and have seen gusts as high as 30mph.  I have a Davis Weather station mounted at 40' that collects wind data.

I currently have the turbine set to furl early.  It seems to start to furl about 10mph and be furled at about 20mph.  So far I've only seen a max of 2500W out of the inverter, so I may adjust the furling up higher."


Boss

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Re: My 17' Turbine so far
« Reply #66 on: October 30, 2011, 08:22:46 AM »
Good looking system, well done
Inspirational
Brian Rodgers
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kitestrings

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Re: My 17' Turbine so far
« Reply #67 on: November 01, 2011, 02:15:38 PM »
Nekit,

This looks great.  I'd say your seeing some pretty respectable output.

I was trying to piece togetehr the dump load information.  9- 6.8 ohm elements (2-l l, 1 series), so I get the 20.4 ohm calc.  They are wired in wye?  And, your dumping at around 400VAC, keeping the DC input safely below the inverter input I assume.  So you're pulling maybe 20A acrossed each group, or maybe ~8 kW?  I'm curious how it impacts the turbine speedm when in operates (if you seen it at pre-set), since it is an on - or off loading as I understand it.

Also, you had a three postion angle.  You started at the lowest angle?

Nice stuff.  thanks for sharing.

~kitestrings

nekit

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Re: My 17' Turbine so far
« Reply #68 on: November 01, 2011, 08:15:24 PM »
Nekit,

This looks great.  I'd say your seeing some pretty respectable output.

I was trying to piece togetehr the dump load information.  9- 6.8 ohm elements (2-l l, 1 series), so I get the 20.4 ohm calc.  They are wired in wye?  And, your dumping at around 400VAC, keeping the DC input safely below the inverter input I assume.  So you're pulling maybe 20A acrossed each group, or maybe ~8 kW?  I'm curious how it impacts the turbine speedm when in operates (if you seen it at pre-set), since it is an on - or off loading as I understand it.

Also, you had a three postion angle.  You started at the lowest angle?

Nice stuff.  thanks for sharing.

~kitestrings

Yep everything you figure is correct, but should be max approx 6kw at 400V or 15A. 

When I turn on the Dumpload it drops the RPM and voltage drops approximately 50, so should slow it slightly when the load comes on.  So far gen hasn't put out more than 310VDC.

The angle that your refering to I assume is the tail angle?  If so its in the middle angle currently.  I can also add lead shot to the end of the tail in sections in the tube.

Thanks,
Rob
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kitestrings

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Re: My 17' Turbine so far
« Reply #69 on: November 03, 2011, 10:31:09 AM »
nekit,

I may have missed that 400V was your target DC threshold (limit for the inverter), but even at that wouldn't your AC be around 285V, or (15 * 285 * 1.732 = ) 7.4 kW?  I'm sure i've missed somthing here, sorry to belabor.

Anyway, overall it sounds relatively 'soft' - the impact to the turbine when you connect your dump.

~kitestrings

nekit

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Re: My 17' Turbine so far
« Reply #70 on: November 13, 2011, 07:24:05 PM »
Updates:

Kitstrings 400VAC is my target max Volts which should be about 520 VDC going into the inverter.

So far I haven't had the dump come on except when then power went out once.  Worked fine.

Hit 350 VDC today and 4000W  it was a 42 mph gust.  Everything seemed to me working fine, but I got nervous and shut it down for a few hours while the wind was 35-40 mph with gusts to 50.  Shut down fine.  I turned the dump load on to slow it down some and the flipped the shorting brake in about 35-40 mph winds.  Stopped fine.

Changed the tail angle to 18 degrees two days ago, seems to be more consistannt in generating with less fluctuating in and out of furled. Furls about 25-30mph.
 
Yesterday generated 28 kWh for the day with an average wind speed 13.5mph.

If I hadn't shut it down I think it might have got close to 40 kWh today, but better safe than sorry. 

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nekit

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Re: My 17' Turbine so far
« Reply #71 on: November 13, 2011, 07:45:41 PM »
One other thing I wanted to note was how I balanced my blades.  I have the Royal Wind blades and the heaviest was about 2# heavier than the lightest.  I think it is just the different densities of woods.  I didn't want to add a bunch of weight to the mounting flange.  By adding it to the tips I was able to use a lot less weight.  I wasn't sure if this was going to work so I didn't post it till I was sure.  It's been running for several month and seems to be fine.

To add the weight to the tips I figured out how much weight each tip needed, then I figured weight of lead solid in a 3/4" hole bored into the tip.  By figuring the area need I was able to figure how deep I needed to bored the 3/4" paddle bit into the tip.  I was concerned that lead might work its way out of the tip, so before I poured in the molten lead I drove a stainless nail perpendicular to the hole to keep the lead in place.  I then poured molten lead in the hole.  It's better to have the hole a little extra deep, you can easily drill some out if it's too heavy later.

In the lightest blade I used two holes, as you can see in the picture.  Not sure if this would work on other style blades, but worked well on the meaty profile of the GOE222 blades I have.  Hope this helps someone.
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jarrod9155

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Re: My 17' Turbine so far
« Reply #72 on: November 13, 2011, 08:44:39 PM »
I have the the same inverter and similar generator with 20 foot goe 222 . That's impressive 28 kwh the most I saw last march was 16 in a day  and the bearings lock up the day after . If you get a chance what is your updated mppt tables look like. . Just got  my new mill up and running ,but no real wind yet .

SparWeb

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Re: My 17' Turbine so far
« Reply #73 on: November 13, 2011, 08:45:27 PM »
It looks fine to me.  There's a way to calculate how well your design will hold but frankly I'm not concerned about the lead weights, so I won't bother to do the research to prove it's okay.  Forgive my laziness!

