Actual Logged data and Graphs 12ft machine

[scoraigwind]

I apologise if my previous post came over as proud and defensive, and I guess that's what it was.  However I did want to make sure that readers don't give up on the furling systems that I have published just because others are having difficulties with making similar things work.  We discuss our problems here on this forum and it can sometimes appear that there is no such thing as a properly furling, well behaved machine, whereas for me that is the norm.  If the furling is not working its a rare thing and easily fixed by adjusting the weight of the tail or the angle of its hinge.

I do remember putting my own blades on a Bergey turbine (over twenty years ago)and trying to adjust the tail.  This was a very early Bergey 1000 machine that I got without blades.  In the end I took the tail right off and it still would not furl with such a small offset.  It just pulled itself into the wind and ran hard with no tail.  In the end I concluded that it must work with their blades but it would never work with mine and I had to modify the frame to furl correctly.

Overspeeding or stalling can both interfere with the way a turbine furls.  Much depends on the blades that you use too. 

The distance forward of the blades from the tower can be worth playing with too, as Dan has mentioned - although I agree with Chris that the effects are a lot less dramatic than the effects of changing the offset.

The case under discussion where Seekscore's machine does not furl is different because it is stalling so heavily it doesn't really reach its proper output at 20 mph.  That's where most of my turbines start to furl, and the power is governed at windspeeds above that.  In this case it's running much too slowly and so the power is being governed more by stalling than by furling.  It's not ideal behaviour in the first place, so I don't find it a very interesting problem to study.  But it does emphasise the fact that furling can be a black art.

Fabricator wrote: "And, the larger a machine gets it appears the less likely it will be to ever get a gravity furling tail to work in fool proof manner."  We have a couple of 5 metre diameter (over 16') machines here on Scoraig that furl nicely.  The offset is 12 inches to the side.  The tail hinge angle is rather small and is controlled by the way a chain wraps around a cam at the top.  We can adjust the power output at any windspeed by adjusting the shape of the cam.  These machines run in a very exposed location at the top of the beach and spend a lot of their lives in a partially furled condition pumping out several kW.

I don't always keep abreast of the many discussions on this forum.  I prioritise dealing with the many individual correspondences that I have by email with people around the world.  Maybe that's a mistake, but it often seems to me that there are enough experts here to answer people's questions and too many experts can be worse than too few.  But every now and then I get riled by assertions that will mislead the readers and I dive in and make a fool of myself. 

Hundreds of people build machines following my recipes including the furling tails.  I did publish a bad design for a 12 footer in 2005, but other than that i stand by them as machines that will furl properly if built as described.  And it is very rare that I get reports of the furling not working properly.  As far as I know most people have good results.

[Watt]

Most readers know you and your work.  While a few will always pick greener pastures, most of us know for certain that field is greener than all other surrounding pastures.  You have no reason to apologize,  you have reason to defend this design.

Seems every time I fix a flaw in my turbine, I find my fix caused another issue I wasn't experienced enough to head off. 

Thank you for your help.

I apologise if my previous post came over as proud and defensive, and I guess that's what it was.  However I did want to make sure that readers don't give up on the furling systems that I have published just because others are having difficulties with making similar things work.  We discuss our problems here on this forum and it can sometimes appear that there is no such thing as a properly furling, well behaved machine, whereas for me that is the norm.  If the furling is not working its a rare thing and easily fixed by adjusting the weight of the tail or the angle of its hinge.

I do remember putting my own blades on a Bergey turbine (over twenty years ago)and trying to adjust the tail.  This was a very early Bergey 1000 machine that I got without blades.  In the end I took the tail right off and it still would not furl with such a small offset.  It just pulled itself into the wind and ran hard with no tail.  In the end I concluded that it must work with their blades but it would never work with mine and I had to modify the frame to furl correctly.

Overspeeding or stalling can both interfere with the way a turbine furls.  Much depends on the blades that you use too. 

The distance forward of the blades from the tower can be worth playing with too, as Dan has mentioned - although I agree with Chris that the effects are a lot less dramatic than the effects of changing the offset.

