for the sake of discussion, and fleshing out the idea a bit
what if one were to do the following
use an anemometer to measure windspeed, and provide that frequency to a micro controller
input as one data input
use the alternator frequency and feed as another data input to the same microcontroller
develop a lookup table for the microcontroller to compare windspeed/frequency and compare it to alternator rpm/frequency
and provide an output to a mosfet driver or a controlled rectifier or to provide control of a buck converter.
this leaves the problem of how to control the dump load, because as the machine produces more than what is needed the duty cycle
of the controlled rectifier/buck converter will reduce to a low number, so
we use another micro controller that takes an input from the duty cycle of the driver output of the first microcontroller, it then has its own
lookup table which is similar to the one used for the first microcontroller.
so when for instance the duty cycle of the first controller goes down to 25% the remaining off time (75%) would turn over control to the second
controller which would use the lookup table and compare wind speed, alternator speed, and compare against the available duty cycle (in this case 75%) and set a duty cycle appropriate to the driver for the dump load that would keep the alternator speed at the optimum speed for the available windspeed.
the two controllers would have to hand off one to the other control as the duty cycle shift, giving priority of course to the first controller which provides for primary battery charging.
there would also need to be a fail safe controlled by a watchdog timer to take control of the windgen should one or both controllers lock, fail, or lose their minds.
in all likelihood this could all be done on a single micro controller, but i think it might be safer to do it with two microcontrollers, wherein if one fails the
other would provide some level of safety.
the controller part should be fairly straight forward, and relatively inexpensive, the buck converter however might be significantly more expensive unless one is pretty handy at surplus parts.
i am no expert on microcontrollers, but i think i could put together a working prototype using a couple bs2 microcontrollers, and those that are
very good with pic chips could probably put together a working system in an afternoon if they had a clear objective related to them on what is needed.
as for the buck converter, they don't get terribly complicated until they get to running at above 25khz or so, below that they are noisey but
from what i can tell easier to work with?
i would sure like to see some development in this area, and see it done in the diy community rather than some commercial concern where
there is no way to tell how they do it.
bob g