New direct drive on a solid shaft

[ontfarmer]

would you give some details on the blades is there any taper or twist in them?
        Grant

[jarrod9155]

There isn't  much for taper  or twist  . Royal wind and solar makes these blades  I believe there is still a web site out there .

[ontfarmer]

Thanks for getting back I thought you had made the blades. Does it take much wind speed for them
to start turning?

            Grant

[jarrod9155]

No 3mph they start ,  but they don't make any real power till 6 mph and so on . There is a thread here on making these blades with a table saw very interesting .

[jarrod9155]

Just had a noreaster come through and gust to 35 mph the inverter peaked out at 4.5kw . The problem  is that my inverter is a 4.2 kw aurora starting to think my next step is cuting these blades down .

[halfcrazy]

Jarrod
I learned a neat trick with these blades. The Classic has 16 set points for the power curve and I simply programmed the last 2 so the voltage would be above the TSR by a "good bit" (Scientific term) and then what happens is the Classic unloads the turbine at those high speeds to try to get to that voltage and the turbine slows down.

The issue with these blades good bad or indifferent is the harder you load them the harder they pull. So it is like running down a hill in a mack truck and being told to let off the brakes and the truck slows down. I can not explain it but it works here and I think Chris has documented this as well.

Just a thought anyhow.

[jarrod9155]

I ended up shutting down for 3 hour wile the 30 to 40 mph winds passed , but  I like your idea will try . I was trying to do it the other way with more load .

[nekit]

Jarrod
I learned a neat trick with these blades. The Classic has 16 set points for the power curve and I simply programmed the last 2 so the voltage would be above the TSR by a "good bit" (Scientific term) and then what happens is the Classic unloads the turbine at those high speeds to try to get to that voltage and the turbine slows down.

The issue with these blades good bad or indifferent is the harder you load them the harder they pull. So it is like running down a hill in a mack truck and being told to let off the brakes and the truck slows down. I can not explain it but it works here and I think Chris has documented this as well.

Just a thought anyhow.

halfcrazy
Interesting.  Do you think that when you unload them they speed up and lose efficiency, then they slow down?  Seems like they would slow down enough to start working again and then speed back up.  I've thought that my 17' with these blades might be somewhat self governing, as when they get up to a high rpm the profile would start to work less efficiently. 

Jarrod,
Cool to hear your making good power.  My 17' so far has peaked out at around 4Kw around 40mph.  I've shut mine down a couple times in the last 6 months because of high winds too.  I always want to see what it will do, but want to have a mill in one piece at the end of the day.  So far mine works fine up to 40mph winds.  One way or another someday I'll probably find out if it can handle 45mph+.

[Menelaos]

Hi there,

I learned a neat trick with these blades. The Classic has 16 set points for the power curve and I simply programmed the last 2 so the voltage would be above the TSR by a "good bit" (Scientific term) and then what happens is the Classic unloads the turbine at those high speeds to try to get to that voltage and the turbine slows down.

I don't think that this is a good idea as this makes it easy for the turbine to run out of controll....
Youa re right when thinking that you can unload the turbine by cutting on either end of the cp curve....

As the TSR rises, blade efficiency will decrease but it will not decrease as fast as it does due to stall. Furtermore the prop will continue to spin up- do you really want that?
When in such a situation a gust will hit that turbine, the TSR will decrease closer to its optimum again and the power output will rise verry quickly- to limits that might be dangerous.

If you on the other hand stall that turbine, the TSR will be low already and further decrease in a gust. That way the reduction of power continues in a gust and also the turbine is under controll.

