pumping water with DanB style axial flux turbine

[BullCreek]

I posted the details of this in "Water" yesterday, but didn't get many replies:

http://www.fieldlines.com/story/2006/7/13/23825/3220

Grundfos pumps say they will operate at 30-300VDC with built-in MPPT - drawing a max of 900W.  Further, Grundfos used to sell a version of the SWP H80 with these pumps for my intended application (livestock watering in remote locations) - but recently stopped because of overvoltage problems with the turbine burning the pump up.

Last year I bought a DanB 11 footer on eBay which I got flying about a month ago.  It has been working beautifully - so much so that all I can think about is building more and bigger turbines.

My question to you - would a DanB style turbine work with one of these pumps if you lightened the tail up so it furled early and peaked around 900W?  Back of the napkin calculations make me think it would be ok if you wound the stator for around 30V at cut-in, but I'm still new at this, so my following calculations may not be correct:

130. RPM @ 7MPH around 50W @ say 35V
     
329. RPM @ 18.5MPH around 900W @ around 89V
     
     

if 130RPM makes 35V, then that is 35/130=.27V per RPM

so 329RPM would be around 89V correct?

If I can get this working, my Dad said he'll take this turbine off my hands for what I paid, which in turn will give me funds to build a bigger one for my house - and several smaller ones for him for water pumping.

Thanks in advance for your comments.  --B

[TomW]

Bull;

Well, I thought you got a good response to that original question. Too bad you chose not to take the information to heart.

It is a fact that if you ask a question enough times you will get the answer you want but that may not be the one that is factual.

Just my opinion.

TomW

[Flux]

It should be possible to make it work but there are too many unknowns to give a definite answer.

I don't like the bit where you say the pump has mppt capability, it would be far simpler if it hadn't.

What is it? true mppt for solar or a linear current booster. That bit will most likely cause you problems.

If the pump can be had in a version with just a motor that works between 30 and 300v life would be easier.

Your main problem is going to be controlling the windmill to prevent over speed, furling without the stall load as Dan intended it will not be effective.

You need a voltage clamp and you will have to clamp well below 300v to protect the windmill and you will have to be sure that the pump can meet the demand at lower volts.

If you have the ability to make a suitable voltage clamp to prevent blade overspeed and you are sure the mppt thingy in the pump is not going to do odd things then it will work.

You will not get any windmill to operate over a 10:1 range in voltage without some form of external control.

Yes it can be done and it is not really a difficult problem but if you need to ask the question then I doubt that you can do it reliably.

Flux

[Nando]

It seems that You want a solution your way only !!

But the solution may not be like you want it !

If you need to protect the pump input voltage, DO the proper steps, not the one you want that may not be the right one and not the only one, you may need to have two steps if such is the case.

Analyze and listen to others !!

What is the SWP 80, detail its use and its specifications.

There are several ways to make sure that the voltage does not go beyond a certain value.

PITCH CONTROLLED Wind Mill

Accurate Furling point -- many times difficult to set up

The Ballast controller

A High Voltage converter

A marriage of them in a proper manner.

Several schemes have been implemented in Center america, for the same purpose with the wind mills power interconnected to feed several semi deep wells.

Nando

[BullCreek]

Hi Flux,

Thanks for the response.  In regards to the pump controller really being MPPT like the brochure says or what exactly, I e-mailed and called grundfos yesterday but have yet to hear anything back but hopefully will.  I was hoping someone else had already been down the path and I could learn from their experience rather than pioneer.  It must not be as simple as it looks or SWP probably wouldn't have failed at their attempt.

At this point, since I have the panels, I may go ahead and proceed down the solar path, and since I'll have the pump, I might try to make another axial flux altenator I can hook up to a variable speed motor or the PTO on my tractor, and try and figure out how the two would interact depending what if anything I learn from Grundfos.  I'll also research voltage clamps.  Thanks for your advice!  --B

[RogerAS]

Bullcreek,

You never told us how deep the wells are. Do you know? Here in Arkansas they make us register wells. Location, depth, water quality etc.... So you should be able to find out unless these are really old wells, as I'm sure Arkansas (my 1020) is the last state in the union to do anything.

I still say the batteries, panels and inverter setup with a standard, off the shelf, 110 pump is the way to go. They make these in 110, and are reliable enough. My nieghbors system is over 10 years old. You could use Dans' mill to help the panels, or maybe eliminate them entirely.