The case under discussion where Seekscore's machine does not furl is different because it is stalling so heavily it doesn't really reach its proper output at 20 mph.  That's where most of my turbines start to furl, and the power is governed at windspeeds above that.  In this case it's running much too slowly and so the power is being governed more by stalling than by furling.  It's not ideal behaviour in the first place, so I don't find it a very interesting problem to study.  But it does emphasise the fact that furling can be a black art.

Fabricator wrote: "And, the larger a machine gets it appears the less likely it will be to ever get a gravity furling tail to work in fool proof manner."  We have a couple of 5 metre diameter (over 16') machines here on Scoraig that furl nicely.  The offset is 12 inches to the side.  The tail hinge angle is rather small and is controlled by the way a chain wraps around a cam at the top.  We can adjust the power output at any windspeed by adjusting the shape of the cam.  These machines run in a very exposed location at the top of the beach and spend a lot of their lives in a partially furled condition pumping out several kW.

I don't always keep abreast of the many discussions on this forum.  I prioritise dealing with the many individual correspondences that I have by email with people around the world.  Maybe that's a mistake, but it often seems to me that there are enough experts here to answer people's questions and too many experts can be worse than too few.  But every now and then I get riled by assertions that will mislead the readers and I dive in and make a fool of myself. 

Hundreds of people build machines following my recipes including the furling tails.  I did publish a bad design for a 12 footer in 2005, but other than that i stand by them as machines that will furl properly if built as described.  And it is very rare that I get reports of the furling not working properly.  As far as I know most people have good results.

[Flux]

Again much depends on the blades but normally I would think that 400rpm would be the speed to start furling a 12ft machine so 250 seems very low.

I am not sure what your machine voltage is Mike but it would be very interesting to add another 12v on a temporary basis and do another data logger run, I suspect we should learn a lot.

I wouldn't bother with the furling issue for now, sort that later when you have the machine characteristics right, but just make sure it is safe during the tests.

I don't want to go down the furling issue route here as it was a side issue from the performance thing but I think what you saw was a case of wind seeking, where the blades are held into the wind, the tail has no effect on furling except for its weight component acting on the inclined hinge, it's angle to the blades can be confusing and I really don't know what happens to the air flow behind the machine to cause these things, but you will find that your blade disc was not at right angles to the wind direction.

Flux

[fabricator]

Like pretty much everybody is saying, if it were me, the first time you lower the tower open the gap .010 or so then run for a few more weeks and see what happens, my seventeen foot machine is set right now so starts up and makes great power in low winds and stalls badly in winds over 20 mph. I'm tickled pink with this setup because it will furl if the wind blows hard enough to push it out of stall but this may happen two or three times a year around here.

[DanB]

What would be a good target RPM to shoot for? 250 seems to be my max now. What would be reasonable?

Hi Mike - I'd see if you can get it up around 350 give or take a bit.

[Seekscore]

Thanks for the feedback. Should be interesting to see how these changes affect the data.

This is what I got yesterday. 7.34 kWh

Mike

[ChrisOlson]

This is what I got yesterday. 7.34 kWh

Mike, that isn't bad for a 12 footer.  It's the kWh that gets the work done in your house, not the big Power Smoke at 30 mph.  You need to know the average wind speed that amount of power was made at to effectively evaluate what changes to the machine does to total power production at the same wind speed.  That's an average output of 305 watts per hour, assuming the data was gathered over a 24 hour stretch.

I shoot for average output of 350 watts per hour @ 12 mph with my 12 footer when making adjustments to tune it, if that helps for a baseline to adjust for.  But keep in mind I live at 1,200 altitude, and that would have to be adjusted down for 6,800 feet where you live.
--
Chris

Adding a quick footnote for Mike:
That 350 is my goal.  I just took a quick glance thru my records on that machine and the best I've gotten out of it is 337 watts/hour over a 24 hour stretch @ 12 mph average wind.  The best power I've ever gotten in one day was 27.34 kWh @ 19.6 mph ave wind speed for the day.

[XXLRay]

Which program did you use to evaluate the data?

[Seekscore]

XXLRay,


The data logger has an output which is basically a text file with the fields separated by a Comma.

