Want to select low cost generator for small wind turbine

Energy Topics
Post Reply
lasarpk
Corporal
Corporal
Posts: 5
Joined: Mon Apr 05, 2010 9:15 pm

Want to select low cost generator for small wind turbine

Post by lasarpk » Thu Apr 15, 2010 9:51 am

Hi All ,

I am going to make a small scale wind turbine , for battery charging , which should be generated 100 W instantaneous power , in average wind speeds. Can any one tell me , how to make a low cost generator for this power rating ?
There are lots of generators available in the market , but there cost is huge.

Thanks,
User avatar
Magneto
Major
Major
Posts: 430
Joined: Wed Jul 15, 2009 1:52 pm
Location: London

Re: Want to select low cost generator for small wind turbine

Post by Magneto » Thu Apr 15, 2010 3:31 pm

Dear Friend,

You can use a car alternator as a generator for small scale wind turbine. Recondition alternator can buy for the price of
Rs. 1500 /= ( 15 USD ). You can go about 1:4 gear ratio with this.
Normally alternator has designed for generating current in high RPM and for generating sufficient power , it has to
be rotated in about 700 RPM.

So if the wind velocity of your area is low , you will generate less power with a normal alternator. But you can increase
this power generation capacity , by modifying the existing generator. having more power means you have to increase
the rate of flux changing. there are two simple ways to do this with an existing alternator.

1. Increase the number of coil turns in the alternator by rewinding it with a low gauge coil.
2. Set some permanent magnets around the rotor

So these modifications , will enable generating high power from your wind turbine , even with low wind speed.

And also try to concentrate of your turbine blade design also , because it is also significantly effecting to generating
power. If the blades are not design , aerodynamically well , it cause to have wakes , when the turbine rotating and
this cause wasting lots of energy of available wind flow and little transfer to turbine rotation.


Good Luck !!!
lasarpk
Corporal
Corporal
Posts: 5
Joined: Mon Apr 05, 2010 9:15 pm

Re: Want to select low cost generator for small wind turbine

Post by lasarpk » Fri Apr 16, 2010 12:13 am

Thanks lot. Good Idea. I can find an car alternator easily. I will try with it.
User avatar
SemiconductorCat
Major
Major
Posts: 455
Joined: Mon Aug 22, 2011 8:42 pm
Location: currently in hyperspace

Re: Want to select low cost generator for small wind turbine

Post by SemiconductorCat » Mon Jan 07, 2013 2:57 pm

This is not easy as you think. You could do this as a hobby project or for a university exhibition,but.
in industry this is somewhat difficult.

There is something called maximum power transfer point.
You need to bias your load matching and keep it's point in that maximum power transfer point.
Otherwise power output will be exponentially attenuated[like a bandpass filter].

For that you need a charge controller, where it's microprocessor system will calculate it's operating point and
balance it. You see why output power attenuated exponentially , see the graph bellow.

Image
^-this is for a solar cell.But applicable also in here.

In other words every RPM value would have a different curve. So the microprocessor inside your charge control
would dynamically calculate the point. There are some charge controller which does not have a maximum
power transfer point calculator unit.

FYI: http://en.wikipedia.org/wiki/Maximum_po ... nt_tracker
Post Reply

Return to “Energy”