Hello Murlin,
Last April I started out with a goal to design a 10kw wind turbine.
Design started out exactly like the 17 footer on otherpower.com except 24'.
During the course of the summer I read about 3 fried stators, all were the larger wind turbines. This caused me to revisit the design.
Furling system problems, several systems had tails bashing into the blades.
A discussion with Sampower offered up a eureka moment for the final detail I didn't understand, started working on a wind turbine simulator. For a given blade, wind, battery etc can predict charging current. Fun stuff. Side tracked now, working on the FIRST robot competition for the next 4 months.
In summery
Active pitch control required. Wind turbine will be destroyed by wind gusting without furling or active pitch control. I do not like furling. For me, a brushless 3ph motor on the hub to control pitch, powered by a very small 20watt PMA generator. Controllers goal will be to max RPM within a window. Sort of like MPPT for solar.
PMA or induction motor generator? For $300 I can buy a 15ph 3 phase induction motor, use as generator. How much will a PMA cost to produce 15hp, How big, etc. The large wind turbines are induction generators (motors), so why not do the same thing? One down side is speed up gears are needed, so will use parts from rear end, and transmission from a vehicle. Plan to put the generator on the tower, No cable to deal with, wireless control for shutdown on the pitch controller.
Induction motor requires near constant speed, good thing already on board with active pitch control!
I could go on, if interested, drop me a line or check my back posts (might take a while!-)
Have fun,
Scott.