Author Topic: Iced up axial flux charger  (Read 881 times)

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bruce

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Iced up axial flux charger
« on: December 02, 2005, 02:02:50 PM »
     I have an axial flux system that I have had a huge success with over the summer, it beats anything I have built on my own. We have had some snow/ice over the last few days, and the other morning the sun was shining and the wind was dead still. Now my rotor is locked up, I am going to guess its iced up to be locked that tight. Is there anyway to induce a light dc current through the windings to warm up the stator and melt the ice, WITHOUT damaging the windings. Thats the key part.

     I'm wondering if anyone has tried doing this?


                                Thanks, Bruce

« Last Edit: December 02, 2005, 02:02:50 PM by (unknown) »

DanB

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Re: Iced up axial flux charger
« Reply #1 on: December 02, 2005, 08:48:42 AM »
Hi Bruce - I've had this happen a couple times with my 17' 48V machine.  I find that it breaks loose rather quickly if I just bypass the rectifiers, usually for about 30 seconds, although longer wouldn't hurt it I dont think.  I think the idea arrangement would be a push button switch on each phase.  One phase will usually melt it (since the current flows through 2/3 of the coils) loose, and while its doing that it's also providing some kind of torque on the rotor which also helps.  Being able to do one phase for a bit, then another might help too, since you'd be putting torque in a couple directions on it.  


I don't worry too much about hurting the windings - if there's ice on it (or even water) its going to stay fairly cool till it dries off I expect.  The worst abuse mine ever had like this is when we got hit by lightning, and a couple of my rectifiers were blown to closed circuit.  It was over 10 min before I'd realized what had happened (there was smoke coming from the tower top) and unplugged the machine.  While it did get hot, and the stator was slightly warped, the damage was minimal and the machine still works fine.  I dont think you're endangering your cold/iced up stator to bypass the rectifiers for a min or two.

« Last Edit: December 02, 2005, 08:48:42 AM by DanB »
If I ever figure out what's in the box then maybe I can think outside of it.

bruce

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Re: Iced up axial flux charger
« Reply #2 on: December 02, 2005, 10:39:45 AM »
     Great, you've run across this before! I'm alittle confused by 'bypass' the rectifier. I've got a stator wired in WYE, 3 leads to the rectifier, 24vdc on the other side of the rectifier. Give me a short explanation of bypassing that. Straight 24vdc into 2 leads of the stator?

      Thanks a bunch Dan, and thanks for all the help you gave me this winter/spring in building this setup. Its doing great.


                                  Bruce


                       

« Last Edit: December 02, 2005, 10:39:45 AM by bruce »

windstuffnow

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Re: Iced up axial flux charger
« Reply #3 on: December 02, 2005, 10:58:11 AM »
  I've had this happen several times through the winter.   We often get freezing rain while there is no wind.   Simply take a jumper from battery lines directly to the phase lines by passing the rectifier completely.  It's basically like driving a heater element from the battery.  The stator will warm up and melt the ice.   Like dan said about 30 seconds should do it.   I'll give it a little jump from one side to the other.  That is put the ground on the center lead of the 3 wires comming from the turbine, run the positive from the battery to one side then the other.   Keep in mind this works like a motor so if you just tap the lines it will jerk the turbine in motion, its better to hold it there for a little bit before releasing it otherwise it might break it free and drag the ice around a bit before warming and spitting it out.   I've never seen any damage from doing this but a couple times I could hear the crunching of ice as it started moving.  


.  

« Last Edit: December 02, 2005, 10:58:11 AM by windstuffnow »
Windstuff Ed

bruce

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Re: Iced up axial flux charger
« Reply #4 on: December 02, 2005, 12:26:08 PM »
      Well guys, thanks for the tips, and the first time I get ice in there, I'll know what to do. But unfortunately, I found that wasnt the problem. I checked it out at noon with a pair of binoculars and its not pretty. I have stator chunks hanging out around the bottom edge. What little testing I did, I think my rectifier is OK, so I didnt burn up my stator that way. I'll bring it down this wkend and evaluate the situation. I'll probably be back on next wk asking questions about correcting what went wrong.


                         Until then, Bruce

« Last Edit: December 02, 2005, 12:26:08 PM by bruce »

jmk

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Re: Iced up axial flux charger
« Reply #5 on: December 17, 2005, 09:59:15 AM »
 Hey Bruce, Is everything ok? I hope you are fixing the stator. You don't post often anymore. When I joined you told me to stay on this board. With this last post I hope everything is okay. You're probably building a biger one. You are off grid so I hope you are okay. John
« Last Edit: December 17, 2005, 09:59:15 AM by jmk »