The purpose of variable pitch control
The leaf angle in a certain range (0 degrees ---90), in order to adjust the output
Power, avoid fixed pitch units in determining the angle of attack, may have low power in summer,
And winter super fat. At low wind speed, power optimization, better
The wind energy into electric energy.
Control strategy for variable pitch unit:
A below the rated wind speed by controlling the rotational speed of the generator so that the tracking speed, so you can
Optimal tracking Cp;
B above the rated wind speed by the speed controller and variable interaction paddle controller, making power
The rate is relatively stable, the torque power curve is better.
The wind speed is below the rated stage: to achieve the main goal is to make as much as possible to absorb more wind impeller.
The bigger the Cp, the more wind energy absorption. Because the wind speed is below the rated wind speed is small, therefore, there is no need to pitch at this time, this will only need to set the minimum angle of the blade pitch angle regulation.
Above the rated wind speed: while playing the role of speed controller and pitch controller. The speed controller of the generator is controlled by the constant torque and constant power. Through the pitch adjusting the rotational speed of the generator, which always set point tracking speed.
Below is the Cp and lambda curves of different pitch angle corresponding to the minimum
