Proposed piggyback doubler to extend useful wind-speed range.

[DamonHD]

Hi,

I think that where wind speeds are generally low and/or gusty, extracting a little power below the normal cut-in speed to continue to trickle-charge the battery while avoiding stalling the turbine, for the cost of a handful of components may be worthwhile.

I'm rather jumping ahead here since I don't have the electrical specs for the MotorWind generator, nor have I measured its actual characteristics at my site, but I have speculatively designed a simple 'range booster' for 3 extra caps and 6 extra diodes piggybacked on the normal 3-phase bridge rectifier:

http://www.earth.org.uk/wind-power-pilot-autumn-2007.html#MotorWind-doubler

The cap values in particular may need significant adjustment to match generator winding resistance and AC output frequency in low wind (dependent in turn on turbine speed and generator poles I guess), but are unlikely to be vastly sensitive.

I put the design here because it might usefully and cheaply scale for significantly bigger turbines than the one I have ordered, ie with beefy power-supply caps of 10,000uF or more it might be a useful supplement for a ~500W turbine.

Any comments welcome: not a penny has yet been spent on this!

Rgds

Damon

[Flux]

At the low power levels you are looking at you may have some luck with these multiplier circuits. They really are no use for serious power levels, the capacitors become humongous.

I am sure you would do far better with a boost converter where you have control of the characteristics or even better to start with higher voltage and use a buck converter to keep you from stalling in the higher wind.

Flux

[DamonHD]

OK, sure, I hear you!  Thanks!

But I have an aversion to flyback EMF and electronics in the same way that mixing mains electricity and water and gas in my boiler/furnace is something that I leave to experts!

Maybe with a small real turbine source I will feel brave enough to try an inductive boost converter, or even a high-frequency capacitive one.

I'm trying to build on things that I know and take advantage of the generator output as-is.

(The design here recently using the generator windings as the flyback inductor looked to me to be a clever economy, which is where I might start.)

Rgds

Damon