2011-02-17 00:00:05,11.7,14.1,126,162.3,167.0,206,,,,0.00,0.00,,,,,,,27.206,2.991,,,146

I personally use OpenOffice Calc to import them into a meaningful form I can use and manipulate. You could use Excel as well. Once imported, I create some formulas using the data thats there to show what I want to see. I also use it to graph the data. Graphing is another issue. I don't do it enough to be an expert so that took quite a bit of playing around with. Then the creative thinking started and I wanted to see what else I could do with the data. Efficiency, TSR were examples of being somewhat creative with the data like you see above.

Mike

[XXLRay]

Thanks - I was not aware that OpenOffice could look that fancy.

[DamonHD]

There may be more life in the new LibreOffice variant/fork of OpenOffice, but for now they should be very similar.  So if you haven't got either then get LibreOffice I'd suggest.

Just FYI: http://www.theregister.co.uk/2011/02/09/michael_meeks_talks_libreoffice/

Rgds

Damon

[ChrisOlson]

Mike, do you know what the parasitic power draw of your data logging system is?
--
Chris

[Seekscore]

Chris,

This is out of the manual:

8 to 32 volts DC
2.1 x 5.5 mm power jack
50mA peak power while writing to SD card
35mA  with backlight on
15mA  with backlight of

Mike

[ChrisOlson]

2.1 x 5.5 mm power jack
50mA peak power while writing to SD card
35mA  with backlight on
15mA  with backlight of

Wow!  That system is a little pricey, but that's pretty nice.  I've been looking for a low power draw data logging system like that that doesn't require running a PC 24/7, and that one you got looks pretty interesting.
--
Chris

[Seekscore]

I am very happy with it. They have a lot of different sensors you can attach to it depending on what your needs are. Their support is outstanding and they are pretty good guys.

Mike

[SparWeb]

Hi Mike,

Oh I'm johnny-come-lately but this thread is so interesting no wonder it generated a lot of discussion in just one day!

I thought I'd ask if you are sorting the data into "bins" and if so, do you find yourself filtering out what appears to be bad data?
Just one of my pet peeves, as I do much the same kind of analysis with my logger's data.  While I've got the spreadsheet pretty much automated for the sorting and plotting, it's the picking out the strange blips and results of noise and whatnot interfering from time to time.

Also interesting to see your scatter plots have less scatter than mine - your advantage is in clearly having the anemometer high up on the tower instead of a separate tower, like mine.

The APRS logger has a lot more data channels than I thought it did. 

Do you measure RPM from AC frequency at the rectifiers, or do you have a more sophisticated system?

Thanks again for the plots - that's fun to read!

[Seekscore]

Spar,

I am measuring RPM at the rectifier. The only problem is that it takes a certain amount of voltage to register. Its still well below my cut in but above my start up. I didn't edit any data on those scatter charts. What you see is was I got. I do have the anemometer fairly high on the tower. Its probably up 49ft and placed on the side with my more predominate wind direction. 

http://www.aprsworld.com/sensors/wtss/

Someone else asked me about "bins". I am not familiar with that. This logger saves data in a .csv format. Text based - comma separated values. I work with a software engineer so I will have a way to plot the data and sort automatically in the near future. Probably a Java application.

Mike

[fabricator]

Mike, what is the resolution of the rpm sensor? Does it read in one rpm increments or by fives or tens?

[SparWeb]

Hi,

It didn't really show, so that's why I was wondering about the "bins".
It refers to using statistics to clean up the data before making the graph out of it.
Takes a bit of processing power on the part of the spreadsheet when you get upwards of 7000 data points.

Later I'll give you a graph showing what it looks like after sorting like that.  It's the preferred practice of the professionals, and it prevents erroneous data points from screwing up the curve.
Right now I'm using the wife's Mac and the graphs I need are on my PC.  They two computers only barely talk to each other (thankfully my wife and I do!).

Reason I'm so keen on this topic is that I used to just plot lines through the data points but the "bins" method fixes a lot of mess.  Once it was explained to me the curves make a lot more sense.

[Seekscore]

I'll have to read up on bins and see if that will help with the plotting I want to do.

