An alternator's effect on the system is also much more complex than just a variable voltage source.
Dave, that's right. I already burnt up one clipper, that I thought was big enough and I had it all figured out, to a crisp with this MPPT turbine. When you're working with a high voltage turbine where the voltage is allowed to track the wind (MPPT on battery charging, driving a pure resistive load, or grid-tie), the power on this little turbine can go from 1.8 kW @ 25 mph to 3 kW @ 30 mph in the blink of an eye, before it can even THINK about furling.
And what happens with it is that once the blades go into over-speed (more than 450 rpm) it refuses to furl at all. And once it refuses to furl and the wind climbs to 40 mph, now I got a real problem with a little 3.2 meter turbine developing almost 10 kW of shaft power with the rotor spinning at 650 rpm. That was real fun the first time it did it. And fortunately, the wind died down and didn't sustain 40 mph for very long. But the thing I don't really like about 222's at that point, is that even throwing the shorting switch to try to stop it is a Smoke Show.
You HAVE to keep the rpm's down on 222's or they'll get away from you. And once you got the rpm's up so the point of thrust on the rotor swept area shifts to the inside towards the yaw, your generator that was built for 3 kW (or whatever) @ 28 mph with the blades furling normally at normal speeds is as worthless as tits on a boar pig to brake that rotor at 40 mph facing dead into the wind.
At that point you need blades that you can stall easily by pulling them down below their optimum TSR, and GOE222's just refuse to give up once they're lit. IMHO, they are best suited to slow turning turbines that have a "stiff" generator, aka my geared 12G machines, or on a grid-tie system with an induction generator where they run at constant speed to maintain freq to match the line. With the awesome torque they can make running at very low TSR, they would be dynamite on a constant speed induction generator grid-tie setup, IMHO.
Marcellus Jacobs, as he was preparing to climb a Jake tower at age 71, told his son Paul "you can't learn anything about wind power on the ground". Well, you can't learn anything about wind power sitting in front of a computer and drawing pictures and simulations of it either. You have to build 'em and fly 'em.
This MPPT project had a pretty steep learning curve to it. You can do all the calculations and simulations and stipulations that you want. And you can look at your figures and see that there's 27 kW of power flowing the swept area of a ten and a half foot turbine @ 40 mph, and you go "Ho Hum big whoop, ya' know"? But when you got that little ten and a half footer on the tower, spun right the frick up to 650 rpm and pumping out 9+ kW your indifference at all the numbers that you looked at earlier turns into "HOLY S^&T!!!"
--
Chris