Wind Project

Slammer
Slammer Registered Users Posts: 12
What I have is a prebuilt Wind Generator, and my own home made wind generator. The prebuilt one is supposed to be capable of generating 300Watts. The one i built consists of a 90V 1725RPM DC motor. The prebuilt one has no brushes so I can leave it hooked to the batteries all the time. The one I built needs a blocking diode, or rectifier so my batteries dont feed voltage back to the motor, and drain them. My question is, I have both of these units spinning pretty much non stop, upwards of 306RPM at any given time. I am seeing voltage from them, but never any amps. From either unit. So I'm wondering where the amps are going? When I bench tested each of these units, I could spin them by hand and get a low amount of amps with my multimeter. Currently I have an ammeter run inline with the positive wire of each generator, then run to a circuit breaker, then straight to the batteries. The prebuilt one runs steady at 22 volts, but no current will flow to the batteries. It's almost as if the generators dont see my batteries as a load, so it wont charge them.
Thanks in Advance.
Trevor

Comments

  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: Wind Project

    If you are seeing 22 volts when they are hooked to the battery, then it appears that they are not really hooked to the battery for some reason. Unless there is something wrong with the battery hookup, the generator output voltage will be the same as the battery.
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    Correct, 22 volts open circuit, then as soon as I flip the breaker on, it drops to the battery voltage.
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: Wind Project
    supposed to be capable of generating 300Watts
    The tricky part is the "capable of" - at what speed? A lot of those small wind generators spec a max output at a pretty unrealistic wind speed, and power output drops drastically as wind speed goes down. As can be seen from this page, if the wind speed drops by 1/2, the power out drops to 1/8th.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    No one is surprised. :p

    Your pre-built one is a PMA - Permanent Magnet Alternator. Your home-built one relies on a small amount of power from the batteries to excite the rotor coil.

    First test: connect the PMA unit only, through an ammeter capable of handling the expected current: 300 Watts / 12 VDC = 25 Amps. Don't expect to ever see that much current because: 1). Batteries only take the current they need. As they charge their resistance increases and the current will go down. 2). Commercial small wind turbines are habitually grossly over-rated for power output. 3). There probably isn't as much power in the wind as you think. Unless it is blowing at about 20 mph you really won't see good output even if everything else is right. 4). Everything else may not be right.

    If at all possible, connect the turbines one at a time with them on the ground and spin them up with a motor. That will tell you if it is low wind that simply isn't producing any power or if there is something wrong with the turbine or wiring.
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    The prebuilt one is a Gudcraft WG300 12Volt unit. The specs say
    "Low wind speed start up of just 5mph or 2 m/s.

    -So even in the lightest winds a trickle charge can be seen at the battery

    Charges up to 300 Watts.

    -Produces 108 Watts @ 11 m/s and 24 Watts @ 5 m/s"
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project
    Slammer wrote: »
    The prebuilt one is a Gudcraft WG300 12Volt unit. The specs say
    "Low wind speed start up of just 5mph or 2 m/s.

    -So even in the lightest winds a trickle charge can be seen at the battery

    Charges up to 300 Watts.

    -Produces 108 Watts @ 11 m/s and 24 Watts @ 5 m/s"

    This is typical of misleading claims from manufacturers. There's practically NO power in a 5 mph wind. Just because it will start spinning and put out some Voc at that speed doesn't mean it can put out any power. 1 million Volts at 0 Amps is still no Watts at all.
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: Wind Project
    Slammer wrote: »
    The prebuilt one is a Gudcraft WG300 12Volt unit. The specs say
    "Low wind speed start up of just 5mph or 2 m/s.

    -So even in the lightest winds a trickle charge can be seen at the battery

    Charges up to 300 Watts.

    -Produces 108 Watts @ 11 m/s and 24 Watts @ 5 m/s"

    5 m/s is about 11.2 MPH, 11 m/s is around 24.6 MPH.

    Without some way to actually measure the wind speed, you are kind of shooting in the dark, but just for comparison you can see here from the windspeed map that almost no place in the US exceeds 11 m/s http://www.windpoweringamerica.gov/wind_maps.asp
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Wind Project

    When you connect the battery, does the turbine slow down a bit (or a lot)?

