12v/24v to a 3 phase smartdrive motor

Discussion in 'General Electronics Chat' started by wooly123, Aug 26, 2010.

  1. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    First timer on here and novice. I have seen various sites showing the many different configurations that these fisher and paykel 3 phase smartdrives (from washing machines) can be rewired to suit a wind generator situation. What I want to do is convert the smartdrive into a DC drive motor, Not to receive the electricity. Can someone explain my options on doing this?

    I know the star and delta configuration options to bring down voltage to induct the power.. I want to know if I supply the unit with power that it will spin. Thanks in advance.
     
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
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    There have been a multitude of people trying to turn motors into generators but I never heard of a three phase motor being used, much less a common household appliance that ran from a 3 phase supply.

    I'm going to assume you mean the common capacitor start motors that are so prevalent in washers and dryers and that these people are using the start winding as part of the excitation method for the rotor.

    Sadly most reports I've seen on using AC motors as generators has led to the conclusion that it's more trouble than it's worth but don't let that stop you. There are going to be a lot of specifics involved, can you direct us to one or more example articles?
     
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  3. marshallf3

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    Jul 26, 2010
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    This also reminds me of something I started to pursue and forgot all about. I live in an area where storms abound and on occasion some neighborhoods often have to go without electricity for extended periods of time. This has led to a ton of people buying those small backup generators.

    Whenever we do get hit the good generators go first, then the junk ones start appearing all over the place and they sell out of them as well. Sadly most of those are powered by cheap Chinese engines like you often see on the kid's minibikes that abound at various retailers. Those engines don't have a reputation of lasting very long and when people try to get them serviced parts availability and costs often send the whole thing to the junkpile.

    Seeing that the generator portion is probably still perfectly fine I'd love to get a hold of some of these but haven't figured out a good way to get the word out. Anytime I list in the "wanted" section of craigslist, no matter how clear I am about not wantng to spend much if anything on their junk, about all I get are offers from people that have working ones they want a high price for or "I was told it just needed a tuneup" items they still think are worth about what they paid for them.

    I guess I need to generate a flyer I can send out to every small equipment repair place and maybe I'll get lucky. While I really have no need for one I would like to build a small wind generator to put on the roof of our business just to power a few lights in one area that would be capable of remaining on should we lose power.

    Car alternators are always an option but they're a hassle to work with as well.
     
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  4. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    thx for replying. Here are the smartdrives in question. I will also supply the rewiring process for 12v/24 and even 7 phase configuration to reduce cogging.
    http://www.yourgreendream.com/diy_fp_rewire.php

    http://www.yourgreendream.com/diy_fp_rewire2.php

    http://www.thebackshed.com/windmill/articles/coglessFP.asp

    The above shows the reconfigurations to reduce the power to 12 or 24v for induction. I want to know if I send power down those configurations, Would the motor spin? ie: Act as a 12v motor?
     
  5. wooly123

    Thread Starter New Member

    Aug 26, 2010
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  6. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    In regards to getting these motors, I use ebay for my area. I look up faulty washing machines that i have researched have these powerful motors. I just bought a washing machine for $30 that the pump was faulty. Now I have a 1.4kw generator. I have some ideas and that is why I am going down the avenue of trying to get this to spin with a 12v input.
     
  7. marshallf3

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    Jul 26, 2010
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    You can get washers and dryers for free off craigslist here - more than you can haul. If I were to bother I'd take some tools, remove the motor then drive the rest across the scrap iron scales.

    Long week, I'm probably going to relax tonight rather than trying to think much.
     
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  8. massive

    Member

    May 7, 2010
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    There was a guy who had a deal going with F + P and got fresh motors to make generators but the factory is now mostly over seas so Id say he went under like the workers who got ditched from the factory. (get stuffed F+P)
    Here n'NZ the motors 50hz 230v AC and feeds it out pulsed on 3 phases ,its like a big version of a computer hard drive motor.
    The chance of running straight 12 V DC is slim as .
    Im guessing you want to utilise the fly wheel energy of the rotor for something .
     
  9. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    I actually want to drive the rotor with a 3rd DC and induct 2/3rd's AC. Catch my drift?
     
  10. retched

    AAC Fanatic!

    Dec 5, 2009
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    You are trying to making an inverter?

    You want to run the 'motor' with 1 of the 'phases' with DC

    then use the other 2 'phases' to produce AC

    Is this correct?
     
  11. wooly123

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    Aug 26, 2010
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    Now you are smelling what I am treading in..lol
     
  12. retched

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    This may be more trouble than it is worth.

    But, maybe not.

    The way I see it, you will need a pretty accurate speed controller.

    In order to get a 50Hz or 60Hz AC source, you are going to have to first find a good operating speed for the motor(generator). If you drove it at 60 RPM, that should get you a 60Hz signal.

