Shorting generator to use as brake?

Discussion in 'General Questions' started by mowindpower, Aug 22, 2011.

  1. Hi, just found this sight, and have questions. I've been trying my hand at building a wind generator. I'm new to all of this, as you will probably be able to tell by some of the questions I ask. First, a little history about what I've done. I started out with a 40' tall, 3 leg Aeromotor windmill. I put one side of a 3/4 ton free floating pickup rearend in the top of the tower for the pivot. the free floater style has the hole through where the axle goes through the hub. I then took another car style rearend, made a cradle out of a 1 ton bud wheel. The whl. is welded to the car rearend so that the pinion points through the center of the wheel. The 8' aeromotor prop is mounted to the wheel flange on the car rearend. Then the whole assembly is bolted to the truck hub in the top of the tower with the truck wheel and lug bolts. This points the pinion down through the center of the tower. I then connected a shaft to the pinion flange, to drive an alternator mounted in the tower at the platform level of the tower. This setup drives the alt. 3 1/2 revolutions to 1 revolution of the prop. In looking on the internet, I decided not to use a delco alt.. I switched to a treadmill motor that I had. It is a 2 1/2 hp dc motor. I've got the tower all up with the motor mounted in it, but I'm still making the tail furling mechanizm, so I haven't put the drive assembly up yet. When I do, though, hopefully it will be generating from that time on. Sorry for going on and on. This is my first attempt, so I admit I know very little about any of this. Now to the questions. I was wondering if I can short the motor across to cause it to act as it's own braking system for extended lengths of time, say when a storm with high winds are coming, without damaging anything? This might be for days at a time. I live in NW Mo., where we get tornados once in a while. My main reason for starting this project was for decoration, then things started changing as it progressed. I plan to make a battery bank at the base of the tower to power a small water pump for circulating water from an old hand pump, to a cast iron tub/watertrough, and maybe some christmas lights on the tower. I also thought about running a line to the barn to hook up to my machinery as battery maintainers. My other question is, if it makes enough power, can I hook this type of a setup to the grid and maybe cut my electric bill down a little. I do plan on getting a controller and dump resisters, once I find out how much, if any juice this puts out. I'm sorry again for taking so long to get to the point. Thanks a lot for any info anyone has to share with me.
  2. windyguru

    windyguru WindyNation Expert

    For all the time, money and energy you have put in, I would not use a treadmill motor. The most you will probably ever see out of it is ~250 Watts and that is in high winds.

    You can definitely short the generator but if you have a well designed furling tail on your wind turbine, there is no need to short the generator. The furling tail will protect the generator in high winds. I do not completely understand why you are worried about protecting the wind turbine from tornadoes. If a tornado does come, I would think the tower would be ripped to shreds along with the wind turbine? A well designed furling tail should be able to protect the wind turbine in wind speeds up to ~125 mph.

    Sure, you can hook it up to the grid with a grid tie inverter.
  3. Thanks windyguru for your info. Like I said, this is my first attempt at this, and it didn't start out to be anything more than decoration at the end of my driveway for the wife. It was going to cost more than I wanted to spend, just to rebuild the aeromotor. So I decided to try converting the drive system to a wind generator, but retain the looks of an old windmill, somewhat. As far as cost, I live on a farm and have collected a fair amount of what the wife would call junk. I call it stock for future projects. As it sits, I've got some time invested, but only about $100.00 for a lovejoy coupler and to have an axle turned down for the prop shaft. As far as the controller and load diversion coils, (as of yet to be purchased), I hope to be able to use them on future wind generator projects. I had everything else laying around. I've also got 2 more new treadmill motors. If the treadmill motor doesn't workout, I hope to be able to mount just about any other type of generator in this tower without to much trouble. It's all trial and error for me. Maybe one day I'll hit on the right combination. Probably a lot faster now that I know about this sight. Thanks again windyguru. mowindpower

Share This Page