The data logger records RPM in 10ths. I think there may be a way to average out the RPM based on how many revolutions happened during the logging period. That is what I am doing with wind speed to figure average.  Here is how the RPM is reported in the data for my 1 minute logging period. I believe it is an instant report of when the data is logged but I'll have to check to be sure.

129.9
110.9
122.3
124.5
127.9
141.7
148.2
141.5
150.3
150.3
145.3


Mike

[fabricator]

That's good resolution.

[SparWeb]

Definitely.  Mine logs in steps of 30 RPM!
Mike may be using a machine with 12 or 16 poles, while my genny has only 4-poles - it makes a big difference.

That's good resolution.

[ChrisOlson]

I'm pretty interested in this data logging system.  It looks to me like a nice, low power draw unit that can do just about anything you want.  I'm going to call the company and see what they recommend for my setup, and what system parameters I want to keep records on.

Mike, being the data is written to the card as CSV you could easily dump that data into a MySQL database and have your software engineer write an application to analyze and graph your data making database queries.  Databases are much more robust with handling large amounts of data than spreadsheets.
--
Chris

[Seekscore]

Chris,

I believe that is what his plans are. We started on it yesterday. We are going to start out pretty easy till he gets a better understanding of wind. Voltage, current, watts and kWh. We'll add more as we go.

Mike

[ChrisOlson]

I believe that is what his plans are. We started on it yesterday. We are going to start out pretty easy till he gets a better understanding of wind. Voltage, current, watts and kWh. We'll add more as we go.

That's pretty cool.  If you don't mind me asking, which sensor are you using to measure turbine rpm at the rectifier?
--
Chris

[Seekscore]

Chris,

I am using the WTSS sensor. There is an offset you adjust in the logger based on the number of poles in the alternator.

Mike

[ChrisOlson]

I am using the WTSS sensor. There is an offset you adjust in the logger based on the number of poles in the alternator.

That's what I wondered.  I'm trying to decide if I should use that board or use a hall effect.  My generator on my 12 footer is geared so it runs a lot faster than the rotor.  If I use an offset of 10 for the 12 poles that will log generator speed, then I would have to enter the gear ratio into my spreadsheet to convert the generator speed to actual rotor speed.

It's a little confusing there because it says the generator has to reach 25 volts to log rpm with that board.  I don't know that my generator runs at 25 volts most of the time.  With the bus voltage at 26 I think the AC voltage is only about 19.5 or 20.

To simplify things I might use use one of the hall effect sensors on the rear of the rotor and run a twisted pair phone wire down the tower to the logger.

I'm trying to put together a "custom" package here for my system   

Thanks,
--
Chris

[Dave B]

Chris,

  Maybe I can help. I have a pretty extensive remote monitoring and data logging set up here custom to my set up and have done others as well. Send me an email and we'll see what I can offer. Thank you,  Dave B.

[ChrisOlson]

This is the stuff I'd like to log because sometimes this happens when I'm not around watching it:
http://www.youtube.com/user/OlsonFarms?feature=mhum#p/u/6/VRRBxUrkHyo

The way I do it now is to record kWh over usually a 24 hour period, take the average wind speed for that 24 hour period that was calculated by my recording anemometer, then enter the data into a spreadsheet to keep track of it and have the spreadsheet calculate the average output of the turbine at that average wind speed.

It's a tedious process recording output data this way but it works I guess.  Mike's setup is a lot nicer than mine, for sure.
--
Chris

[SparWeb]

Mike,
I "chopped" a hunk out of one of my spreadsheets to show you the "bins" method.
If you want to see I can e-mail an excel file to you.

Steve

[Seekscore]

Steve,

Thanks for the offer. E-mail sent.

Mike

[walp]

I found another alternative to the logger you mentioned,

Its a combination of my Weather station which logs windspeed and gust´s up to three months continously and a more advanced model from VoltCraft(R) Power\Volt\Amp\Hz\CosPi monitor\logger for 100$ incl shipping\handling and tax. And there´s no need for programming and such Just some Exceling'!


I will buy that thingy later on, and install it when I have a little more time on my hands



ChrisOlson, that's excellent output, what was the current wind, and what is the magnet configuration? 12' blades only?



Btw, seekscore It's oooon!