Wind charge controller question

machineman
machineman Solar Expert Posts: 129 ✭✭✭
in Wind Power Generation #1
Is there such a controller that when the batterys are full it disconnets the wind generator from the batterys and then brakes the generator. Brakes meaining it switches the wind gen to resistive load and eventualy shorts the generator leads. All the charge controllers I've found have the wind generator hooked directly to the Battery and a diversion load running from the battery's when fully charged. I don't want a diversion load running constantly from the batterys and want the wind gen to stop or be significantly slowed when no longer needed. So the wind gen is only connected to the batterys when needed.

Off Grid Cabin, 24V 440ah 6V GC battery bank, Xantrex MPPT60-150 CC, Magnum MS4024 inverter-charger, >1200w Solar bank

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,654 admin
    #2
    Re: Wind charge controller question

    In theory, you just need the diversion charge controller set to turn on a single pole (break before make), double throw relay to disconnect the wind turbine +lead from the battery and connect it to the -lead (return) to the wind turbine. The "dead short" should provide enough torque to stall the blades. (Common to ++ead; N.O. to +Battery; N.C. to -Lead/battery ground of wind turbine--Or switch NO and NC to reduce relay power draw).

    In practice, I have read (here?) of at least one wind turbine that overheated the windings in the alternator when in "shut down" (shorted output).

    You could setup a little programmable controller that did a two stage switching, first to a resistive load (slow down without high current surge), then a few seconds later shorted out the heater to make the full current/stall condition.

    I agree that it would seem to be a better idea (less turbine "on time", so less bearing wear, etc.).

    However, I have not seen anybody talk about building/testing such a controller here.

    Also, you probably want some sort of backup/fail safe setup... I believe the NEC actually requires a second, independent, dump controller and load because of the results of failure (overcharged battery bank may cause fire, and for me, a run-a-way turbine starts shedding parts).

    For commercial turbines, they probably have two or three ways of shutting down for redundancy (brake, shunting, feathering blades, turning sideways to wind are a few I can think of--Can you do that with your controller and some sort of actuators?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #3
    Re: Wind charge controller question
    BB. wrote: »
    In theory, you just need the diversion charge controller set to turn on a single pole (break before make), double throw relay to disconnect the wind turbine +lead from the battery and connect it to the -lead (return) to the wind turbine. The "dead short" should provide enough torque to stall the blades.

    -Bill

    That's the set-up that I had when I had the "Hornet". Worked great in low to medium wind speeds. But I got a total shock when during one of our famous Fall Tropical Storms that come up the Atlantic Coast, we had some pretty brisk winds. Finally when the blades were threatening to launch an attack against our American Neighbors a thousand miles away, and knowing such an attack might well be answered in a rather unpleasant way, I applied the short circuit to shut it down. Much to my surprise and horror, there was so much power in the wind that it made absolutely no difference whatever. The sparks flew from the contacts on make and break, but the turbine showed no response whatever.
    And no, I no longer have the Hornet.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,654 admin
    #4
    Re: Wind charge controller question

    Don't let that happen again Wayne "...now go away or I shall taunt you a second time."

    -Bill "Monty Python" B. :p;):D
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #5
    Re: Wind charge controller question
    BB. wrote: »
    Don't let that happen again Wayne "...now go away or I shall taunt you a second time."

    -Bill "Monty Python" B. :p;):D

    Hahahahahaha - - - - :p:p:
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  • machineman
    machineman Solar Expert Posts: 129 ✭✭✭
    #6
    Re: Wind charge controller question

    One Idea I have is to use the Aux ouput on my solar Xantrex XW CC to trigger a wind gen disconnect and brake at a pre determined voltage, maybe 28V or so. The Aux could easily drive an SSR. The sticking point is building a circuit that runs in timed sequence which is safe to the hardware.

    1. Disconnect from Batterys.
    2. Slow down turbine.
    3. Stop turbine.

    The main reasons for not using a constant diversion load and wanting to brake the wind turbine are:
    -- All my Solar batterys, CC, Inv, etc are in a small close concrete shed. Running a heating diversion could over heat this area. I only visit once a month and that worries me.
    -- Wind Gen lifetime and wear.
    -- Don't wnat to interupt the float cycle of my solar system with a diversion load kicking in.

    Off Grid Cabin, 24V 440ah 6V GC battery bank, Xantrex MPPT60-150 CC, Magnum MS4024 inverter-charger, >1200w Solar bank

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  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    #7
    Re: Wind charge controller question
    machineman wrote: »
    One Idea I have is to use the Aux ouput on my solar Xantrex XW CC to trigger a wind gen disconnect and brake at a pre determined voltage, maybe 28V or so. The Aux could easily drive an SSR. The sticking point is building a circuit that runs in timed sequence which is safe to the hardware.

    1. Disconnect from Batterys.
    2. Slow down turbine.
    3. Stop turbine.

    The main reasons for not using a constant diversion load and wanting to brake the wind turbine are:
    -- All my Solar batterys, CC, Inv, etc are in a small close concrete shed. Running a heating diversion could over heat this area. I only visit once a month and that worries me.
    -- Wind Gen lifetime and wear.
    -- Don't wnat to interupt the float cycle of my solar system with a diversion load kicking in.

    The disconnect voltage although set to 28v must allow for some hysteresis. Basically, a high gust of wind can temporarily raise the voltage to 28v and then the voltage will fall back once the gust is over. You'll need a circuit to disconnect only if the 28v is held for some time, a minute say.... I have built something similiar but instead of braking, I'm switching between 12v and 24v battery sets. My braking system is manual.

    I've blogger here what I just described above. I'm no electronics expert however you can get some ideas from my circuits and adapt them to your needs.

    Regards
    Brian
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,023 ✭✭✭✭
    #8
    Re: Wind charge controller question

    My good old Southwest windpower H80 controller does what you ask. \You can set the controller's setpoints to whatever voltage you want diversion to start/stop at, and there is a resistive load (looks like toaster wires) integrated in the controller. When the "on" setpoint is reached power diverts to the heat dump, when the "off" setpoint is reached on the way down the "toaster" shuts off and the controller reverts to charging. And like Wayne, my short-out brake works in light to medium winds only.

    I used to brake it when heavy winds were expected until my wife woke me at 2 am and asked if we should be hearing the stall flutter...the wind had overcome "braking" and started the turbine up to maximum speed. We don't bother to brake anymore.

    Ralph
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  • snuffy
    snuffy Solar Expert Posts: 72 ✭✭✭✭
    #9
    Re: Wind charge controller question

    I've got one of these but don't know if it would work on yours. http://www.tlgwindpower.com/ccontrollers.htm
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