So I would suggest to programm the inverter the other way round and for the high windspeeds  ask it to take a lot of load from the turbine, far more than it could deliver in order to stall it and decrease TSR. This way your prop cannot run away and lead to disfunktions of furling and such things...my 2 cents... :-)

Max

[jarrod9155]

Nekit ,
          My max power was 4,800 watts at 200volts dc at 35 mph wind . from what i observed in this last storm was the blades do to seem to have the ability to self govern lets say instead of holding a tar of 6.5 loaded they will do 8 to 9 tsr unloaded then stall or just hit a peak rpm for that wind speed . Any one who has a aurora knows when you upload a change to the table that the inverter goes of line for 5 seconds and the turbine is unloaded till ether you engage the backup or the inverter comes back on . Durring this time i let the wind turbine just go unloaded in 20 plus mph winds for that 5 to 6 seconds and the volts hit 230 ac 322 dc unloaded again that 270 rpms if my prediction early on says my turbine does .85 volts per rpm . In my case with these blades I have seen more rpms loaded than unloaded . last night I saw the turbine actually track in to a 30 plus mph gust and not furl correctly and hit if I had to guess 270 to 300 rpms and put out 4500 watts . My tower is only 60 feet so the wind isn't that great and nor'easter storms bring winds that change direction a lot , I believe this to be the cause of the furling not being spot on .
   
     Halfcrazy ,
                       Unloading the blades a little on the top would work to stall a little but the furling in my case suffered . I ended up dialing in my dump load to come on just at the right time to help get the furling to start . My next turbine will have more offset right now it is around 10 inches i believe this will help make the furling more consistent in gusty winds .
                I do have to report my first problem with direct drive structurally , the inverter throw the dreaded ground fault i thought the stator burned up !!! nope the magnet plates just glazed the stator found this out last night when I lowered it to see what was going on .  What is happing is the stator is moving or vibrating during furling when the inverter is applying load still causing that growling and also a vibration that you can fill in the ground near the pole . You can hear this turbine howl from 100 yards in big winds not sure if there a fix or what for that . But what i have to do next now is beef up the stator brackets . I could move the stator if i pushed hard enough by hand , poor  design on my part . The stator bracket bolts in between the bearing and housing so not to hard to redo but will cost me some time . Now even in 30 plus mph winds the shorting of the stator stops it instantly .

[jarrod9155]

Mppt table
values:      This is a updated table from Rob Becker , this keeps the tsr at 6.0

Wind (m/s)   RPM   Freq. (Hz)   Heat (W)   Eff. (%)   DC (V)   P (W)
2   38   6.3   3   94%   40   9
2.5   47   7.8   8   93%   49   54
3   56   9.4   16   91%   57   118
3.5   66   11.0   29   90%   66   206
4   75   12.5   49   89%   74   319
4.5   85   14.1   78   87%   81   460
5   94   15.7   117   86%   89   632
6   113   18.8   239   83%   103   1075
7   132   21.9   435   80%   115   1660
8   150   25.1   733   78%   127   2398
9   169   28.2   1160   75%   137   3295
10   188   31.3   1750   73%   146   4352
11   207   34.5   2538   70%   155   5569

[nekit]

Mppt table
values:      This is a updated table from Rob Becker , this keeps the tsr at 6.0

Wind (m/s)   RPM   Freq. (Hz)   Heat (W)   Eff. (%)   DC (V)   P (W)
2   38   6.3   3   94%   40   9
2.5   47   7.8   8   93%   49   54
3   56   9.4   16   91%   57   118
3.5   66   11.0   29   90%   66   206
4   75   12.5   49   89%   74   319
4.5   85   14.1   78   87%   81   460
5   94   15.7   117   86%   89   632
6   113   18.8   239   83%   103   1075
7   132   21.9   435   80%   115   1660
8   150   25.1   733   78%   127   2398
9   169   28.2   1160   75%   137   3295
10   188   31.3   1750   73%   146   4352
11   207   34.5   2538   70%   155   5569

This looks more aggressive than your old table, is that correct?

I've thought that with this blade profile I could probably have a more aggressive (more watts at lower volts) too.  I think that will be my next change.  Keep us informed how this table works out.

Rob L.

[jarrod9155]

I started the new table last night it really slowed the tsr down but the output is right were the table says it should be with wind speed . Last night and today I have had average 6 mph winds so I haven't tested the high end yet . 
    Yes it is more aggressive  than my last table and from what I have heard and seen these blades like to be loaded up so this will be a good test of that .