    If you are considering selling this back to the POCO (power company) using a grid-tie application, you will have to ENSURE that the frequency stays stable over loading.

    This could be tough. Your speed controller will need the juice to power the motor through load spikes and settle after without varying the freq. for more than a few cycles.

    And, just in case you are thinking of it, you cannot take the 2nd AC and convert it to DC to drive the motor so it can run itself providing power for the world.

    Friction losses and heat losses require that output power be less than input power. (POWER not VOLTAGE)
     
  13. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    I couldn't:) have said it any better... Is there any way.. I am a novice and would take time to evaluate any conclusion.

    I actually want to induce via a 3rd of the rotor and induce AC the other 2/3rds
     
  14. retched

    AAC Fanatic!

    Dec 5, 2009
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    Is there any way to what?

    Your last post lost me a little.

    You want to induce AC in the 2nd and 3rd phase coils correct?

    Remember that using the creation of torque to turn the motor requires power.

    In order to "generate" the AC, you will be "FIGHTING" the magnetic forces in the AC windings. When you plug something in, the magnetic force increases.

    This is done to provide more current to the load.
     
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  15. marshallf3

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    Jul 26, 2010
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    3 phase motor. One of the stator coils excited to introduce magnetism to the rotor which in turn induces voltage back into the other two idle windings.

    You end up with 2 phases of a three phase generator as the output. Nicely rectifies down to DC but is of no use trying to feed back into the grid as it stands unless you've got three phase in the area to start with.

    Speed control has always been the real kicker in wind generator design, you need an almost constantly variable ratio to hold 60 Hz.
     
  16. marshallf3

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    Jul 26, 2010
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    Oh, and I also thought of a rather inexpensive power storage option.

    Almost any town in America has at least one warehouse in it, most have thousands and most of those involve the use of forklifts. There are generally four ways to power a forklift - gasoline, diesel, propane and battery. We have a mix of propane and battery types.

    The batteries on these forklifts are massive units, usually 36V (but sometimes 24V) and, in time, they don't hold a charge as long as the warehouse operator needs them to so he can make it through the day without a recharging break.

    Eventually they get replaced and the old cells are usually stilll good enough for less demanding use, in addition most are just a huge bank of 2V cells that can be separated. I wouldn't even want to predict how many amp hours one of those monsters is capable of but it's massive.

    So where do all the still fairly good ones go after they're replaced? To the recycling place where they probably get 8 cents a pound for them due to the lead content.

    If you had the space, and a way to move the things, you could build one heck of a storage pool for DC out of them for very little cash outlay, most of the cost would probably be just getting the thing delivered. If this interests you it could be that if you contacted all the companies in your area that services these things they could call you when they were going to replace one and deliver it to you instead of back to their shop or a recycling place. Matter of fact some of these places may have a pile of them sitting out back already.
     
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  17. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    Sorry, I miss quoted my comment. What I want to do is break the three phases. Use 12 or 24v to power one wind and collect AC with the other 2 phases. With the AC that I collect I can fast charge the 12 or 24v battery that is powering the motor, While still inducung ample AC.
     
  18. retched

    AAC Fanatic!

    Dec 5, 2009
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    Thats called perpetual motion.

    The problem with this:

    As you need more power from the 3rd AC winding, like turning the radio on,
    causes more magnetic pull on the rotor.

    In order for the speed controller to keep the motor spinning at the correct speed, it has to pull more amperage from the battery to overcome the load.

    That makes the battery drain faster.

    The only way to "quick charge" a battery is to increase the amperage TO the battery.

    In order to get the 2nd winding to produce more power to feed the battery, you will need to run the motor faster.

    If you run it faster, you no longer have the REQUIRED 60hz you need to run the radio in the first place.

    This is no different than trying to connect 2 generators to the shaft of a motor.

    In essence, thats EXACTLY what you would be doing.

    Read through the eBook at the top of every page on this site to get more of a grasp of how this stuff works.

    It isn't just the spinning of the motor that makes the power. The size of the wire in the windings and the number of turns in the windings, the distance from coil to rotor, and friction losses all come into play.

    Just converting the AC to DC in the battery charger will loose too much power to make this work.

    AND the battery charger and the radio are both loading the DC winding.
     
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  19. wooly123

    Thread Starter New Member

    Aug 26, 2010
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    Ok, I will indeed read that ebook. Thanks for your input. It has answered a lot of questions. As they say, "back to the drawing board"
     
  20. marshallf3

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    Jul 26, 2010
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    The old saying "you don't get something for nothing" applies to energy as well.

    I had assumed you were making a wind generator, in which case rotation of the motor shaft would be where the power comes from, the "motor as a generator" merely serves to convert rotational torque into electrical power.
     
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