Originally Posted by Canibul
I guess I am asking you specifically what that reason is.
PWM regulation works on alternator regulators, battery chargers and solar because the pulse time can be varied to match the output current
needed to both maintain yet not overshoot the voltage set point.
An alternator field can be PWM'd as can the power supply in a charger
or a solar panel. Wind generators can not have have the load cut entirely or PWM'd at high SOC's or they can destroy themselves when the battery gets close to or full and the gen is spinning wildly.
Instead of PWM regulation for absorption wind gens use what is called ON/OFF regulation or shunt based regulation and brake (shorting) or use a dump load to slow or stop the blade when the batteries are decaying back down from the OFF voltage to the ON voltage.
MPPT is only useful in bulk and a wind gen can
use MPPT but once it hits a regulation voltage it then needs to become an ON/OFF/BRAKE controller or have a dump feature during the OFF period. Most MPPT controllers simply become PWM once absorption voltage has been attained. Shunting or ON/OFF regulation is horrible at fully charging
batteries and the last bit can take forever. This is why solar is far superior for the last few % than wind is. Wind is great in bulk, but not so much for finish charging
, which is where solar wins...
A typical win gen controller will turn OFF at say 14.2V +/-, brake or slow the blade, and then not come back ON again until the battery voltage has decayed to 13.0V +/-. During the OFF time the blade is stopped or slowed drastically through shorting it or dumping it to a large load bank that slows the blade to a crawl.. If you used PWM the blade would be spinning like a banshee when the batteries neared full and this is NOT GOOD for a wind gen......