Testing 3 phase HAWT (corrected--Not VAWT)

rithymrithym Posts: 5Registered Users ✭✭
edited September 10 in Wind Power Generation #1
Hi to all just looking for a little guidance. No experience with a WT bought a cheap Chinese 500W 24V and got it up last weekend about 12 meters up in nice clean air I live on a hill in the countryside with no tall trees/ buildings anywhere near. Very disappointed with the output the wind is blowing 10 m/s tonight when I put DC clamp meter on cable from controller to battery I get 0.1 - 0.2 amps?? The 5 blade turbine is absolutely flying around if I measure across the AC cables going from PMG to controller getting around 16 - 18V. This does not seem enough to charge a 24V battery. 

Before I put the turbine up I connected the PMG direct to controller and spun with a 500 rpm electric drill... the DC clamp meter showed 9 amps going to battery. Half the rating claimed at 500 rpm but still usable power. I then connected in the 15 meter cable between PMG and controller and did the same test. This time 7.5 amps flowing so I assumed the losses were in the cable which is a bit on the thin side but what I have laying around at no extra cost. 

Am I expecting too much from this little turbine I was hoping to get a few amps in to the water pump battery to supplement the solar during the night. Maybe 10 m/s is just not enough to get it generating properly my average wind is a little lower than that...

How can I test the PMG 

TIA  
Eternity 48V 1000Ah. 2 x Tristar MPPT 60A. 1 x 4KW array South East, 1 x 5KW array South West 6KW Voltec Inverter for house
Trojan L16 435Ah. 1 x Sunsaver MPPT 15A. 1 x 1KW array South. 2KW Studer Inverter for water pump

Comments

  • BB.BB. Posts: 27,788Super Moderators admin
    edited August 30 #2
    Around 22 mph winds, that is usually near optimum wind velocity.

    Is the 16 the 18 volts with the turbine connected to the batteries and current flowing, or with the turnin turbine disconnected?

    Your test demonstrated that the pmg alternator works sort of ok at rpm.

    So it's the problem the blades are not turning the pmg alternator to rpm, or is there an wiring or controller issue?

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rithymrithym Posts: 5Registered Users ✭✭
    Hello Bill thanks for your reply

    The 16 - 18 volts is with everything connected and a small amount of current flowing, . I have a 20 amp DC breaker on the +pos output between controller and battery when I disconnect this the AC volts goes up to 20 - 22. I would have thought with the turbine disconnected from the battery the voltage would have shot up a lot more in this wind?

    This morning 5am I have been out to the battery house the wind is now a little stronger average 11 m/s with gusts of 14 or 15 the top part of the scaffold pole tower which is unsupported is actually bending in the gusts. According to the supplier the PMG reaches max output at 13 m/s or 500 rpm so with 11 m/s I would expect to see at least 4 or 5 amps going to battery? I already know from tests the output is down on what is claimed. Occasionally I see the current meter go up to 1 or 1.5 amps but generally it is showing 0.2 - 0.3 amps flowing. The 435Ah Trojan L16 battery is showing 25.32V if the turbine was charging proper I would expect to see that higher. 

    I don't have a separate rectifier to try bypassing the (All IN One) controller and I don't know what to try to test the PMG now it is in place. When the wind dies down next few days I am going to drop the tower and take off the hub & blades and try rotating the PMG 500 rpm with my drill and see what output I get. It may well be the tower needs to go higher to get cleaner air I can do that but will need to guy the new top part to support. In the mean time any suggestions on further tests I can do would be much appreciated.   
    Eternity 48V 1000Ah. 2 x Tristar MPPT 60A. 1 x 4KW array South East, 1 x 5KW array South West 6KW Voltec Inverter for house
    Trojan L16 435Ah. 1 x Sunsaver MPPT 15A. 1 x 1KW array South. 2KW Studer Inverter for water pump
  • BB.BB. Posts: 27,788Super Moderators admin
    edited August 30 #4
    Sorry for the typo "sorry" should have been "sort" of ok operation... (phone auto correct).
    Anyway, I would differ to the people that sold you the system for diagnosing.

    I am not a fan of small wind turbines. But it sounds like you have a good location (windy, clean air) and a tower that is a bit over 10 meters (~33 feet). That is pretty much the minimum requirement for a turbine.

    The problem with the tower bending--Yea, wait until you get some scary level wind storm. Between the tower bending and the turbine (potentially) overspeeding (and possibly self destructing)--You are seeing the issues with under engineered wind systems.
    Wind turbines can find many wild and wonderful ways to fail.

    Guessing you are in the London/Southhampton region of the UK? I would normally be suggesting more solar panels vs a wind turbine (typically less issues, more reliable than wind). But, you probably do not have very good sun in the winter:

    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Southampton
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 24° angle from Vertical:
    (Optimal winter settings)

    JanFebMarAprMayJun
    1.55
     
    2.45
     
    3.14
     
    4.05
     
    4.34
     
    4.29
     
    JulAugSepOctNovDec
    4.30
     
    4.30
     
    3.63
     
    2.71
     
    1.80
     
    1.23
     

    I would be suggesting for a 435 AH @ 24 volt battery bank somewhere around 5% minimum and 10% nominal charging current (not talking about your loads at this moment):
    • 435 AH * 29 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 819 Watt array minimum
    • 435 AH * 29 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 1,638 Watt array nominal
    And if you went with a 10% array, in December, you would generate and average daily energy of:
    Not a lot of power--Enough for a cabin (lights, cell phone charger, small RV type water pump, etc.). 

    The wind turbine, perhaps if you can give us a link or more information, perhaps somebody here will have some experience with your model/unit.