    And how are you measuring current--I like to suggest getting an inexpensive DC Current Clamp Meter--They are very safe and easy to use (vs a DMM where you have to set it to 10 amp scale and break one lead to insert meter in series--Lots of things to mess up with if you are not familiar with DMM's and electricity--and more than a few of us who know the difference have caused our fair share of sparks). This unit from Sears is only ~$60--And is "good enough" for debugging (it also has AC current clamp plus all of the normal DMM functions too).

    The end results for most wind turbines is that they do not output useful current until around 10-12 miles per hour minimum--and don't reach rated current until ~25 MPH.

    As has been already said, you (probably) have a Permanent Magnet Alternator. Assuming you are getting 3 phase AC to the 6 diodes (rectifier/3 phase bridge)--I.E., slip rings/down lead is OK, and the rectifier is OK--Then you need to double check your current readings are accurate...

    And, if you can, do a bench test. Spin the turbine with a variable speed motor of some sort--and connect the output to your battery. Measure the RPM and Current Flow at that RPM into your battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    The only one that slows down is my home built generator, it is DC with just a red and black wire coming out of it. The WG300 doesn't slow down a single bit, it is also a DC, with a red and black wire coming out of it. Neither are 3phase. I'm going to get one of those DC Meters right now. I have a fully operational Solar setup, and had been looking for a DC amp meter (in my price range) since I started that project.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Wind Project

    If it is a PMA--Then the output before the bridge rectifier is 3 phase... After the rectifier, it is rectified DC +/-

    One of the ways to "stop" a wind turbine is to short the +/- outputs together (obviously, not when connected with the battery bank) and it should cause the turbine to stop spinning or to only spin very slowly. Most turbines should support this fine--however there have been a few turbines that have overheated/failed when shorted in high wind conditions--So there is a slight risk.

    If you want to do the test, disconnect the positive lead from your battery bank and ground it to the alternator return (-) lead--Be careful of sparks/shorts (hydrogen gas in battery bank, etc.) (people even put a double throw switch in to shut down the turbine before a wind storm/for service). If all of the wiring is in good shape, then the turbine should slow way down (and you can measure the short circuit current flow to confirm). If the turbine stays spinning at speed and you have no short circuit current flow--then you have a poor electrical connection some where and/or an open bridge rectifier/stator in the alternator.

    Just guessing here from behind a keyboard.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    note to self, not a good idea to disconnect wires from batteries in a wind storm..... It let loose and it appears to have it's own braking device for high wind, because it spun extremely fast for about 20 seconds then came to a stop.
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Wind Project

    Not familiar with your turbines, but reading your post brought a big smile to my face. Not because I was laughing at you, but because I was down that same road, and got more or less the same results. Yes, they do indeed "start up" at that low wind speed, but "start up" means they begin to turn, and has nothing to do with producing usable power, but rather that it starts to look pretty spinning against a clear blue sky. My unit looked real pretty most of the time, and very satisfying to lay back in the grass and watch the wheels go round. Unfortunately the only time this factory built unit, The Hornet" ever produced any usable power, was during tropical storms that came up the East Coast in the Fall. Those same times, it would scream and roar like some demonic creature that had escaped the pit of Hell, and I always expected the blades to be in another part of the world come morning. But not to worry, all was not lost. I saved the PMA and it's been producing power for about 3 years now, powered by a micro hydro cross-flo turbine :)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Wind Project

    Well, you answered one question--The turbine is loading--So then perhaps the amp reading is not accurate?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    OK, update. I now own a shiny new craftsman DC amp Clamp. With the same wind as earlier, 15mph, and gusts of 30, I can now read what my amp output is to the batteries. 0.10 amps. so a tenth of an amp in a 30mph gust, with two turbines attached.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    Never try to test two at once.
    Also, if the battery is fully charged the current will be minimal.
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    So basically, wind wont do any good because my batteries never drop below 12.7 volts?? The solar fully charges them during the day, the only reason I wanted to put the wind in because it's always windy here, and I wanted to attach a grid tie inverter to the whole system. If I leave my wood stove fan, refridgerator, and lights on all night, I can come out in the morning and the batteries will never be below 12.7 volts. These are numbers from before I even attached the wind turbines.

    My current Setup is, 300W of solar panels, Xantrex C35 Charge controller, 3x 115 Ah battery bank, and have a grid tie inverter that i manually switch the solar over to when batteries are fully charged, usually around 10:30 am.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    If the batteries are charged, no charge source will feed current into them. If you have charged batteries with panels attached and turbines, the current flow is bound to be low. Turn on everything you've got and try to get them down a bit. Disconnect the PV and see what the reading is.