[rickysmartz]

Hi Jarrod,
Nice work.
Id have to agree with Manaleos when he says-
I don't think that this is a good idea as this makes it easy for the turbine to run out of control...
You are right when thinking that you can unload the turbine by cutting on either end of the cp curve....

As the TSR rises, blade efficiency will decrease but it will not decrease as fast as it does due to stall. Furtermore the prop will continue to spin up- do you really want that?
When in such a situation a gust will hit that turbine, the TSR will decrease closer to its optimum again and the power output will rise verry quickly- to limits that might be dangerous.

If you on the other hand stall that turbine, the TSR will be low already and further decrease in a gust. That way the reduction of power continues in a gust and also the turbine is under controll.

So I would suggest to programm the inverter the other way round and for the high windspeeds  ask it to take a lot of load from the turbine, far more than it could deliver in order to stall it and decrease TSR. This way your prop cannot run away and lead to disfunktions of furling and such things...my 2 cents... :-)

I think this approach may be heading for trouble, it'll seem to work for a while but then the wind will do its unpredictable thing and you'll run away.

A question- you are running a Powerone 6Kw inverter, right?

Cheers
Richard

[jarrod9155]

   New stator bracket

[jarrod9155]

stator recasted

[jarrod9155]

mold

[jarrod9155]

 21 inch magnet plates

[jarrod9155]

    Pulled the stator and bracket off this weekend do to the magnet plates grazing the stator . What I believe was going on was any time the turbine hit over 3,500 watts the stator or bracket would flex under the load causing a ground fault. I recasted the stator matching it to the new bracket plus was able to fix a lot of the previous defects in the first attempted casting biggest improvement in the process was only adding half of what  was recommended for hardener to the fiberglass and adding aluminium inserts to the cast for the jacking bolts. Today it survived 24 mph gust peaking at 4,000 watts without setting a ground fault hope this patches the problem .

Jarrod

[nekit]

Jarrod,
Just curious as to what you are using to get your turbine rpm?  I want to come up with something on mine.

Thanks,
Rob L

[Rob Beckers]

Jarrod, good looking machine!
I hadn't checked your thread on this forum until now. Glad to see the MPPT table helped, and it's working well.

-Rob-

[jarrod9155]

Thanks Rob ,the new mppt table help alot slowed things down and reduced the growling  durring extreme loads and has helped to tame the goe 222 blades durring big gusts of wind . 
  Nekit , I use two volt meters one on hz and the other on ac volts . In my case take 120 / by number of polls or magnets and * that by your hz so if I'm making 20 hz that would be 120 rpms  at the rotors 21 inches from dead center of turbine . I tried using a 100. Dollar meter from homedepot for hz but only a good fluke will give you a accurate reading so I have found . Note I read hz from the ac side .
       Yesterday was average day for wind , started blowing around 7:00am till sunset around 5:00 I was able to pruduce 6 kw in this time my Davis weather station will only graph high wind speed for that hour through out the day  . I wish there was away I could get the days average I have the vantage view if any one out there knows away to configure it let me know .

Jarrod

[rickysmartz]

Hi Jarrod,
Lovely work, I like the look of your new stator bracket.
Ive been working with Dan Lennox on a bit of software called the power Dashboard which will solve all your measuring and logging problems.
You connect the Davis directly to a Labjack or any Data acquisition module along with a shunt from the turbine AC wires and a transformer for voltage and RPM samples.
You can see all parameters : Volts, amps, RPM, windspeed and direction, watts out, daily average, weekly and yearly too.
It logs everything and can also allow remote access and shut down control so you can see how your baby is doing when away and send it control signals.
It should be ready in a month or so and is designed specifically for axial flux machines which Dan has built (see the forum).
It might solve lots of your problems- I know its doing that for me! 
Good luck with the rebuild
Richard

[nekit]

Thanks Rob ,the new mppt table help alot slowed things down and reduced the growling  durring extreme loads and has helped to tame the goe 222 blades durring big gusts of wind . 
  Nekit , I use two volt meters one on hz and the other on ac volts . In my case take 120 / by number of polls or magnets and * that by your hz so if I'm making 20 hz that would be 120 rpms  at the rotors 21 inches from dead center of turbine . I tried using a 100. Dollar meter from homedepot for hz but only a good fluke will give you a accurate reading so I have found . Note I read hz from the ac side .
       Yesterday was average day for wind , started blowing around 7:00am till sunset around 5:00 I was able to pruduce 6 kw in this time my Davis weather station will only graph high wind speed for that hour through out the day  . I wish there was away I could get the days average I have the vantage view if any one out there knows away to configure it let me know .