    Otherwise, I can give you some links to other forums that may be able to give you some more information/help:

    www.otherpower.com (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post)
    www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)

    Wind Turbines are one product that can work better with Do It Yourself construction vs factory manufactured. However, building your own turbine + tower is not for the faint hearted.

    If you had access to a different set of blades that could get the RPM up, that could help.

    I agree that I would expect >>20 volts (40 volts or more VAC?) from your unloaded turbine running near rated RPM.

    I do not know near enough about wind turbine design to be that much help... But be careful with yours. If you get a good windstorm, things could go south pretty quickly.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rithymrithym Posts: 5Registered Users ✭✭
    Thanks again Bill for all the info

    I am actually located in the South of Portugal close to the old capital, Silves.  I already have total 10KW solar arrays spread between South East and South West so get good charging on both 48V (house) & 24V (water pump) battery banks throughout the day. I have a load of spare scaffolding lying around the farm so out of curiosity wanted to stick a wind turbine up just to see how it produces as we do generally get a stiff breeze here a lot of the time but we also get some crazy storms :)  It looks to me that the blades are whizzing around in 10 m/s wind but it may be the 5 blades are preventing the higher speed necessary for a decent output, if it had 6 blades I could remove 3 to see if a higher speed was possible. When I get a chance I will drop the tower and test the pmg with an electric drill @ 500 rpm to see what amps are going to battery. If it is still 7 or 8 amps as before then clearly the problem is lack of speed from the wind and under engineering by the manufacturer. I have been in touch with Hugh Piggott he thought the output was very low and could be a 12V pmg? and that it is normal for these small turbines to output less than half what is claimed. The supplier has offered me a 30 Euro (20%) refund rather than supplying a return address but I think it will be going back for a full refund...      
    Eternity 48V 1000Ah. 2 x Tristar MPPT 60A. 1 x 4KW array South East, 1 x 5KW array South West 6KW Voltec Inverter for house
    Trojan L16 435Ah. 1 x Sunsaver MPPT 15A. 1 x 1KW array South. 2KW Studer Inverter for water pump
  • BB.BB. Posts: 27,788Super Moderators admin
    edited September 10 #6
    NOTE: Typo in title... Is actually a HAWT (horizontal axis wind turbine--Not Vertical...).... Rest of my post does not address HAWT (although, there are a lot of issues with those too.  -Bill)

    I missed the title of your post that you have a VAWT (vertical axis wind turbine). If that is true, I am not sure I have ever read anything where a VAWT was worth the effort to even bury it.

    VAWT units seem to be the darlings of architects and people that spend lots of money on signature office buildings and museums.

    VAWT tend only produce a very small percentage of their "rated power", and tend to be unreliable too.

    VAWT units seem to be unreliable too (mechanical failures from wind/vibration stresses).

    HAWT (horizontal axis wind turbines--The typical type you see around) tend to be more reliable and more efficient at harvesting wind energy.

    HAWT units tend to be much easier to mount on a high tower (10-20 meters or more). Most VAWT seem to be mounted lower or on buildings--Generally big mistakes to do either/both.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • rithymrithym Posts: 5Registered Users ✭✭
    Sorry that was a typo on my side the title should have been 'Testing a 3 phase HAWT'  Fortunately, I purchased via Ebay and I put a claim in to their customer service against the defective turbine and they have now refunded the full amount paid inc. shipping. I await the supplier emailing me the return address but I doubt they will even want the item back it's fit only for scrap ally. I was looking forward to tinkering and learning a little... I'm sure a decent HAWT will put out some useful amps during the night or in cloudy weather to offset the house loads but after this little incident I will only invest in a proven & robust turbine, if such a thing exists. Seems to me the internet is full of cowboys who will claim almost anything to outsell their competitors. 
    Eternity 48V 1000Ah. 2 x Tristar MPPT 60A. 1 x 4KW array South East, 1 x 5KW array South West 6KW Voltec Inverter for house
    Trojan L16 435Ah. 1 x Sunsaver MPPT 15A. 1 x 1KW array South. 2KW Studer Inverter for water pump
  • Dave AngeliniDave Angelini Posts: 3,960Solar Expert ✭✭✭✭
    Ebay says it all. You get what you pay for if you need quality that will stand the test of time.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • rithymrithym Posts: 5Registered Users ✭✭
    edited September 13 #9
    Getting back to my original post what is the best way to test a 3 phase AC PMG assuming I can spin it at any speed I like on a 'bench test'?
    I have a multi meter that measures Hz so presumably I can put this across any two phases set @ 60 Hz and I am reading rpm? or should it be DC ground and one phase?
    What is the best way to measure the AC voltage - DC ground and individual phases or phase to phase?  
    The turbine can be both connected and disconnected from battery. Any help appreciated

    Eternity 48V 1000Ah. 2 x Tristar MPPT 60A. 1 x 4KW array South East, 1 x 5KW array South West 6KW Voltec Inverter for house
    Trojan L16 435Ah. 1 x Sunsaver MPPT 15A. 1 x 1KW array South. 2KW Studer Inverter for water pump
  • BB.BB. Posts: 27,788Super Moderators admin
    There is no reason to ground any of the alternator phases... You can measure each phase with a meter and resistive load, or your can use a rectifier to change from 3 phase AC to DC and then load the output.

    Since what you want is to charge your battery bank, rectifying to DC and loading with your 12/24/48 volt battery bank would be a good functional test. I would only measure each AC phase if I was debugging (low output, etc.). Measure output current (and battery voltage) at several different RPM up to maximum RPM rating (or maximum current--whichever occurs first).

    Note that 3 phase alternators (and motors) can be wired 2 different ways... One is "Wye" or "star" and the other is Delta:

    http://www.reuk.co.uk/wordpress/education/star-delta-wiring-for-alternators/

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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