    You've got three 115 Amp hour batteries in parallel? 345 Amp hours at 12 Volts? 300 Watts of panel would be a bit minimal for that much battery; maybe 19 Amps peak potential charge current. That's just the 5% recommended minimum. You must have very low power usage. Also, check your batteries individually as it can be tricky to get power flow even through three parallel connections.

    You're not going to go Grid Tie with 300 Watts of panel and 345 Amp hours of 12 Volt battery. It's really a whole 'nother ballgame going GT.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Wind Project

    Also, are you measuring the current in just one wire at a time? If you clip on black and red at the same time, you will read zero amps.

    Also, you can practice on your car's wiring to make sure everything is reading correctly.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    ok, I have converted all my lighting over to 12v LED's, the refridgerator is only 9 cu.ft., and the woodstove fan is only about a 38W draw. The max input I have seen from my panels is 14 Amps, usually on a good sunny day, the batteries are fully charged up by 10:30 am, (2 hours of sunlight at 10:30am), then I switch over to the Plug and Play Grid tie, making my power meter run backwards. Been doing this for over a month. When I test the wind turbines output, I have been checking one wire at a time, inside my shop, and I have just tested them right out of the of the bottom of the masts with the same result, (0.05 amps each). Batteries are parallel at 12v, and I have the current flowing through the batteries, positive on one end, and negative on the far end so the current has to flow through all the batteries, and my load is also attached that way. I also put a 50 amp load on my batteries and let it sit like that for about an hour, and tested my input again from the turbines, same result.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    Time for the disclaimer again: "Plug and Play" GT inverter systems are neither legal nor safe. None are UL (or other certifying agency) approved in North America. Even if the units were, the install would not be. By using such a device you are risking problems with your utility (they can shut your power off) and your insurance company. Proceed at your own risk.

    Now about these temperamental turbines.
    Like Bill said, you can short the turbine output and measure the short-circuit current. With the PMA unit it should be substantial, if you can spin the shaft fast enough. The non-PMA unit will probably just not produce anything when shorted as the armature windings seem to be fed internally (like a "one wire" automotive alternator).

    When testing anything you have to eliminate as many variables as possible. Running the turbine on the ground from a motor eliminates the wind variable. Checking the current on a short circuit eliminates the load variable. If at that point it produces no output then there is a wiring fault, up to and/or including defective slip rings, open rectifiers, or broken windings.

    And people wonder why we're not keen on small wind power? Here's yet another example of how troublesome they are!
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    I understand the disclaimer :D. Power company wants thousands and thousands of dollars to integrate power systems for net metering, not really worth it for small scale projects. Yah as far as the turbines go, The one is a factory unit, I tested it on the bench and spun it by hand and was able to generate 4 amps short circuit. The home made one came from an electric motor shop, tested all the way up to the 90 volts it was rated at, His exact words were "This motor is perfectly linear across the board". It's on loan to me right now to see if it will work for my project. When I tested it, it created great voltage on the bench, and when I would short circuit it to test amps, I can definatly tell that it was much harder to turn, but was able to produce 1.25 amps by hand. and now I have a 52 inch span set of blades attached to it.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    "... perfectly linear across the board." :confused: I wonder what on Earth that is supposed to mean.
    Do I need to say that motors aren't generators (dynamos, alternators) and don't work that well when used as such? By the same token, generators aren't motors and don't work well as such either. Spinning permanent magnets within a wire-wound field usually works fairly well for generating electricity. Faraday thought so anyway.

    Now if you could put a resistive load on your PMA and attach both Volt and Amp meters to it you could get a VA reading at a given RPM and have some idea if it is capable of producing any usable power or if it's just another weird lawn ornament waiting to happen. I wouldn't hold out much hope for the motor-based one; best to take it back and say it wasn't suitable to your application. ;)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Wind Project

    It sounds like you might be placing the DC Current Clamp meter across both + and - wires... If you do that the total current through the Clamp is zero amps (0.050 is leakage/bottom limit of accuracy--probably).

    Also, you have to make sure you have selected DC amps (not AC amps) and the right scale (40 amps vs 400 amps).

    And--I would suggest playing with your car battery wiring... For example, you should see ~10 amps or so drain with the headlamps on and the engine not running. Starting the engine, you might see ~100 amps. And with the alternator spinning, you may see ~10-40 amps charging the battery backup.