I also see the strip protecting the leading edge.  You're all set for years of service.

How much did each blade weigh before balancing?  I'd be worried if the variation in blade weight was more than 10-15%, but I couldn't guess what is the baseline weight of a blade for a 17-foot rotor, to judge a 2 pound difference.
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

nekit

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Re: My 17' Turbine so far
« Reply #74 on: November 14, 2011, 06:52:53 PM »
Jarrod9155 the MPPT table is still the same one I listed earlier in this post. The more I observe the turbine, wind and inverter outputs the more I think the table is off.  It seems to be producing well, the data just doesn't seem to matchup. The more data I get I'll play with the table.

SparWeb the blades weighed 18-20#, so that's within the 10-15%. I thought it was a little bit much, but Dave at Royal wind said it happens with the differences in wood.  They did seem to balance out fine in the end. 

jarrod9155

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Re: My 17' Turbine so far
« Reply #75 on: November 15, 2011, 05:58:09 PM »
Back when I had 18 foot ash blades from royal wind  I had a mppt table that was well dialed in spent close to 4 months tweaking it but I lost it and all my notes long story  . The 20 foot popular blades I have now  are not working out as well , they flex more and one blade is way heavier .but for the aurora  I wonder if you have noticed the same things I have like the blades will take off before the inverter applies  load and then applies to much load causes them to stall expecialy if you try to keep a tsr below 7 .

nekit

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Re: My 17' Turbine so far
« Reply #76 on: November 16, 2011, 08:41:18 PM »
Back when I had 18 foot ash blades from royal wind  I had a mppt table that was well dialed in spent close to 4 months tweaking it but I lost it and all my notes long story  . The 20 foot popular blades I have now  are not working out as well , they flex more and one blade is way heavier .but for the aurora  I wonder if you have noticed the same things I have like the blades will take off before the inverter applies  load and then applies to much load causes them to stall expecialy if you try to keep a tsr below 7 .

The inverter does have 1.5 sec lag so I do see what your talking about, but it doesn't slow it to a stall. It seems to just make it fluctuate in gust wind.

kitestrings

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Re: My 17' Turbine so far
« Reply #77 on: November 18, 2011, 12:08:48 PM »
Nekit, or others,


Sorry to be so long getting back to this, but...

Quote
Kitstrings 400VAC is my target max Volts which should be about 520 VDC going into the inverter.

If your target is 520VDC, wouldn't the RMS phase volts/ph be 214 VAC; VL =~371.  With a resistance of 20.4 ohms, I would have expected the phase current to be just over 10A, or about 6.7 kW assuming it is balanced (which I think it is now).

Alternatively, if as you say the most the generator has put out is 310 VDC, wouldn't the Vph =~127; VL = 221; Ip = ~6A, or roughly 2.5 kW?

Please understand, I'm not trying to be smart @#SS, just would like to understand it if I'm off-base.  Perhaps the resistance changes as they heat up, like say a light filament, or perhaps the 15A was measured prior to your reconfiguration?

One more question, I assume you parallel one pair to just hit somewhere near the desired risitance with the individual elements that you had, but logically the pair is not loaded the same as the third element in each group.  Just curious how close to capacity of the individaul elements it put you?

~kitestrings

nekit

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Re: My 17' Turbine so far
« Reply #78 on: November 19, 2011, 09:37:58 PM »
KItestring
Not sure if I'm following your question. My math may be a bit off, but seems to be working well.  I'm only using the dump load as a fail safe if the system get close to my 600 VDC.  Haven't needed to use it yet, 400vdc and approx 5000 watts is the max. I've seen from the gen at about 45mph gust.  I have turned on the dump at about 300vdc and it just slightly slows the turbine more than the inverter does.

The resistors measure pretty close to their rated sums and are even between phases.

I've had average 16mph winds the last two days and have generated 32kwh and 34kwh each day.  I'm pretty happy with that.

Thanks

nekit

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Re: My 17' Turbine so far
« Reply #79 on: November 20, 2011, 07:14:05 AM »
By midnight last night my inverter exported 36kwh for the day.  Even better than I thought it would.

LifeIsGood

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Re: My 17' Turbine so far
« Reply #80 on: December 22, 2011, 10:43:14 AM »
nekit

My wife and I are new at this discussion about wind mills. We have picked this up by reading the book 'homebrew wind power'. We are currently attempting to build a 20' to 21' wind mill similar to your 17', and we see your work is impeccable. Having seen that I cannot sleep well, I requested to become a member of the forum to speak with you because we think your work is amazing. We are also attempting to reach 100' feet up with a large surface to cover, our alternator is slightly different, as we are using 12 strands of 18 AWG with 24 wraps to hook up in series and parallel to achieve our 4.3 Volts at 60 RPM's. We have tested and proven its working so we continued wrapping. We have completed all 15 coils in their individual casts with west system 105, 206 epoxy resin from Ellsworth adhesives. We are currently stuck on a few dilemmas or questions if you're willing to share your knowledge. Q#1: should we use a different adhesive to cast all 15 coils together? Q#2: are we tying all three phases together to start, then exit the cast with just the three? I'm not sure what your fourth slip ring is for? Our magnets are on a 22" diameter steel plate being 1/2" thick, also our 1.5"x.75"x3" magnets fastened between 22" and 16" diameters on our plates. We have vents in the fist plate accepting air flow and then being vented perpendicular once air is in side alternator to pass over both sides of stator. Finally, Q#3: Not sure if I can do this, but possibly contact your over the phone because I'm not too brilliant with computers and it takes me quit a bit of time to type.  I can give you info if you wouldn't mind answering further questions over the phone?