Jarrod

Jarrod,
I have the Davis Vantage Pro2.  If the Vantage Vue uses the same WeatherLink software you can look at the NOAA button and it will show your average wind speed for each day in a log.

Rob L

[jarrod9155]

Thanks Richard , I will be interested in that when it ready . Right now I have a D link camera set up to monitor things but that it ,this new set seems just what I need. So far the new stator bracket and recasted stator are holding up good , right now as I type the inverter just maxed at 4400 wh and haven't seen the dreaded ground fault . The winds to night are predicted around 15 to 25 mph , a good test .
   Nekit, your set up is very similar to mine , and if your like me you wonder a lot what is going on when your not in front of the inverter so what I did was I went to best buy and bought a dlink camera that runs into your router wireless and can be ass ed from a smart phone or computer remotely and I set it up in front of my inverter , I did have to go into setting and set the back light on all the time instead of auto on the inverter  . You can  add to the cameras so my next one will be pointed at the turbine .

Jarrod


   

[nekit]

Thanks Rob ,the new mppt table help alot slowed things down and reduced the growling  durring extreme loads and has helped to tame the goe 222 blades durring big gusts of wind . 
  Nekit , I use two volt meters one on hz and the other on ac volts . In my case take 120 / by number of polls or magnets and * that by your hz so if I'm making 20 hz that would be 120 rpms  at the rotors 21 inches from dead center of turbine . I tried using a 100. Dollar meter from homedepot for hz but only a good fluke will give you a accurate reading so I have found . Note I read hz from the ac side .
       Yesterday was average day for wind , started blowing around 7:00am till sunset around 5:00 I was able to pruduce 6 kw in this time my Davis weather station will only graph high wind speed for that hour through out the day  . I wish there was away I could get the days average I have the vantage view if any one out there knows away to configure it let me know .

Jarrod

Jarrod
Just curious what brand of multimeter are you using?  Mine is a Mac Tools, which I thought was pretty good quality, and it  doesn't read the frequency correctly. I had heard the Aurora inverter can send some feedback that would cause this, but maybe it just my meter?

Thanks Rob L

[Flux]

I have not found many multimeters that will measure frequency directly from wind turbines. Nearly always I have had to include a filter to remove the offending higher frequency mess. Something as crude as a series 47k resistor and shunt 0.1uf capacitor is often good enough. Some of the more up market meters seem capable of reading frequency to the mHz and are very difficult indeed to filter.

Even if you get stable readings you need to satisfy yourself they are correct.

Flux

[nekit]

Jarrod
Curious if you got it back together?  If so how's it running? 
Hope it's going well.
Rob L

[nekit]

I have not found many multimeters that will measure frequency directly from wind turbines. Nearly always I have had to include a filter to remove the offending higher frequency mess. Something as crude as a series 47k resistor and shunt 0.1uf capacitor is often good enough. Some of the more up market meters seem capable of reading frequency to the mHz and are very difficult indeed to filter.

Even if you get stable readings you need to satisfy yourself they are correct.

Flux

Thanks Flux.  This worked great and I now get a stable frequency reading.

[jarrod9155]

Nekit,
        Been up and running for about a month with out any problems surviving 40 plus mph winds without throwing a ground fault from rotor contact . Max power out has been around 5 kw plus my dump load adding another 2kw for a total peak around 7kw . I have only seen once that both the dumpload and aurora both stayed on longer than a minute 90 percent of the time the furling can limit the kw s to 4.5 kw max The heating elements come on around 4 kw and stays on till the kw drop down below 2kw . This stops the relay from constantly kicking on and off .

Jarrod