Why are you so dead set on using this Grundfos pump?

I wish you would respond to the posting in your other thread on same subject!

RogerAS

[RogerAS]

Bullcreek,

I just popped over to Grundfos web site and looked at these sqflex pumps.

Quote from their web site:

"ANY VOLTAGE:

A wide voltage range enables the motor to operate at any voltage between 30V and 300V DC or 90-240V AC, which makes installation and sizing especially easy."

So it seems to me that if you absolutely have to use their pump you CAN run it from an inverter, and a relatively cheap 110V would do it.

Like Burger Queen, have it your way.

RogerAS

[BullCreek]

I just replied to your reply in the other thread - and I'm not so much dead set on the grundfos - I just started with it because they have been around a while in the solar arena - and it works over a wide voltage range.  Although the $1800 for an Outback inverter that might get fried by lightning puts me off, it wouldn't be very expensive to use a cheap $149 1000W inverter from HF or the like and some sort of sealed maintenance free battery(s).  Assuming the cheap inverter would run the pump (grundfos or otherwise) - you have provided another possibility I guess.  Another thing to try once I choose a pump.  Sorry if it took me a while to get it.

[ghurd]

Maybe I'm still just disgruntled.

I will 'avoid anything with wires' and a connection to HF.

Read the manual in regards to 'max power' and the duration thereof.

[BullCreek]

On HF, some of their stuff is pretty crappy!  I bought one of their $29 fuel pumps last year - which said it would pump 25GPM - and it might - unfortunately it probably leaks about 5 GPM while doing it.  Altenergystore.com sells a 1000W inverter for $133 that appears to be made in Canada from the documentation - but it's hard to tell where stuff is really made anymore.

[Flux]

I dont know the pump, but my guess is that pump is positive displacement brushless dc and will pump over a wide voltage range.

The 110 and 220v are induction motors and centrifugal pump and will only work at rated volts.

If the thing is positive displcement and brushless dc it should be ideal for wind application, but I suspect it has been adapted for solar use with the mppt or possibly LCB. LCB will not be a serious problem with wind but if it is mppt and samples by going open circuit you will have all the problems that is holding back wind mppt.

Your main problem is that the wind generator was never designed to run virtually open circuit and will need clamping and done in such a way that spikes don't kill the pump.

Several manufacturers produce direct wind electric pumping schemes and to me it seems far better than batteries and inverters but you are in unknown territory and need to know more about the pump and wind generator control.

Flux

[Flying Z]

Check this out. http://www.cisolar.com/CatWindPump.htm

I know they can be homebrewed also.

[Countryboy]

scratches head in confusion

Why would anyone use a windmill to generate electricity to power a water pump?  It just does NOT make sense.  It is far less efficient than using a windmill to directly pump the water, plus it is more expensive and prone to high repair costs if struck by lightning.

Wind energy is GREAT for performing mechanical work, such as pumping water.  That's why you see so many 'traditional' windmills used to pump water.

Wind energy is much poorer being used to generate electricity, which is why we have to constantly try to increase efficiencies.

Windmills have been used to pump water for thousands of years.  Why?  Because they are DEPENDABLE and cost efficient as compared to other ways of pumping water.

If you want to replace the traditional windmills with a different style windmill, you may want to think about building a VAWT with 55 gallon barrels for water pumping.  (If you click on the Links button on the Otherpower site, I believe it has a link to a guy who built a really nice water pumping mill with 55 gallon drums.)

[RP]

Why couldn't he simply build a simple relay controlled dumpload system?  I'd think some relays and resistors could start kicking in around 100 volts and clamp it off well before it got to 300V.  

With this kind of range 30-300VDC I'd think everything needed could be had at RadioShack and a hardware store.

[wlcoldiron]

Bullcreek

 I live between SA and Corpus If you e-mail me I may be able to help  WLC

[domwild]

Countryboy,

Your comment is correct, why not pump water directly? As an aside, here in Oz we have lots of windmills, probably more than in the US. What has happened here on the sheep stations is that the manager can no longer send the "jackeroo" up the tower to fix things. This "jackeroo" has to have a rigger's license, would you believe or the manager or owner has to fix it himself. This is all part of OHS, or Occupational Health and Safety legislation in Oz.

As our cyclones or your hurricanes also snap all the mills which have not been furled in time by hand, there is more and more of a trend to go solar.

*