How to Variable Pitch in different wind speed by wind turbine

1.Under the wind speed of 0m/s ~ 3m/s, the turbine blade remain static ,and the start-angle formed between the blade and turbine plane;The blade angle will under a start-angle,the blade is most easily to be started up.

2.As long as the wind speed reached 3m/s, the blades will begin to rotate, during the rotation, the outermost edge of the blade will be driven by the centrifugal force generated by the rotation of the blade to tilt toward the turbine plane, the blade angle will decrease until 0° when the blade is in parallel with the turbine plane; at this angle ,the turbine has nearly reached its rated output power.

3.When the wind speed is between 11m/s ~25m/s ,the blade will keep adjusting its position forth and backward slightly to let the angle  fluctuate a little bit but maintain at around 0°roughly, so as to stabilize its rated power.

4.Within the wind speed of 25m/s ~ 50m/s ,when the wind has exceeded its rated speed , the wind will keep drawing the blade by the centrifugal force,so the blade angle will continue to decrease and turn into a negative angle ,under this negative angle, the rotation of blade will produce a resistance on the rotation of turbine blade to slow down the rotation and protect the wind turbine from over speed operation, the maximum RPM of the turbine will be no more than 277 RPM.