    Regarding "12.7" volts--That is the resting voltage of a fully charged battery at ~77F (25C). If the battery is colder, the resting voltage will go up a bit. If the battery is hot, it will go down some.

    If the battery is under load, you will see somewhere around 11.5-12.5 volts (depending on load, state of charge, etc.)...

    Charging, you should see around 13.2 to 13.8 volts if float charging, and as high as ~14.5 volts or so with heavy charging current (current tapers down as battery reaches full charge).

    Everything you are typing--to me--seems to indicate that you are getting some "real" charging current out of your wind turbines--It may only be on the order of 1-10 amps or so--But much more than 0.1 amps.

    Also--Depending on your turbine design--Many are setup to permanently attach to the battery and dump all available current into the battery bank. And you have a "dump"/"diversion" charge controller that (for example) turns on a "Dump Load" (typically resistor bank/heater of some sort) to keep the battery from exceeding ~14.5 volts.

    Again--I suggest just "playing" with your car battery and see what happens. Turn the headlamps on for a few minutes and see the -10 amp load and have a second DMM (assuming you have one) setup for reading voltage and watch the voltage fall below 12.7 volts over time.... Then start the engine, and watch the voltage rise to 13.8-14.2 (common voltages for car alternator output) and see the battery charging current slowly fall (from 20-40 amps to 10 amps or less--and less the longer the engine runs).

    I encourage you to do this (I sure did)--Even this "low end" meter is sort of complex and it takes a bit of learning to use it correctly.

    Also, there is a "zero" mode on the meter that you use for DC Current Measurements. DC Clamp meters are different--They have a sensor that is sensitive to AC and DC current--And it can drift from Zero over a period of a few minutes... So, you have to disconnect the current clamp, re-zero the meter (set zero off then back on), then clamp back on the wire you are trying to measure current.

    And DC Clamp meters have a +/- current direction (AC does not). The meter can tell you if it is 10 amps going into the battery or 10 amps coming out of the battery--depending on which direction you clamp the wire.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    Ok, just to clarify about the battery voltage, As long as I have had it setup and the solar charging, it has never been below 12 volts, even under heavy load. Since 3:15pm my time, 4 hours ago, I have had a 50 amp load on my batteries. All my lights are DC, the rest is through my inverter. My current battery voltage is 12.5 volts, and it started at 12.7 volts, 4 hours ago. 50 amps tested with my DC analog amp meter, and my new DC amp clamp, I understand how they work. The solar has also been disconnected since 3:15. Test one wire at a time, which I have done both where the wires come to the breaker, and at the base of the mast's. So I'm not sure what's going on with them, The home made unit is completely disconnected from the system, and I have manually stopped the factory unit.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind Project

    Wire size & distance can make a big difference too. Long/small wire can add so much resistance that regardless of the battery state the whole "A = V/R" ends up make "A" essentially zero.

    Something else you can do to test the wind turbine is to connect it to some 12 Volt incandescent bulbs and see if and how much it can light. A 1057 bulb is 21 Watts and a good place to start. With one of those on the turbine's output you can get a Voltage and current reading into a fixed load.

    It sounds like your PV set-up is working okay, so it's just a matter of determining if either turbine is actually capable of putting out any practical amount of power. Once you've eliminated any problems with the functioning of the turbine & wiring you will have only the usual #1 problem with small wind to deal with: insufficient air force. Unfortunately there's nothing you can do about that.
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    I do know that each of them can light my 12v LED bulbs. But it only takes 4 volts to light them, and they have a max draw of 5 watts, lights them up very easily. The wire distance for each of them is roughly 30 feet, and at this stage I only have them wired up with #12 wire. If I am gonna try wind again, I'm going to go with 3 phase output, run 3 wires from the turbine into the shop, then use the rectifier. The factory unit is only a 2 wire unit, even inside the housing, online it says it's a 3 phase PMA, When I was putting it together, I never saw 3 wires inside there, 2 wires to a rectifier, then 2 wires down the slip ring, and that's it.
  • Slammer
    Slammer Registered Users Posts: 12
    Re: Wind Project

    Just an Update. We had some serious wind yesterday and I did see the output up to 2 amps going into the batteries several times. It was only for a few seconds, but it's progress.
    Thank For all your help